How to setup a static ip in Ubuntu? Where i need network, broadcast, dns parameters to fill in from my ISP?

I have a public ip as below which is static (my isp provided) as below:  IP Address: x.x.146.50 Subnet Mask:    255.255.255.240 Default Gateway:    x.x.146.49 DNS1:   x.x.1.196 DNS2:   x.x.7.196   But what is my Network, Broadcast and DNS (this scared me for ages, looking for a easy way to do 100% accurate calculating/math).  iface eth0 inet static     address x.x.146.50     netmask 255.255.255.240     network ????????????     gateway x.x.146.49     broadcast ?????????   Follow up: (short cut)  $ ipcalculator 8.8.8.8/28 Address:   8.8.8.8              00001000.00001000.00001000.0000 1000 Netmask:   255.255.255.240 = 28 11111111.11111111.11111111.1111 0000 Wildcard:  0.0.0.15             00000000.00000000.00000000.0000 1111 => Network:   8.8.8.0/28           00001000.00001000.00001000.0000 0000 HostMin:   8.8.8.1              00001000.00001000.00001000.0000 0001 HostMax:   8.8.8.14             00001000.00001000.00001000.0000 1110 Broadcast: 8.8.8.15             00001000.00001000.00001000.0000 1111 Hosts/Net: 14                    Class A  1) It tells me Broadcast what to copy and paste 2) It tells me Netmask what to copy and paste 3) It tells me Network what to copy and paste   Now its Easy! i was always finding them complex in my head to do manual calculation and server is down for 20 days :P. Not not anymore.


Union of definable sets is a definable set

I tried to prove this question but without a success: Let $K_1 \text{and } K_2$ be definable sets, prove that $K_1∪K_2$ is definable.  What I tried to do is to assume: $K_1=\text{Ass}(X)=\{v\mid v\models X\}$ and $K_2=\text{Ass}(Y)=\{v\mid v\models Y\}$ and to say that $K1\cup K2=\text{Ass}(X\cap Y)$. But I couldn't prove that: $K_1\cup K_2\supseteq\text{Ass}(X\cap Y)$.  I would like to get help with this proof


On Ubuntu 16.04 after a recent apt-get upgrade, X login is not working.  Why?    The login screen (which I understand is X-based) is working.  However all attempts to login, including via the guest account fail.  When I switch to a text terminal and look at .xsession-errors, I see:      X Error of failed request:  BadValue (integer parameter out of range   for operation)     Major opcode of failed request:  154 (GLX)     Minor opcode of failed request:  3 (X_GLXCreateContext)     Value in failed request:  0x0     Serial number of failed request:  34     Current serial number in output stream:  35   The Xserver being used is NVIDIA, however it seems like this must be an Ubuntu login issue as X itself appears to be working and /var/log/Xorg.0.log is uninformative (everything looks fine).  Any ideas how to debug further?


My phone screen has been broken, I have root access and my usb debugmode is on. when i connect my phone to Moborobo, moborobo shows the screen shot on my phone, is there any way to touch my phone screen with pc ? something like real remote that give me this chance to use my mouse for accessing my phone ?


EOL while scanning string literal even using r

I am trying to define a name for a long server folder path below.  May I know why I still get "EOL while scanning string literal" error?  Many thanks. path= (r '\\hbap.adroot.abb\HK\Finance\00210602\AMH_A2R\1KY\Drv Reengine\Python\')


I installed ubuntu 14.04 over my 13.10 but was trying to keep my data so I deleted all partitions (I didn't have a separate home directory) used manual partitioning and allocated 12 GB of my HD for installing the new OS. Everything went fine and 14.04 installed ok. But now I don't know how to recover the data in the free space that I left unpartitioned. I tried partitioning that space without erasing data and mounting it but when I opened it it was empty. How can get my data back?  Thank you  P.S. I have backed up my most important files but still it would save a lot of time if I could get the rest back.


How to copy a windows 7 user profile when changing domains

I need to connect my machine to a new domain soon. When I do so a new user profile will be created and I would like to copy all the settings/data from the old profile to the new one. This is a local profile only (no roaming). Running Windows 7 Enterprise 64 bit.   I found  previous question on the same topic, it however only seems to address Windows XP and the solutions do not seem to apply to Win7.


Prove $KN\cong K\times N$ if $K\cap N=\{e\}$

Let $K$, $N$ be normal subgroups in $G$.  I would like to show that if $K\cap N=\{e\}$, then $KN\cong K\times N$.  My original thought was to invoke the first Isomorphism theorem.  Therefore I would have to find an appropriate mapping $\varphi$ whose kernel is $\{e\}$.    In a previous exercise, I showed, again by the first Isomorphism theorem that   $$\frac{KN}{K\cap N}\cong\frac{KN}{N}\times\frac{KN}{K}$$  thus, if $K\cap N=\{e\}, $ i would just have to show that $\frac{KN}{N}=K$ and $\frac{KN}{K}=N$.  Thus my idea was to prove that under the condition that the intersection of $K$ and $N$ that elements in $KN$ can commute freely.  We know that $KN=NK$, but this does not imply commutativity, only that if $kn\in KN$, then $kn=n'k'$ with $n$ not necessarily equal to $n'$ and such with $k$.  I just can't come up with a commutativity proof.  EDIT: I forgot to define $KN=\{kn|k\in K, n\in N\}$.


Is it possible to import comments into a chat room without the link appearing?

Question: For an answer on a stack exchange site with say 8 comments, how can I / is it possible to import the comments into a chat room? Background: I was helping with a  and made several comments before I saw the link to auto-import comments into a chat room.  This was awesome by the way!! Note that the person who asked the question left a link to the chat room in a comment. I wanted to make a similar chat room  because I edited an answer which wasn't mine and added a paragraph.  I wanted to chat with the answer's author @JonHopkins to say, 'hey feel free to remove my edit -- just wanted to add my $0.02' -- especially as the stack exchange engines said not to add an additional answer.  HOWEVER, there was no link to auto-import the comments -- probably because I hadn't previously left one, but I'm not sure. So I ask here, Stack Exchange Gurus, could a static link be added to auto-import a series of comments into a chat session?


How should I handle possible revenge downvotes?

I don't like such kind of questions on Meta, so I will try to make it a good question and describe all with a details.  Today I down-voted  added a comment with explanations why I down-voted it, and flag it as non constructive (my flag was marked as helpful). An hour later  was downvoted, without any comment left about the reason. Yes, that wasn't my best answer, but in my opinion it answers the question. Well, even if somebody considered my answer incorrect he could add the correct answer, or up-vote the competitive ones. I checked the  who made competitve answer, and he didn't get any rep today for that answer.   It was my second down-vote on Stack Overflow, so I was a little bit down, after that. I think who could considered my answer so completely wrong, and that I thought that maybe it was revenge down-vote. So I checked  of the user I down-voted today, and it was clear that he down-voted some answers today. After I checked that that user cast only 19 downvotes in 8 months, so chances were very big that this was revenge down-voting.  I came to this meta, and searched what I should do in this case. I found that most questions about down-votes, were closed as duplicates. After I found , and found that a team member of Stack Exchange suggested to cast a flag for moderator attention, and explain the situation there.  I did that, and create next flag:     I think after I down-voted this question (and a comment about this), the OP down-voted me in revenge; it's clear from his today's reputation and from timing of my down-vote of his question, and time when one of my answers was downvoted. I cannot be 100% sure about that, but if somebody can check this, and point him that it's not the good way to do.   As you can see, I didn't ask for returning any reputation, or banning that user, I just wanted, somebody to point him, that he did wrong. And after I get this respons on my flag: "declined - flags should only be used to make moderators aware of content that requires their intervention." So in the end I also lost 10 points of the flag weight.  After describing all situation in details, I want to know were exactly I was wrong here. And what should I do next time something like this happens?


Configure unattended upgrades notification e-mail's from address

I've recently built a server using 14.04.1 LTS, I wanted a very quick and simple way for it to let me know if, for example, it needed a system restart after installing upgrades.  I decided e-mail was the best option.  I've installed, configured and tested ssmtp to use one of my usual e-mail services.  Also, I've configured unattended-upgrade to e-mail me after any upgrades, at least initially.  Can I get the unattended-upgrade e-mail to come from a specific address?  I know I can do that using just mail or ssmtp directly but if I don't specify a "from" address then it defaults to my mail service's default account and I want it to be clear it came from this particular machine.  Where can I specify a "from" address for the mail command that unattended-upgrade uses?


In the Star Trek reboot movie, why did Nero's ship have such powerful weaponry?

In the Star Trek reboot movie, Nero's ship the Narada was a mining ship.  However, it was very heavily armed with devastating weaponry that far outmatched any ships from the earlier time.  While the Romulans are a warlike race and a mining ship may need to defend itself against pirates or the like, the sheer level of offensive weaponry on the Narada seems very out of place on a civilian vessel*.  The fact that the ship has decades newer technology doesn't really explain just how well armed it is.    If I understand the timeline, the Narada encountered Spock's Vulcan ship just as it had failed to prevent the destruction of Romulus, which would have given no opportunity to arm itself beyond what it was already provisioned with.   So my question is, What canon reason would there be for the Narada to be carrying such extensive weaponry when it is a mining ship?  * In my head I pronounced this as "wessel" in honour of Chekov :)


Can a relation with less than 3 elements be considered transitive?

The generalize rule for a transitive relation is   a -> b b -> c therefor a -> c   If an element has less than 3 elements, can it still be transitive? If so, does that provide any useful information?


Which of these two words is proper in denoting a friend?

"Our mutual friend" or "our common friend" - which is more suitable ? Why is that so ?


Finding the formula of the sum $\frac1{1\cdot2} + \frac1{2\cdot3}+ \frac1{3\cdot4} + \cdots + \frac1{n\cdot(n+1)}$?

I am having some trouble finding out the formula for this sum:  $$\text{?} = \frac1{1\cdot2} + \frac1{2\cdot3}+  \frac1{3\cdot4} + \cdots + \frac1{n\cdot(n+1)}$$  I am not sure where to start finding the formula. I know the answer is $1/(n+1)$ but how do you get that without using INDUCTION.


Show that the closed ball in $C([0,1])$ of center $0$ and radius $1$ is not compact.  I thought it will be compact since every closed and bounded set in $\mathbb{R}$ is compact?  Why is it not compact and how can I prove it?


How widely accepted/supported is inflation theory?

To the less well acquainted, inflation theory seems like a rather far fetched proposal.  It makes very specific claims about the earliest moments of the universe, without being explainable in terms of well established physical theories, e.g. QFT or GR (correct me if I'm wrong).  Specifically, it suggests rapid expansion of space in the first $\sim 10^{-33}$ seconds after the big bang.  That is a very very short time, billions of years ago, to make such a strong claim about a large, formative event of our universe.  I understand there exists evidence ( such as large scale inhomogeneity ), but couldn't this be explained with a simpler model?  Are there competing theories that also explain evidence used to support expansion theory?  In short, help a skeptical non-cosmologist understand why this theory is so strongly supported.


How to know the partition where grub is installed

I am Dual Booting Maverick with Natty. I want to know which partition has Grub installed.   I want to make sure that grub is installed in the maverick partition not in natty, so that when I remove the natty partition, I don't have booting problem in the absence of grub.  On maverick there is no menu.list file in /boot/grub but natty has one.  Here is the output of fdisk -l  gaurav@gaurav-desktop:~/Desktop$ sudo fdisk -l  Disk /dev/sda: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x9cdb9cdb     Device Boot      Start         End      Blocks   Id  System /dev/sda1   *           1        7295    58592773+  83  Linux /dev/sda2            7295       25475   146033664   83  Linux Partition 2 does not end on cylinder boundary. /dev/sda3           25476       32194    53970367+  83  Linux /dev/sda4           32195       35483    26414081    5  Extended /dev/sda5           32195       32444     1999872   82  Linux swap / Solaris /dev/sda6           32444       35483    24413184   83  Linux gaurav@gaurav-desktop:~/Desktop$


What to do if my professor is plagarizing

I was in the middle of doing my homework for a class (its a worksheet for a word document) and I noticed that the author of the word document is not my professor.  I looked it up, and it turns out that the person who wrote the document teaches a related class at a different university.  I checked the rest of the document, and nowhere (other than the word metadata) says that it comes from this other person.  Should I do anything with this information, and if so, what?


horizontally align center the div with red border

I want to horizontally align center the div with the red border and vertically align middle the image. Vertically align middle is working but horizontally align center is not working. Here is my code:    .vcenter {   display: table-cell;   vertical-align: middle; }

xyz


I've been trying my hand at sourdough bread for a few months now and it is getting better and better, but this keeps happening, and I have no idea what might be the cause:    My impression is that during the rise, the crumb tears into two pieces in the middle.  This is probably relevant: The dough is 80% hydration white bread flour, around 3 hours autolysis, then lamination and three stretches and folds spaced out. Altogether around six hours of bulk fermentation, overnight in the fridge (5 °C), and baked in the morning on a pizza stone, with 250 °C with steam for 20 minutes and 220 °C for 20 minutes (the oven has the air convection turned on).  My problem is I have no idea which part of the recipe is to blame for the outcome, so I'm not even sure where I am deviating from the recipe I'm trying to copy (to be very exact, I'm trying to follow this one now: )  I'm not sure if this is important, but it also doesn't open up so well (but I don't have a proper lame, so I'm struggling with the scoring):


I am new to the pgf package ant I wrote that code but when I compiled it (successfully), the picture was not shown.   The code:  %% LyX 2.1.2 created this file.  For more info, see http://www.lyx.org/. %% Do not edit unless you really know what you are doing. \documentclass[11pt,english,hebrew]{article} \usepackage[T1]{fontenc} \usepackage[cp1255]{inputenc} \usepackage{geometry} \geometry{verbose,tmargin=2cm} \setlength{\parindent}{0bp}  \makeatletter %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands. \usepackage{enumitem}       % customizable list environments \newlength{\lyxlabelwidth}      % auxiliary length   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands. \usepackage{tikz}  \makeatother  \usepackage{babel} \begin{document}  \title{����������}  \maketitle ������  \begin{tikzpicture}     \draw[fill=yellow] (0,0) -- (60:.75cm) arc (60:180:.75cm);     \draw(120:0.4cm) node {$\alpha$};      \draw[fill=green!30] (0,0) -- (right:.75cm) arc (0:60:.75cm);     \draw(30:0.5cm) node {$\beta$};      \begin{scope}[shift={(60:2cm)}]         \draw[fill=green!30] (0,0) -- (180:.75cm) arc (180:240:.75cm);         \draw (30:-0.5cm) node {$\gamma$};          \draw[fill=yellow] (0,0) -- (240:.75cm) arc (240:360:.75cm);         \draw (-60:0.4cm) node {$\delta$};     \end{scope}      \begin{scope}[thick]         \draw (60:-1cm) node[fill=white] {$E$} -- (60:3cm) node[fill=white] {$F$};         \draw[red] (-2,0) node[left] {$A$} -- (3,0) node[right]{$B$};         \draw[blue,shift={(60:2cm)}] (-3,0) node[left] {$C$} -- (2,0) node[right]{$D$};          \draw[shift={(60:1cm)},xshift=4cm]         node [right,text width=6cm,rounded corners,fill=red!20,inner sep=1ex]         {             When we assume that $\color{red}AB$ and $\color{blue}CD$ are             parallel, i.\,e., ${\color{red}AB} \mathbin{\|} \color{blue}CD$,             then $\alpha = \delta$ and $\beta = \gamma$.         };     \end{scope} \end{tikzpicture} \end{document}   Any suggestions?


I've read about closures many times .  But I'm really confusing to know exactly what do closure mean?   Is variable a closure ? Or, is function is a closure ? Or, both can be called a closure ?


Initializing class member variables in constructor of derived class

I am learning C++ from tutorialspoint. In the topic of polymorphism, they have the following code (only relevant parts added):  class Shape {    protected:       int width, height;     public:       Shape( int a = 0, int b = 0){          width = a;          height = b;       }       int area() {          cout << "Parent class area :" <<endl;          return 0;       } }; class Rectangle: public Shape {    public:       Rectangle( int a = 0, int b = 0):Shape(a, b) { }        int area () {           cout << "Rectangle class area :" <<endl;          return (width * height);        }   I don't understand this line: " Rectangle( int a = 0, int b = 0):Shape(a, b) { }", specifically this part: ":Shape(a, b)". I read earlier that in constructors of a class, we can assign values to the class member variables using the following syntax:  Classname ( type arg1, type arg2, ...) : member_variable1(arg1), member_variable2(arg2), ... {.. }   But here Shape is a constructor (a function) of base class. Moreover, I also read that constructors (along with destructors, overloaded operators and friend functions) cannot be inherited - so how can we use a call to Shape?


Why does this work? Shouldn't the let reset the variable?

I don't understand why this works. wouldn't the >>> let timeoutID <<<< reset the variable each time, so that the timeoutId is always empty? I would put the 'let' outside of this assuming that's the only way it would work. However this works, I just don't get it. This is from a Udemy course. I get everything else. I'm an amateur here, so..... const debounce = (func, delay = 1000) => {     let timeoutId;     return (...args) => {         if (timeoutId) {             clearTimeout(timeoutId);         }         timeoutId = setTimeout(() => {             func.apply(null,args);         },delay)     };  }; const onInput = event => {         fetchData(event.target.value);   }; input.addEventListener('input', debounce(onInput,1000));


Proving the bilinearity of a certain form

I have a question regarding a paper:  let $φ, ψ: ℝ^3 \to ℝ$ two linear maps with $φ(v)= 〈a,v$〉 and $ψ(v)=〈b,v$〉with $a,b ∈ ℝ^3$. We define the map with $ℝ^3 \times ℝ^3 \to ℝ$ by  $$s(v,w):=  φ(v) * ψ(w).$$  I need to show that s is a bilinear form and determine the transformation matrix of s regarding the canonical basis of  $ℝ^3$.  I have no clue how to do this, so help would be much appreciated


network manager says "device not managed"

I used to be able to share my network connection by editing the Auto Eth0 to share with other computers in the Ipv4 section and now I upgraded my laptop to 11.10 .  Now are there no wired connections in the network manager. When I click my connections applet at the top of the tray it also says wired device not managed!  when I type ifconfig -a  daniella@daniella-1001HA:~$ ifconfig -a eth0      Link encap:Ethernet  HWaddr 90:e6:ba:83:d6:fc             UP BROADCAST MULTICAST  MTU:1500  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)           Interrupt:45   eth0:avahi Link encap:Ethernet  HWaddr 90:e6:ba:83:d6:fc             inet addr:169.254.13.40  Bcast:169.254.255.255  Mask:255.255.0.0           UP BROADCAST MULTICAST  MTU:1500  Metric:1           Interrupt:45   lo        Link encap:Local Loopback             inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0            RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)  wlan0     Link encap:Ethernet  HWaddr 00:25:d3:90:43:41             inet addr:192.168.0.6  Bcast:192.168.0.255  Mask:255.255.255.0           inet6 addr: fe80::225:d3ff:fe90:4341/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:12881 errors:0 dropped:0 overruns:0 frame:0           TX packets:12867 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:8851081 (8.8 MB)  TX bytes:2343199 (2.3 MB)


What is the angle at which water is splashed when a vehicle tyre rides in water on the road?

I would like to know the following:   What is the angle at which water gets splashed when I ride my vehicle through a water on the road? How does angle of water varies with speed? What is the relation between the distance the water goes with the speed of the vehicle?   Thanks!


Increase font size of entire document in \documentclass{exam}

I am setting up a question paper using:  \documentclass[12pt]{exam}   However, I would like to increase the font size to 15pt for the entire document.   I found out from  question that we can use extsizes and use something like extarticle instead of article and increase the font size up to 20pt.   How can it be done for the \documentclass{exam} ?


Why does WinSCP use a .com binary for the CLI version and an .exe binary for the GUI?

I thought .com is an ancient form for executable, leftover from early MS-DOS days? Why do they use that today in WinSCP? And why only for the CLI version?  I tried asking this in their chat room, but received not a single reply for days. As always.


Sort Generic list of generic objects by multiple values and specific value of generic object

There are two Generic list of Inspectors and InspectorRates.   RateType has three different values (0 = Not Select ,1 = Day Rate ,2 = Hourly Rates).  I want to show all inspectors with Day Type Rate first and then lowest rate. If user selects option "Hourly Rates" then list needs to be sorted by Hourly Rate and thenlowest rate. Not seleted rate will always be at the bottom.      I have tried LINQ but its not working.  listI.OrderBy(Function(i) i.DefaultRate.RateType = Rates.RateTypeEnum.Day_Rate).ThenBy(Function(i) i.DefaultRate.Rate)


Solving functional equation $f(x)+f(1/x)=f(x)\cdot f(1/x)$

Let a function $f(x)$, and $x$ not equal to zero be such that: $f(x)+f(1/x)=f(x)\cdot f(1/x)$ then $f(x)$ is ? I tried differentiating it but did not find any useful outcome. answer given at back of book is A)$1+x^n$, $n$ belongs to $\mathbb R$ B)$1-x^n$, $n$ belongs to $\mathbb R$ C)$\pi/(2\arctan|x|)$ D)$2/(1+k\ln|x|) $


What, precisely, does "reset network settings" do on an iPhone?

I use "internet sharing" on my Mac, but lately I've been having trouble connecting my iPhone 5 to the resulting WiFi network. I've read advice online to do Settings -> General -> Reset -> Reset Network Settings on the iPhone, but I can only find very vague information on what this actually does. From the name it sounds like a bit of a nuclear option, and before I try it I want to make sure that it's not going to affect my ability to use the cellular network.  So, does the iPhone's "reset network settings" just reset WiFi settings, or does it reset cellular network settings as well? If the latter, is there any danger that this would delete any settings installed by my phone company, causing problems with using internet or telephone services via the 3G or 4G networks?


I need the characters «» in my LaTeX document.  I'm writing in English though, and I don't want to use Babel.  I have the following hack but I'd like a better way:  \newcommand{\q}[1]{{% \font\larm = larm1000% \larm% \char 190}{#1}{% \font\larm = larm1000% \larm% \char 191}}


The process is gradually stabilizing vs the process is stabilizing gradually

I found this sentence in a university test: "the process....gradually", and I was supposed to fill the gap with either the present simple or the present continuous form of the verb "to stabilize". Without context I really didn't know which tense I had to use. I ended up using the present continuous tense because I thought it made a bit more sense. So, is it correct to say "The process is stabilizing gradually"? I do know that adverbs should be placed after the verb "to be", therefore from a grammatical standpoint "the process is gradually stabilizing" is probably the better sentence of the two. It seems to me, though, that in this case putting the adverb at the end of the sentence does not sound terrible.


A beamer file that I had created last year will not compile now. Here is a minimal example:  \documentclass{beamer}  \begin{document} test \end{document}   The log file is long but here is the relevant part:  (C:\Users\petrovic\AppData\Roaming\MiKTeX\2.9\tex\latex\beamer\beamerbasetranslator.sty (C:\Users\petrovic\AppData\Roaming\MiKTeX\2.9\tex\latex\translator\translator.sty Package: translator 2019-05-31 v1.12a Easy translation of strings in LaTeX ) ! Missing = inserted for \ifnum. <to be read again>                 - l.15 \usedictionary                {translator-basic-dictionary} I was expecting to see `<', `=', or `>'. Didn't.  )   I have reinstalled translator and beamer packages, but it did not help. I am using MikTex (which I also updated).


F-mount to EOS adapter from Nikon to Canon

I bought a Canon EOS 500N body (EF mount) and I want to also buy a Nikon N65 (F mount) camera. The question is if with  I can use a lens for both cameras?  maybe you have some similar experience?


Regression: centered vs. uncentered predictors

I'm trying to understand how/why centering predictors in a 2 predictor regression model would change the coefficients  Lets say I have 2 centered predictors and an interaction term, predicting a continuous Y variable that is not centered, and I have gone through the process of calculating all the regression coefficients (b0-3).  Now, the question is, if I were to uncenter the 2 predictors, how would the coefficients change (if at all)?  From my understanding, the distribution of data points would not change, nor would the regression plane. However, by centering/uncentering we change the (X1, X2, Y) value of each datapoint. I don't believe this would change the b3 interaction coefficient because the relationship between the simple slopes would not be affected. The coefficients for the intercept and the 2 predictors, however, should change because we've essentially changed the scale for each of the predictors.  Can anyone shed some light on why/how this happens? and how do you determine the magnitude/direction of these changes?


Does $P(A\cap B) + P(A\cap B^c) = P(A)$?

Based purely on intuition, it would seem that the following statement is true, when thinking of the events as sets:  $$P(A\cap B) + P(A\cap B^c) = P(A)$$  However, I am not sure if this is true, and cannot find out how to prove it, or describe a straight forward intuition of it.  Is this equation true? And if not, is there another way to link $P(A\cap B)$ and $P(A\cap B^c)$ with $P(A)$?


About a week ago my Windows 10 Pro started waking up in a middle of the night. I've had similar problems about half a year ago, but managed to configure the cause - unruly UpdateOrchestration task and disable it - using  answer. Disabling the "Wake the computer..." option in Reboot task helped.  However, about a week ago the computer started waking in the middle of the night again and I am unable to convince the Reboot to stay down this time. When I uncheck "Wake the computer..." option a window appears that asks me to provide login credentials for some mysterious S-1-5-18 user that I have never heard about (see the picture below, I use the Polish Windows version).     I have no idea what the password for S-1-5-18 should be. This window's dropdown allows me to choose other users though, besides the mysterious S-1-5-18 - in fact there seems to be about 5 accounts with names similar to my Windows username (why there is a multitude of them? I have no idea, Control Panel shows me as the only user of this computer); when I select one of them in the dropdown and enter my password I get the following message (translated from Polish to English):     The supplied variant structure contains invalid data   Do you have any idea how to disable the computer from rebooting at night?   --  EDIT: To clarify the multiple username thing: there is a single S-1-5-18 user in the dropdown. The multiple user thing I said pertains to my original Windows username. The following picture shows the content of the users dropdown. I have edited out the names that show my original email address, my real name or the names of my computers..  EDIT2: I tried disabling the "Wake to run" option on the task using PowerShell, with the following script and it also did not work. No error is given but the WakeToRun stays true.   ?{ $_.Settings.WakeToRun -eq $true -and $_.State -ne 'Disabled' } | %{     write-host $_     $_.Settings.WakeToRun = $false;     Set-ScheduledTask $_  }


What is the Capacitance of a spherical capacitor when either Inner/outer shell is grounded (Earthed)

The capacitance of a spherical capacitor is given by $$C=\frac{4\pi \varepsilon_{0}}{\left ( \frac{1}{a}-\frac{1}{b} \right )}$$     How can I find out the capacitance of the capacitor when   The inner sphere is earthed. The outer hollow sphere is earthed.


How can I get the Windows 8 start-screen in Windows 10?

I was skeptical about the modern-UI interface in Windows 8 (and 8.1), having been a Windows 7 user for a while, but slowly got used to it.  My laptop got the upgrade to Windows 10 yesterday that I had reserved a while back; the upgrade process was fast and overall Windows 10 runs far better than Windows 8 did on my laptop.  The only thing wrong with it (in my opinion) is that the start menu has changed again:    It's nice to use on a desktop, but as my laptop is touch-screen, I find it somewhat annoying to use. I know that the start menu in Windows 10 is still touch-oriented, but it's still annoying as I had got used to the start screen in Windows 8.  Is it possible to change back to the start-screen that was in Windows 8?


I'm running Debian Stretch and Linux kernel version 4.9.110-3+deb9u4, with a modified config. I'm observing the following weird behaviour   Set the hardware clock to 2016-01-01 00:00:00 UTC Reboot dmesg reports reading the hardware clock similar to what was set previously date reports 2016-11-03 17:16:42 UTC   The above behaviour is observed with any date before 2016-11-03 17:00:00 UTC. I haven't narrowed down any further than that.  The kernel source code has not been changed, nor am I running any custom kernel modules. I have also observed this with using the 4.9.168 kernel from the Debian repos, as well as the 4.19.37 kernel from stretch-backports. I have also been able to reproduce this on a DigitalOcean droplet running Stretch and 4.9.168.  I have not seen this problem occur when I set a date after 2016-11-03. It doesn't seem likely, but it seems like the kernel is forcing some minimum date.  Does anybody have a clue on this?  Logs from my VM:  root@debian-vm:~# timedatectl        Local time: Thu 2016-11-03 17:17:02 UTC   Universal time: Thu 2016-11-03 17:17:02 UTC         RTC time: Fri 2016-01-01 00:29:00        Time zone: Etc/UTC (UTC, +0000)  Network time on: yes NTP synchronized: no  RTC in local TZ: no root@debian-vm:~# dmesg | grep rtc [    0.985653] rtc_cmos 00:01: registered as rtc0 [    0.985670] rtc_cmos 00:01: alarms up to one month, y3k, 114 bytes nvram, hpet irqs [    1.032409] rtc_cmos 00:01: setting system clock to 2016-01-01 00:28:37 UTC (1451608117)   Logs from a DigitalOcean droplet:  root@debian-s-1vcpu-1gb-sfo2-01:~# timedatectl                                                                                Local time: Thu 2016-11-03 17:17:05 UTC   Universal time: Thu 2016-11-03 17:17:05 UTC         RTC time: Fri 2016-01-01 00:00:46        Time zone: Etc/UTC (UTC, +0000)  Network time on: yes NTP synchronized: no  RTC in local TZ: no


Post Link for Tag Info Wiki's display text should be better than "unknown"

The displayed text for a [Post Link] where the underlying Id corresponds to a Tag/Info Wiki (where the link redirects successfully) is just "unknown". For example, if you've ever edited a tag wiki: . It would be nice if this could be better identified.


Evans PDE(2nd edition) Problem 5.11: If $Du=0$ a.e. , does $u=c$ a.e.?

Let $W^{1,p}(U)$ be the Sobolev space, where $U$ is a connected   bounded domain in $\mathbb{R}^n$ and $u\in W^{1,p}(U)$ satisfying   $Du=0$ a.e. in $U$. Then $u$ is constant a.e. in $U$.   I don't know how to prove this. Especially, I don't know how to use "connected".  Please guide me.


How to apply a png texture over my material?

everybody! I making a Barbie style doll model. I've UV mapped the face part and created her eyes and lips using photoshop and saved the texture as a png. The face has a node setup for plastic looking skin and I would like to add my texture over it. I've found similar questions on this website but the ones I found were for older blender versions and I couldn't figure it out how to do it on Blender 2.91. Below is my current node setup and also the texture I want to apply.


Find $\lim_{x\to 1}(\frac{p}{1-x^p}-\frac{q}{1-x^q})$    My attempt: I took LCM and applied lhospital but not getting the answer.Please help


Why are some usernames on comments not a link to user profiles?

Sometimes when reading through user comments on a particular answer, some usernames that appear like user[digit] e.g user12345 are not links. Is this a known behaviour or any other thing I am not aware of?


Does full device encryption protect my data from Google and the government?

Apple recently made waves within the tech community by refusing to comply with law enforcement in regards to accessing encrypted user data.  Their statement was that they do not have the technical ability to decrypt this data.   As an Android user, is there any similar possibility (preferably built in to the OS instead of third party) that I can use to achieve similar protection from even Google and my device manufacturer? I know there is the "Full Device Encryption" in my settings, but does this prevent Google etc. from accessing it?   For reference, my device runs Android Lollipop and is a OnePlus Two. If other versions like Marshmallow would allow me to do this that's fine.


NullPointerException during nested copy construction

I tried to make copy of an object with list of other objects. I came up with  solution which threw NullPointerException. After a lot of time spending on it I managed to make it work but I am very confused about the origin of exception. I seek for an logical explanation of described issue.  After changing return type from long to Long everything works fine as described in comment line in code sample.  import java.util.ArrayList; import java.util.List;  public class JustDontGetItApp {      public static void main(String[] args) {         Dog dog1 = new Dog("Max");         Dog dog2 = new Dog("Buddy");          AnimalSchelter animalSchelter = new AnimalSchelter("Hope");         animalSchelter.getAnimals().add(dog1);         animalSchelter.getAnimals().add(dog2);          AnimalSchelter copy = animalSchelter.copy();     } }  class AnimalSchelter {      private String name;     private final List<Animal> animals = new ArrayList<>();      public AnimalSchelter(String name) {         this.name = name;     }      public AnimalSchelter(AnimalSchelter animalSchelter) {         name = animalSchelter.getName();         animalSchelter.getAnimals().stream().map(Animal::copy).forEach(animals::add);     }      public AnimalSchelter copy() {         return new AnimalSchelter(this);     }      public String getName() {         return name;     }      public List<Animal> getAnimals() {         return animals;     } }  abstract class Animal {      private Long id;      public Animal() {}      public Animal(Animal animal) {         id = animal.getId();     }      protected abstract Animal copy();      //LINE long -> Long fixes everything     public long getId() {         return id;     } }  class Dog extends Animal {      private String name;      public Dog(String name) {         super();     }      public Dog(Dog dog) {         super(dog);         name = dog.getName();     }      @Override     protected Animal copy() {         return new Dog(this);     }      public String getName() {         return name;     } }


Sorry for the broken english  hallo i have this small problem with my duelshock 4 controller  it wont connect with my ps4 i tried to reset and it still doesn't work  the licht doesn't blink if you push the ps4 button.  i tried to use it on my pc it works a little bit but it loses connection every 6 seconds   I don`t know if a part is broken because this controller is 3 years old


Can Alice encrypt a message to Bob without hiding anything from Eve?

I know that if Alice and Bob both have secret-public key pairs, they can use RSA for example. If we remove the possibility that Alice can know anything which Eve doesn't (ie Alice's secret key), is there an algorithm which makes encryption still possible?  (I am new in the topic and haven't been able to find an answer.)


I'm trying to learn Vim and I'm seeing a lot of documentation use syntax like <C-v>. Is there a general guide on how to read this correctly? I've attached an example SO post below that uses this syntax:   Do yourself a favor by droping the Windows compatibility layer. The normal shortcut for entering Visual-Block mode is <C-v>.


How to avoid being asked passphrase each time I push to Bitbucket

I set up my ssh stuff with the help of , and it used to work well (I could run hg push without being asked for a passphrase). What could have happened between then and now, considering that I'm still using the same home directory.  $ cat .hg/hgrc  [paths] default = ssh://hg@bitbucket.org/tshepang/bloog  $ hg push Enter passphrase for key '/home/wena/.ssh/id_rsa':  pushing to ssh://hg@bitbucket.org/tshepang/bloog searching for changes ...


Refreshing a post via the "change" notice causes the question notice to disappear

I noticed a minor bug today. If a question has a post notice, that notice disappears if any of the answers (or the question itself) are refreshed. By "refreshed" I mean by clicking on the little gray bar at the top of the post that says something like "this post has changed... click this to refresh it".  Here is sample post, with the notice:        And this is what happened when I refreshed the answer post:        I noticed this on MSO just shortly prior; I also noticed this behavior on SO with a question close notice (not 100% sure on the latter though).  I should add that the notice disappearing is temporary. It comes back when the entire page is reloaded (e.g., pressing F5).


This code outputs "10 5" but doesn't give a compile error. How? Why? Is there any such rule that if we write multiple values in a return statement then only last one is returned or is it something else? #include <stdio.h> int f(int, int); int main() {     int a, b;     a = f(5, 10);     b = f(10, 5);     printf("%d %d", a, b);     return 0; } int f(int i, int j) { return (i, j); }


Is there really no way to power a DSLR by USB?

I made some scripts on my Raspberry Pi to automate a daily shot at a specific hour.  My DSLR is plugged in through USB. I thought this would keep its battery charged, but no.  Is there really no way automate a DSLR to shoot every 24 hours without having to pick it up, charge/replace its battery, and put in back on the same spot?


How to add a custom class attribute into code wrapper?

By default, after publishing codes, the post shows a html like this,
              some codes here
   I have plenty posts with codes and don't want to edit them one by one. How do I add a custom class attribute globally for all posts? to make it look like this
              some codes here
   Thanks in advance.


Software to read PDFs with inverted colors

I sometimes want to read a long PDF file in a computer, but because white background I can read only a few pages until my eyes weep.  Is there any software to invert colors of a PDF (PDF converter, PDF viewer with "invert colors" option, a program to invert all colors in Windows...)?  I tried "magnify" for Windows XP, but I don't like to split my screen to do that or to move the mouse a lot to see only a page. I would like to see the document in full screen...


How do I get a CD version of El Capitan suitable for a Macbook Pro?

I have 2 Macs, and am downloading El Capitan from the app store.  I want to see if I can install it on an older MacBook Pro that has a broken Command-R feature that prevents me from installing the OS.  (It says contact apple support)  Since that costs $, I'd rather see if I can simply boot and reinstall the OS in a clean way.  How do I locate and burn the downloaded El Capitan in a way that will make it bootable on the other mac?


What kind of coin was given by Jaqen H'ghar to Arya?

A comment an an answer of mine on  made my wonder about the iron coins used by the Faceless Men, one of which was given by Jaqen H'ghar to Arya.  Was the iron coin given by Jaqen H'ghar to Arya regular Braavosi currency? Or were they a different kind, minted just by/for the Faceless Men as a mean to let them being recognized when they wanted to?  I've always assumed that the Faceless Men used their own coins, without any legal value and distinct for the regular Bravoosi currency; my rationale is that regular currency is used by anyone and is too much widespread to be instantly recognized as a symbol of the Faceless Men, like the sailor to whom Arya shows his coin:     "Wait," Arya said suddenly. "I have something else." She had stuffed it down inside her smallclothes to keep it safe, so she had to dig deep to find it, while the oarsmen laughed and the captain lingered with obvious impatience. "One more silver will make no difference, child," he finally said.   "It's not silver." Her fingers closed on it. "It's iron. Here." She pressed it into his hand, the small black iron coin that Jaqen H'ghar had given her, so worn the man whose head it bore had no features. It's probably worthless, but...   The captain turned it over and blinked at it, then looked at her again. "This... how... ?"   Jaqen said to say the words too. Arya crossed her arms against her chest. "Valar morghulis," she said, as loud as if she'd known what it meant.   "Valar dohaeris," he replied, touching his brow with two fingers. "Of course you shall have a cabin."   A Storm of Swords - Arya XIII   From this passage, it seems to me that the captain is somewhat shocked to see that iron coin, but he is from Braavos, so the mere sight of an iron coin should not be a great surprise to him; but he is "bought" only after Arya say the words, so the whole passage instead of clarifying the situation, gives me even more doubts about the whole subject.   Like, I said, I tend to support the hypothesis that the coins fo the Faceless Men are not regular currency, but I don't have any official reference to support this opinion of mine; for what I know it could be just an assumption made without any established fact.    The only references that I was able to collect are that Arya's coin (given by a Faceless Man) was      a piece of iron no larger than a penny and rusted along the rim. One side had writing on it, queer words she could not read. The other showed a man's head, but so worn that all his features had rubbed off.   A Clash of Kings - Arya X   and about Braavosi currency     Yet they brought him money: leather purses plump with gold and silver and the square iron coins of Braavos.   A Dance with Dragons - The Ugly Little Girl    book has pictures of both of these coins and they seem to be two different things, but they are both depicted as round coins, and we know that the Bravoosi currency is made of square coins, so I'm inclined to consider these illustrations as inaccurate and to not use them as a solid and valid reference.    So, do the Faceless Men use their own distinct iron coins, or just the regular Braavosi currency?  Please note that I'm only interested in answers about the books, not about the TV show.


same problem but cant find power management tab in the settings.


Terms of a monotone, convergent series must be $o(1/n)$

Let $(x_n)_{n\in\mathbb N}$ be a non-negative, non-increasing sequence such that $\sum_{n=1}^{\infty} x_n<\infty$. I want to show that $$\lim_{n\to\infty}\{nx_n\}=0.$$ I’ve definitely seen this question asked on this forum before, but I’m unable to find it now. Any reference or hint would be appreciated.


I have written a test class for a trigger on the lead object.  When i run the test class i get the following error:  Methods defined as TestMethod do not support Web service callouts, test skipped  There is an other trigger on lead that has a call to a webservice so i get this error.  I have wrapped the call with:  if (!Test.isRunningTest()) {    // do callout }   But i’m still getting the same error.  Any other way to run correctly the test class?  Thank you in advantage.


Is TV harmful to my infant's development?

My wife and I use our TV to watch shows and streaming movies. Our 2 month old daughter is sometimes drawn to the TV and will turn her head towards it and will 'focus' on it. I know that their eye sight is not developed to the point where they can really watch it. But perhaps the moving shapes and the sounds pique the interest for her growing brain and senses.  Is TV harmful at all to my infant's development?  I also want to clarify that we are always interacting with the baby, except when she is asleep, or when we're trying to cook dinner. So, we're not neglecting the baby and depriving her of social interaction.


Why does chmod 777 -R / leave the system unusable?

I'm only granting permission to all to do anything but why does the system crash by giving permissions only? I'm only modifying the permission not changing the files.


Group with $a=a^{-1}$ for all $a\in G$ is abelian

Let $G$ be a group, and suppose that $a= {a^{-1}}$ for every $a\in G$. Prove that $G$ is Abelian.    I know that I need to prove that ${a^{-1}}$ = a and use right multiplication. I also know that I need to declare a, b $\in$ G and go from there, but I'm confused when I get to   (${a^{-1}}$${b^{-1}}$) = ab.


Misplaced \noalign error with \input in a table after the 2020 fall LaTeX release

With the 2020 fall update, the behaviour of \input{} changed. Before, I would have a main latex document (main.tex) and then the table contents in another file (table.tex) . Importantly, the file table.tex could be anywhere on my PC, because I could add directories that the \input command went through. So my set-up looked like this: The main.tex document: \documentclass[11pt, a4paper]{article}    \makeatletter \providecommand*{\input@path}{} \g@addto@macro\input@path{{"C:/Users/me/inpath/"}}% \input finds files in this directory \makeatother  \begin{document}  \begin{tabular}{lll} \hline \input{table.tex} \hline \end{tabular}  \end{document}  Then the file table.tex that would be placed in the directory "C:/Users/me/inpath/": 1 & 2 \\ 3 & 4 \\  Unfortunately, this set-up no longer works. My question is: What is the best way to replicate this behaviour? For now, my solution would be to change the main.tex to: \documentclass[11pt, a4paper]{article}        \newcommand{\inpath}{"C:/Users/me/inpath/"}  \makeatletter\let\expandableinput\@@input\makeatother    \begin{document}  \begin{tabular}{lll} \hline \expandableinput{\inpath table.tex} \hline \end{tabular}    %%% Or alternatively \begin{tabular}{lll} \hline \input \inpath table.tex \hline \end{tabular}  \end{document}  Is there a more elegant way to achieve this? A solution similar to how things worked before the latex fall update? In which I can tell the TeX primitive \@@input where to look for files? What I have found so far is the information  and .


I have a valid visa for 2 years, how to apply visa for wife and children

I have a two years multiple C Class visa and i want to take my wife and children for a holiday in UK. I will be bearing all expenses of their travel. What will be procedure to apply for the visa for them, whether my wife will be the primary applicant in this case.


How to find $\lim_{n\to\infty}\frac{1!+2!+\cdots+n!}{n!}$?

How to evaluate the following limit? $$\lim_{n\to\infty}\dfrac{1!+2!+\cdots+n!}{n!}$$  For this problem I have two methods. But I'd like to know if there are better methods.  My solution 1:  Using Stolz-Cesaro Theorem, we have $$\lim_{n\to\infty}\dfrac{1!+2!+\cdots+n!}{n!}=\lim_{n\to\infty}\dfrac{n!}{n!-(n-1)!}=\lim_{n\to\infty}\dfrac{n}{n-1}=1$$  My solution 2:  $$1=\dfrac{n!}{n!}<\dfrac{1!+2!+\cdots+n!}{n!}<\dfrac{(n-2)(n-2)!+(n-1)!+n!}{n!}=\dfrac{n-2}{n(n-1)}+\dfrac{1}{n}+1$$


Python Regex - How to Get Positions and Values of Matches

How can I get the start and end positions of all matches using the re module? For example given the pattern r'[a-z]' and the string 'a1b2c3d4' I'd want to get the positions where it finds each letter. Ideally, I'd like to get the text of the match back too.


I have list of url(near about 50k) of images in text file which I want to download.  Is there anyway I can download it in async way using wget command or any other way, by reading it from text file.


Proving that a function from $N\times N$ to $N$ is bijective.

I am stuck on this problem:  Define $f: N\times N \rightarrow N$ by   $f(i,j)=\frac{(i+j-1)(i+j-2)}{2}+i$.   How do you prove that $f$ is a bijection thus $N\times N$ and $N$ are numerically equivalent?  Work: First I tried to prove that $f$ is injective by setting $f(i,j)=f(x,y)$. However, from here I am stuck and I cannot reduce it properly. My work really does not get anywhere significant and its really messy.


Linked list: Exception thrown: read access violation. B was 0xCDCDCDCD

I've posted my first attempt at a linked list code below. The objective is to get a linked list of 10 integers and to traverse the list to double the odd numbers and half the even ones. As I'm new to linked lists I'm just currently working on the first part: Generating the list.  From the examples I've seen it looks ok to me. It compiles fine but when I go to run it I get the following error message: "Exception thrown: read access violation. B was 0xCDCDCDCD." This is on the line that says "C=B->next".   Does anyone know what this means and/or why it is occurring? Any input would be appreciated :)  #include<stdio.h> #include<stdlib.h> #include<time.h>  struct node {     int data;     struct node* next; };  void freeList(struct node* head);  int main(void) {     srand(time(NULL));       struct node * A = NULL;     A = malloc(sizeof(struct node));     struct node* B = malloc(sizeof(struct node));     struct node* C = malloc(sizeof(struct node));     struct node* D = malloc(sizeof(struct node));     struct node* E = malloc(sizeof(struct node));     struct node* F = malloc(sizeof(struct node));     struct node* G = malloc(sizeof(struct node));     struct node* H = malloc(sizeof(struct node));     struct node* I = malloc(sizeof(struct node));     struct node* J = malloc(sizeof(struct node));      A->data = (rand() % 10) + 1;     B->data = (rand() % 10) + 1;     C->data = (rand() % 10) + 1;     D->data = (rand() % 10) + 1;     E->data = (rand() % 10) + 1;     F->data = (rand() % 10) + 1;     G->data = (rand() % 10) + 1;     H->data = (rand() % 10) + 1;     I->data = (rand() % 10) + 1;     J->data = (rand() % 10) + 1;      B = A->next;     C = B->next;     D = C->next;     E = D->next;     F = E->next;     G = F->next;     H = G->next;     I = H->next;     J = I->next;     J->next = NULL;      struct node* current = A;     while (current != NULL)     {         printf("%d-->", current->data);         current = current->next;     }      freeList(A);      return 0;  }  void freeList(struct node* A) {      struct node* temp;      while (A != NULL)     {         temp = A;         A = A->next;         free(temp);     }  }


Do I have more than 265GB memory on my 8GB RAM laptop?

I wrote a program, that allocates memory, and computes the size between adress of lowest, and highest pointer. I am suprised with results. When I start it, it takes 20mb of memory, 40, 60 ... 200, 220, 240,... 3000mb, 3020mb, and then suddenly bang, 262000 mb, and so on. Could somebody explain me why?  #include <iostream> using namespace std; int aaa; int *max1=&aaa; int *min1=&aaa;  void results(){     cout<<"min "<<min1<<endl;         cout<<"max "<<max1<<endl;         double mln= 1e6;         cout<<"min-max= "<<(max1-min1)/(1024*1024)<<"mb"<<endl; }  void logic(int *c){     if(c>max1){         max1=c;     }     if(c<min1){         min1=c;     }     static int i;     i++;     if(i%800==0)     results(); }   int main(){     int *x;     int l=0;     while(l<=500000000){         l++;         x=new int[20000];         logic(&x[19999]);     }  }


\subseteq + \circ as a single symbol ("open subset")

I'm trying to create symbols \opn for "open subset" and \cls "closed subset". I want them to look like this:      My current solution is:  \def\opn{\!\ensuremath{\subseteq\!\!\!\!\!\raisebox{1pt}{$\circ$}}\,}  \def\cls{\!\ensuremath{\subseteq\!\!\!\!\!\raisebox{1pt}{$\bullet$}}\,}   But the problem is when I use this, Latex doesn't treat \subseteq and \circ as a single symbol, so the spacing is incorrect when for example I write $U~\!\!\!\opn\!\!\!~X$:    How can I make the position of the circle be fixed in the middle, so that \opn becomes a single symbol that is resizable, i.e. responds well to \huge?  Edit: @egreg @MartinScharrer: When using your command (to define the stalk of a sheaf)   \mathcal{F}_x:=\frac{\bigsqcup\{\mathcal{F}(U);\, x\in U \opn X\}}{s\sim s'  \,\Longleftrightarrow\, s\in\mathcal{F}(U)\text{ and }s'\in\mathcal{F}(U')\text{ and } \exists x\in W \opn U\cap U'\!:s|_W=s'|_W}   I get ugly results, namely (egreg's solution)  and (Martin Scharrer's solution) .  Currently, I like this edited Martin's solution the most aesthetically appealing:  \def\opn{ \ensuremath{\mathrel{\subseteq \!\!\!\!\!\raisebox{1.63pt}{$\scriptstyle\circ$}}}}    %odprta podmnozica \def\opnn{\ensuremath{\mathrel{\subsetneq\!\!\!\!\!\raisebox{1.63pt}{$\scriptstyle\circ$}}}}    %prava odprta podmnozica \def\cls{ \ensuremath{\mathrel{\subseteq \!\!\!\!\!\raisebox{1.63pt}{$\scriptstyle\bullet$}}}}  %zaprta podmnozica \def\clsn{\ensuremath{\mathrel{\subsetneq\!\!\!\!\!\raisebox{1.63pt}{$\scriptstyle\bullet$}}}}  %prava zaprta podmnozica   but there is still a problem in the above code. Could anyone edit this last code to fix the problem with spacing?


Sorting questions/answers in user lists based on accepted status

I would like the ability, in all SE sites, to sort the lists of questions and answers in a user's profile page primarily by whether that user's question has an accepted answer, or equivalently whether the user's answer was marked as the accepted answer.   It would probably be of value to be able to specify a secondary sort by one of the existing criteria, so this might be an "on/off" criteria that can be toggled. When "on", results are sorted first by this "acceptance status", then by the other specified criteria (votes/newest/activity)


How to keep the size of the parenthesis in different lines when using multline?

I am using overleaf and I am trying to write the following equation into my main text but since it is longer than a line I have to break it into smaller parts and for that I am using the miltline. However, when I am doing that the brackets and parenthesis I used in the first line do not continue to hold for the second line. I read online that the parenthesis should open and close in the same line but if that is not possible I can use the \left. and \right. commands. I've tried to do that too but the size of the parenthesis change (for example I was using big parenthesis and became small). This is how I am trying to write it: \begin{multline}     \dot{z} = \left(\frac{\phi_z - \alpha}{\phi_{zz} } \right) \left\{ \delta - \frac{u_P \theta}{u_c(\alpha-\phi_z)}+ \frac{U_P \xi}{U_c} + \beta \left[ \phi_x - \tau + \frac{wm\big(\theta-\xi(\alpha-\phi_z)\big)}{e^{-\rho t} U_c \theta} \\ + \frac{U_x \big(\theta-\xi(\alpha-\phi_z)\big)}{U_c \theta} \right] + \frac{(\beta - 1) (\phi_z - \alpha)}{\theta} \right\} - \frac{\beta \phi_{zx}}{\phi_{zz}} \left[ \phi(\beta S, z) - \alpha z - c - \tau \beta S \right] \end{multline}   Any help would be very much appreciated. Thanks in advance.


Evaluating $ \lim_{x\to \infty} x \left({{\left(\frac{x}{x+1}\right)}^{x}-\frac{1}{e}}\right)$

Evaluate the following:    $$ \lim_{x\to \infty}  x \left({{\left(\frac{x}{x+1}\right)}^{x}-\frac{1}{e}}\right)$$   I tried to first solve the interior portion as $1^\infty$ indeterminate form but ended up getting a different indeterminate form of $\infty\cdot 0$.


Flip over min/max values in a stretched symbology for raster data

In ArcMap 10.1, we can render a raster in a colour ramp (stretched) symbology to draw a raster layer based on each pixel value. However, the legend for the layer by default starts from the max value (top, red) down to the min value (bottom, green).  How can I draw it like form min (top, green) to max (bottom, red) instead?  Tried Invert checkbox but it didn't help as it was the colour that was inverted.


I would like to put a \xRightarrow into a list instead of a bullet, unfortunately I get  ! Argument of \\xRightarrow has an extra }. <inserted text>                  \par  l.8     \item[$\xRightarrow[continuous]                                     {norm}$] Test   This is from the MWE:   \documentclass{article}  \usepackage{amsmath} \usepackage{mathtools}  \begin{document} \begin{itemize}     \item[$\xRightarrow[continuous]{norm}$] Test \end{itemize} \end{document}   using  $ pdflatex --version pdfTeX 3.14159265-2.6-1.40.20 (TeX Live 2019/Arch Linux) $ lualatex --version This is LuaTeX, Version 1.10.0 (TeX Live 2019/Arch Linux)   How can I fix this?  Edit: as @Phelype Oleinik points out in the comments, this is related to parsing the braces [,].


Extracting text from HTML file using Python

I'd like to extract the text from an HTML file using Python.  I want essentially the same output I would get if I copied the text from a browser and pasted it into notepad.    I'd like something more robust than using regular expressions that may fail on poorly formed HTML.  I've seen many people recommend Beautiful Soup, but I've had a few problems using it.  For one, it picked up unwanted text, such as JavaScript source.  Also, it did not interpret HTML entities.  For example, I would expect &#39; in HTML source to be converted to an apostrophe in text, just as if I'd pasted the browser content into notepad.  Update html2text looks promising. It handles HTML entities correctly and ignores JavaScript.  However, it does not exactly produce plain text; it produces markdown that would then have to be turned into plain text. It comes with no examples or documentation, but the code looks clean.    Related questions:


Have been using 14.04 LTS for years with no problems.  Have tried sudo apt-get update and get:  E: Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) E: Unable to lock directory /var/lib/apt/lists/ E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?


United Login for Stack Exchange sites which a Person has Signed Up

I am wondering why a user who has SE accounts in several sites has to login to each site separately?   I understand the logic behind not creating a SE account on all SE sites and having separate sign-up procedure for each site.  But why am I required to login separately (or as is the case, I get logged in after I open a site and then asked to refresh page) into each page?  I also understand that one person may have different accounts across the SE sites.  What I am asking is why not login one account of a person into all the sites in which (s)he is a member of using that account?  This is not about 1. Signing up (at all) 2. Feature-request (maybe changed depending on answer)


I will arrive to Bombay airport at 11:00 pm and my flight is the next day at 6:00 pm. Can i spend that time in the airport waiting room? Is there any problem for safety?


What does the Spider-man symbol on 1980's comic covers mean?

I've noticed a Spider-man symbol on several of my Marvel comics from the 80's.  Any ideas on what it could mean?


How to rename multiple files into their parent directory names using find

I have many files with the same name (summary.txt) each in different directories. I want to rename these files into their parent directory names using find. What I tried was: find . -name 'summary.txt' -exec mv '{}' $(dirname '{}') \;  But after running this command, all summary.txt files were moved into the current directory, resulting in all except one being deleted. Fortunately I backed up these files before. How can I do this correctly?


Discrete Valuation Rings with property that $v(x+y)=\min(v(x),v(y))$

Let $R$ be a discrete valuation ring on a fraction field $K$ of $R$.  If $x,y\in K$ such that $v(x)< v(y)$, prove that $v(x+y)=\min(v(x),v(y))$.    By definition of discrete valuation, we have that $v(x+y)\geq \min(v(x),v(y))$.    So, we must show the other direction, but I'm not sure how to do this.   I tried something like $v(x)<v(y)$ implies $v(x)-v(y)<0$ implies $-v(xy)<0$, but don't know how that helps.


How to create static pages that are translatable?

How to create Drupal 8 static pages that are translatable (3-lingual site)?   I already have HTML code and about 15 static pages which some have dynamic content (latest news etc).  What's the best approach in Drupal?  Do I create lots of blocks with my html or something else?


I have the following command:  find / -name libGL.so.1   Which returns lots of lines with "Permission denied". I want to exclude such lines, so I added the following:  find / -name libGL.so.1 | grep -v 'denied'   But the output is the same - my grep -v 'denied' is not filtering out the lines with Permission denied. I've tried many variations, looked over grep tutorials, but I cannot figure out the problem. Any suggestions?


Online course that covers Unix/Linux Systems programming

I am looking for an online course, something similar to the Berkely and Stanford Courses that covers Linux systems programming. A course which could use Stevens ( with some supplemental material covering  linux idiosyncracies ) as the text ( observe: could use not does use ).    Purpose: I've read through a large chunk of Stevens--somewhere between 1/3 and 2/3. Essentially I would like to plug in the gaps as easily as possible. A set of video lectures seems the best way. But not some youtube dweeb trying to show he can tie his Linux shoelaces. [1]  [1] Not all youtube entries are like that, but you will have to wade through a lot to get to the worthwhile ones. Unless you get lucky.


Pasting into terminal, two steps vs one step

This is a weird problem -- for pasting text into terminal, I've seen two types of behaviors, two steps vs one step, and I had never figured out why. Let me start with the "one step" behavior, it is as normal as you can think of. Pasting in multiple-line texts will behave just like they are typed in, nothing special at all. As for the "two step" behavior, the pasted text are shown in revers color:  and it needs me to press return for the pasting to actually happen:  Moreover, sometimes the pasted text will somehow stays in the revers-color stage, making the visual clue completely out of order:  How to get rid of the two-step behavior and get back to the one-step one? $ uname -rm 5.10.0-6-amd64 x86_64  $ lsb_release -a No LSB modules are available. Distributor ID: Debian Description:    Debian GNU/Linux bullseye/sid Release:        testing Codename:       bullseye


What is happening when I type ctrl+shift+e, then type and underlined text appears?

In Ubuntu 20.04, if I type ctrl+shift+e, then start typing in any app (terminal, browser, whatever), underlined text appears. It could even be in gedit. There are no spaces in what appears, and if I hit escape, the text vanishes.  Here's a GIF:    In the first example, I hit enter when I'm done typing the sentence. In the second line, I hit escape and it all vanishes.  I assume I'm accessing some kind of accessibility feature, but I have no idea what.  In summary: What is ctrl+shift+e doing in Ubuntu?


I am studying complex analysis and I have problem understanding the concept of branch cut.  The lecturer draw this as some curve that starts from a point and goes on and on in some direction (for example, something like $y=x$ for $x\geq0$ , but it doesn't have to be straight).  The definition given in the lecture is      A branch cut is a curve that is being presented in order to define a   branch    and then he added a note      Points on the branch cut are singular.   Can someone please explain how does such a curve define a branch of a function ?  As I understand it, if $f(z)=u(r,\theta)+iv(r,\theta)$ then we want $\alpha<\theta\leq\alpha+2\pi$ for some real $\alpha$. How does a curve define this $\alpha$ ?  Why are the points on a branch cut singular? Are we also assuming something about the function that we are trying to define a branch of it?


Prove that if $u_n\rightarrow \infty$ then $\frac{1}{u_n} \rightarrow 0$  Could someone please point me in the right direction? I don't know how to show this at all. Any help would be much appreciated :)


I messed up bashrc codes and reboot the Linux mint to black screen

A few days ago, I accidentally replaced my desktop in Mint 18 with a virtual console with an errant keystroke. Not having an obvious way to reverse the changes, I logged in and typed exit to exit the console and go back to the desktop. Instead, the computer rebooted, and I lost God-only-knows-how-much unsaved work.  After showing the Mint logo and flashing a message underneath it far too quickly to read, the computer now boots only to a black screen. By pressing esc during reboot, I can get to a Startup Menu. I ran disk checks and memory checks using it, and they all came up clean. None of the other options in this menu help. I have no idea what to do.  The screen is clearly receiving power, and the black screen that it boots to shows a dash or underscore in the top right corner.  How do I get my computer back? It's an HP Pavilion laptop.


This is something I've pseudo-solved many times and have never quite found a solution for.  The problem is to come up with a way to generate N colors, that are as distinguishable as possible where N is a parameter.


I keep getting a NullPointerException when I want to draw my polygon Pizza object. I get this error message:  Exception in thread "main" java.lang.NullPointerException     at Pizza.<init>(Pizza.java:9)     at PolyDemo$PolyDemoPanel.getRandShape(PolyDemo.java:91)     at PolyDemo$PolyDemoPanel.<init>(PolyDemo.java:54)     at PolyDemo.<init>(PolyDemo.java:19)     at PolyDemo.main(PolyDemo.java:28)   I didn't have problems with circles and rectangles, why is this not working? Here is my Pizza class:      import java.awt.*;      public class Pizza extends Shape{         private Polygon P;          public Pizza(int x, int y) {             super(x,y);             P.xpoints = new int[]{x, x+100, x+200};             P.ypoints = new int[]{y, y+100, y};             P.npoints = 3;         }          @Override         public void draw(Graphics g){             g.setColor(Color.RED);             g.drawPolygon(P);         }     }   Here is the driver:      import java.util.*;     import java.awt.*;     import javax.swing.*;      class PolyDemo extends JFrame {         public PolyDemo() {             getContentPane().add( new PolyDemoPanel());             setSize( 300,300 );             setVisible( true );             setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );         }     public static void main( String args[] ) {         PolyDemo myApp = new PolyDemo();     }     public class PolyDemoPanel extends JPanel {              Shape[] myShapes= new Shape[20];          public PolyDemoPanel() {             for( int i = 0; i < 20; i++ ) {                 myShapes[i] =  getRandShape();             }         }         public void paint( Graphics g ) {             super.paint(g);               for( int i = 0; i < myShapes.length; i++ ){                 myShapes[i].draw( g );               }            }         public int getRandInt() {             return ( (int) ( Math.random() * 200 ) );            }         public Shape getRandShape() {             Shape retVal = null;             final int x = getRandInt();             final int y = getRandInt();                 retVal = new Pizza(x, y);                 return retVal;             }         }        }


Choosing the number of bootstrap resamples

Say we have the following sample and we are trying to estimate the variance of the sample mean of the population.  X = [0, -1, 2, 10, -3]   If I take an increasing number of bootstrap (e.g. 100, 1000, 10,000, 100,0000), the bootstrap distribution of the sample mean gets narrower and narrower. In other words, I can make the bootstrap distribution arbitrarily narrow.   Given the above, what's the point of using a different number of bootstrap samples here? And wouldn't this mean that I could make the standard error of the mean arbitrarily small by just taking more and more bootstrap samples? What am I missing?  Please note that I am doing a proper bootstrap sample in the sense that each bootstrap sample has the same exact size as the original sample (input array).


What means "equal" in Euclid 4th postulate?

In his 5 postulates Euclid said:"All the right angles are equal". What he really meant by that ? Does he meant that we can impose any right angle on each other or the meaning there was that if you find this angle through the length of arc and radius of the circle then you get the same number ? I also heard that this postulate can be proven (and I remembered that I saw such a question there, but now I can't find it). So what is the proof (based on the definition of a right angle like right angle is an angle which is equal to its adjacent angle)


$dx=\frac {dx}{dt}dt $. Why is this equality true and what does it mean?

$dx=\frac {dx}{dt}dt $. I know that this deduction is obvious from the chain rule, given that we treat our dx and dt as just numbers. But I find it quite unsatisfactory to think of it in that sense. Is there a better / more "calculus-inclined" way of thinking about this equality. Can you please explain both the LHS and RHS individually.


What should I do about wrong address in my UK visa application?

I am from Pakistan. My husband and I have applied for UK visit visas. I filled both applications. After submitting and paying, when I took the prints, I realized that I had made 3 minor (in my opinion) mistakes:   My husband visited France in September 2014. I checked 02 instead of 09 for month  I wrote my husband's personal cell number instead of his employer no. I wrote the wrong postal code of our sponsor in my application. I also write the wrong house no. of our sponsor in my application.   Now I have an appointment at Gerry's on 4th March for the application submission. I am really worried. Will these mistakes matter?  It's worth mentioning that I visited the UK in 2016 with my kids, and this time only me and my husband.


Units in $\mathbb{Z} [\text{some root of unity}]$

The assertion is that for $\xi$ a primitive root of unity of degree $n$, then in $\mathbb{Z}[\xi]$, $\xi-1$ is a unit if $n$ is not a prime power. It should be an easy proof, but I still don't have a good idea. Any hint is appreciated!


Why didn't Harry draw gold from Gringotts?

In the first book of the Harry Potter series we are told that Harry has piles of galleons inside his vault at Gringotts. Why didn't Harry draw a few gold coins from his safe and sold them in the muggle world to earn some money? That way he could've improved his quality of life in the muggle world quite a bit  I know the subject has been approached in other questions, but the closest answer I got was what would happen if Harry bought silver in the muggle world and sold it for gold in the magic world. I want to know what would happen exactly in this case.


Can I enter Colombia with an expired passport if I possess a second nationality?

Hi i have tried on several occasions to get in touch with the colombian consulate in london and to no avail. My british passport is an electronic passport but my colombian one is not. I plan to travel to colombia in a months time. Is it possible to travel with my british passport to colombia and my non electronical colombian passport which states it expires on the 2017? i have my colombian cedula identity card up to date. Will i have problems entering Colombia?? please someone help and advise


Is there a cryptographic algorithm which is immune to side channel attacks?

Is there any cryptographic algorithm immune to side channel attacks based on scan chain? In VLSI point of view.


How do I install extra LaTeX packages in Sublime Text 3?

I have LaTeXTools installed and I'm trying to figure out how to install the moderncv package (or for future reference, how to install packages in general). Is this done through Sublime Text's package control?   I'm fully aware I can download it straight from , but I don't know what to do with it after I open the file. Where is the proper place to put it? If possible, I would prefer to take a non-hands-on approach so that I don't mess things up.  Another concern is that I this is contained in MiKTeX and TeXLive, does this mean it won't work with MacTex?


How to get friendly with the police again in Cyberpunk 2077?

Police want to catch me after I accidentally fired a weapon in public. Now, if I meet a police guy standing around he wants to bust me and one blue star appears by the minimap. How do I end the chase?


The direction of friction in rolling without slipping

I know there are multiple SE questions talking about this subject but I still don't understand: If I have three balls as seen in the picture, what is the direction of friction on each ball if:  No forces are applied on the first ball except gravity and N in the Y axis (I don't about friction, that's why I'm asking)  Some force passing through the COM is applied on the ball  Some force not passing through the COM is applied on the ball.   In the 3rd case, does it matter where the force is applied or how big it is?


Adobe Forms Central had a decent level of security. I've been told some software providers state in T&C's that they own the data you submit!  What's the score with Cognito?  Is submission content encrypted?


printf thousand separator not working on MacBook

I am using the following command on Terminal in MacBook.  printf "The number is %'d\n" 123456   I expect the output:     The number is 123,456.   But I am getting:     The number is 123456.    Please point out my mistake.


Combining two physical drives into a logical one

I currently have a 1TB hard drive when I store all my media - music, movies, etc. It's getting quite crowded so I want to buy another hard drive. However, I would like to  add new space to the current drive and not create a new one (i.e., all the files should be under drive letter Q, for example).   Is there any way to do this?  EDIT: to clarify, the drive I store my media in (the one I wish to expand) is not used for anything else - Windows is installed on a different drive.  EDIT 2: Also, the drives are not the same size, if that matters.


A non-noetherian ring with noetherian spectrum

Question 1: Does such a ring exist? Note: The definition of a noetherian topological space is similar to that in rings or sets. Every descending chain of closed subsets stops after a finite number of steps (Question 2: is this equivalent to saying that every descending chain of opens stops?)


Showing that $\left(\operatorname{Im}\left(T^*\right)\right)^\perp=(\ker T)$ (solution verification)

I have been told that my proof is not true at all without any explanation why, I would like if any one can help. Let $T: V\to V$ linear operator in finite inner product space, show that $$\left(\operatorname{Im}\left(T^*\right)\right)^\perp=(\ker T)$$ My attempt: $\left(\operatorname{Im}\left(T^*\right)\right)^\perp=(\ker T) \iff \operatorname{Im}(T^*)^=\ker\left(T^{}\right)^\perp$ Let  $\vec v\in Im(T^*) $ and let $\vec w \in \ker(T)$ so we can write : $\langle T^*(v),w\rangle=\langle v,T(w)\rangle=\langle v,0\rangle=0$


Changed my Password with Root and now I'm stuck out of my own laptop

cool nerds of the Internet  I changed my forgotten password with root and it won't work, I'm currently using guest login which is so annoying so I was thinking I'm being a smart-head when I deleted the password with root but it still won't login!!! help me to reinstall it or whatever solution you guys might have.  PS : when I change the password with root and it gives me that "type new password" line I try to type and it doesn't do anything, like the keyboard is numb or something, the only thing that works in this stage is "Enter" so I entered two empty lines and it gave me the "password not changed" I don't even know how I changed it the first time.   HELP A SISTER


I have a string of the following type:   "23 + 323 =" or "243 - 3 ="   So the format is: number + operator + number = equal.  And I also have an int which is the answer to that question.  How can I parse the string and check if the answer is correct?  Thank You, Miguel


My name is Abbas and I am from Pakistan. I have visited the UK in 2010 on a general visit visa, and again in 2013 on a study visa. I got married last year with a British girl who stayed with me in Pakistan and went back to the UK in February of this year. I have a job here in Pakistan in a well-reputed organization.  I applied for a UK visit visa to see my wife who is expecting right now. I made a very strong case and didn't hide anything in my visa application, but my visa got rejected as they said they are not satisfied with my financial status.   I showed living expenses in the UK as 2000 UK pounds which were well above my salary. Two transactions were showing in my salary accounts which were not part of my salary. Even though it was the amount that transferred from my account and then returned to my account on the same day.   Now my question here is that if my wife applies for a spouse visa in the future, will this visit visa rejection affect my case for a spouse visa? I didn't try to act clever and hide anything but my application still got rejected. Maybe the immigration agency thought that I have intentions of staying in the UK.


QGIS Extract elevation data only for one country

I have a map built with a shapefile for country contours and a raster from .hgt files with elevation representation. How can I only select the area corresponding to the country?  I found some thing for matlab  but not in QGIS. I'm thinking of using a polygon, but I am not familiar with how to do so. Or in a subtraction of the outside, but how to determine that? On the image, the red lines show the parts I want to eliminate.


I'm using this  to make a bigger arrow head. I would like to use this new arrow head as my default arrow head (both in pgfplots axis and in tikz pictures). Here is a MWE:  \documentclass[tikz]{standalone}  \usepackage{pgfplots} \pgfplotsset{compat=newest,  standard/.style={   axis lines=middle, axis line style=-triangle 45 % I WANT "big arrow" HERE  } }  \usetikzlibrary{arrows,decorations.markings} \tikzset{  big arrow/.style={   decoration={markings,mark=at position 1 with {\arrow[scale=2.5]{latex'}}},   postaction={decorate}}, >=triangle 45 % I ALSO WANT "big arrow" HERE }  \begin{document} \begin{tikzpicture} % \draw [big arrow] (0,0) -- (0,5) node [left]{$y$}; % \draw [big arrow] (0,0) -- (5,0) node [right]{$x$}; \begin{axis}[standard, xmin=0, xmax=5, xlabel=$x$, ymin=0, ymax=5, ylabel=$y$] \end{axis} \end{tikzpicture} \end{document}   In a pgfplot axis instead of having  axis line style=-triangle 45   I would like to have something like  axis line style=-big arrow   In a tikz picture, instead of the lines   % \draw [big arrow] (0,0) -- (0,5) node [left]{$y$}; % \draw [big arrow] (0,0) -- (5,0) node [right]{$x$};   I would like, for instance, to write  \draw [<->] (0,5) node [left]{$y$} |- (5,0)  node [right] {$x$};   and have the arrow head be "big arrow".


Panel and Launcher are missing in Ubuntu 13.04

i have upgraded Ubuntu desktop from 12.10 to 13.04. Since then I can't see the Panel or Launcher, but I'm able to open the terminal using the keyboard shortcut Ctrl+Alt+T.  When I use the Guest login there is no such problem. I am facing the problem only with administrator account.  I have tried this , but I couldn't find the result.


Is it safe to keep my camera in the hot car?

I'd like to keep my large format camera in the car during the day at work, along with filters, adapters, tripod, etc. The car sits outside and I'm sure the temperature soars to over 120F some days inside that car. If I take the film inside with me, is it possible the camera or lenses will suffer damage in heat like that?  Please note I am not asking about operating temperature ranges, as answered in . I am asking about long term damage that can occur during storage, specifically in temps higher than normally occur while operating.


Why does the mean have $n-1$ degrees of freedom?

When calculating the standard deviation of a set of measurements of $X$, you use the formula $$\sqrt{\frac{1}{n-1}\sum_{i=1}^n(x_i-\bar x)^2}$$ A common explanation I have found for the  $n-1$ factor is that it refers to the degrees of freedom. As I understand he degrees of freedom is the number of values you can pick, which is equal to the number of samples minus the number of relations between them.  Let's say $n=3$ and we pick values until our vector is fully determined. $$(x_1,x_2,x_3,\bar x)\\(4,x_2,x_3,\bar x)\\(4,9,x_3,\bar x)\\(4,9,x_3,7)$$ At this point we have enough information to calculate that $x_3=8$. We could also have picked $x_3$ to calculate $\bar x$. So why isn't the degrees of freedom $n$ since we had to pick $n$ values to fully determine the standard deviation?


how to remove this "and" before the mail address?

I am using sharelatex aps journal template to write a paper.      \documentclass[%  reprint, %superscriptaddress, %groupedaddress, %unsortedaddress, %runinaddress, %frontmatterverbose,  %preprint, %showpacs,preprintnumbers, %nofootinbib, %nobibnotes, %bibnotes,  amsmath,amssymb,  aps, %pra, %prb, %rmp, %prstab, %prstper, %floatfix, ]{revtex4-1}  \usepackage{graphicx}% Include figure files \usepackage{dcolumn}% Align table columns on decimal point \usepackage{bm}% bold math %\usepackage{hyperref}% add hypertext capabilities %\usepackage[mathlines]{lineno}% Enable numbering of text and display math %\linenumbers\relax % Commence numbering lines  %\usepackage[showframe,%Uncomment any one of the following lines to test  %%scale=0.7, marginratio={1:1, 2:3}, ignoreall,% default settings %%text={7in,10in},centering, %%margin=1.5in, %%total={6.5in,8.75in}, top=1.2in, left=0.9in, includefoot, %%height=10in,a5paper,hmargin={3cm,0.8in}, %]{geometry}  \begin{document}  \preprint{APS/123-QED}  \title{Exact Solutions of Einstein's Field Equations in TOV Formulations}% Force line breaks with \\   \author{U.A. Mofiz*}  \author{Tazkera Haque}%  \affiliation{Plasma Astrophysics Laboratory}% \affiliation{Department of Mathematics and Natural Sciences, BRAC University}%  \affiliation{66 Mohakhali, Dhaka-1212, bangladesh}%  \affiliation{Email:mofiz@bracu.ac.bd}%  \end{document}    the output creates an "and" before the email address. Without using affiliation multiple times, how to write things in one place?


Find a bijection between the open interval (0, 1) and the closed interval [0, 1].

This was part of a three part question where I was supposed to prove two sets have equal cardinality by finding bijections. I've created a bijection $f: \Bbb Z \Rightarrow 2\Bbb Z$ by $f(x)=2x$. I've created a bijection $g: (0,1) \Rightarrow (4,50)$ by $g(x)=46x+4$. I think those are both correct. My last question is finding a a bijection between (0,1) and [0,1]. I've seen this question several times on this board, but I've yet to understand them and I can't really go back and ask any questions to the original posters. I know a bijective function exists between (0,1) and $\Bbb R$, but I don't think that helps me here.


Why CASE statement doesn't work without nesting?

I have a requirement to sort the results dynamically based on the column selection. I know that only first query below works and 2nd one fails. But am unable to understand why it fails, as per my understanding based on @SortDirection value it should give ASC or DESC, which will get appended to the earlier CASE which is returning column name. Can you please explain why it fails?  create table EmpData ( EmpID int identity, FName varchar(20), LName varchar(20), Email varchar(30), City varchar(20), DOB date ) GO INSERT INTO EmpData values ('Mark','Smith','Mark.s@email.com','London','02-Jun-1980') INSERT INTO EmpData values ('Mark','Marsh','Mark.m@email.com','Paris','02-Jul-1981') INSERT INTO EmpData values ('Steve','Elgar','Steve.e@email.com','Canada','12-Jun-1980') INSERT INTO EmpData values ('Michael','Jones','Michael.j@email.com','France','22-Jan-1980') GO ----------QUERY 1-------- DECLARE @SortByColumn varchar(20)='City', @SortDirection varchar(5)='ASC' SELECT EmpID,FName AS FirstName, LName AS LastName, Email, City, DOB as 'Date-Of-Birth' FROM EmpData ORDER BY     CASE @SortDirection WHEN 'ASC' THEN         CASE @SortByColumn             WHEN 'FirstName' THEN FName             WHEN 'LastName' THEN LName             WHEN 'Email' THEN Email             WHEN 'City' THEN City             ELSE ''         END     END,     CASE @SortDirection WHEN 'DESC' THEN         CASE @SortByColumn             WHEN 'FirstName' THEN FName             WHEN 'LastName' THEN LName             WHEN 'Email' THEN Email             WHEN 'City' THEN City             ELSE ''         END     END DESC GO ----------QUERY 2-------- DECLARE @SortByColumn varchar(20)='City', @SortDirection varchar(5)='ASC' SELECT EmpID,FName AS FirstName, LName AS LastName, Email, City, DOB as 'Date-Of-Birth' FROM EmpData ORDER BY         CASE @SortByColumn             WHEN 'FirstName' THEN FName             WHEN 'LastName' THEN LName             WHEN 'Email' THEN Email             WHEN 'City' THEN City             ELSE ''         END         CASE @SortDirection             WHEN 'DESC' THEN DESC             ELSE ASC         END


let $a,b,c\in \mathbb{R}$, if such  $$\dfrac{1}{bc-a^2}+\dfrac{1}{ca-b^2}+\dfrac{1}{ab-c^2}=0$$ show that $$\dfrac{a}{(bc-a^2)^2}+\dfrac{b}{(ca-b^2)^2}+\dfrac{c}{(ab-c^2)^2}=0$$  Does this problem has nice methods? My idea:let $$(ca-b^2)(ab-c^2)+(bc-a^2)(ab-c^2)+(bc-a^2)(ca-b^2)=0$$ then I can't. Thanks


I'm doing tests to query layers in Leaflet with WMS.  I'm seeing this    and   .  I'm trying to take WMS data from my Geoserver and replaced the WMS URL, the name of the layer, and the name of the fields in the popup window but I have a problem: I see the layers in the map, but it does not make me select, and I do not see the fields in the popup.  Do I need to change some settings in my Geoserver?


how to use Matlab ifft to calculate the following integral?

$$R(t)=\int_{-\infty}^\infty\dfrac{\omega e^{i\omega t}}{(3-\omega^2)^{2}+4\omega^2}\,d\omega$$  where t is a integer and $t>0$  I used to calculate this integral by numerical integral,but it seems that using ifft in matlab is more effcient.  The ifft equation in Matlab is $$x(n)=\frac{1}{N}\sum_{k=1}^N X(k)e^{i2\pi\frac{k-1}{N}n-1}$$  where n=$1,2...,N$  I have no idea how to link the above Eq with the above-mentioned integral. Do someone have an idea?


Compute the limit $\lim_{n \to \infty} \frac{n!}{n^n}$

I am trying to calculate the following limit without Stirling's relation.  \begin{equation} \lim_{n \to \infty} \dfrac{n!}{n^n} \end{equation} I tried every trick I know but nothing works. Thank you very much.


I have a small cast iron pan which I am working with, trying to make sure I understand seasoning/cleaning before moving on to a larger one. I seasoned with flaxseed oil (4 light coats, hour in the oven), and have cooked a few things - I made some Ghee, fried some onions, stuff like that. After each I washed with hot water (no soap), heated until dry on the stove and coated with a thin layer of canola oil.  Now, when I take a dry paper towel and rub it on the pan, a black residue shows up on the paper towel. I can't feel anything with my fingers and I haven't noticed anything cooking with it. I'm fairly confident this occurred after the initial seasoning - although I'm not sure I did this exact test with the paper towel.  Is this a) normal, or b) what is wrong and c) how can I fix it?  There are quite a few questions (and good answers!) regarding cast iron cookware on this site but I haven't been able to find one that deals with this specific issue.


So, I've been trying to install ubuntu 14.04.03 LTS the past few days but I always face this error, when I hit install the screen turns extremly white(x32) or extremly black(x64) then I get the ACPI PCC Probe Failed then the screen stays the same for as long as it's on. I also tried live in both x32/x64 and didn't work either with the same problem. I tried to boot live a Kali Linux and it worked fine(version 1.1 not 2.0). I don't know what information I should provide as I already made several searches and some said it's related to GPU and some said it's related to the bios mode and some said it's a harmless error and will disappear after few attempts which hasn't happened yet, hopefully someone can help me.


What causes the tendency for two non-stationary time series to be highly correlated to each other?

When two variables are non-stationary, there is a very high probability that they are strongly correlated to each other. For example, $x_t$ and $y_t$ were generated independently and randomly using different seed values. $$x_t = x_{t-1} + \epsilon_t$$ $$y_t = y_{t-1} + u_t$$  set.seed(123) x <- cumsum(rnorm(100,10,10))  set.seed(321) y <- cumsum(rnorm(100,5,5))  cor(x,y)^2  [1] 0.989947   I can repeat this 10,000 times with different seed values, means, and standard deviations. The correlations are extremely high almost all the time. What is driving this spurious correlation?  spuriousRegression <- function(seed1=123, seed2=321, mean1=10, mean2=5, sd1=10, sd2=5, nsize=100){    set.seed(seed1)   x <- cumsum(rnorm(nsize,mean1,sd1))  ### non-stationary    set.seed(seed2)   y <- cumsum(rnorm(nsize,mean2,sd2))  ### non-stationary    lm.mod <- lm(y ~ x)   summary.mod <- summary(lm.mod)    return(summary.mod$r.squared)  }  spuriousRegression()  repeatKTimes <- mapply(spuriousRegression, seed1=1:10000, seed2=10000:1,                        mean1=0:9999, mean2=9999:0, sd1=1:10000, sd2=1:10000)  summary(repeatKTimes)        Min.  1st Qu.   Median     Mean  3rd Qu.     Max.  0.000007 0.934600 0.983500 0.893100 0.992200 0.999100


Having trouble playing DVDs on my laptop. They are .vob files. Neither VLC, Mplayer nor SMPlayer seem to help. Anything else I could do?


How is the data in /proc/* gathered, and how reliable is it?

Recently I've been working with a cluster monitoring tool (ganglia) which aggregates system metrics from /proc/* on each machine.   How is the data in /proc/* gathered? Who writes the data there? How often is the data updated? Can I tune the way it is gathered so that it is more accurate?


how to get the correct input value from the pointer

I want to use a function that receive a pointer to an array together with its size and sets all element value to zero.   But the value of the array was checked in the function, the value is not 1234 which should be 1234 if correct, because the input value is 1234.   Just want to know where's the mistake in my following code.   #include <stdio.h> #include <stdlib.h>  void receive(int *point, const int size);  int main(void) {     int a;     int *b;     scanf("%d", &a);     b=(int*)malloc(sizeof(int)*a);      printf("size of input: %d\n", sizeof(b));     receive(b, sizeof(b));     free(b);     return 0; }  void receive(int *point, const int size) {     int c=sizeof(*point);      printf("filling the array to zero");     int i;     for (i=0; i<c; i++) {         printf("\n previous_value:%d\n", point[i]);         point[i]=0;         printf(", current_value %d\n", point[i]);     } }


How to detect whether monitor turned off/on?

The problem is that on the text file i see all the results - True or Not. Even when i turned off the monitor for 5-10 seconds and turned it on on, then the text file shows True.  Not sure why it's not detecting it.  I tried this:  using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; using System.Runtime.InteropServices; using System.IO; using System.Net; using System.Diagnostics; using System.Management;  namespace Detect_Monitor_Settings {     public partial class Form1 : Form     {         [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]         static extern EXECUTION_STATE SetThreadExecutionState(EXECUTION_STATE esFlags);          [FlagsAttribute]         public enum EXECUTION_STATE : uint         {             ES_AWAYMODE_REQUIRED = 0x00000040,             ES_CONTINUOUS = 0x80000000,             ES_DISPLAY_REQUIRED = 0x00000002,             ES_SYSTEM_REQUIRED = 0x00000001             // Legacy flag, should not be used.             // ES_USER_PRESENT = 0x00000004         }          StreamWriter w = new StreamWriter(@"e:\monitordetector.txt");          public Form1()         {             InitializeComponent();         }          private void DetectScreenName()         {            if (stopdetecting == false)             {                 var query = "select * from WmiMonitorBasicDisplayParams";                 using (var wmiSearcher = new ManagementObjectSearcher("\\root\\wmi", query))                 {                     var results = wmiSearcher.Get();                     foreach (ManagementObject wmiObj in results)                     {                         // get the "Active" property and cast to a boolean, which should                          // tell us if the display is active. I've interpreted this to mean "on"                         var active = (Boolean)wmiObj["Active"];                         w.WriteLine(active.ToString());                     }                 }             }         }            private void Form1_Load(object sender, EventArgs e)         {          }          bool stopdetecting = false;         int counttimer1 = 0;         private void timer1_Tick(object sender, EventArgs e)         {             DetectScreenName();             counttimer1 += 1;         }          private void button1_Click(object sender, EventArgs e)         {             w.Close();             stopdetecting = true;             timer1.Stop();         }     } }


I need to render wikitext (pulled from the database of a mediawiki of it's relevant) and display in some other format (ultimately to be rendered as a PDF, but basically any other format will do).  I can definately hack together something that does the job but ultimately I'll be writing it as I go along, and I can see that the overhead of implementing new tags as people in my team use them will eat up a lot of my time.  Is there a project to do this?  I saw TiddlyWiki which is written in python, which I will look into borrowing their library, but in the meantime I figured there may be a project that's a bit more niche that someone knows?  Cheers


Choosing a book to gain general knowledge about biology

I will be first year undergraduate at Physics department next year and last year I was at the Medicine faculty. I want do double major in the second year of faculty with Molecular Biology and Genetics. The intersection of biology and physics is my interest. I have two books about biology, first one is What is Life?-Mind and Matter by Erwin Schrödinger and the second one is This is Biology by Ernst Mayr. Which one should I read to acquire general knowledge about Biology?


If Earth spun faster, would I be able to jump higher?

I'm asking mostly in relation to the forces acting on a person, but it would also be nice to know if there would be any impact on muscle strength, similar to when an astronaut goes into space.


Assume $K$ is a compact metric space with metric $\rho$ and $A$ is a map from $K$ to $K$ such that $\rho (Ax,Ay) < \rho(x,y)$ for $x\neq y$. Prove A have a unique fixed point in $K$.  The uniqueness is easy. My problem is to show that there a exist fixed point. $K$ is compact, so every sequence has convergent subsequence. Construct a sequence ${x_n}$ by $x_{n+1}=Ax_{n}$,$\{x_n\}$ has a convergent subsequence $\{ x_{n_k}\}$, but how to show there is a fixed point using $\rho (Ax,Ay) < \rho(x,y)$?


How to detach modal dialogs from main window? Popup dialogs attached to window title and not movable

Not sure of the terminology here, but most of my popup dialogs (see screenshot below) are attached to the window title and cannot be moved. If the parent window is moved, the popup moves with it. Is there a way to get rid of this and have all popup dialogs be opened as movable windows?    Ubuntu 17.10+ with GNOME Shell    Ubuntu 11.10 with Cinnamon