Countable sets have the same cardinality as the natural numbers (or a subset of the natural numbers, depending on who you ask).  Can one make the same claim about uncountable sets and real numbers?  In other words, do all uncountable sets have same cardinality as real numbers?


It has been known since long time that / Since long, it has been known that

I need to start a sentence by saying that something has been known for a long time. What is the most elegant way of writing that? Two possibilities that come to my mind are:      1) It has been known since long time that ...      2) Since long, it has been known that ...   Personally, I prefer the second option. The first sounds ugly to me. But since I'm not a native English speaker, I would like to ask for suggestions of what would be the best way of saying that. Please feel free to suggest other forms.


I am currently migrating a website, and my usual method is working with mail clients, and copy the old mailbox to the new server mailbox.  But, if you have a website, with multiple mailboxes, and those mailboxes have numerous folders, the work usually takes all day.   I have searched the Internet for a far more easy and faster way, preferably open-source, but most tools are ancient, and the .  Wat is the faster and easier way of migrating mailboxes?  Paid tool:      Free Tool      Note:    I have root access on the destination server, and not on the source. I downloaded the e-mails with the following settings   mail.DONAINNAME.com: IMAP (for receiving)  smtp.DOMAINNAME.com: SMTP (for sending)


Today I was walking using my iPhone 6S running iOS 9.3 as a pedometer and it shutdown.   When I got home and plugged it in, it said 30% capacity.   That seems strange. I would expect it for 2% or 5% to preserve RAM, but 30%? Maybe there is a setting I don't know about.   My question is: Why does my iPhone power off when the battery is down to 30%?   Edit: this is not a duplicate of the low battery crash as I witnessed the low power shutdown and it was not a crash.


How to skip duplicate value from list comprehension using built in only methods

Using a list comprehension   myList=[-2,-1,0,1,2,3,1,2,3] result=[each for each in myList if each>0]    Results to:  [1,2,3,1,2,3]   How to avoid the duplicated values in returned list?


How can I find the maximum curvature of $y = \ln x$?

Title says it all. I know that you can use the following equation to find curvature (kappa) for a parametric curve, $$\frac{\|r'(t) \times r''(t)\|}{\|r'(t)\|} $$ but I don't know how to do this for regular functions. Answer is at the point $\left(\frac{1}{\sqrt2},\ln\big(\frac{1}{\sqrt2}\big)\right)$.


how to install panda via terminal in ubuntu 18.04 and 19.04?

I want to install panda via terminal. I tried  sudo pip install panda    But it shows the error below:   sudo: pip: command not found


How can I type a Unicode character (for example, em-dash —?)

The title pretty much says it all: how can I type Unicode characters - specifically the em-dash —?


What is the difference between the following set of pointers? When do you use each pointer in production code, if at all?  Examples would be appreciated!   scoped_ptr shared_ptr weak_ptr intrusive_ptr   Do you use boost in production code?


I am using a Mid 2012 MacBook and recently upgraded it to OS X 10.11 El Capitan. I was having trouble with it's new SIP feature and wanted to disable it.  I tried to boot into OS X Internet Recovery using Cmd+R, which started Internet Recovery. When I tried csrutil disable in Terminal, it returned -bash: csrutil: command not found. Then I tried booting into Recovery HD and tried the same command in the recovery mode there to get the same error.  My question is how can I access csrutil command to disable SIP? Am I missing something?  Update I am putting the recovery terminal commands I have tried in the following screenshot. Kindly zoom it to see clearly


RAM upgrade for ASUS Sabertooth X58 motherboard

I want to upgrade my home rig with more memory, but I don't know which RAM chips I should buy. I currently have 6GB, I need more to be able to run VMs.   I am considering buying Kingston HyperX Red Fury 16GB RAM modules, a kit of 2x 8GB DDR3 1866Mhz CL10. These are "DDR3" but I am not sure if it's compatible with my rig. How can I tell?  This is my Motherboard:    and the CPU:    and the RAM:


restore multiple .trn logs in SQL 2008 R2

I am using SQL server 2008 R2 and need to restore 36 .trn logs to a database. I have restored the first 4 using the restore transaction log functionality in SSMS (right click database > tasks > restore > transaction log). Is there a way to restore them all in order using this tool or with a script? The .trn files are in a folder on a remote server. I do not not need to restore all the files in the folder, only ones between specific dates.  Thanks in advance


In an iOS enterprise app i need to implement an idle timeout. The application's idleTimerDisabled property is set to yes, that's not what I want.   It's a journal type of application for an exhibition, in which the app should jump back to the first page after a specific time. Is there some way that doesn't need me to adjust each touch/gesture callback with a function that resets the timer?


Why did the Death Star Plans have to be Physically Carried?

As the title, how can the galaxy have instantaneous wireless 3D video communication across arbitrary distance, but the Death Star plans had to be carried in one copy by the space travel equivalent of ?  They seem important enough that the Rebels might be willing to send them to a bunch of different ships in different areas of the galaxy (remember, they can send data instantaneously over any distance, albeit with some difficulty as shown when they had to bounce a signal in Episode I, so perhaps they couldn't send it just anywhere, as noted by Richard) and then immediately have them make the jump to hyperspace with the destination somewhere else, to evade Imperial interception (assuming the signal could be intercepted and traced in the first place).    I do realize that the real answer is that the writers had no idea that FTL communication opens up such a huge can of worms, I'm just interested if it was ever explained in-universe.


Use sed to append a file into another file

I've been trying to append file.bak into file.php using this command:  sed r file.php file.bak   It gives correct output as desired. However, it doesn't save that appended file.bak into file.php.  Any idea how to get it done?


What is the word for a path that is made naturally by the action of people walking?

I remember one day, when I was supposed to be at school, hanging out at a friends house and watching an episode of  and there was a word that meant something like:     A path that is made (e.g. across a field) by people consistently walking along the same way   For example something like this (updated as some pointed out that my original picture was actually a footpath):    So, it is 15+ years later and I cannot for the life of me remember it so does anyone know what that word is?


Support Rust language syntax highlighting on Stack Overflow

Support proper syntax highlighting for code sections containing  code.


Creating an array of Random Strings [Java]

I was wondering if anyone could give me any insight as to how I would go about creating an array of random Strings?   I want to use this array to test the time it takes different sorting methods to execute.


Is Newton's First Law an actual law, or just the definition of force?

Newton's first , as you all know it, states:      Every body perseveres in its state of rest, or of uniform motion in a   right line, unless it is compelled to change that state by forces   impressed thereon.   Now what is force? To me force means action by which the velocity of an object changes. Now following this definition of force First Law doesn't seem any law.  It is just like saying that; If in a world where there are no mangoes, in that world there can't be any mango juice. When I/we say that "If their were no force" , it means that "If  there were no things/action to change our motion".  So clearly in such world where there is no force/friction then there can't be any thing which can "change our motion". So that implies that object will continue to be in uniform motion . You can see that first law is not a law, but is mere an implication from a trivial definition of force. So why then first law is a law?


Should I use center or centering for figures and tables?

What is the correct way to center figures and tables (figure, table)?  \begin{center} ... \end{center}   or   \begin{centering} ... \end{centering}


I just installed Ubuntu 14.04 but it does not detect my network. Do I have to do this manually? Or is there an automatic network discovery tool?  I am running strictly wireless right now and I did add wireless network details but it does not connect. The output of lspci -nn | grep Network is:   Network Controller [0280]: Intel Corp Wireless 7265[8086:095a] rev 61


Prove that there is prime number and natural so $n\times q$ digits are $1$.

I need your helping to prove that there is a prime number $ 2\lt n\in \mathbb N$ and $ 5\neq q\in \mathbb N$ so that the digits of $n\times q$ are only $1$.  for example:if $n=3$ then $3\times 37=111$  if $n=7$ then $7\times 15873=111111 $  also if $2<n\in \mathbb N$ is odd and not divisible by $5$,  $q\in \mathbb N$* , so $n\times q$ are only $1$ digits.


Why did Walter White choose the name Heisenberg?

In Breaking Bad Walter White uses the name Heisenberg in the meth business.  Why Heisenberg and not some made up name? Was it because the real  was a scientific genius who used his knowledge for evil? (Werner Heisenberg worked on . If he succeeded, then World War 2 would have had a very different outcome.) Is it a reference to some other aspect of Heisenberg?  If this is not mentioned in the TV series, then can you provide quotes from Vince Gilligan or other sources?


Does all objects really fall with the same acceleration?

I know that acceleration due to gravity is independent of mass : $$a = \frac{F}{m} = G\frac{M}{r^2}$$  Meaning that a hammer and a feather fall with the same acceleration on the moon.  I am confused, let's say that instead of a regular hammer, it is a "super hammer" with the same mass as moon. If you drop it on the moon, the "super hammer" will accelerate toward the moon and the moon will accelerate toward the "super hammer". Wouldn't the moon's acceleration make the "super hammer" falls faster than the feather?  In other words, when an object falls, the body it is attracted to "receive" a smaller acceleration in the opposite direction. Wouldn't that acceleration make the object falls faster?  What am I missing?


Method to add predefined database into user's phone when app is installed

Is there a method to add predefined SQLite database into user's phone when the app is first installed   Thank you


Given any sequence whatsoever of real numbers (a_r), there is a smooth function $f: \mathbb{R} \to \mathbb{R}$ such that $f^{(r)}(0) = a_r$.  Pugh's hint says to try $f=\sum \beta_k(x)a_kx^k/k!$, where $\beta_k$ is a well-chosen bump function.  I'm working with a few other people and we're trying to define a bump function $\beta_k(x)$ = bump $*b_k*x$ where from 1/2 to 1, $(exp(\frac{1}{|x|-1}))(1-exp(\frac{-1}{|x|-1/2}) + C_k$ but have no idea how to define


I am trying to setup a crontab to execute a command from a specific user.  Here is my code in "crontab -e". Why is this not working ?   */5 * * * *   user /home/user/whoami>swag.txt   I am running ubuntu14.  EDIT: I am using a personal crontab. I am running whoami>swag.txt to test what user is running the crontab.   This is my new crontab.   */5 * * * *   ./whoami>swag.txt   I am now not seeing anything in swag.txt


Quickest way to find the largest file in a directory and subdirectories

I need to find the largest file in the current and subsequent directory. I tried   ls -Rlh | awk '{print $3 " " $5 " " $9}'    but do not know if it is ok, how to sort and select the largest file.


How do I reproduce a calligraphic Z (that looks like an L) from a text by Abramowitz and Stegun?

I am trying to produce a type of "Calligraphic L" using LaTeX. Please see the image below. The wobbles are down to me, possibly too much sugar over the Christmas holiday period.    This type of "L" is used in Abramowitz and Stegun , see the reference , in particular in result 9.6.26 which gives recurrence relations for modified Bessel functions.  So, how might I produce this type of "L" using LaTeX?  Other Info.  I have searched using Google, with the search string "latex fancy L" and also used "Detexify" on a mobile phone but did not find anything useful. I also considered other "Math Alphabets" the packages "eufrac" and "rsfso" do not appear to give the type of "L" I am looking for. I have also searched on StackExchange using a mobile phone.  The "L" I want is like that in the package "calrsfs", like the symbol given by the command \mathcal{L} but with an extra  loop at the top left of the symbol and a little crossing line part way up the main stem of the symbol.  Reference Handbook Of Mathematical Functions, ninth Dover printing,  Ed M. Abramowitz and I.A. Stegun, Dover Publications, Inc., New York.  Response to duplicate issues.  How to look up a symbol or ...  I recomend the post in question. I think that is where I found out about Detexify from. Apparently the advice in this post should have led to an answer to my question. It's over to the powers that be now ...  How to do the 'curvy L' ...  My question is about a particular symbol, one that appears in an equation in Abramowitz and Stegun. This symbol is not a symbol normally used to represent the Lagrangian or a Laplace transform. In fact it is not even an "L".  Scanned Symbol


EM Radiations, wavelength and Wein's Law of Displacement

Why can black bodies emit all wavelength radiations?  Also, in Wein's law of displacement, how do we sat that wavelength corresponding to the max intensity of the radiation is inversely proportional to the temperature?


My goal is to be able to write:  \newcommand{\сlient_name}{Имя}   and use \client_name all over in my document. Right now I'm getting following errors like this:  Underfull \hbox (badness 10000) in paragraph at lines 670--670 [][]|\l_fontspec_font –ü—Ä–æ-–≥—Ä–∞–º-–º–∏-—Ä–æ-–≤–∞-   Full errors screenshot here -   I tried  and tried using  \newcommand{\сlient_name}{\foreignlanguage{russian}{Имя}}   but it didn't help.  How can I accomplish using cyrillic values in /newcommand variables?


Is Universal Law of Gravitation a 'law'?

My textbook mentions that the universal law of gravitation cannot be proved. If so, then why is it called a 'law' and not a 'hypothesis'?


Email address deleted from profile keeps reappearing

I have Stack Overflow, Meta and Super User accounts. I have been trying to remove my email from my profile. So I delete the email and then choose:     "Save and copy profile to all Stack Exchange Accounts"   A couple of days later, somehow the email addres is again showing in my profile. If an admin is seeing this, I'm asking to remove my email from your system before you fix the bug.


Windows 10 upgrade assistant stuck at 99%

Installed Windows 7 Ultimate (64-bit) on a fresh PC and after installing service pack 1 started the upgrade to Windows 10. The assistant app downloads and verifies but gets stuck at 99% in the upgrading window phase. Even after hours it remains stuck there.  I've tried to reboot the machine and that doesn't help either. I've googled and found out that others have faced the exact problem but so far there isn't any solution that works.  Has anyone seen that situation and is there a fix for it?


Is there an easy way to know what edition a World of Darkness sourcebook is?

I've recently started getting into World of Darkness and I'm realizing there are 5 different editions of sourcebooks:   First edition  Second edition Revised (3rd) edition V20 (4th) edition Fifth edition   Is there an easy way to know what edition a sourcebook is without having to look it up?  Like can you tell what edition it is by looking at the cover?


My girlfriend just purchased a Pixel 4 from Verizon. Apparently, the Verizon representative rushed through the initial setup flow, and my girlfriend didn't get a chance to configure her phone the way she wanted. Is it possible to re-run the onboarding flow?


How do I export a model with multiple objects to a friends computer (over the internet) to import into UE4?

I created a model and textured it using nodes. I'd like to export it to any file format (that UE4 can import) in order to send it to a friend to use in Unreal Engine 4. I am aware that none of the non .blend files support the node-texturing. Is there a solution to this? there are multiple different objects with different textures/materials part of the same model. I heard about baking but none of the tutorials about it are clear especially with multiple objects with multiple textures/nodes/materials. I saw the other forum thread about it but it did not work. any help is appreciated, thanks


Yes, question sounds strange. But I have a big code that wasn't written by my own and contains a lot of while loops and if statements and therefore a lot of braces. WHat I need is the automatic code rebuilding like MS Visual Studio does - no matter where I placed open-brace it will move at right place when I write close-brace. For example:  //I write: function func() { if(//some statement) { echo('hello world'); } }  //It will look like this: function func() {     if(//some statement)     {        echo('hello world');     } }


In MIT Opencourware Probabilistic Systems Analysis and Applied Probability course, there's a recitation problem for Lecture 4:     Quotestion: Imagine that 8 rooks are randomly placed on a chessboard. Find the   probability that all the rooks will be safe from one another, i.e.   that there is no row or column with more than one rook.   And the solution is like that:      Solution: We will count the number of favorable positions in which we can safely   place 8 rooks, and then divide this by the total number of positions   for 8 rooks on a 8 × 8 chessboard. First we count the number of   favorable positions for the rooks. We will place the rooks one by one.   For the first rook, there are no constraints, so we have 64 choices.   Placing this rook, however, eliminates one row and one column. Thus   for our second rook, we can imagine that the illegal column and row   have been removed, thus leaving us with a 7 × 7 chessboard, and thus   with 49 choices. Similarly, for the third rook we have 36 choices, for   the fourth 25, etc... There are 64 · 63 · · · 57 total ways we can   place 8 rooks without any restrictions, and therefore the probability   we are after is: 64 · 49 · 36 · 25 · 16 · 9 · 4 / (64!/56!)   I understand the part that placing the rooks that all will be safe but I could not understand the part that we find the sample space(total number of positions for 8 rooks on an 8 × 8 chessboard). Why don't we just say that there are C(64,8) ways to choose the cells that we will place the 8 rooks? For example, placing a1 first and e7 second does not matter for us, it could be e7 first and a1 second. It means the ordering is not important for us. So why does the solution counts step by step?


I believe this is another easy one for you LINQ masters out there. Is there any way I can separate a List into several separate lists of Some Object, using the item index as the delimiter of each split?  Let me exemplify: I have a List<T> and I need a List<List<T>> or List<T>[], so that each of these resulting lists will contain a group of 3 items of the original list (sequentially).  example:   Original List: [cat, dog, pane, wolf, pig, sun, queen, fox, x'mas, yak, ice, mark, cold] Resulting lists: [[cat, dog, pane], [wolf, pig, sun], [queen, fox, x'mas], [yak, ice, mark], [cold]]


Why do tracert latencies not add up to ping latency?

One might expect the sum of the tracert latencies to equal 267ms:


My PostgreSQL database version is  PostgreSQL 9.3.10 on x86_64-unknown-linux-gnu, compiled by gcc (Ubuntu 4.8.2-19ubuntu1) 4.8.2, 64-bit  In both databases, datestyle is set to"ISO, DMY".    ATTEMPT 1  Query :  insert into station(name , date) values('test' , '21/1/2016')   Error Log:        ERROR:  date/time field value out of range: "21/1/2016" LINE 1: select '21/1/2016'::date                ^ HINT:  Perhaps you need a different "datestyle" setting.  ********** Error **********  ERROR: date/time field value out of range: "21/1/2016" SQL state: 22008 Hint: Perhaps you need a different "datestyle" setting. Character: 8   ATTEMPT 2  Query :    select '21/1/2016'::date   Error log :   ERROR:  date/time field value out of range: "21/1/2016" LINE 1: select '21/1/2016'::date                ^ HINT:  Perhaps you need a different "datestyle" setting.  ********** Error **********  ERROR: date/time field value out of range: "21/1/2016" SQL state: 22008 Hint: Perhaps you need a different "datestyle" setting. Character: 8   On one system it works and on other system it doesn't. Both have Ubuntu and the same PostgreSQL version.  COLLATE SETTINGS ON BOTH SERVERS     Query works successfuly on this server and has below COLLATE setting   show lc_CTYPE   -> C show LC_CoLLATE -> C SHOW lc_time;   -> "en_IN" select '21/1/2016'::date   -> "2016-01-21"      Query Does not Works on this server and has below COLLATE setting   show lc_CTYPE  -> "en_IN" show LC_CoLLATE ->  "en_IN" SHOW lc_time -> "en_IN" select '21/1/2016'::date  -> above error log


Why don't we give visual priority to top answers over top questions in the network profile page?

On the "top" network profile page, top questions appear before top answers. For users with several top questions, the top answers may not even be visible without scrolling down.    The network profile pages are in part, a way to show a user's work in relation to community values. The "top" page is also the default page on the profile, which makes it the most visible. If our community values answers over questions, , should we not give prominence to the top answers before the top questions? Is there a reason why we place questions above answers?


I need to make the code below disregard any case sensitivity Here's the code:  sentence=str(input("Enter sentence") words=sentence.split() uword=input("enter word from sentence") if uword in words:     print("Word is in sentence") else:     print("Word isn't in sentence")   For example if I inputted the sentence "Hello World" as the sentence variable and then inputted "hello" as the uword variable the code should recognise that hello and Hello are the same and print (" Your word is in the sentence")


A proof of the fact that the Fourier transform is not surjective from $\mathcal{L}^1(\mathbb{R})$ to $C_0( \mathbb{R})$

Let $f_n = \mathbb 1_{[-n,n]}$ for all $n \in \mathbb{N}$   Compute explicitly $f_n \star f_1$ for all $n \in \mathbb{N}$.  Show that $f_n \star f_1$ is the Fourier transform of $g_n = \frac{  \sin{(2\pi x)} \sin{(2 \pi nx)}}{\pi ^2 x^2}$  Show that $\| g_n \|_1 \to \infty$  Deduce that the Fourier transform is not surjective from $\mathcal{L}^1(\mathbb{R})$ to $C_0( \mathbb{R})$    Here, $C_0(\mathbb{R})$ is the space of continuous functions $f : \mathbb{R} \to \mathbb{R}$ that tends to $0$ at $-\infty$ and $+\infty$. I managed to compute 1) and proved 2). But I don't know how to prove 3). Moreover, I don't see how can 1), 2) and 3) prove 4). Can anyone help?


Is there some way to see all of a user's messages in a chat room?

Here's the situation: I'm investigating a user's behaviour in a couple of chat rooms because I find the overall patterns concerning, and may need to direct some official attention their way discreetly. They haven't spoken there often, and I suspect a high % of their activity will be of interest.  Is there some way I can find the various instances of someone's activity in a room? Either their messages, or the days on which they have spoken, would be useful.  The best I can think of is to open up the Transcript and search it for very common words, but "the" turns up no results, and "you" isn't picking up much. I also tried Google ({username} site:chat.stackexchange.com/transcript/{roomnumber}), but that digs up a lot of false positives, and doesn't turn up incidents I know are there (I was there for them).


How to create a core dump even if the process is normally running?

Under Linux, when a process crashes, a core dump will be created.  However, I want to create a core dump when the process doesn't crash, but looks buggy. A remote expert need the core dump to analyze.  Under Windows, we can create a dump file of a process through task manager, and after that, the process is still running.  Is it possible under Linux?


I am trying to keep an icon floated left on a liquid text container that has line breaks.  The problem is that when the line breaks, there is a large gap before the text ends and where the div ends. Which makes my floated element start where the gap ends.  Is there a way to make the div only the size of its contents?  Check this codepen:   Resize the output area to see the gap of space.  The button will auto resize it to see the gap.   *{ padding:0; margin:0; top:0; left:0;   }  #mainContainer{  width:100%;       border:black solid thin; }   #lt{  color: black;  background-color:gray;  tex-align:left;  max-width:90%; float:left;  } #icon{ width:20px; height:20px; background-color:blue; float:left; }

This is The information This is The information This is The information

   <input type='button' onClick='showBadSize()' value="click to auto resize to show gap" style='margin-top:20px;float:left; clear:left' />


How get Expresions en arreglos divididas pro parametros a partir de un string

Good afternoon community: I would like to obtain an array from the following expression, I want to use two delimiting parameters that vary according to my need, so that the its a substring is obtained but if it finds parameters in this substring identical to the delimiters it does not affect the substring. Is somewhat similar to grouping signs but with strings. For this case, the delimiting parameters are the this BEGIN END For example I have next string: "Is a testing    BEGIN extract third      BEGIN  extract second        BEGIN extract first expression END     expresión END    expresión END Thank you very much"  This array I would like to obtains as follows:   [    "extract first expression",//substring More Internal    "extract second BEGIN extract first expression END expression",//Second...    "extract third BEGIN extract second BEGIN extract first expression END expression END expression"//....     ]    I've seen these post Regular expression to get a string between two strings in Javascript and Get Substring between two characters using javascript   var str = 'Is a testing BEGIN extract third BEGIN extract second BEGIN extract first expression END expresión END expresión END Thank you very much';      console.log(str.split('(').pop().split(')'));    and I also tryed   var str = 'Is a testing BEGIN extract third BEGIN extract second BEGIN extract first expression END expresión END expresión END Thank you very much';      function testString($string,$textBefore,$textAfter)  {     var regExString = new RegExp("(?:"+$textBefore+")((.[\\s\\S]*))(?:"+$textAfter+")", "ig");     var testRE = regExString.exec($string);     if (testRE && testRE.length > 1)     {         return testRE;     }  }  $all = testString(str,"(",")"); for(var i = 0; i < $all.length; i++){     console.log($all[i]); }    But they don't give me the expected results


How does my screen look to a mantis shrimp?

As a human, I have one 3 color receptors that activate somewhere around the colors red, green, and blue. However, as , a mantis shrimp has 16 different color receptors!  It is no coincidence that the screen I'm looking at is composed of tiny dots of only three colors, red, green, and blue. This is sufficient for me, but dreadfully lacking for a mantis shrimp I suspect. But I don't know... I've never been a mantis shrimp!  How can I imagine what my computer screen must look like to mantis shrimp. Is there any analogy that might help?


Under what conditions on the sets $A$ and $B$ will it be true that $A\times B= B\times A$?   I think it should be set $A$ $=$ set $B$ but don't know how to prove it or is there any other way for those two cross product to be true?


$\sin\sqrt x$ is not a periodic function. How can one prove this?


why is ! character used in shell scripts

I recently encountered a situation where I tried to use ! as a record separator for my string array in shell script. When I used it in my shell script, the script got expanded automatically. An example to reproduce the situation can be as below.   check_variable="Hello" echo "$check_variable" Output: Hello ###For multiple strings, I tried to concatenate with ! as a record separator.  echo "$check_variable !" Output: echo "$check " > Results.txt   Then after some research, I had figured out ! is in fact a special character and should not be used as record separators. So, exactly why is ! used? Is there any way I can turn off the ! character and use it in my shell script?


What is the "time" mean in the command line arguement "time node app.js"?

App.js contains this code:   function add(num1,num2){     let sum = num1+ num2; } let sum = add(2,2);   When I run "time node app.js" In the command line I get the response:   real    0m0.312s  user    0m0.000s  sys     0m0.015s  What does this mean? What is the time flag measuring? How is the runtime calculated? Can you point me to documentation on this flag?


I am a physics student and as far as I know dark matter is beyond the topics included in my grade career. Are there any serious book on the subject? Any serious set of lectures somewhere in Internet?


'The company I work for' cannot be shortened to 'My company'?

My English teacher said that it's not correct to say 'my company' for indicating the company I work for, because 'my company' means the company I own. But I don't think this kind of confusion happens often. It's too long to say 'the company I work for'.   So can't I use 'my company'? If so, what about 'my apartment' or 'my band' or 'my country'?


Make a hole in the ground of a video which is camera-tracked?

With my trial and error learning, I managed to track a video in Blender 2.67 and make a cube (the one which is there by default) appear on the "ground" (which is a table).  But how can I make a hole in the ground?    Edit:  I used the two buttons shown below:    The two functions seems to do a bunch of things to the scene, which seems to include setting the background and foreground layers, and adding a Ground object to the scene.  The problem is, what do I need to do to create a hole that appears to sink into the table?


Pass Variable from inside a shell script to be used outside

I have a shell script that has multiple variables , I would like to export a specific variable from the script to a command I want to run after the shell script is executed #!/bin/sh  a=10 b=20 c=a+b echo $a export a  and the command I want to run is echo $a


Limits involving greatest integer functions, and analyzing behavior of functions as it tends to a value

I have a question, that asks me to find the following limit  $$\lim_{x\to 0}\bigg\lfloor\frac{x^2}{\sin x \tan x}\bigg\rfloor$$  Now, here's what I know, that, $$\lim_{x\to 0} \frac{\sin x}{x} = 1$$ and $$\lim_{x\to 0} \frac{\tan x}{x} =1$$  But according to that, the answer to my question should be $1$, but it is given as $0$  Now, my book states that $$\lim_{x\to 0} \frac{\sin x}{x} \to 1^-$$ and $$\lim_{x\to 0} \frac{\tan x}{x} \to 1^+$$  or, $$\lim_{x\to 0} \frac{\sin x}{x} = 1-h$$ $$\lim_{x\to 0} \frac{\tan x}{x} = 1+h$$ How do they get this? How do I analyse the behavior of a function near around a point? A detailed explanation would really help.


I have some queries that are parameterized, but they are still creating a new execution plan each time. I am using SQL Server 2016.  Queries are like:  (@P1 varchar(1043),@P2 varchar(6)) UPDATE table  SET FILEDATA=@P1  WHERE FILEID=@P2   This query is not using the already generated execution plan from the cache, rather it is creating a new plan each time.


How to add 24 to the %H part of the enter variable, then store it as the same variable?

from datetime import datetime run = 1 list1 = [] for i in range(2):      while run > 0:           print("")           reg_num = input('reg num')           enter = input('time  enter in the form "HH:MM:SS" in 24 hours format')           ext = input('time exit in the form "HH:MM:SS" in 24 hours format')           total_time = '%H:%M:%S'           if int(enter[0:1]) > int(ext[0:1]):                total_time = enter[0:1] + 24           t_diff = datetime.strptime(ext, total_time)- datetime.strptime(enter, total_time)           t_diff1 = str(t_diff)           print(t_diff)           t_diff2 = int(t_diff1[4:5])           t_diff3 = int(t_diff1[7:8])           time = ((t_diff2/60)+(t_diff3/60/60))           speed = run/time           print("{:.2f}".format(speed), "mph")           if speed > 70:                list1.append(reg_num)           break for item in list1:      print(item, "is over speeding")   This is code to work out the speed of something as it enters and exits a checkpoint that is set a mile apart.  What I am trying to do here is to find the difference in time when the time entered hour is greater than time exited hour. i.e. enter = 23:59:00 and ext = 00:00:00. I know that I have to add 24 to the %H but I don’t know how to do it and when I try to run it in the shell the message is:  total_time = enter[0:1] + 24 TypeError: Can't convert 'int' object to str implicitly   The problem I think comes from this part of the code:  if int(enter[0:1]) > int(ext[0:1]):     total_time = enter[0:1] + 24   Can you help me find out a way to add 24 to the hour section and then store it into the same variable.


Determining ring of integers for $\mathbb{Q}[\sqrt{17}]$

I'm trying to find the ring of integers of $\mathbb{Q}[\sqrt{17}]$, and it comes down to determining the set $\{(a,b)\in\mathbb{Q}^2\mid 2a\in \mathbb{Z}, a^2-17b^2\in\mathbb{Z}\}$. How can I determine this set?


A Banach space $X$ is relfexive iff $X^*$ is reflexive.

I am trying to prove the following:  A Banach space $X$ is reflexive iff $X^*$ is reflexive.  Thus far, I have proven the forward direction:  Let $J_X:X\mapsto X^{**}$ be the mapping defined by $J_X(x)=x^{**}$ and let $J_{X^*}:X^*\mapsto X^{***}$ be defined by $J_{X^*}(x^*)=x^{***}$. The statement above is equivalent to showing that $J_X(X)=X^{**}$ if and only if $J_{X^*}(X^*)=X^{***}$. Suppose that $J_X(X)=X^{**}$. Let $y\in X^{***}=B(X^{**},\mathbb{R})$. We show that there is some $x^*\in X^*$ such that $J_{X^*}(x^*)=y$, thus showing that $J_{X^*}(X^*)=X^{***}$. Note that $yJ_X:X\mapsto \mathbb{R}$, and hence, $yJ_X\in B(X,\mathbb{R})=X^*$. Since $J_X(X)=X^{**}$, if $z\in X^{**}$, then there is some $x\in X$ such that $J_X(x)=z$. We have $$ y(z)=y(J_X(x))=(J_X(x))(yJ_X)=z(yJ_X)=(J_{X^*}(yJ_X))(z). $$ Thus, $y=J_{X^*}(yJ_X)$, implying that $X^*$ is reflexive.   I have no clue how to prove the other direction. I wanted to try a similar approach, but it's turning out to be kind of difficult (and ugly looking). I would greatly appreciate some help! Thanks!


Why Dumbledore never thought to check on Moaning Myrtle?

The more times I read the series, the more I come across things that should have been obvious.  In the book Harry Potter and the Chamber of Secrets, Harry suddenly guesses that the girl who died in the girls' bathroom 50 years before was Moaning Myrtle.  “Ron — that girl who died. Aragog said she was found in a bathroom,” said Harry, ignoring Neville’s snuffling snores from the corner. “What if she never left the bathroom? What if she’s still there?” Ron rubbed his eyes, frowning through the moonlight. And then he understood, too. “You don’t think — not Moaning Myrtle?”    And I'm sure his dialogue between Tom Riddle and Albus Dumbledore figures that Dumbledore meant 'since' the death of the girl.  “Well, hurry off to bed,” said Dumbledore, giving Riddle exactly the kind of penetrating stare Harry knew so well. “Best not to roam the corridors these days. Not since . . .” He sighed heavily, bade Riddle good night, and strode off.    And then as per Professor Binns,  Professor Binns looked faintly annoyed. “The whole thing is arrant nonsense, of course,” he said. “Naturally, the school has been searched for evidence of such a chamber, many times, by the most learned witches and wizards. It does not exist.”    Ministry of Magic could have predictably overlooked the clues that unfairly lead to the expulsion of Hagrid. But Dumbledore always thought Hagrid was innocent.In such a case , I just wondered why Dumbledore or any others not make out this obvious connection and question Myrtle as Harry did.


If $r$ (mod $p$) is a primitive root, then $r+p$ is also a primitive root mod p

I've struggled with this problem for a while...I tried to figure it out using a reduced residue system's theorem but I honestly have no idea how to work with the given hypothesis.


Real analysis - inductive proof- help please

I ran into this problem in my real analysis class. It sounds easy enough on the surface, and maybe it is, but I can’t seem to figure out what to do inductively as the product on the LHS is throwing me a bit off. In short, HELP, please. The question is as follows: Let n ∈ N. Show that if, a1,a2,...,an are non-negative real numbers less than 1 (0 ≤ ai < 1 for i = 1,...,n), the following holds:                             1−a1)(1−a2)···(1−an)≥1−(a1 +a2 +...+an)


I find that the graph of $f(x)=\Gamma(x)^{1/x}$ or $(x!)^{1/x}$ is nearly a line when $x$ is large enough. And when $x$ gets larger, $f'$ will come to a limit. For example: x      f'(x) 1    -0.577216 2     0.211392 3     0.290511 4     0.316217 ...   ... 10    0.349503 20    0.358720 ...   ... 1000  0.367695 2000  0.367787 ...   ... 9000  0.367859  (calculated using SymPy) The answer given by WolframAlpha is $1/e$. It is amazing, and why is it? PS. $f'(x)=(\mathrm{polygamma}(0,x)/x-\ln(\Gamma(x))/x^2)*\Gamma(x)^{1/x}$


Postfix: Using google apps for smtp errors

I am using postfix and need to send the mail using google apps smtp.  I am getting errors after I thought I had set everything up correctly:  May 11 09:50:57 zedsaid postfix/error[22214]: 00E009693FB: to=<www-data@zedsaid.com>, relay=none, delay=2466, delays=2462/3.4/0/0.06, dsn=4.7.0, status=deferred (delivery temporarily suspended: SASL authentication failed; cannot authenticate to server smtp.gmail.com[74.125.155.109]: no mechanism available) May 11 09:50:57 zedsaid postfix/error[22213]: 0ACB36D1B94: to=<www-data@zedsaid.com>, relay=none, delay=2486, delays=2482/3.4/0/0.06, dsn=4.7.0, status=deferred (delivery temporarily suspended: SASL authentication failed; cannot authenticate to server smtp.gmail.com[74.125.155.109]: no mechanism available) May 11 09:50:57 zedsaid postfix/error[22232]: 067379693D3: to=<www-data@zedsaid.com>, relay=none, delay=2421, delays=2417/3.4/0/0.06, dsn=4.7.0, status=deferred (delivery temporarily suspended: SASL authentication failed; cannot authenticate to server smtp.gmail.com[74.125.155.109]: no mechanism available)   main.cf:  # Debian specific:  Specifying a file name will cause the first # line of that file to be used as the name.  The Debian default # is /etc/mailname. #myorigin = /etc/mailname  smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU) biff = no  # appending .domain is the MUA's job. append_dot_mydomain = no  # Uncomment the next line to generate "delayed mail" warnings #delay_warning_time = 4h  readme_directory = no  # TLS parameters #smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem #smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key smtpd_use_tls=yes smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache  # See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for # information on enabling SSL in the smtp client.  myhostname = zedsaid.com alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname mydestination = #relayhost = mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 mailbox_command = procmail -a "$EXTENSION" mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all delay_warning_time = 4h smtpd_recipient_limit = 16 # how many error before back off. smtpd_soft_error_limit = 3 # how many max errors before blocking it. smtpd_hard_error_limit = 12  ## Gmail Relay relayhost = [smtp.gmail.com]:587  smtp_use_tls = yes smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtp_sasl_security_options = noanonymous smtp_sasl_tls_security_options = noanonymous smtp_sasl_mechanism_filter = login smtp_tls_eccert_file = smtp_tls_eckey_file = smtp_use_tls = yes smtp_enforce_tls = no smtp_tls_CAfile = /etc/postfix/cacert.pem smtpd_tls_received_header = yes tls_random_source = dev:/dev/urandom  transport_maps = hash:/etc/postfix/transport debug_peer_list = smtp.gmail.com debug_peer_level = 3   What am I doing wrong?


Why do old questions have so many points?

On Stack Exchange there are some old questions—3-4 years old—that have something like 3500 votes. Now I understand that over time the questions will naturally accrue the odd vote, but this is ridiculous.  Did everyone go through a phase in the early days where they were just giving each other excessive vote, like a pat on the back?  And some of these 3000+ vote answers to questions aren't so great either. I often come across 200+ questions and answers that would go into negative territory if they were posted nowadays.


Integral of (tan inverse ax)/x(1+x^2) from 0 to infinity using contour integration

Integral of (tan inverse ax)/x(1+x^2) from 0 to infinity. I tried using substitution method keeping ax = tan inverse k, but could not get the answer. Later found an article where it was mentioned that such problems could be solved by contour integration. Any help appreciated. Thanks


Levi civita and kronecker delta properties?

I'm trying to grasp Levi-civita and Kronecker del notation to use when evaluating geophysical tensors, but I came across a few problems in the book I'm reading that have me stumped.   1) $\delta_{i\,j}\delta_{i\,j}$  2) $\delta_{i\,j}  \epsilon_{i\,j\,k}$  I have no idea how to approach evaluating these properties. Without knowing i, j, or k, how would I approach? I don't feel confident using the notation further until I can understand these properties.


I was writing a book about royalty and I needed to use the word suitor in it, but the "suitors" were female. Should I keep using the word suitor or suitress?


Correct way to calculate Perspective Matrix

I have seen at least 3 different ways to calculate the perspective matrix and I'm confused as to which one I should be using and what the differences are?  OpenGL says to do it this way:  f = cotangent(fov * 0.5)  f / aspect, 0, 0, 0 0, f, 0, 0 0, 0, (far + near)/(near - far), (2 * far * near)/(near - far) 0, 0, -1, 0   glm does it this way:  range = tan(fov * 0.5) * near;   left = -range * aspect; right = range * aspect; bottom = -range; top = range;  (2 * near) / (right - left), 0, 0, 0 0, (2 * near) / (top - bottom), 0, 0 0, 0, (far + near) / (far - near), -1 0, 0, (2 * far * near) / (far - near), 0


We will say a metric space $X$ is bounded if, for some $M>0$ and $x\in X$, the entire space $X$ is contained in $B_M(x)=\{y\in X:d(x,y)\leq M\}$. Show that a compact metric space is bounded.  I was attempting to write it up as a totally bounded compact metric space using a finite set so that all the $B_M$'s cover $X$. I am not sure if this is the correct and I am struggling with how to write it up.  I have been researching it for a very long time and this so far seems to be an approach, not sure. Please show details so I can understand.


How can I find the angle by the sin, cos, and tan without using the calclator?

What is the rule or law to find out the degree of the angle using sin, cos, and tan without using the calculator? What does the calculator do to calculate the angles by given it the sin , cos, or tan ?


SELECT    SUM(a)-SUM(b) AS c1,    SUM(a) AS c2,    SUM(b) AS c3 FROM tbldoc GROUP BY Cid  WHERE c1<>0   If you take ( WHERE c1<>0 )  not error  Thank you Answer


I do yet not know everything about coding with tikz but I am learning. I need to draw this system and I would really appreciate it if someone helped me make this.  I want it to have the same kind of structure as this system, not too bold just simple and thin.


In linear regression, when is it appropriate to use the log of an independent variable instead of the actual values?

Am I looking for a better behaved distribution for the independent variable in question, or to reduce the effect of outliers, or something else?


Let G be a group. The function $f:G \rightarrow G$ defined by $f(x)=x^2$ is a homomorphism iff G is abelian.  I am having trouble with the 2nd part of the proof.  Proof:  Assume the function $f:G \rightarrow G$ is defined by $f(x)=x^2$ then:   Assume $f$ is a homomorphism then $f$ satisfies the property: $$ f(xy)=f(x)f(y) $$   where $x,y \in G$  Notice how: $$f(xy)=(xy)^2=xyxy$$ $$f(x)f(y)=x^2y^2=xxyy $$  Since $f(xy)=f(x)f(y)$ then by substitution:  $$xyxy=xxyy$$  Multiplying the right by $y^{-1}$ and the left by $x^{-1}$ then:  $$yx=xy$$ which means G is abelian   Assume G is abelian, we want to show $f$ is a homomorphism   For the 2nd part of the proof, would I just work backwards from the first part of the proof? Here is an outline:  then for $x,y \in G$  $$yx=xy$$ by definition of abelian groups.  Multiple the right by y and the left by x, we have:   $$xyxy=xxyy$$  which is equal to: $$(xy)^2=(x)^2(y)^2$$  since we are given $f(x)=x^2$ then translating this to the above statement: $$f(xy)=f(x)f(y)$$  which satisfies the property of homomorphism.  Does that look right?


I have a question for which I don't seem to be able to find the answer. Where can I find the translations and the translation process of Ubuntu?  I 'm currently in a revival project of the Gothic language and if there is enough demand I could maybe, depending on the amount of text, try to translate a part of Ubuntu in this language. As providing operating systems in this language might be a good step to reviving it.


Do spells other than the Patronus Charm affect Dementors?

I know the Patronus Charm is the only effective spell against Dementors - but does any other spell have an effect on a Dementor? E.g. in The Order of the Phoenix Mundungus Fletcher was supposed to look for Harry Potter in Little Whinging. If he had not left he would have had to help Potter with the Dementors. But I really doubt that he was able to perform the Patronus Charm so he would have tried any other spell on the Dementors. edit:  and  are related to this question but both do not answer how especially spells could have affected Dementors. Mundungus Fletcher couldn't have helped Harry Potter just by controlling his feelings, becoming an Animagus or getting a ghost, he would have tried something like the Stunning Spell - maybe without any success.


Creating a reflective surface without lighting effect

Heyyo all :), I'm a bit stuck, I'm working on a 3d packshot and I want it to have a reflection below the pack but without a visible surface underneath as the PNG image will be used in various places but can have a background except a reflection under it. As you can see I've made the reflective surface no issue but its the white haze in the horizon that i want to get rid of :S Cheers Calpol


As you may have seen, this was ’s last week at Stack Overflow. To say that he has been a staple of this company for a very long time is an understatement. Tim has served , evangelist, thought leader, anthropologist, psychologist, and mediator for this site for almost as long as it’s been around. For me personally, Tim has been my right hand in this role. He has educated me on the history of our community, been the person I’ve gone to to ask “why is this thing this way?“, bounced ideas off of, collaborated with, and relied on as a steady voice and a thoughtful teammate. We’re all proud to send him off and support him in any way we can in his next role. Tim has agreed to meet with me once a month to talk these things through moving forward and I’m excited to continue getting his feedback on our initiatives and goals. Thank you, Tim, for being such a stalwart here for so long. We’ll miss you, and look forward to sneaking you into our “Among Us” games for as long as we can. We're also excited to see you request to rejoin the ranks of Stack Overflow moderators and continue to be a pillar in the community.


It charged me a amount of 50 does it take a single time or for every purchase and y is this money taken and will I get the amount back and if there any one with the return of the money


Why am I seeing people marking technical parts of texts (names of functions, files) a code (e.g. `explorer.exe`), while logically it is not a code? I agree that these things should be somehow highlighted, but I don't see the code marking an appropriate way of doing it.


I've got a laptop that came without operating system and Windows 7 Home Premium were installed on it later using CD (which I do not have)  Its' HDD started running slow, so we've decided to upgrade it to SSD.  I've found what's the CD Key using   That's the result:  Windows 7 Home Premium Service Pack 1 Product Part No.: X15-0000 Installed from 'OEM' media. Product ID: 00000-00000-00000-00000  match to CD Key data CD Key: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX Computer Name: LAPTOP Registered Owner: Owner Registered Organization:   However, I cannot download ISO file from  page if I enter my CD Key. I've downloaded another installation media from internet, however it does not accept my key as well once I installed it on SSD.  How can I download a ISO file that would accept this or make cd key work?


What's the centered fluffy art piece called in an article?

I know this, but I can't recollect at all.   What is this thing called?   They are usually centered in a book or writing and I'm certain they have a name but I can't remember for the life of me. They also come in all shapes, colors and sizes.


Return value of 0 from MySQL query if empty

I use this query to get a value for a range of months. For example, January 1.10, February 2.37.  "SELECT SUM(DISTRIBUTED_AMOUNT / EXCHANGE_RATE) FROM royalties WHERE DATE BETWEEN '".$datemin."' AND '".$datemax."' GROUP BY DATE  ORDER BY DATE ASC"   Is there a way to return a value of 0 if there are no rows within a certain month?


Where does the '2' Factor come from in the Coriolis Force?

Say we have a disk rotating at $\omega$, and an observer standing at radius $R$. The observer throws something of mass $m$ with radial velocity $v_r$, and the goal is to make this object go in a straight path along the radius. The Coriolis force says that we must exert a horizontal force of $2m\omega v_r$ - however, when I derive this myself, I get only $m\omega v_r$, as follows.  From an outsider's perspective, if we want the object to stay in a straight line, as the object proceeds towards the center, its horizontal velocity must change according to its position on the disk, such that $dv=\omega dr$. Thus the force on the object must be $m\frac{dv}{dt}=m\omega\frac{dr}{dt}=m\omega v_r$. Where did I go wrong in my derivation?


A rather new user self-answered their question. Yet not by adding and answer, instead the question was edited. See this example:   My first feeling was to edit their answer out of the question into its own answer. Yet that would mean that I would post the answer and perhaps recieve up/downvotes on it. This made me think that this could be considered as copy-catting and rude.  Would it be rude?  Another approach would be to comment on the question to educate the user to post one's answers as answers.  How should we deal with this kind of answers?


why my custom object count is differ from system overview count?

I am using below code to list all the custom object  Integer count = 0;  for ( Schema.SObjectType o : Schema.getGlobalDescribe().values() ) {     Schema.DescribeSObjectResult objResult = o.getDescribe();      if(objResult.isCustom())        {          count++;         //system.debug(objResult.getLabel());     } } system.debug('Total custom object :'+ count);     // USER_DEBUG [11]|DEBUG|Total custom object :576   But when i see the system overview is different ? How to get this count match with system overview count. ?  SetUp -> System overview     Custom object - 515  Custom setting -113  Finally got to know apex code gives all installed object which is not counted in UI data.


update .jsp file with new DB data from servlet

I have created a servlet that gets credentials from a .jsp file (works). The servlet connects to the DB, gets the data and forwards it to another .jsp file (works).  Getting the data and displaying it is happening in one function getLaneInfo().  Now I have implemented a DBListener which executes getLaneInfo() every time the data in the DB changes (doesn't work). getLaneInfo() is called first when the connection has been established and it works fine. But I get a NullPointerException when the DBListener wants to execute it. The exception is thrown when I want to access the variable request (HttpServletRequest).  I'm forwarding the data like this:  request.setAttribute("Info", infoList); request.getRequestDispatcher("WEB-INF/show.jsp").forward(request, response);   This is the exception that I get:  java.lang.NullPointerException at org.apache.catalina.connector.Request.setAttribute(Request.java:1509) at org.apache.catalina.connector.RequestFacade.setAttribute(RequestFacade.java:503) at banner.Index.getLaneInfo(Index.java:237) at banner.Index$1.onDatabaseChangeNotification(Index.java:122) at oracle.jdbc.driver.NTFRegistration.notify(NTFRegistration.java:208) at oracle.jdbc.driver.NTFConnection.unmarshalNSDataPacket(NTFConnection.java:582) at oracle.jdbc.driver.NTFConnection.unmarshalOneNSPacket(NTFConnection.java:405) at oracle.jdbc.driver.NTFConnection.run(NTFConnection.java:182)   Any ideas?


$SL_n(\mathbb R)$ is a subgroup of kernel of $f\in$ Hom$(GL_n(\mathbb R), A)$, $A$ is an abelian group.

Try to prove the following proposition.     $SL_n(\mathbb R)$ is a subgroup of kernel of $f\in$ Hom($GL_n(\mathbb R), A)$, where $A$ is an abelian group.   My first attempt is to show that $SL_n(\mathbb R)$ is in form of $ABA^{-1}B^{-1}$, then it's clear that $ABA^{-1}B^{-1}$ is in $ker(f)$. However, there exists an elementary row reduction matrix, i.e. $E_{ij}(m)$ adding m times $j$-th row to $i$-th row. Then $E_{ij}(m)\in SL_n(\mathbb R)$. Now, it is possible that $E_{ij}(m)$ is not in $ker(f)$. Then I try to find any relation between $\mathbb R^{\times}$ and $A$, but, except knowing they are both abelian groups, I cannot figure out what else connects those two group. Could you give me some hints?


Idiom to describe something that has little to no effect?

I'm looking for an idiom to describe something that has a negligible effect.   The only similar question I found here was: , but I'm looking for something else.  I remember it being something to do with water or fire. Something along the lines of throwing a very small amount of water on a large fire? Does anyone know what I'm thinking of?


Why doesn't my bright blue in in RGB match when I convert to CMYK?

I can't apply selected color in CMYK mode but can apply RGB mode.


foreach loop error in generating diagrams


Java protected modifier accessible in another package having the same package name

I have programmed in Java for some time and I just realized that the protected access modifier allows members to be accessed also in the same package. So here is the situation and the question:  I have a class having a protected method, and a test class using Mockito to stub that method. The two classes are located in different folders (a src and a test), but their package names are the same! The funny thing is, I can call the protected method in the test class! I would like to know how it is possible? Because their package names are the same? In this case the protected modifier does allow a very wide access!


Why won't the truffle NPC move in to my house In the above ground mushroom biome during hardmode

I unlocked hardmode by beating the wall of flesh. I have an above ground mushroom biome. I see the giant mushrooms in the background and I see mushroom biome monsters. I keep getting the notification that the truffle wants to move in and he won't. I have a house big enough I have torches, chairs, and a table. I know that there is no Crimson of corruption nearby because other NPCs have moved in.  Here is a picture of my above ground mushroom biome.


I want to set the RUN to yes in the /etc/default/saned, as mentioned in .  Here is a snippet of the file :  # Defaults for the saned initscript, from sane-utils  # Set to yes to start saned RUN=no  # Set to the user saned should run as RUN_AS_USER=saned   How can I edit the saned file from within the tty1 terminal?


Creating Direct Limits and Inverse Limits using Tikz

I am trying to make something that looks like   I am trying to go from here (works):  \begin{tikzcd} A \arrow{r}\arrow{rd} &B \arrow{d}\arrow[leftarrow]{r} &C \arrow{ld}\\ &D \end{tikzcd}   to here (doesn't work):  \begin{tikzcd} A \arrow{r}\arrow{rd} \arrow{rdd} &B \arrow{d}\arrow[leftarrow]{r} &C \arrow{ld} \arrow{ldd} \\ &D &E\\ \end{tikzcd}   I try many combinations but don't see how the tikz@x-y-z values work. Any help is appreciated.  Thanks,  Brian


To harp is to talk or write persistently and tediously on (a particular topic).  Example: "I don't want to harp on about the past"  Is there a similar, non-tedious equivalent?


Spikes in loss function of deep neural network training

I'm training a simple feed-forward Deep Network with standard relu/sigmoid activation functions, using Tensorflow. I tried several optimizers and I noticed that those belonging to the Adam family show a strange behavior in loss trend, as you can see in the picture.    I've read about  , but their loss trends appear to be quite different than mine.   Have you any idea of the possible source of this problem? Can you suggest some possible references to investigate this issue?  However, I verified that using SGD or RMSprop as optimizer the problem disappeared, but the obtained final loss value was much higher.


if $f:[0,1] \to \mathbb{R}$ is increasing, show that $f$ is the pointwise limit of a sequence of continuous  functions over $[0,1]$  Intuitively this makes sense but I am having trouble with showing why there would be a sequence of continuous functions converging pointwise to $f$.  Clearly there is a sequence converging pointwise to $f$, I can set: $\forall n \in \mathbb{N}, f_n = f$.  How to prove there is at least one which is made up of continuous functions $f_n, \forall n \in \mathbb{N}$ over $[0,1]$ I can't quite figure out the argument.


ext4: How to account for the filesystem space?

I've recently formatted a 1.5 TB drive with the intention of replacing ntfs with ext4.  Then I noticed that the files I saved don't fit on the new partition.  df:  ext4 (ext3 & ext2 show the same behavior) Filesystem      1K-blocks   Used  Available Use% Mounted on /dev/sdb1      1442146364   71160 1442075204    1% /media/Seagate  ntfs (similar to all other options that gparted offers): /dev/sdb1      1465137148  110700 1465026448    1% /media/Seagate   That 1K-blocks difference means a glaring 22 GiB less usable space.  I have already executed  tune2fs -O \^has_journal tune2fs -r 0 tune2fs -m 0   with, unsurprisingly, no effect as that does not affect blocks that just aren't there.  Still, fdisk reports that the ext4 partition covers the entire disk.  fdisk -l /dev/sdb:  WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util fdisk doesn't support GPT. Use GNU Parted.  Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000    Device Boot      Start         End      Blocks   Id  System /dev/sdb1               1  2930277167  1465138583+  ee  GPT   And thus e. g. resize2fs reports that there's "Nothing to do!"  dumpe2fs -h /dev/sdb1: dumpe2fs 1.41.14 (22-Dec-2010) Filesystem volume name:   <none> Last mounted on:          <not available> Filesystem UUID:          d6fc8971-89bd-4c03-a7cd-abdb945d2173 Filesystem magic number:  0xEF53 Filesystem revision #:    1 (dynamic) Filesystem features:      ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize Filesystem flags:         signed_directory_hash  Default mount options:    (none) Filesystem state:         clean Errors behavior:          Continue Filesystem OS type:       Linux Inode count:              91578368 Block count:              366284288 Reserved block count:     0 Free blocks:              360518801 Free inodes:              91578357 First block:              0 Block size:               4096 Fragment size:            4096 Reserved GDT blocks:      936 Blocks per group:         32768 Fragments per group:      32768 Inodes per group:         8192 Inode blocks per group:   512 Flex block group size:    16 Filesystem created:       Sat May 21 17:12:04 2011 Last mount time:          Sat May 21 17:15:30 2011 Last write time:          Sat May 21 17:24:32 2011 Mount count:              1 Maximum mount count:      32 Last checked:             Sat May 21 17:12:04 2011 Check interval:           15552000 (6 months) Next check after:         Thu Nov 17 16:12:04 2011 Lifetime writes:          1372 MB Reserved blocks uid:      0 (user root) Reserved blocks gid:      0 (group root) First inode:              11 Inode size:           256 Required extra isize:     28 Desired extra isize:      28 Default directory hash:   half_md4 Directory Hash Seed:      c334e6ef-b060-45d2-b65d-4ac94167cb09 Journal backup:           inode blocks   What is using that missing space?


Can I have an unregistered guest come over at a hotel?

Can I let my friend come and join me in my hotel room, just for visiting? Not sleeping or eating.


Replacing variable containing \ with sed

i am trying to replace $old  string with $new string in file where:  old=ESX_10.1.1.1\@11.11.11.11 new=host_15_11_0_111.static   I am using sed command:  sed i "s/${old}/${new}/g" /filename   but it does not replace the word and also not shows any error. I have tried it with many ways, like replacing:  sed i "s,${old},${new},g" /filename   and  sed i "s=${old}=${new}=g" /filename   but it does not work. Help me to solve this


Anomaly detection within periodic time series

I would like to detect anomalies in a time series data using a moving average approach. Basically, the system will rise an alarm when a data point is far away (3*std for example) from the current mean.   The problem is that the data contains periodic deviations and I do not want to rise alarms for these periodic deviations (even if they are far away from the mean). In other words I would like to rise alarms only at non-periodic deviations. What basic approaches I can try to achieve this?  Thank you. Mario


How to fix no active image found in material slot

I'm learning the texturing,give color, uv unwrap and baking through tutorial on youtube.  Somehow i got this error "no active image found in material slot"  ( link 1:  ) ( link 2:  )  tried to solve it by reading forum but still cannot understand what does it mean by material slot, let alone to fix it.  what did i do wrong? need help. version used: 2.8


Can unconscious characters be unwilling?

Some spells like  and  specify that only an unwilling creature makes a saving throw:     If the target is unwilling, it can make a Constitution saving throw.    and     An unwilling creature must make a Wisdom saving throw to avoid the effect.   ... but is an unconscious character able to make this judgment (and therefore be eligible to make a saving throw)?  Mind you, I've seen  on opting in to certain spells, but I'm specifically asking about opting out so as to be eligible for the saving throws.


Georeferencing 1990 U.S. county names / FIPS for CartoDB?

I have a data  with columns of county and state names as well as FIPS codes for 1990 U.S. counties.   I cannot easily merge shape data into the data (e.g. the Census ), but CartoDB does not recognize the "administrative regions" being these counties at all when I ask to georeference this data.   Is there a way around this?


I am very new to PostGIS/PostgreSQL. In fact, I downloaded it because of the answers I got to this question:   I installed both PostgreSQL and PostGIS. But I am not able to import a shapefile to the database? It gives an error, "Shapefile import failed". What am I doing wrong?


What is the difference between canon 5D mark II and mark III?

Now I am using Canon 5D mark II, I want to upgrade my camera into Mark III. I want to know what is the difference between each them.


Finding all integral solutions of $x^4+y^4+z^4-w^4=1995$

Find all the integral solutions of   $$x^4+y^4+z^4-w^4=1995.$$  Please elaborate the solution. I tried but can't understand what to do.


Parts of mesh appear dark in 3d view and in render

I have an issue with a part of my model. It looks weird in object mode as well as in a render. Please look at the attached screencaps.          I checked and all the geometry in and around this problem have all 4 verticies and 4 edges, making one face. this entire section was rebuilt after I forgot to extrude something. The odd thing is that just these two faces look weird but not the surrounding ones that I stitched together in the same manner.  I looked in ortho views and they are all aligned so it isn't that some verts may be offset.


Every section of a measurable set is measurable? (in the product sigma-algebra)

I'm studying measure theory, and I came across a theorem that says that, given two $\sigma$-finite measure spaces $\left(X,\mathcal M,\mu\right)$ and $\left(Y,\mathcal N,\nu\right)$, and a set $E\in \mathcal M\otimes\mathcal N$, the function $x\mapsto \nu\left(E_x\right)$ is measurable.  The definition of the product-$\sigma$-algebra $\mathcal M\otimes\mathcal N$ is the $\sigma$-algebra generated by the rectangles $A\times B$ with $A\in\mathcal M$ and $B\in\mathcal N$. Also, the $x$-section $E_x$ is defined as $E_x=\left\{y\in Y:\left(x,y\right)\in E\right\}$.  My problem is that I can't even convince myself that, given $E\in\mathcal M\otimes \mathcal N$, the sections $E_x$ are in $\mathcal N$ for all $x$. It looks like it has something to do with unitary sets being measurable (which shouldn't be necessary, I think), but I can't prove it even assuming that $\left\{x\right\}\in\mathcal M$ for all $x$.


My gravatar stopped working on most of stack exchange

Upon visiting Meta Stack Exchange today, I noticed that my gravatar had been replaced with the default geometric art image.    Upon further research, it appears that it is still there on , , and , but seems to be gone    .  I used to have this same gravatar on all Stack Exchange sites.  What caused it to stop working?  How can I get it back?


Anonymous inner Comparable class in Java method?

My professor offered this bit of code in an exercise about scope and lifetime:  class AnonymousInnerClassInMethod {      public static void main(String[] args) {         int local = 1;         Comparable compare = new Comparable () {             public int compareTo(Object value) {                 return (Integer)value - local;             }         };         System.out.println(compare.compareTo(5));     }  }   Putting aside the fact that local isn't accessible (that's the exercise) and that Comparable isn't parameterized (oversight?) ... I have never seen this construct and had no idea it was even possible.   Is it done this way to avoid extending Comparable for the whole class? If so, why?  Is it that much easier/readable/something else? Can this type of anonymous class be written for any interface?


Be G a graph and let's assume that for every sub graph G^'=(V^',E^' ) |E^' |≤2|V^' |. Show you can direct the graph edges so every exit is at most 2.

Be G a graph and let's assume that for every sub graph G'=(V',E' )  |E' |≤2|V' |Show you can direct the graph edges so every exit rank is at most 2.  So my idea was to say there exits at least one exit rank in every way we can direct such that it is >=3, then take the subgroup(of the vertices and the subgraph made from them) without the vertices with exit rank >=3 and try to get a contradiction but I'm getting stuck


Flexible and inflexible models in machine learning

I came across a simple question on comparing flexible models (i.e. splines) vs. inflexible models (e.g. linear regression) under different scenarios. The question is:  In general, do we expect the performance of a flexible statistical learning method to perform better or worse than an inflexible method when:   The number of predictors $p$ is extremely large, and the number of observations $n$ is small?   The variance of the error terms, i.e. $σ^2 = \text{Var}(e)$, is extremely high?   I think for (1), when $n$ is small, inflexible models are better (not sure). For (2), I don't know which model is (relatively) better.


How can I set sources.list to have the latest stable version?

Is it possible to set the sources.list file to automatically have the latest stable version of the operating system, like in Debian when you set "stable"?


Does the definition of factorial fail for $0!$

How does one understand $0!=1$. Is it purely a theoretical value for convenience? as the definition of factorial i.e., $n!=n\times(n-1)\times(n-2)\times...1 $ actually fails here. How can it be logically understood by the definition of factorial.


Would just like a sanity check.   I don't see the necessity of the locally path connected condition on $A$. The proof that $\tilde{A}$ is a covering space seems straightforward.  We use the path-connectedness of $A$ obviously to talk about a single $\pi_1$. For the other part, take $i$ as the inclusion map of $A$ in $X$.  If we have $[f]\in p_*(\pi_1(\tilde{A}))$, we have a homotopy to the constant map already since $\tilde{X}$ is simply connected, so $[f] \in \ker(i_*)$.  For any $[f] \in \ker(i_*)$, by Proposition 1.31 the image of $f$ in $X$ lifts to some loop $\tilde{f}$ in $\tilde{X}$ with basepoint in $\tilde{A}$.  Here the path connectedness of $\tilde{A}$ is useful.  Then $[p(\tilde{f})] = [f]$, so $[f] \in p_*(\pi_1(\tilde{A}))$.  And that should be it?


I have some different configurations and I need to get the combination of them all to run a python script  versions = ['lg', 'sm'] start_time = ['0', '1'] end_time = ['2']   What I want is snakemake to do this for me:  python my_script.py -v lg -s 0 -e 2 > lg_0_2.out python my_script.py -v lg -s 1 -e 2 > lg_1_2.out python my_script.py -v sm -s 0 -e 2 > sm_0_2.out python my_script.py -v sm -s 1 -e 2 > sm_1_2.out   but I can't seem to figure out how to do this in snakemake. Any ideas?


Why can I change the value of a const char* variable?

Why does the following code in C work?  const char* str = NULL; str = "test"; str = "test2";   Since str is a pointer to a constant character, why are we allowed to assign it different string literals?  Further, how can we protect str from being modified?  It seems like this could be a problem if, for example, we later assigned str to a longer string which ended up writing over another portion of memory.  I should add that in my test, I printed out the memory address of str before and after each of my assignments and it never changed.  So, although str is a pointer to a const char, the memory is actually being modified.  I wondered if perhaps this is a legacy issue with C?


Is the Earth orbiting an 'illusory' Sun, owing to the 'speed' of gravity?

We see the Sun about eight minutes after light left it. Presumably this means we are also experiencing the Sun's gravity 8 minutes after it 'left' the Sun.  So are we orbiting around the Sun we can see or around the Sun's actual position?


Deducing a $\cos (kx)$ summation from the $e^{ikx}$ summation

I'm trying to solve    So far I've done the first part, evaluating the summation ;  where a is just n. I'm not sure where to go from here or what it even means deduce the second summation. I understand that the summation of simply $$\sum\limits_{k=0}^n\cos(kx)$$ is derived from looking at the real part of  $$\sum_{k=0}^n{\rm e}^{ikx} $$I'm guessing they want me to see how the second summation in the question is defined by 'playing around' with the original?


How do I compute the principal values of these complex numbers

How do I compute the principal value of a these complex numbers? I have 2 examples I'm not sure how to calculate One being $$\frac{1}{(1+i)^i}$$ the other is $$(-1+i\sqrt{3})^{1+i}$$ Can anyone help please? Anything appreciated


What is the control qubit in this 1D ladder of controlled Z gates?

In the picture above, the last layer with dot-shape, is called 1D ladder of controlled Z gates. It is stated in  to show the barren plateau issue. I want to know which is the control qubit, the higher one or the lower one?


Why Blender Rendering and Previewing Wrong Colors in Video Editor?

I'm quite new in Blender and I have encountered a problem while I was editing a video with Blender Video Editor. Blender makes the colors of my video worse and wrong. Before rendering the video I didn't notice that, but after rendering there was a remarkable difference between the original and rendered colors. I tried some suggestions given on the internet but they didn't work, anything didn't change in both preview and render. I will give an instance here:    In the image above, in comparison to the real one, Blender rendered video has completely wrong colors. It makes my video white to gray. As I mentioned, it is not only happening in the render section, also occurs in the video preview. So while editing the video I can see the difference. When you once noticed that you cannot prevent looking for the wrong colors and it became really terrible situation for me. I have already tried to change my output settings, I tried nearly all the options about video. Also, I tried rendering it as an image in different image formats. But it still occurs and nothing is changing. Do you have any other suggestions about this problem? What are your thoughts about it?


Variable inside thread is null at some point

I have an ArrayList that I am accessing in a Thread inside onStart method in JavaFX. When I am trying to access the ArrayList from another Thread again in a method that is triggered by a MenuItem it's null and I can't understand why.  Sample program:  package sample;  import javafx.application.Application; import javafx.event.ActionEvent; import javafx.fxml.FXML; import javafx.fxml.FXMLLoader; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.stage.Stage;  import java.util.ArrayList;  public class Main extends Application {      private ArrayList<Integer> testArray;     private Thread t;      @Override     public void start(Stage primaryStage) throws Exception{         FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("sample.fxml"));         fxmlLoader.setController(new Main());         Parent root = (Parent)fxmlLoader.load();         primaryStage.setTitle("Hello World");         primaryStage.setScene(new Scene(root, 300, 275));         primaryStage.show();          testArray = new ArrayList<>();         testArray.add(10);         t = new Thread(() -> {             System.out.println("Test number is "+testArray.get(0));         });          t.start();     }      @FXML     public void menuItemActionMethod(ActionEvent event) {         Thread t2t = new Thread(() -> {             System.out.println("Test number is "+testArray.get(0));         });          t2t.start();     }       public static void main(String[] args) {         launch(args);     } }   sample.fxml  <?xml version="1.0" encoding="UTF-8"?>  <?import javafx.scene.control.*?> <?import java.lang.*?> <?import javafx.scene.layout.*?> <?import javafx.geometry.Insets?> <?import javafx.scene.layout.GridPane?> <?import javafx.scene.control.Button?> <?import javafx.scene.control.Label?>   <GridPane alignment="center" hgap="10" vgap="10" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8">    <columnConstraints>       <ColumnConstraints />    </columnConstraints>    <rowConstraints>       <RowConstraints />    </rowConstraints>    <children>       <Pane prefHeight="200.0" prefWidth="200.0">          <children>             <MenuBar>               <menus>                 <Menu mnemonicParsing="false" text="File">                   <items>                     <MenuItem mnemonicParsing="false" text="Close" />                   </items>                 </Menu>                 <Menu mnemonicParsing="false" text="Edit">                   <items>                     <MenuItem mnemonicParsing="false" onAction="#menuItemActionMethod" text="Delete" />                   </items>                 </Menu>                 <Menu mnemonicParsing="false" text="Help">                   <items>                     <MenuItem mnemonicParsing="false" text="About" />                   </items>                 </Menu>               </menus>             </MenuBar>          </children>       </Pane>    </children> </GridPane>   The output is the following:  Test number is 10 Exception in thread "Thread-5" java.lang.NullPointerException     at sample.Main.lambda$menuItemActionMethod$1(Main.java:39)     at java.lang.Thread.run(Thread.java:745)   I have attached menuItemActionMethod in FXML in Delete MenuItem. Running the sample and accessing Delete in the application should run the Method.


How do I delete all empty directories in a directory from the command line?

Say I have a directory named foo/. This folder includes subdirectories. How can I delete all the empty directories in one command?


Can somebody explain to me Cantor's diagonalization argument?

Like..can somebody explain this to me as if I was a 5 year old or something? Every explanation I read repeats the same exact thing that I simply do not understand. This is what my book says:  "The real numbers between 0 and 1 can be listed in some order, say, $r_1, r_2, r_3, ...$Let the decimal representation of these real numbers be   $r_1 = 0.d_{11}$$d_{12}$$d_{13}$$d_{14}$... $r_2 = 0.d_{21}$$d_{22}$$d_{23}$$d_{24}$... $r_3 = 0.d_{31}$$d_{32}$$d_{33}$$d_{34}$... $r_4 = 0.d_{41}$$d_{42}$$d_{43}$$d_{44}$...  Where $d_{ij}$ is an element of {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}. Then for a new real number with decimal expansion r = $d_{1}$$d_{2}$$d_{3}$$d_{4}$... where the decimal digits are determined by the following rule:  $d_{i}$ = {4 if $d_{ii}$ does not equal 4, 5 if $d_{ii}$ = 4}.  And I'm sorry but..what? What in the world is any of this trying to get at? What is the whole r1, r2, r3 thing even mean? Why do we have to create a "new real number"? What is the point? Why? Why are we doing any of this? I don't understand any of the process behind it and I don't understand how it all leads to the conclusion that the real numbers are uncountable. I have absolutely no idea what is going on here.


Numbering each equation, and, have a large curly brace around them

I can create a curly brace around a set of equations (aligned at two positions!) using aligned:  \begin{equation} \left\{ \begin{aligned}[2]     &\rho   &&= \frac{\e^{- \lambda_2 \H/k}}{\e^{1 + \lambda_1/k}}     \\     &\Tr{\rho} &&= 1      \\     &\Tr{\rho \H} &&= \braket{E}  \end{aligned} \right. \end{equation}     Or, I can create a set of equations where every line has a number, but no curly brace, using alignat:  \begin{alignat}{2}     &\rho   &&= \frac{\e^{- \lambda_2 \H/k}}{\e^{1 + \lambda_1/k}}     \\     &\Tr{\rho} &&= 1      \\     &\Tr{\rho \H} &&= \braket{E}  \end{alignat}     How can I create a set of equations (still aligned at two positions) that all have numbers (like in the second example), and they also have a curly brace (like in the first example)??


How to find the number of automorphisms on $\mathbb Z_2\times \mathbb Z_4$

Well, I was trying find out the number of group homomorphisms from $U(20)$ onto $U(15)$ which I reduce to the problem of finding the number of automorphisms for $\mathbb Z_2\times \mathbb Z_4$. But don't know how shall I proceed.   Any help will be appreciated.


Sci-fi series where humans are reduced to a mathematical pattern and sent to another planet

I am searching for a book series ... people were transfer from Earth by way of being reduced to a mathematical pattern and recreated on the other end.  Some people appear as "wizards" on the receiving planet, turns out they just had a connection to the computer and the computer was materializing the object by using the "object" formula and using energy to mater transfer from an energy universe.  I think there were multiple books in the series and I seem to remember that the main character may have undergone a magical sex change at some point.


Why doesn't the comment hint disappear in IE10, when using a touch device?

When you go to add a comment, the hint doesn't disappear if you're using touch gestures tap the "add comment" link. Not sure why this isn't using HTML5 hints instead, as that'd work (assuming that you're up to some browser sniffery).


Error occurred in deployment step 'Recycle IIS Application Pool': Object reference not set to an instance of an object

I get this error in the deployment step of a share-point farm based project. Most of the suggested solutions on the net are a simple Visual Studio re-start, however, a simple VS restart won't fix this.   Any ideas on what might be causing this?


is there any way to recover from a ORA-00257: archiver error?  The archiver disks broke, but DB continue operation 2 sequences more. I have no access to the archiver disk anymore   SQL> archive log list Database log mode              Archive Mode Automatic archival             Enabled Archive destination            /drbak/arch/terdb/pro/va Oldest online log sequence     46612 Next log sequence to archive   46612 Current log sequence           46614     SQL> show parameter db_recovery_file_dest; NAME                                 TYPE        VALUE ------------------------------------ ----------- ------------------------------ db_recovery_file_dest                string db_recovery_file_dest_size           big integer 50000M   SQL> SELECT * FROM V$RECOVERY_FILE_DEST; NAME -------------------------------------------------------------------------------- SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES ----------- ---------- ----------------- ---------------   5.2429E+10          0                 0               0


How to remove a vector QgsVectorLayer from QGIS python plugin

I managed to add QgsVectorLayer in QGIS through a python plugin, for example:  vl = self.iface.addVectorLayer(uri.uri(), layerName, self.dbConn.getProviderName())   But how can I remove it?


Hyper-V File Server Clustering - at my wit’s end

I am at my wit’s end with File Server clustering under Hyper-V. I am hoping that someone might be able to help me figure out this Gordian Knot of a technology that seems to have dead ends (like forcing cluster VMs to use iSCSI drives where normally-attached VHDX drives could suffice) where logic and reason would normally provide a logical solution.  My hardware:  I will be running three servers (in the end), but right now everything is taking place on one server. One of the secondary servers will exist purely as a witness/quorum, and another slightly more powerful one will be acting as an emergency backup (with additional storage, just not redundant) to hold the secondary AD VM and the other halves of a set of clustered VMs: the SQL VM and the file system VM. Please note, these each are the depreciated nodes of a cluster, the main nodes will be on the most powerful first machine.  My heavy lifter is a machine that also contains all of the truly redundant storage on the network. If this gives anyone the heebie-geebies, too bad. It has a 6TB (usable) RAID-10 array, and will (in the end) hold the primary nodes of both aforementioned clusters, but is right now holding all VMs. This is, right now: DC01, DC02, SQL01, SQL02, FS01 & FS02. Eventually, I will be adding additional VMs to handle Exchange, Sharepoint and Lync, but only to this main server (the secondary server won't be able to handle more than three or four VMs, so why burden it? The AD, SQL & FS VMs are the most critical for the business).  If anyone is now saying, “wait, what about a SAN or a NAS for the file servers?”, well too bad. What exists on the main machine is what I have to deal with.  I followed , but I seem to be unable to get things to work. In order to make the file server truly redundant, I cannot trust any one machine to hold the only data store on the network. Therefore, I have created a set of iSCSI drives on the VM-host of the main machine, and attached one to each file server VM. The end result is that I want my FS01 to sit on the heavy lifter, along with its iSCSI “drive”, and FS02 will sit on the secondary machine with its own iSCSI “drive” there as well. That is, neither iSCSI drive will end up sitting on the same machine as the other. As such, the clustered FS will utterly duplicate the contents of the iSCSI drives between each other, so that if one physical machine (or the FS VM) goes toes-up, the other has got a full copy of the data on its own iSCSI drive.  My problem occurs when I try to apply the file server role within the failover cluster manager. Actually, it is even before that -- it occurs when adding the disks. Since I have added each disk preferentially to a specific VM (by limiting the initiator by DNS hostname, and by adding two-way CHAP authentication), this forces each VM to be in control of its own iSCSI disk. However, when I try to add the disks to the Disks section of Storage within Failover Cluster Manager, the entire process fails for a random disk of the pair. That is, one will get online, but the other will remain offline because it does not have the correct “owner node”. I mean, really -- WTF? Of course it doesn’t have the right owner node, both drives are showing the same node name!! I cannot seem to have one drive show up with one node name as owner, and the other drive show up with the other node name as owner. And because both drives are not “online”, I cannot create a pool to apply to a cluster role. Talk about getting stuck between a rock and a hard place!  I’ve got more to add, but my work is closing for the day and I have to wrap things up. I will try to add more tomorrow morning when I get in.  My main objective is to have a file server VM on each machine, the storage on each machine, but a transparent failover in case one physical machine fails. Essentially, a failover FS that doesn’t care which machine fails -- the storage contents are replicated equally on each machine. Am I even heading in the right direction?


upgrade iphone 4 to latest iOS as 9 or 10

Is it possible to upgrade iPhone 4 iOS to 9 or 10 using jail break approach?  Main purpose to install apps which require latest iOS. So is there any method even through security bypass?  Rather throwing the older phone any possibility by experimenting?


Definition of Generating Function and Momentum

At page 44 of Modern Quantum Mechanics by Sakurai it's stated that given the following formula for the translation operator ($T$): $$T(d\vec{x}')=1-i\vec{K} \cdot d\vec{x}'$$ (where for some unknown reason $1$ represents the identity matrix $\mathbb{I}$) we can identify $\vec{K}$ with the momentum operator $\vec{p}$. It's stated that we can operate this identification because in classical mechanics the momentum is the generator of translations. My question is: is there a straightforward way to define what a generating function (for a transformation) is? And then how can we easily show that the momentum is the generating function of translation in both the classical and quantum mechanical scenario? EDIT: just to clarify: I know that we choose this particular formula for the translation operator $T$ because we can prove that this form has all the proprieties that we want and also because this formula is made in such a way that we can interprete $\vec{K}$ as the generator of translation. My problem regards the definition of generating function and the application of this definition to the context of momentum. Is there a way to define what a generating function is in an intuitive manner?


How to ssh to a remote host using from within a bash script function?

I'm new to bash scripting. I want to call a function from my script which will ssh into a remote computer (on my LAN) and run a command.  So far I have:   function run_ssh_command {     target_ip=$1     username=$2     password=$3     cmd=$4      ssh -l ${username} ${target_ip} ${password} }   I invoke the function from the terminal as follows:  (Note: I give script_name, username and password "real" values when executing the function on my machine. 'ifconfig' is the command I want to run on the remote machine.)  source script_name.sh; run_ssh_command 192.168.X.Y username password ifconfig   Result: Running the above command will get me to the password prompt part of the login process (e.g. same as ssh username@192.168.X.Y)   Question: I want to handle the password entry automatically using the script. What is the "best" way to go about this, in general?


I'm working on a project in Visual Studio where I need to embed 2 DLLs. So far, I've been referencing those DLLs, but then I cannot use them without actually having the files in the same folder as my EXE. Obviously, I want my users to only need the EXE to use them, without having to download the DLLs as well. The thing I tried to far is following this tutorial:  But this is only for one file and the tutorial sadly didn't work for me.    What can I do? Thanks!  EDIT: The project was built by Windows Forms Application.


I mean come on guys, do we really need ?  It  and I see no point in having it.  Does anyone agree?    hold on, why am I thinking it does exist?   First of all, someone is suggesting an edit on it! If it didn't exist then a suggested edit couldn't be proposed on it?   Secondly,     How does it not exist while it does? I can't understand that...  It may be removed after 24 hrs if not used etc but it does in fact exist right now.


Visual Studio Snippet - Capitalize first letter

I'm trying to create a snippet for a C# Property with the method NotifyPropertyChanged(). The result of the snippet should be like this: private int _myProperty;      public int MyProperty     {         get => _myProperty;         set         {             if (_myProperty == value) return;             _myProperty = value;             NotifyPropertyChanged(nameof(MyProperty));         }     }  How do I change the case of the first letter of _MyProperty to be _myProperty? See below my current snippet: <Snippet>   <Declarations>     <Literal>       <ID>type</ID>       <ToolTip>Property type</ToolTip>       <Default>int</Default>     </Literal>     <Literal>       <ID>property</ID>       <ToolTip>Property name</ToolTip>       <Default>MyProperty</Default>     </Literal>   </Declarations>   <Code Language="csharp">     <![CDATA[private $type$ _$property$;  public $type$ $property$ {     get => _$property$;     set      {          if (_$property$==value) return;         _$property$ = value;         NotifyPropertyChanged(nameof($property$));               } } $end$]]>   </Code> </Snippet>


Python - Memoization with Decorators - dict vs scalar - understandin nonlocal mem

I try to understand memorization, particularly regarding nonlocal mem with the code below: def mem_last(f):     mem = 0     def helper(x):         print("mem = ", mem)         mem = f(x + mem)         return mem     return helper  def mem_last1(f):     mem = {"0": 0}     def helper(x):         print("mem = ", mem)         mem["0"] = f(x + mem["0"])         return mem["0"]     return helper      def f(x):     print("x = ", x)     return x  f = mem_last(f)  #f = mem_last1(f)  print(f(0))  When I use f = mem_last(f), where mem is a scalar, there is an error: py mem.py  Traceback (most recent call last):   File "mem.py", line 15, in <module>     print(f(0))   File "mem.py", line 4, in helper     print("mem = ", mem) UnboundLocalError: local variable 'mem' referenced before assignment  If I use f = mem_last1(f), where mem is a dict, there is no error and it works well. Please explain why there is a difference between a dict and a scalar var. Thank you very much. PS: I am using 3.7.7 64 bit on Windows 10. I have read the thread you provide and I fix it by add a line "nonlocal mem" before 'print("mem = ", mem)'. However, my question is why I do not need to add line "nonlocal mem" when mem is a dict or a list, and no error occur. So why python treats scalar different from dict or list?


How can I pass a variable to javascript from a preprocess function?

How do I pass $variables['is_front'] from template_preprocess_page() to a jquery script in Drupal8?


In minecraftskins.com my skin wont change

I am keep trying and trying to change my skin and i dont  want to buy mine craft again. Mine craft works fine but  just wont let me get a new skin.This is the first time it did this.I am on pc ASUS


Why use a certain measure of forecast error (e.g. MAD) as opposed to another (e.g. MSE)?

MAD = Mean Absolute Deviation MSE = Mean Squared Error  I've seen suggestions from various places that MSE is used despite some undesirable qualities (e.g. , which states on p8 "It is commonly believed that MAD is a better criterion than MSE. However, mathematically MSE is more convenient than MAD.")  Is there more to it than that? Is there a paper that thoroughly analyzes the situations in which various methods of measuring forecast error are more/less appropriate? My google searches haven't revealed anything.   A similar question to this was asked at , and the user was asked to post on stats.stackexchange.com, but I don't think they ever did.


How does one show that $$\sum_{k=0}^{n}\binom{n+k}{k}\frac{1}{2^k}=2^{n}$$ for each nonnegative integer $n$?  I tried using the  but I guess I am applying it incorrectly. With the snake oil technique we have $$F(x)= \sum_{n=0}^{\infty}\left\{\sum_{k=0}^{n}\binom{n+k}{k}\frac{1}{2^k}\right\}x^{n}.$$ I think I have to interchage the summation and do something. But I am not quite comfortable in interchanging the summation. Like after interchaging the summation will $$F(x)=\sum_{k=0}^{n}\sum_{n=0}^{\infty}\binom{n+k}{k}\frac{1}{2^k}x^{n}?$$ Even if I continue with this I am unable to get the correct answer.  How does one prove this using the Snake oil technique?  A combinatorial proof is also welcome, as are other kinds of proofs.


A maximal ideal is not contained in the union of all the other maximals ideals

Let $A$ be a commutative ring with unit and $\mathcal{M}$ the set of all the maximal ideals of $A$.   I need to prove that $$\mathfrak{m}\not \subseteq \bigcup_{\mathfrak{a}\in \mathcal{M}\setminus \{\mathfrak{m}\}} \mathfrak{a}$$ for every $\mathfrak{m}\in \mathcal{M}$.  I get to this statement trying to prove a remark on Neukirch's Algebraic Number Theory that says that if $\mathcal{F}$ is a set of prime ideals of $A$ omitting only finitely many primes, then if $S=(\cup_{\mathfrak{p}\in \mathcal{F}}\mathfrak{p})^c$ we have that the prime ideals of $AS^{-1}$ are of the form $\mathfrak{q}S^{-1}$ where $\mathfrak{q}$ is a prime ideal of $A$ contained in a prime ideal of $\mathcal{F}$ [Page 66]. (I was able to prove that the statement above is equivalent to this)


I would like to know if there are showers in Dubai terminal 3 transit area. As we only have an hour half between flights


How can I create a yum repository from downloaded packages?

How can one setup local yum repository using the downloaded rpm packages?  This is a note to self. I am not sure if this good way, but I am trying nevertheless.


I have seen at many places that $A=\mathbb{R}^n-\{a\}$ for some $a\in \mathbb{R}^n$ is path connected. But how do we prove it? I understand that we have to show that there is a continuous map $\gamma:I\rightarrow A$ between any 2 points of $a_1, a_2\in A$ such that $\gamma(0)=a_1$ and $\gamma(1)=a_2$. $(I=[0,1])$ But I have no idea on finding such $\gamma$. Any hints?


Rename Site Collection SharePoint Online Using PowerShell

How can I rename a site collection on SharePoint online?  For example, I want to change the URL from /sites/foo to /sites/foobar  Is it possible using PowerShell?


Automatically import ICS to Google Calendar in Chrome on Linux

This questions has been asked and answered before (e.g., ) but this doesn't work anymore, at least for me.  At some websites you can download ICS files for events. Is there a way in which these files are automatically imported to my Google Calendar in a single click, without having to download, go to Calendar, and import? I use Chromium (Chrome on Linux); at Settings -> Content Settings -> Protocol handlers I have enabled calendar.google.com for type "webcal". However, when I click on an ICS link my browser will just download the file.  A  was asked before, but all the answers provided there only work on Firefox and/or Windows, while I use Chrome on Linux. Moreover, most answers seems to suggest I have to associate Google Calendar with Webcal type events, but as explained above, that is already the case in my setup.


Unable to mount NTFS external hard drive

I am having trouble mounting my external hard drive, every time I try and do so I get the following message:    "Error mounting /dev/sdb1 at /media/fuzzy27/My Book: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sdb1" "/media/fuzzy27/My Book"' exited with non-zero exit status 13: $MFTMirr does not match $MFT (record 0). Failed to mount '/dev/sdb1': Input/output error NTFS is either inconsistent, or there is a hardware fault, or it's a SoftRAID/FakeRAID hardware. In the first case run chkdsk /f on Windows then reboot into Windows twice. The usage of the /f parameter is very important! If the device is a SoftRAID/FakeRAID then first activate it and mount a different device under the /dev/mapper/ directory, (e.g. /dev/mapper/nvidia_eahaabcc1). Please see the 'dmraid' documentation for more details."   How do I go about or what do I need to do in order to fix this error/problem without losing any of the data on my hard drive?  Is there no other way of fixing it without having to reinstall windows or finding someone using windows?