Import Excel Sheet and append items to SharePoint list

I have Excel sheet and existing SharePoint list (Import spredsheet app) on my SharePoint server.   We need to append the data from the new excel sheets to the existing lists items of the SharePoint list.   How should I go about creating a solution for this?  Let's say I have 100 records in one excel file. I have imported that file to spredsheet app. It works fine for first time. Now I have 100 records in that list. Now user has added 10 more records in that excel sheet. That 10 records I have to appends to the list which is created very first time.


I have difficulties to include more than 1 pdf image in my latex file. My code is as follow :  \documentclass[a4paper,13pt]{article} \usepackage[english]{babel} \usepackage[utf8]{inputenc} \usepackage{caption} \usepackage{csquotes} \usepackage{graphicx} \linespread{1} \usepackage{fancyhdr} \pagestyle{fancy} \lhead{XXX} \rfoot{Page \thepage} \begin{document}  content   \begin{figure}[hp] \centering \includegraphics[width=65mm, height=65mm]{\xxx\fig1.pdf} \caption{}\label{fig1} \end{figure}  text  \begin{figure}[hp] \centering \includegraphics[width=65mm, height=65mm]{\xxx\fig2.pdf} \caption{}\label{fig2} \end{figure}  text  …  \end{document}   The problem is that the fig1.pdf is shown, but fig2.pdf is shown at the end of my document on the last page, and not after the text that comes after fig1.pdf  Thanks for your help :)


Ubuntu 13.10 Macbook Air Mavericks Parallels 9 Black Screen

I can install Ubuntu 13.10 in parallels ok and then log in.  Problem is Ubuntu does an update and I get black screen / desktop such that I can't see any app windows that I open.  I've tried a few of the other suggestions and they don't work for me.


If $0<r<1$ show that $r^n$ goes to $0$ as $n$ goes to 1.

If $0 < r < 1$ show that $r^n$ goes to $0$ as $n \to 1$.  If $|r| < 1$ then  $r^2  < r$  similarly $r^4 < r^3 < r^2 < r$  so $r^n$ as $n \to +\infty$ will be equal to $1$  how can i finish this problem?


From point 2 I have marked , If the 4 persons are sitting in a round table, then they can be shifted four times. You can see by looking at figure a,b,c and d. Now , I understand that by making ABCD sit in a row and changing their positions . It looks like their arrangements are different . Like CDAB , BCDA but also they have written only 4 orders for this. In real , isn’t it that there will be total 4! Arrangements for it and not 4. Also , from the round table perspective. If you keeping Changing the angle you’re looking at the ABCD. You can see different arrangements but they are also same right. So their total arrangements should be equal to 1. I didn’t understand for 2 , No of linear arrangements is n? I think it should be n!. Also , how did we get 1/n in 4 and n! For 3.


What happens if too many investors want to purchase a given ETF?

I wonder what happens if too many investors want to purchase a given ETF. On one side, the ETF share price is  the sum of the ETF holdings divided by the number of ETF shares, since deviations are corrected by  (). On the other side, unless more shares are issued, the price should raise. Does this mean the ETF managers issue more shares if too many investors want to purchase a given ETF?


I can see it in my lyx editor there is number in my section   but when I render the pdf there is no number in my section   anyone can help me? I think there is a problem with my preamble but I don't know which one because when I delete all my preamble the number is shown  It's seems the problem is with \usepackage{titlesec}  what make me confuse is   it only happen in my computer,   when I try to render the same file in my friend's computer the number is shown  my latex preamble  %% \renewcommand{\chapter}[1]{\chapter[#1]{\centering #1}} \usepackage{titlesec} \usepackage{graphicx} \usepackage{pdflscape} \usepackage{colortbl} \usepackage{amsmath} \usepackage{color} \usepackage{tocbibind} \usepackage{url} \usepackage[titletoc]{appendix} \definecolor{lineno}{rgb}{0.5,0.5,0.5} \definecolor{bcolor}{rgb}{0.98,0.98,0.98} \definecolor{code}{rgb}{0,0.1,0.6} \definecolor{codesty}{rgb}{0.7,0.1,0.1} \definecolor{commandsty}{rgb}{0.1,0.5,0.0} \definecolor{keywordsty}{rgb}{0.4,0.0,0.4} \definecolor{stringsty}{rgb}{1.0,0.5,0.0} \titleformat{\chapter}[display]   {\normalfont\huge\bfseries\centering}{\chaptertitlename\thechapter}{20pt}{\Huge} \renewcommand{\contentsname}{Table of Contents} \setlength{\headheight}{15pt} \pagestyle{fancy} \renewcommand{\chaptermark}[1]{\markboth{Chapter  \thechapter.\ #1}{}} \renewcommand{\sectionmark}[1]{\markright{\thesection.\ #1}{}}  \fancyhf{} \fancyhead[LE,RO]{\thepage} \fancyhead[RE]{\textit{\nouppercase{\leftmark}}} \fancyhead[LO]{\textit{\nouppercase{\rightmark}}}  \fancypagestyle{plain}{ % \fancyhf{} % remove everything \fancyfoot[C]{\thepage} \renewcommand{\headrulewidth}{0pt} % remove lines as well \renewcommand{\footrulewidth}{0pt}} \usepackage[margin=10pt,font=small,labelfont=bf,labelsep=endash]{caption}


A domain controller in Azure ends up public on the Internet with no firewall - is it compromised?

I'm helping a customer stand up an Azure environment and they decided to stand up a server (DC) on their own without asking for help.   The only access method is supposed to be IPsec, but they forgot to disable the Azure-assigned public IP while standing up the server, so their DC ended up public on the Internet with no firewall whatsoever - including Windows Firewall (disabled while troubleshooting other networking/replication issues).  The symptoms that led to this discovery were random account lockouts originating from Chinese IP addresses in the Security log on the domain controller.  I've since fixed the situation by re-enabling Windows Firewall, creating an Azure security group, and deleting the public IP so that it's secured by IPsec. I also recommended they just decommission that server entirely and spin up a new one.  But I'm still curious - what attack surfaces are there for a domain controller that has no firewall whatsoever on the open Internet? If they decide not to decommission it, is there anything to look for in terms of compromise?


I am trying to obtain the full date (created or modified) of a particular file for passing to another program. I have tried variations of options with the ls command but none provide a full date for files less than 6 months old and I have limit usage of the options. When I try certain options I have seen trying to research this I get the following message:  usage: ls [-1ACFHLNRabcdefgilmnopqrstuxEUX] [File...]   None of which seems to provide what I needs as far as I can tell so I tried to use the stat command but it is not available to me.  I am using the Korn shell on AIX 5.3 which has limited commands available, can anyone suggest another way that I might be able to obtain a file's created or modified date as a full date (either dd/mm/yyyy or yyyy/mm/dd).


I want to make a box like this chat bubble

I have typeset some chat app messages, like Facebook or QQ, but iwant some beautiful chat bubbles like this, could someone use tikz or tcolorbox make it


IMO 2005 No 4. : All integers relatively prime to terms of infinite sequence

Here's No. 4 from the 2005 IMO.   Q: Determine all positive integers relatively prime to all the terms of the infinite sequence $$a_n=2^n+3^n+6^n-1,  n\geq1$$   I found the , but I'm failing to understand it.  It reads:   Trivially, $a_2 = 48$ is divisible by 2 and 3. Okay, I get this, assuming they just picked n=2 since it's a small number.  Let therefore p > 3 be a prime number. Wait what? What does p represent - does it represent n, or n+2? And from the previous step, how can we assume this?   Then $6a_{p−2} = 3·2^{p−1} + 2·3^{p−1} + 6^{p−1} −6 ≡ 3 + 2 + 1−6 ≡ 0 (\mathsf {mod \ p})$. Alone, I think I understand this line, although why multiply by 6? Is $6a_{p-2}$, or any term you would place instead, congruent to $\mathsf {0(mod \ p)}$ since that fulfills the definition of a prime number?   And so the only such number is 1. Only such number refers to what number? Proved. So... what would be the answer?  Thank you for helping!


How to remove icon of uninstalled program previously installed via Wine

I recently uninstalled MS Office 2010 on PlayOnLinux and then reinstalled it. However I found that the previous icon is still in the menu as it is shown here:    The same problem also happens with Powerpoint and excel. If I click the previous one, PlayOnLinux will tell me that this app is crashed, however I cound't find these apps inside the PlayOnLinux either.  Any idea?


Hi I have to fetch current users created records in a report. For that I have a field userid__c in a custom object which is storing user SF id (18 digit) and when I am checking userid__c=$user.id it is always returning false but when i am changing the 18 digit to 15 digit id then it is returning true. How can i fix this?


A question on combinatorics: if $p + q + r = 10$, find the number of possible combinations where the condition holds true.

If $ p + q + r = 10 $, find the number of possible combinations satisfying the equation. ( $p,q,r ≥ 0$)    PS - As suggested by Brian Moehring, I used the 'stars and bars' method.   We need the sum as $10$. We have to add $1$ ten times, to get 10. If we add two bars i.e., we are dividing them into p, q and r. So now in total there are $10 \ 1's$ and $2$ bars. We have to find the number of ways to arrange those $2$ bars in $12$ places. Hence, there are $\binom{12}{2}$ ways of selecting $p,\ q$ and $r$ to satisfy the equation.


This is my website: Aviene.pl. I have scanned it by the website valuation tool. My website is 2.9 years old (this is what that tool shows, and that's the truth) but unfortunately every tool shows that my PageRank is 0 or "no data". What should I do to make PageRank working on my website? Should I include a special script to make it work or maybe a file with some code on my server? Please help, I can`t find anything about this situation.


Prove that, there exists no continuous function $f:\mathbb R\rightarrow\mathbb R$ with $f=\chi_{[0,1]}$ almost everywhere.$\textbf(Make\ sure\ that\ your\ proof\ is\ completely\ rigorous)$.   I don't know, which property to use. (It is not allowed to show it with $\epsilon-\delta-criterion$, our last topics were: Lp-Spaces, Radon-Nikodym Theorem, Riesz Representation Theorem,Lipschitz-Functions, Product measures, Fubini Theorem)  but i can't find anything to do with continuity, which of them could be useful ?


Why is $X^4-16X^2+4$ irreducible in $\mathbb{Q}[X]$?

Determine whether $X^4-16X^2+4$ is irreducible in $\mathbb{Q}[X]$.  To solve this problem, I reasoned that since $X^4-16X^2+4$ has no rational roots hence irreducible.  But there is a hint to this question that uses different approach: Try supposing it is reducible, then it must factor into a product of two monic quadratic polynomials with integer coefficients. Then show that it is impossible, then conclude the original polynomial is irreducible.  My questions regarding the hints: 1. Why can't we just show that since $X^4-16X^2+4$ has no rational roots hence irreducible? 2. Why do we have to factorise into a product of two monic quadratic polynomials with integer coefficients? Why monic? And why can't we factorise into polynomial with degree 1 and 3? Also, lastly why the coefficients have to be integers?  Thank you for any explanations!    Edit: Thanks for all the answers.  I saw that Second Gauss Lemma is used. But I only learned the first one in class. Which is: Let $R$ be a Unique Facorisation Domain. If $f,g\in\mathbb{R}[X]$ are primitive, then so too is their product $fg$.  Is it inevitable to use Second Gauss Lemma? Is there any other way around?


How to run a command that requires sudo at login

I made a script that controls my system LEDs and it works great.  I saved it to /usr/local/bin/led-pattern and ran sudo chmod a+x /usr/local/bin/led-pattern so its executable simply by entering the command led-pattern.  Upon doing so, it asks for an administrative password, and upon entering the password, the script runs as intended.  However, when added to my list of startup applications, it does not run at login, presumably because of the lack of sudo permissions, as all my other startup scripts that I've made work just fine and don't require permission.  How can I make it so that this script runs at startup seamlessly - never asking for any password even though it requires sudo permissions?  Edit: by startup, I mean while it's logging the user on, not while booting up the computer


"Ubuntu One discontinuing" annoying message

Good day, people It's been 8 days since the announced discontinuation of Ubuntu One, which I've never used at all, but I'm still receiving the notice for "June 1st discontinuation" every time I boot up my 12.04. Will that message ever go away?  Thanks.


Can a conformal map be turned into an isometry?

Let $f: (M, g) \to (M, g)$ be a conformal diffeomorphism of the riemannian manifold $(M, g)$, with   $$ g(f(p))(Df(p) \cdot v_1, Df(p) \cdot v_2) = \mu^2(p) g(p)(v_1, v_2), \quad \forall p \in M, \, \forall v_1, v_2 \in T_p M, $$  for a certain function $\mu \in C^{\infty}(M)$. Is it possible to conformally change the metric of $M$ so as to $f$ become an isometry?  Explicitly, does there exist a metric $\tilde{g} = \alpha g$ in $M$ such that   $$\tilde{g}(f(p))(Df(p) \cdot v_1, Df(p) \cdot v_2) = \tilde{g}(p)(v_1, v_2), \quad \forall p \in M, \, \forall v_1, v_2 \in T_p M \, \text{ ?}$$   Plugging $\tilde{g} = \alpha g$ in the above equation, we obtain that $\alpha$ must satisfy  $$ \alpha(p) = \mu^2(p) \alpha(f(p)), \quad \forall p \in M. $$  Can we continue?


Why is the voltage across the inputs of an ideal OP Amp zero?

The property that the voltage across the inputs of an ideal OP Amp is zero cannot be taken as an axiom because it isn't a property you can directly "adjust" (as opposed to say the resistance across the input terminals or the gain). It's a consequence of the properties that you can "adjust", hence it must be derived from these properties. All proofs I've come across essentially prove it like this:  Let the voltage across the input terminals of an ideal OP Amp be \$V_{in}\$, the output voltage be \$V_o\$ and the gain be \$G\$. \$V_o\$ is given by: \$V_o = GV_{in}\$ The voltage across the OP Amp is bounded by the voltage being supplied to it. Let the supplied voltage be \$V_s\$. Then \$-V_s \le GV_{in} \le +V_s \$ The gain is a property than can ideally be fixed to any value, so taking the limit of \$G\$ going to infinity gives: \$ \lim_{G \to \infty} \frac{-V_s}{G} \le V_{in} \le \frac{+V_s}{G} \$ \$\implies 0 \le V_{in} \le 0\$ Hence the voltage across the input terminals of an ideal OP Amp must be zero.  The proof above would only be valid if OP Amps were always linear, which isn't true. If the output is greater in magnitude than the supplied voltage, the OP Amp becomes saturated - the proof doesn't take this into account. In other words, the proof assumes that \$V_o = GV_{in}\$ which is false. The correct equation would be: \$V_o = \begin{cases} GV_{in}, \space -V_{s} \le GV_{in} \le +V_{s} \\ +Vs, \space GV_{in} > V_s \\ -Vs, \space GV_{in} < -V_s \end{cases}\$


I went window-shopping and I was window-shopping

Can you tell me about 2 sentences below. I don't know which one is make sense or both of them are right?   I went window-shopping. I was window-shopping.


I want to scale two layers up by the same amount, using Edit > Transform > Scale.  Can I link the layers so that scaling one of the layers also affects the other by exactly the same amount?


How to set environment variables of parent shell in Python?

I'm trying to modify the environment variables on a parent shell from within Python.  What I've attempted so far hasn't worked:  ~ $ export TESTING=test ~ $ echo $TESTING test ~ $ ~ $ ~ $ python Python 2.7.10 (default, Jun  1 2015, 18:05:38) [GCC 4.9.2] on cygwin Type "help", "copyright", "credits" or "license" for more information. >>> import os >>> os.environ['TESTING'] 'test' >>> os.environ['TESTING'] = 'changed' >>> os.environ['TESTING'] 'changed' >>> quit() ~ $ ~ $ ~ $ echo $TESTING test   That's all I've been able to come up with.  Can it be done?  How do I set environment variables of parent shell in Python?


Why are query results shortened in pgAdmin 1.18.1?

I've recently installed pgAdmin 1.18.1 and noticed a strange thing:  Long json query results are shortened to 256 symbols and then ' (...)' is added.  Could someone help me disable this shortening?


is it possible too have unique workspaces in Ubuntu?  For example:   1st workspace:   Programming launcher icons Programming files on desktop  2nd workspace:   libre office launcher icons words and excel files on desktop    What I want to have is unique launcher icons for every workspace and different files on my desktop for every workspace!   Is it possible?  How can I do it?


Evaluate $\lim_{n\rightarrow\infty} (\sum_{k=1}^{n} (\int_{0}^{\frac{π}{2}}(\sin(x))^{k}dx))$

I have to evaluate the following limit of a sum: $\lim_{n\rightarrow\infty}  (\sum_{k=1}^{n} (\int_{0}^{\frac{π}{2}}(\sin(x))^{k}dx))$. I ended in $\lim_{n\rightarrow\infty}  (\int_{0}^{\frac{π}{2}}(\sum_{k=1}^{n} \frac{(\sin(x))^{n}-sin)}{\sin(x)-1})dx$. From here on however I am unsure if I can introduce the limit under the integral or how to continue.


Do I need to re-check my bags when flying into the US on a transit through Newark Airport?

Travveling with SAS 907 from Oslo, Norway to Newark Terminal B. Transfer to Terminal C and further with United 239 to Nashville. Do I have to pick up the luggage at terminal B and bring it to terminal C?


What is the best way to present rank survey data?

I have a survey data where I've asked a local community to rank 6 different issues they face on a scale of 1 to 6. For example,   Survey_ID Water Power Garbage Road Sewage Security  1         1     3     2       6    5        4  2         3     2     6       4     1       5 ...   Now I want to visualize this in a simple bar chart (or whatever is best) to show how these different issues rank. As an initial attempt I've created faceted bar charts which show how many respondents ranked each issue as 1, 2, 3, 4 etc.    But I don't think this is really understandable to people new to the data. Is there a better way to do this? This is a static chart in R for now but I plan to create an interactive version in d3.


Is it possible to do a bindvalue for the table name? mine doesn't seem to pick it up basically the second 2 binds work fine if I remove the :table and add the tablename instead, but I want to use this for more than one table from the same form.  The field for table on the form is defined from a result of the previous query so the table name appears on the form in a value as $table which displays correctly so this should post the value of $table to the table bind???   try {     $sql = 'UPDATE :table SET                 archive = :archive                 WHERE id = :id';     $s = $pdo->prepare($sql);     $s->bindvalue('table', $_POST['table']);     $s->bindvalue('archive', $_POST['archive']);     $s->bindvalue('id', $_POST['id']);     $s->execute(); }


Is "key" as an adjective, meaning "crucial", standard in American English?

As an adjective, key can mean "Of crucial importance" ().  For example: the key facts are the most important facts, or a key worker is an employee whose role is especially vital.  In British English, key in this sense is every bit as common and well-understood as crucial would be. There are some stock phrases where it's especially familiar, but it's not limited to those; you could put it in front of any noun (say, key elephant) and, with the right context, it would make perfect sense ("the matriarch is the key elephant to protect from poachers").  Many years ago, when I was a rookie, someone much more experienced told me that I shouldn't use key as an adjective because "Americans don't understand it".  I've been carrying that "fact" with me ever since then – and was just about to impart it to someone else the other day, when I paused to wonder whether it's actually true.  I can obviously see that the meaning is listed in American-centric dictionaries (e.g. ), but that doesn't help me understand whether it's a common use or an obscure one.  I can't find anything about it in any online American style guide but, again, that might mean it's completely uncontroversial or it might mean it's utterly obscure.  And the fact the word key has so many different meanings makes it a difficult one just to Google for!  So, can anyone help please?


Inequality for the Expected Value of Product of Independent Matrices

The following comes from page 3 of the paper "Matrix Concentration for Products" found here . Given two independent, complex, square matrices Y and Z: $$ YZ=\mathbb{E}(Y)Z+(Y-\mathbb{E}(Y))Z.$$ I understand that $$ \mathbb{E}((Y-\mathbb{E}(Y))Z|Z)=0. $$ Now, this is called an orthogonality property (Why?) and apparently used to show: $$ \mathbb{E}(\left\| YZ\right\|_2^2) =\mathbb{E}(\left\|(\mathbb{E}(Y))Z\right\|_2^2) + \mathbb{E}(\left\| (Y-\mathbb{E}(Y))Z\right\|_2^2) $$ where $\left\| .\right\|_2$ refers to the Schatten 2-norm or Frobenius-norm. Could someone clarify how exactly this property is used here? I assume the tower property comes into play here but I'm not sure how exactly. Thank you.


How do I fully expand the window showing the running operating system inside VirtualBox?

I'm running Win7 64 bit on VirtualBox and it only takes up half the screen.  How can i expand it further?


Can the Shield spell be used against Shocking Grasp?

A few attacks, such as the Shocking Grasp cantrip, can prevent reactions on a target when they hit it.  A few "defensive reactions", such as the Shield spell (+5 to AC including against attack roll), can prevent an attack from succeeding.  I have recently faced the following scenario : I had an AC of 18, and an opponent attacked me with an equivalent of Shocking Grasp, touching with, I believe, a 21. At that moment, I was not sure if I could use my reaction to cast a Shield to jump my AC to 23 (therefore blocking the attack), or if the attack already prevented me from using Shield.  As far as I know, an attack has three phases (make the roll, determine if it hits, then apply the damage and effects). I would believe that the Shield reaction occurs between phase 2 and phase 3, therefore potentially protecting from an attack like Shocking Grasp, but I could be wrong.


Plug in charger in laptop before plugging in mains outlet

Feel free to delete the question if doesn't fit here.  Somebody told me, that a person should plug the charger in the laptop side first, then in the mains outlet, as if there is a current peak, it is less prone to burn the charger.  My knowledge to the data can't make any sense of this.  Does it make any sense?


I have some auto-generated T-SQL, which is probably valid, but I don't really understand.  ALTER TABLE [dbo].[MyTable] WITH CHECK CHECK CONSTRAINT [My_FORIEGN_KEY];   I know what a foreign key constraint is, but what's the CHECK CHECK?


Variables in String.match Regular Expression

I have the following      EmployeeTable.prototype.xmlToArray = function(xml) {      // Parse the XML string into a XMLDocument     var xmlDoc = new DOMParser().parseFromString(xml, 'text/xml');      var nodes = xmlDoc.getElementsByTagName("employee");     var employees = [];      for (var i = 0; i < nodes.length; i++) {         employee = nodes[i];         var innerHTML = employee.innerHTML;         var name = innerHTML.filterEmployeesXML("name");         console.log(name);     }  };   which calls a function   String.prototype.filterEmployeesXML = function(valToFind) {     var regex = new RegExp(/<name>([^<]*)<\/name>/);     var match = employee.innerHTML.match(regex);     return match[1]; };   However, I want to be able to do this for more than just name, i.e. I want to be able to filterEmployeesXML("jobTitle"), etc. where valToFind is the value to be found in the XML collection.  I've tried to do this using basic string concatenation, though I haven't a clue when it comes to Regex, any pointers?


Restore old tabs in firefox with previous.jsonlz4 and recovery.baklz4 files

On MacOS 10.15 Firefox 80, I want to restore last last lost session tabs (with a large number of tabs). I can successfully make display with the tool "https://www.jeffersonscher.com/ffu/scrounger.html" all the pages links like shown on this screen capture :  But I don't know how to convert this list of links into effective tabs in Firefox 80. I saw that I can save with this tool the file json (compressed or not) like illustrated here :  but I can't use these files to display all the tabs into Firefox again. If someone could help me to make open all the tabs into Firefox of my list displayed with the button "scrounge URL" of this tool ?


Trying to get a spotlight to project an image in Blender 2.80

I'm new to Blender and I want to project an image on a plane from a spotlight but I'm having difficulty.  This  says to find Texture panel for the lamp which I can't find. There is a Texture panel in 2.80 but it doesn't seem connected to the spotlight. I presume these instructions are for 2.79 or earlier.  Can someone direct me to a useful link or at least give a general overview of how to do this in Blender 2.80?


Is there any way of checking the max memory consumption of a code that I run with the command line?

The time command is very useful for checking how much time it takes for a piece of code that I develop to run... However, I'd like to have a way to check the memory consumption of the codes that I develop too, regardless of the language that I use. So, if it's bash, python, or node.js... I'd like to have a way of checking how much RAM memory I used on the code, just so I can get more aware of what I'm doing avoiding memory duplication and stuff like that. Is there any command line that I can use for checking the amount of memory that a script that I create consumes?


Multiple monitors (3) in notebook using HDMI and vga port, with a graphic card only

I have a HP dv9830us laptop. It has a vga-out and a hdmi-out port.  I want to know if it's possible to use 3 devices, each one with different displays, using just one graphic card - NVIDIA GeForce 8600M GS? (Original, vga with an external monitor and hdmi with a full hd tv). Where I can find this kind of information?  If not possible, I would like to know alternatives like:   "Usb" solutions to be possible to connect to the external lcd or to a TV. The TV should be flawless, but the second monitor can have slow response times; (I've found some , do these units really work?) Cheap PCMCIA video cards to be possible to connect to an external monitor, so I would use the hdmi with the tv and this second video card to output to another monitor.   I'm using Windows 7 and Ubuntu 10.04. Is this possible in both systems?


How to proof relationship between inverse covariance matrix and linear regression coefficients?

Edited:  I would like to work out the above relationship, more precisely:     Let $(Y_{1}, ..., Y_{m})$ be a zero-mean vector with covariance matrix   $\Sigma$, and let $S \subset \{1, ..., m\}.$ The best linear predictor   of $Y_{S}$ upon $Y_{\setminus{S}}$, defined as $\tilde{\beta}_{S} =  \Sigma^{-1}_{\setminus{S}, \setminus{S}} \Sigma_{\setminus{S}, S}$, is   a matrix multiple of $\Sigma^{-1}_{\setminus{S}, S}$.   It is assumed that$(Y_{1}, ..., Y_{m})$ is jointly normally distributed.  The above statement seems to imply that there is a number of steps from  $\tilde{\beta} = [X^{T}X]_{\setminus{S}, \setminus{S}}^{-1} [X^{T}Y]_{\setminus{S}, S}$  to   $[X^{T}X]_{\setminus{S}, S}^{-1}  c$, where c is some scalar.  I would be interested in those steps.  Thanks!


Hint to find the order of the group of $2\times 2$ matrices under multiplication

Let $G$ be the group of all $2\times 2$ matrices  \begin{bmatrix}a&b\\c&d\end{bmatrix} where $a,b,c,d$ are integers modulo $p$ for $p$ prime such that $ad-bc\not =0$.$G$ forms a group relative to multiplication. Then how do I find the order of $G$?  I really don't know how to proceed. All I could try is look at $p=3$. So, I tried to count the number of solutions to $ad-bc=0 \bmod p$ manually by squaring and adding the number of solutions to $ad=0 \bmod p$, $ad=1 \bmod p$, $ad=2 \bmod p$.Let that sum be $k$. Then the order of $G$ is $3^4-k=81-k$.  The same method however does not work with a general prime $p$. Would someone give me a hint to solve this problem? Thanks.


How to cleanly launch a GUI app via the Terminal?

Some GUI apps launch cleanly via the Terminal command line, but some don't, and they cause the Terminal to wait for the app to terminate. Even then, some don't "release" the command line.  The mysterious ampersand & suffix seems to cause the terminal to put the process into the background (but I'm not sure what happens there).  Is there a way to launch an app via the Terminal so that there is no "hang on" effect, just like launching something via Alt+F2?  I'd like to have the command line available again immediately, without something still in the background and printing in the terminal.


Why are orbits around black holes stable?

Black hole theory involves space (or space-time), itself, being sucked into the black-hole, with the event horizon marking the point at which space/space-time is moving faster than the speed of light. I find it really hard to picture how this could be happening while objects maintained a reasonable stable orbit around black holes. If we take the stars that orbit the super massive black hole at the centre of the Milky Way, the orbital dynamics are used to calculate the mass of the black hole, in the normal way. In other words not taking account of the fact space is rushing at some speed inwards toward the black-hole.  I appreciate I'm missing some knowledge here. That's the motivation for asking the question.


I recently started to learn programming in ARM assembly,  today I encountered annoying problem where my program started to crash when I used the r4 register.  With this simple code the program works fine      .text     .align  2     .global arr     .type   arr, %function arr:     mov r3, #8     mov r0, r3      bx lr     .size   arr, .-arr   But changing to r4 it crashes      .text     .align  2     .global arr     .type   arr, %function arr:     mov r4, #8     mov r0, r4      bx lr     .size   arr, .-arr   What the hell am I doing wrong??? It clearly states in ARM docs this:     In all ARM processors, the following registers are available and   accessible in any processor mode: 13 general-purpose registers R0-R12      The supposed 'duplicate' question regarding  does not help at all, since everyone there has categorized r4 (THE ONE THAT I HAVE PROBLEMS) with others (r5, r6, ... that I dont have problems).  I am looking for explanation why using specifically r4 causes this problem, I do not have problems using instead of r4 registers that are supposed to be the same type as r4 (r5, r6, r7, r8).


"That" - Omitting extra words vs. Grammatically correct

I've read in several places that it's better to omit "that" in sentences, because it's best to omit extra words. Also in programs like "Grammarly" and "Pro Writing Aid" they recommend removing it for that reason.   But sometimes it feels/sounds like it's not grammatically correct. Are there rules that govern whether one can/should remove it? Is it a matter of style?  "...the plane Bill had folded..." vs. "the plane that Bill had folded..."


Android Stringblock.get NullPointer Exception on Lollipop

I am getting a crash on Android Lolipop.  java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.content.res.StringBlock.get(int)' on a null object reference    at android.content.res.AssetManager.getResourceValue(AssetManager.java:213)  at android.content.res.Resources.getValue(Resources.java:1334)   at android.content.res.Resources.getValue(Resources.java:1323)   at android.content.res.Resources.loadXmlResourceParser(Resources.java:2796)  at android.content.res.Resources.getLayout(Resources.java:1143)  at android.view.LayoutInflater.inflate(LayoutInflater.java:412)   Generally happens while inflating a view. Any suggestions why it happens on Lollipop only ?


iTunes music purchases after changing country

Are iTunes music purchases still available once I change the store country, assuming that both stores offer the same content which is associated with my account?  I am just concerned about making a substantial investment in music purchases now and not having the ability to download the files after crossing borders.


Can you become a werewolf vampire hybrid the second time you are trying to be werewolf?

In skyrim I am trying to become a vampire/werewolf hybrid. originally you supposed to do the Dawnguard questline completely so that way you can get turned into a vampire lord again afterwards. You're supposed to completed the companion quest line to a point where you can become a werewolf, then you're supposed to drink the blood to become a werewolf and turn into a vampire lord at the same time to glitch out the game. It allows you to keep both the werewolf form and the vampire lord form without any of the vampire Lords weaknesses and can keep the vampire Lords eyes and face. My Problem is that I've already done the complete companions quest line and became a werewolf and I cure myself of being a werewolf by becoming a vampire lord, but now I want to become a hybrid. So my question is would I be able to become A hybrid but by using the second time u can become a werewolf?


I have a graph. This is my code.    \documentclass[10pt]{article}     \usepackage{pgf,tikz}     \usetikzlibrary{arrows,patterns}     \pagestyle{empty}      \definecolor{ttqqcc}{rgb}{0.2,0,0.8}     \definecolor{ffqqtt}{rgb}{1,0,0.2}     \definecolor{ttqqff}{rgb}{0.2,0,1}     \definecolor{uququq}{rgb}{0.25,0.25,0.25}      \begin{document}      \begin{tikzpicture}[line cap=round,line join=round,>=triangle 45,x=1.0cm,y=1.0cm]      \draw[->] (-3.63,0) -- (3.67,0);     \foreach \x in {-3,-2,-1,1,2,3}       \draw[shift={(\x,0)}] (0pt,2pt) -- (0pt,-2pt)          node[below] {\footnotesize $\x$};     \draw[color=black] (3.48,0.07) node [anchor=south west] { $x$};      \draw[->] (0,-1.93) -- (0,5.57);     \foreach \y in {-1,1,2,3,4,5}       \draw[shift={(0,\y)}] (2pt,0pt) -- (-2pt,0pt)          node[left] {\footnotesize $\y$};     \draw[color=black] (0.06,5.19) node [anchor=west] { $y$};      \draw (0pt,-10pt) node[right] {\footnotesize $0$};      \clip(-3.63,-1.93) rectangle (3.67,5.57);     \draw[pattern color=ffqqtt,pattern=north east lines,fill opacity=0.1, smooth,samples=50,domain=0:1.0]      plot(\x,{\x^4-4*\x^2+3}) -- (1,0) -- (0,0) -- cycle;     \draw[pattern color=ttqqcc,pattern=crosshatch,fill opacity=0.1, smooth,samples=50,domain=1.0:1.7320508075688772]      plot(\x,{\x^4-4*\x^2+3}) -- (1.73,0) -- (1,0) -- cycle;      \begin{scope}[xscale=-1]     \draw[pattern color=ffqqtt,pattern=north east lines,fill opacity=0.1, smooth,samples=50,domain=0:1.0]        plot(\x,{\x^4-4*\x^2+3}) -- (1,0) -- (0,0) -- cycle;     \draw[pattern color=ttqqcc,pattern=crosshatch,fill opacity=0.1, smooth,samples=50,domain=1.0:1.7320508075688772]        plot(\x,{\x^4-4*\x^2+3}) -- (1.73,0) -- (1,0) -- cycle;     \end{scope}      \draw[smooth,samples=100,domain=-3.6342419080068153:3.665758091993186] plot(\x,{(\x)^4-4*(\x)^2+3});      \fill [color=uququq] (-1.73,0) circle (1.5pt);      \fill [color=uququq] (-1,0) circle (1.5pt);      \fill [color=uququq] (1,0) circle (1.5pt);      \fill [color=uququq] (1.73,0) circle (1.5pt);      \end{tikzpicture}     \end{document}   When I see the DVI output DVI, I have    And if I look at the PDF file, I have


My problem is that  pointOnMap() runs before xmlPreparer() despite on order. I think it has something to do with using AJAX. parseXML creates object i need . So when i use pointOnMap() it already should be initialized.  On page is first that i see from pointOnMap - 0 and after that from parse ..So it is not in right order . Thank you for your advices.  var mesta= new Array();   function init() {     xmlPreparer();     pointOnMap();    }  //add source function xmlPreparer() {        $.ajax({     type: "GET",     url: "./mesta.xml",     dataType: "xml",     success: parseXml   }); }  function parseXml(xml) {      var type;     var name;     var latitude;     var longitude;    $(xml).find("city").each(function()   {     type=$(this).find("type").text();     name=$(this).find("name").text();     latitude= $(this).find("latitude").text();     longitude=$(this).find("longitude").text();     var mesto = {type:type, name:name, latitude:latitude, longtitude:longitude};     mesta.push(mesto);   });     alert(mesta.length);//this prints right size }  //add source function pointOnMap() { alert(mesta.length);//for no reason prints 0 and runs before xmlparser? $('#dot').css('top', YLatToPixel(0,$('#jpMapa'))) $('#dot').css('left', XLngToPixel(0,$('#jpMapa'))+'px'); }  function YLatToPixel(lat,elem){ var containerHeight=$(elem).height(); lat+=90; var calculatedHeight=((lat*containerHeight)/180); return $(elem).offset().top+($(elem).height()-calculatedHeight); }   function XLngToPixel(lng,elem){ var containerWidth=($(elem).width()); lng=lng+180; return $(elem).offset().left+((lng*containerWidth)/360); }


linux + .bash_profile + correct PATH syntax

regarding the file:  .bash_profile  what is the different between    PATH=${PATH}:${HOME}/bin:/usr/local/   to   PATH=$PATH:$HOME/bin:/usr/local   and what is the correct syntax?


What to do with a very big sample size? (effect size)

We have a peculiar problem, for which we have many questions, but cannot seem to find satisfactory answers (we did find a few ideas as to what to do, but we are not very certain they apply to our problem). If you find any of the following questions to have already been answered, and those answers should apply to my problem, then a pointer in the right direction would be very much appreciated.   First some info about the data. Different models (that work differently) are feed the same data from which the models produce a numeric value for each input. These numbers become our (scale variable) data. We would like to use these values to show with some statistical certainty that different models produce different (or not) results. For this we planned on using the Wilcoxon signed rank test or the Sign test (depending on the distribution of differences; the related samples t-test is not really an option, because the differences are never normally distributed).   The problem becomes the sample size that we use. In total each model produces 12million values. We have read that big samples tend to lead to significant differences between groups even though there might not be one (the samples mentioned however, were always much smaller). Legacy dialogs tests in SPSS confirm this by returning the sig. of 0.0 followed by 35 more 0 (which is as far as we can tell the most decimal places one can get out of SPSS) for all the combinations of models (even though some look somewhat similar from their descriptive statistics and histograms). What further confuses us is the use of Wilcoxon sign rank test in the "new" dialog, where sig. value for all the pairs of data equals 1.0 (even for models that are clearly very very different). We cannot find a suitable reason for such differences between what should be, as we understand it, the same test (we do realize that a different functions are been called in the background (NPAR TESTS and NPTESTS), we are not however aware how this would cause such drastic differences; the fact that sig. values alternate between 0 and 1 makes us think that something is very wrong (let us just add here that Sign test returns sig. 0.00 in the "new" dialog as well).  So, to sum up we are interested to know:    is there any point in even using tests like Wilcoxon signed rank test or the Sign test on sample sizes this big? could some other method me used instead (or should we just use descriptive statistics)? and what causes the differences in the test results for the same test in different dialogues?   Finally we would like to mention that we are not competent statisticians (or mathematicians) so we would ask you to be tolerant if we have made a mess of things ;). We would be happy to provide any more information. Any help would be appreciated.  Edit  Apparently the best solution to our problem would be to use the effect size. We chose to expand on the original post rather than ask a new question, because the circumstances are connected (although maybe that would be a better option).  Anyway our current plan is to first do a Friedman test to show there are differences between models, followed by the Wilcoxon and Sign tests and report that sig. is smaller than $\frac{0.01}{Bonfferoni\hspace{2mm}correction}$ (and kind of gloss over the fact that as far as SPSS is concerned it's complete 0) - is it viable to use different tests for Post-hoc testing (Wilcoxon and Sign tests) or would it be more appropriate to just use Sign tests?. After that we will calculate the effect size. We are considering using the $r = \frac{z}{\sqrt{N}}$ calculation as suggested . We believe this formula can also be applied to the Sign test, but we are not certain? Would it then be reasonable to also add ? Basically what we are asking is if this sequence of tasks is reasonable and viable.  Thanks to everybody for the previous and future help ;).


What do I do when a user deliberately asks a duplicate that is not answered

I while ago, I saw 1 legitimate question, that did not have an answer yet, and another question (not by the same user), which looks something like:     I have the same problem as link.   followed by a brief explanation of the question that was linked.  Naturally, I would flag such question, but that duplicate question does not have any answer.  Should I flag the post, or is this tolerated?


I would like to export users into a CSV in Drupal 7. I believe I can use the module , but I am not sure how to do that or if it is the correct module I would like.


Prove that $|\sin 1| + |\sin 2| + |\sin 3| +\cdots+ |\sin 3n| > 8n/5$

So, the question is as follows: Prove that $\left|\sin 1\right| + \left|\sin 2\right| + \left|\sin 3\right| +\cdots+ \left|\sin 3n\right| > 8n/5.$ I have tried quite a few approaches, including using the Taylor expansion or the A.M-G.M inequality, but to no avail. It would be of great help if this problem could be proven. Edit: Angles are in radians, $n$ is a natural number.


It's 2019, How to *disable* automatic reboots and updates in Windows 10? Old methods are no longer working

Many of the solutions to prevent windows 10 from doing their auto reboot updates are not working anymore. The solutions posted here:   No, this question is not a duplicate. Hence: "It's 2019"    Are outdated and just a waste of time for everyone to try as they do NOT work anymore. It's 2019, what tricks does Microsoft have up their sleeves to force an auto shutdown update?  Many people seeking help want to disable updates completely. Not just auto reboot. Please do not post answers that only disable auto reboot. Alot of the times when windows update with new patches, it removes certain programs that it deems unnecessary. In my case it constantly removes my work's vpn software. wtf!? I just want to disable updates completely!  What are the latest ways of preventing further updates on Windows 10? Home and Pro versions. Solutions that don't need to install software would be best, but also installing 3rd party software can be possible too for the non-tech savvy.


Divide Page into Two independent Columns with Different Backgrounds

I wish to divide my page into two independent columns from each other (one large 33% of the page width) and with different background colors.  Which is the best strategy to do this? I also would like to set margin into the columns so I started by putting zero the margins of the page. The class i'm using is "letter".


Bash rename 360 000 files using find -exec

I've got around 360 000 files like:  ./001/1/1.jpg ./001/1/2.jpg ./001/2/1.jpg ./002/1/1.jpg ./003/1/1.jpg ... pattern: [60 dirs]/[1000 subdirs]/[4-10 files].jpg   I want to rename files using rename for example from *.jpg to *.jpeg. I can't do it with single rename, because I get the error argument list is too long.  Searching for solution, I figured out this, but it renames nothing:  find -maxdepth 2 -mindepth 2 -type d -exec rename -n 's/jpg/jpeg/' {}/* \;  When I check if the {} is expanded replacing rename with echo:  find -maxdepth 2 -mindepth 2 -type d -exec echo "rename -n 's/jpg/jpeg/' {}/*" \;  I get expected result:  rename -n 's/jpg/jpeg/' ./061/61430/* rename -n 's/jpg/jpeg/' ./061/61431/* ...   If I run any of these rename commands, I rename works. So the should be problem with the {}.  Thank you for help!


Why is the eigenvalue of a stochastic matrix always $1$? I have found lots of articles simply saying it is obvious that the eigenvalue is $1$ but can't get my head around the proofs.


Is it possible to analytically solve the expression $x^{x^x}=3$? And how to solve this problem numerically? Simply testing some results, I found that $\sqrt{2.6}<x<\sqrt{2.7}$. What matches the result provided by  in the comments. But in addition to a numerical solution, like the technique posted by , is it possible to find a "closed" formula for the solution of this problem?


First of all I am a beginner. Yes I have researched several articles and done lots of reading about file systems. I am using ubuntu server 18.04. I did successfully download and use gparted and have a 3.64 Tib ext4 partition. I am now at the point where I want to mount the drive and tell it to mount on boot. The drive is going to store zoneminder files. (Yes I successfully installed and have zoneminder running with cameras displaying). I am frustrated because I am having trouble doing something that I think should be simple so I am asking for help please. How do i mount the drive and use it?


Not flying the last segment of the first half of a return flight

I have booked a A->B->C | C->B->A flight. What I want to do is to not fly the B->C segment. While skipping the final B->A would be totally fine (just walk out of the airport), I'm afraid that the airline might cancel my return flight if I skip the B->C. Should I worry about that or is this a non-issue? Also - is there any way to make it with checked luggage (for example letting them know when I check in at A that I will actually not fly all the way to C) or is that impossible?


Single quotation marks: punctuation marks outside or inside?

I use single quotation marks to provide translations of foreign terms and to highlight titles of parts of my dissertation.  I'm confused where I should put commas and periods when they appear next to the inverted comma, meaning inside or outside?  Thank you


How to hold terminal open (excepting gnome-terminal)?

I find useful the gnome-terminal feature of editing (and creating) profiles with the option of holding the terminal open after the command exists.    (I like to use context menu file manager to run commands to display info about a file in a terminal, to show info in a terminal while processing, etc.)  I wasn't able to find the same feature in other terminals, so I have to install gnome-terminal even when it's not the default terminal.  Are there other terminal emulators with this feature? Is there a command to be used in a given terminal that would have the same effect?    I want, with a single line (to be added as context menu entry), to open the terminal, run a command and display info in the terminal window that stays open.   Example: in pantheon-files (elementary os) I add a context menu entry for media info using a contractor file with a line like Exec=xterm -hold -e "mediainfo -i %f" (according to a comment below) or Exec=gnome-terminal --window-with-profile=new1 -e "mediainfo -i %f".


How do I avoid run-time error when a worksheet is protected in MS-Excel?

The code snippet below changes the data validation state of a cell and runs when the Excel-2003 worksheet is unprotected. However, when I protect the work sheet the macro doesn't run and raises a run-time error     Run-time error '-2147417848 (80010108)':      Method 'Add' of object 'Validation' failed   I have tried wrapping the code with   Me.unprotect ... Me.protect   But this does not work properly.  So, how can I modify the code below to work (ie have the code modify the unlocked cell's validation) when the sheet is protected without the above run-time error?  Update  My original work book is an Excel 2003. I tested @ solution in Excel 2007 with the following definition for Workbook_Open  Sub WorkBook_Open()     Me.Worksheets("MainTable").Protect  contents:=True, userinterfaceonly:=True  End Sub   The code still fails with the following run-time error when the worksheet is protected     Run-time error '1004':   Application-defined or object-defined error   Thanks, Azim    Code Snippet  'cell to add drop down validation list' dim myNamedRange as String dim modifyCell as Range  modifyCell = ActiveCell.Offset(0,1)    ' set list values based on some conditions not defined for brevitity' If myCondition then    myNamedRange = "range1" Else    myNamedRange = "range2" End If  With modifyCell.Validation    .Delete     'Run time error occurs on the next line'    .Add Type:=xlValidateList, AlertStyle:=xlValidAltertStop, _         Operator:=xlBetween, Formula1:="=" & myNamedRange     ...     ' skipping more property setting code '    ... End With


I have PATH=foo set in /etc/profile  According to /etc/password the root and myaccount users have /bin/bash as the login shell.  When I log in as myaccount, the PATH has been set correctly from /etc/profile. If I then sudo su, PATH does not include the value set in /etc/profile.  If I sudo su - instead then /etc/profile is sourced. I know it is good practice to do this anyway but I don't see why it's necessary in order to source /etc/profile.  Why does sudo su clobber PATH, disregarding /etc/profile and how to I make it not?


80s-90s Sci Fi book about a transformed Earth invaded by aliens

Looking for a book from the 80-90s. Earth has been infected by alien life forms, sort of seeded. The planet has been transformed, and a group of humans are fighting it, I believe they were a military hold over.  There was a lot of sexual innuendo, with the characters having to traverse through a giant "sphincter" to get to the heart of the invasion to attack, and humanity has shifted to more of an androgynous/bisexual side.  The main character, however, is a man's man, not interested in that lifestyle, and actually has an interest in one of the lead females, part of the team.


Finite subgroup of the multiplicative group of a field is cyclic

Dummit and Foote's Abstract Algebra contains a proof that a finite subgroup of the multiplicative group of a field, $F$, is cyclic. However the seems unnecessarily complex to me. Certainly their version works (pictured below), but I'm curious why they don't simply take the approach of adding $(1,...,1)\in(\mathbb{Z}/n_1\mathbb{Z}\times\cdots\mathbb{Z}/n_k\mathbb{Z})$ to itself $n_1\cdot n_2\cdots n_k$ times to show that the group necessarily has a generator. Does that approach somehow fail?  Dummit & Foote's proof:


Conditionals work, Listings work, but when put together, no

In an earlier question I learned the following code to define conditionally compiled text (for a teacher guide)  \newtoggle{teach} \toggletrue{teach} \NewEnviron{teachr}   {\iftoggle{teach}{\BODY}{}} \newcommand{\cpp}{\begin{lstlisting}[language=C++]}   If I want to embed code within this conditionally compiled text, it fails. Conditional text works fine.  \begin{teachr}  \cpp class foo {}; \end{lstlisting}  \end{teachr}   The error message is:     ! LaTeX Error: \begin{teachr} on input line 166 ended by \end{lstlisting}.  I assume this is some obvious failing, but if I should construct an mwe let me know and I will edit the question.


Why is .join() a property of string not list?

When joining a list in python, join is a function of a str, so you would do >>>', '.join(['abc', '123', 'zyx']) 'abc, 123, zyx'  I feel like it would be more intuitive to have it as a property of a list (or any iterator really), >>>['abc', '123', 'zyx'].join(', ') 'abc, 123, zyx'  Why is this?


Given a generic class definition BaseClass<T>, is it possible to test this condition?  if (myvar is BaseClass<>)  I would like to know if myvar derives from the generic class, but I do not know (or care) what T might be.  I assume the answer is no... my backup plan is to caveman this via myvar.GetType().ToString().Contains("BaseClass<"), or something.


What underlying structure/framework defines the charge of an antiparticle or regular particle (specifically a proton)?

I can't seem to find an answer to this. For a given configuration, say for a Hydrogen atom: the proton has properties which give it a positive charge. This is a known truth.  Now lets take Hydrogen's antiparticle (anti-Hydrogen) and compare the structure - All the information I've found so far only points to a difference in charge without explaining the structure that governs the charge of the proton or anti-proton.  I'm trying to understand what structural differences define a particle as being either matter or antimatter.  Can anyone help with this?


OrderBy does not change list when sorting a list according to date

I have a struct and a list as follow, I just wanted to sort the Inputpoints according to date. I have used the following commands but I can not see any sorting.  public struct Points {     public Date Date;     public double Quantity; } _test = new List<Points>(InputPoints); _test.OrderBy(t => t.Date);


Place answers into demilitarized zone instead of 5 minute grace period

I'm going to piggy back off  but suggest that instead of having first drafts included in revision history, just change to a 5 minute demilitarized zone.  The way this would work is that any answers that have been submitted within 5 minutes of the question being asked can be answered, but won't be visible until that 5 minute period has expired. At this point, any submitted answers will be displayed and future changes become permanent revisions.  This will allow users the time to properly form their answer instead of competing for first answers. In addition, users will no longer be able to piggy back off other answers encouraging that each user form their own unique answer. Lastly, answers will be able to more fairly evaluated by the community.  The process would look something like:   User submits question Community can begin submitting answers 5 minutes after the user has submitted their question, any answers will be displayed and any future changes to these answers will be part of the revision history of the answer


It says this is not valid housing when i'm pretty sure it is. this is 1.2. is the floor too high up?


I am new to this site, but I know there is a similar question on it, it's just not quite the same. What I mean by "all things X" could, for example, be like this:  "He was interested in all things baseball." meaning that s/he is interested in everything that has something to do with baseball. In this example there is a noun after "All things..." Now, would it be proper for an adjective to replace the X? I.e. s/he did all things possible but still couldn't find the solution. Thank you in advance


Let $x \in R$. I would like to know if it is true that if $$ R/(x) \cong R/(x^2) $$ as $R$-modules then $(x)=(x^2)$.   I was trying to play with the isomorphism and it's inverse but no luck so far. Any suggestions? Is it even true?


Let $K = \{ x :  Ax \le b, x \ge 0 \}$, $b \ge 0$. If there are solutions $x \ge 0$ different from zero of $A x \le 0$, show that $K$ is unbounded.(A is mxn, x is 1xn b is 1xm matrix.)


Are the eigenvalues of $AB$ equal to the eigenvalues of $BA$? (Citation needed!)

First of all, am I being crazy in thinking that if $\lambda$ is an eigenvalue of $AB$, where $A$ and $B$ are both $N \times N$ matrices (not necessarily invertible), then $\lambda$ is also an eigenvalue of $BA$?  If it's not true, then under what conditions is it true or not true?  If it is true, can anyone point me to a citation?  I couldn't find it in a quick perusal of Horn & Johnson.  I have seen a couple proofs that the characteristic polynomial of $AB$ is equal to the characteristic polynomial of $BA$, but none with any citations.  A trivial proof would be OK, but a citation is better.


How to create and maintain separate repository for subfolder of another repository?

I currently have a git repository with several folders, for example: /folder1     /folder1/subfolder1-1     /folder1/subfolder1-2 /folder2     /folder2/subfolder2-1     /folder2/subfolder2-2 /folder3     /folder3/subfolder3-1     /folder3/subfolder3-2  I want to make /folder2/subfolder2-1 a repository of its own because I want to push and share its code as an independent functionality. However, I want to keep this folder as a part of the main repository because its further development happens in pace with the whole application it makes part of. How can I accomplish that using git?


What's the difference between a normal user and a system user?

Some  I'm going through has a boolean switch on whether or not a user is a 'system' user or a 'normal' user (defaulting to 'normal').  What is the difference between these two modes of user-ship?  I don't need to learn what a user is or why you need them (even 'fake' ones), but this particular distinction isn't intuitive to me.


I recently switched to a new PC at work, one with two (identical, Dell 23") monitors. I'm running Linux Mint 15 64bit / Cinnamon. Is there a way to set it up in such a way that, instead of both monitors sharing the same huge workspace, they are on separate smaller ones? E.g. left monitor on workspace 1, right monitor on workspace 2, and I could switch either monitor to workspace 3 if needed?  Failing that, is there a way to duplicate the bottom panel onto the second monitor? Currently it is only displayed on the left one.


How to split a string by character by one or larger index

The split method for strings only takes a parameter for the delimiter, but how do I easily split by every (or every other, etc) letter? This method works to split by every letter, but seems clumsy for a simple task.  a=' '.join(string.ascii_lowercase).split()   I suppose a function could do this:  def split_index(string,index=1):     split=[]     while string:         try:             sect = string[:index]             string = string[index:]             split.append(sect)         except IndexError:             split.append(string)     return split  print(split_index('testing'))   # ['t', 'e', 's', 't', 'i', 'n', 'g'] print(split_index('testing',2)) # ['te', 'st', 'in', 'g']   I am surprised if no one has wished for this before, or if there is not a simpler built in method. But I have been wrong before. If such a thing is not worth much, or I have missed a detail, the question can be deleted/removed.


I see after some updates on Ubuntu 18.04 desktop and server that JXplorer doesn't want to open. I'm trying to figure out what happened as this application is necessary to my work.  Code from terminal:  wrz 12, 2018 12:42:20 PM com.ca.directory.jxplorer.JXplorer printTime INFO: main start TIME: Wed Sep 12 12:42:20 CEST 2018  (407)  wrz 12, 2018 12:42:20 PM com.ca.directory.jxplorer.JXplorer checkJavaEnvironment INFO: running java from: /usr/lib/jvm/java-11-openjdk-amd64 wrz 12, 2018 12:42:20 PM com.ca.directory.jxplorer.JXplorer checkJavaEnvironment INFO: running java version 10.0.2 Exception in thread "main" java.awt.AWTError: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper     at java.desktop/java.awt.Toolkit.newAWTError(Toolkit.java:472)     at java.desktop/java.awt.Toolkit.fallbackToLoadClassForAT(Toolkit.java:488)     at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)     at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)     at java.base/java.util.HashMap$KeySpliterator.forEachRemaining(HashMap.java:1608)     at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)     at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)     at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)     at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)     at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)     at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)     at java.desktop/java.awt.Toolkit.loadAssistiveTechnologies(Toolkit.java:532)     at java.desktop/java.awt.Toolkit.getDefaultToolkit(Toolkit.java:613)     at java.desktop/java.awt.Window.getToolkit(Window.java:1375)     at java.desktop/java.awt.Window.init(Window.java:518)     at java.desktop/java.awt.Window.<init>(Window.java:549)     at java.desktop/java.awt.Frame.<init>(Frame.java:423)     at java.desktop/java.awt.Frame.<init>(Frame.java:388)     at java.desktop/javax.swing.SwingUtilities$SharedOwnerFrame.<init>(SwingUtilities.java:1919)     at java.desktop/javax.swing.SwingUtilities.getSharedOwnerFrame(SwingUtilities.java:1995)     at java.desktop/javax.swing.JWindow.<init>(JWindow.java:183)     at java.desktop/javax.swing.JWindow.<init>(JWindow.java:135)     at com.ca.directory.jxplorer.JXplorer.JXplorerFullInit(JXplorer.java:84)     at com.ca.directory.jxplorer.JXplorer.<init>(JXplorer.java:76)     at com.ca.directory.jxplorer.JXplorer.main(JXplorer.java:58) Caused by: java.lang.ClassNotFoundException: org.GNOME.Accessibility.AtkWrapper     at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)     at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:190)     at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)     at java.base/java.lang.Class.forName0(Native Method)     at java.base/java.lang.Class.forName(Class.java:374)     at java.desktop/java.awt.Toolkit.fallbackToLoadClassForAT(Toolkit.java:485)   What could be the problem and how can I fix it?


Difference between 'later' and 'later on'

Is there any difference between the usage of 'later' and 'later on'?         I'll see you later.   I'll finish it later on.


Can you compile C# so it doesn't need the .NET Framework at runtime?

Is it possible to force the C# compiler to pull all the referenced calls out of the framework and pack them into dlls or even a single executable?   I like writing quick 'one-off' applications with C#, however I don't want to have to install the whole framework on the target machine once it's ready to go.


I have a nested for and if structure as in below:  for i in range(n):     for j in range(n):         if i!=j:             if i<j:                 if i!=0 and j!=0:                     if max==saving[i,j]:                         c1 = i                         c2 = j   I want to break all of the if conditions and for loops when c1 and c2 are found.  Where should I use "break" control ?  Thanks.


I want to be able to update my software, how can I do this?  Its asking for a password and I don't know where to get it from.


Why every time I use the Arrays modifier with Object Offset, the duplicates begin to increase in size exponentially?

Every time I use the Array modifier with Object Offset, when I increase the count over 1, the duplicates begin to increase in size exponentially. How can I keep their size constant?


it starts here   I have tried Jesús Hagiwara and Kilisi answers, and nothing work      Microsoft Windows [version 6.1.7601]     Copyright (c) 2009 Microsoft Corporation. Tous droits réservés.      C:\Users\Dell>D:      D:\>dir\ah      Le volume dans le lecteur D s'appelle Princesse      Le numéro de série du volume est 40D9-4FE9       Répertoire de D:\      Fichier introuvable      D:\>attrib /s /d -s -h -r *.*     Impossible de modifier l'attribut - D:\.Trash-1000\files\Autorun.inf\lpt1.UsbFix      La cible du lien symbolique D:\.Trash-1000\files\Screenshot from 2015-10-01 18:2     1:32.png n'existe pas D:\>   What is this reputation thing I can't even make a comment


Using a string as a name of an attribute of a class in C#

the question probably already has been answered, but i honestly dont know what to search for, an "Reflection" did not solve my issue.   I want to call a field by a string such as:      string str = "Green";     Color colorForPurpose = Color.str;   Of course this does not work, but the purpose should be clear.   Anyone has an idea?


Python: assign values to a 2D list array with elements being sets

Let a be a 2-dimentional list with each element being a set. For example, let a be a (3,3) list, I initialize as follows a = [set()] * 3 a = [a] * 3  I now want to assign a[1][1] with another set. I do a[1][1] = set([1,2,3])  But in doing this, not only a[1][1], but also a[0][1] and a[2][1] are assigned to this new set. It's so weird to me. How does this happen? How should I correct it? Thanks!!  I set a to be a 2D list array because I want a to work like a = cell(3,3) as in Matlab.


NULL Pointer when Activity starts without intent. 'int java.lang.String.hashCode()' on a null object reference

Brief description about what I am trying to do:   It's a simple messaging app  In my first activity I have a list-view and few buttons.    User presses any of the button and the information about which button was pressed was stored in shared preferences. When user presses any list item, an intent is triggered that takes him to new activity where which list item was pressed is analyzed by putExtra() from intent.  In second activity, depending on which value came with intent, a string value for newString is decided.   Problem When screen rotates, app crashes with this error -     Attempt to invoke virtual method 'int java.lang.String.hashCode()' on a null object reference   Following is the code in second activity -   String newString = "Default_Channel";  public static final String MyPREFERENCES = "MyPrefs" ; SharedPreferences sharedpreferences;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_chat2);      .     .     .      sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);      String restoredText = sharedpreferences.getString("CurrentUser", null);     if (restoredText != null) {         currentUserName = sharedpreferences.getString("CurrentUser", "unknown");//"unknown" is the default value.         .         .         .     }     else     {         currentUser.setText("not signed in");     }       if (savedInstanceState == null)     {         Bundle extras = getIntent().getExtras();         if(extras == null)         {             newString= "Default_Channel";         }         else         {             newString= extras.getString("LIST_ITEM_CLICKED");         }     }     else     {         newString= (String) savedInstanceState.getSerializable("LIST_ITEM_CLICKED");     }      // *** GETTING ERROR HERE On this line *** //       switch (newString)     {         case "User_1":             .             .             .             break;         case "User_2":             .             .             .             break;         case "User_3":             .             .             .             break;         case "Default_Channel":             .             .             .             break;     }   I am getting NULL pointer exception where I have mentioned it in code ! Its Line between Else statement and Switch.  Also, I understand what is NULL pointer exception and this is not what I am asking. I am getting NULL pointer when screen rotates, i.e. when activity restarts without intent.   I am new to android programming and not able to figure out what's going wrong here.   Edit: This is not duplicate question with "What is NULL pointer exception".


While i was writing today i've met a very stupid problem: On one place i must give a long value like 0x70, 0x3BC0 or something like that. This values i must take from a text file. I am using System.IO like this:  string[] stringTakenByFile = File.ReadAllLines(@"thePathToFile.txt");   From here i can take the value but in string format. I mean the same value like 0x70 but not like a long or int but like a text (string). When i try to parse it or convert it from string to int/long it gives me an exception witch says: Input string was not in a correct format. If you could help me that would be awesome! Thanks! EDIT: I dont wanna "How to convert numbers between hexadecimal and decimal in C#?" i need from string to LONG


Let A and B infinite sets and |A|<=|B|. Is that equivalent to |P(A)|<=|P(B)| in ZF? P denotes the powerset. I think it is equivalent, but I dont know exactly how to prove it.


Proving a seemingly simple inequality is proving difficult

After what feels like an embarrassing hour of scribbling I can't seem to find a direct solution to the following problem  $Show \space that: a^2 + b^2 + c^2 \geq ab+bc+ca \space \space  \forall [a,b,c] \in Z^{+}_0 $  I've tried placing each integer in an arbitrary order like so:   $a\leq b \therefore ab \leq b^2$  $b \leq c \therefore bc \leq c^2 \implies$   $a \leq c \therefore$ $ac \leq c^2$  Naturally I tried to add up the inequalities but this clearly yielded no results, but by nature of the third inequality I run into issues; what have I missed?  EDIT  I've constructed newer perhaps more insightful inequalities from one of the Dr's answer below:  $a-b \leq ab \leq b^2$  $b-c \leq bc \leq c^2$  $a-c \leq ac \leq c^2$  EDIT 2  While I've seen this flagged as a possible duplicate, this question appears towards the beginning of an intro book to mathematical proofs without any prior knowledge given, I feel aso though this should be provable using pure inequalities from first principals


I don't understand why I'm having this errors and how to solve them, on the following code in mine MainActivity file. I've searched on Google but I can't relate the solutions to mine code. I have also passed -Xlint:unchecked to javac, but can't get any wiser either.   I'm pretty new to Android and Java programming and trying to solve any highlights in mine code.  Thanks in advance.     Unchecked assignment: 'java.util.ArrayList' to   'java.util.ArrayList' less... (Ctrl+F1)  Signals   places where an unchecked warning is issued by the compiler, for   example:      void f(HashMap map) {       map.put("key", "value");   }    Hint: Pass -Xlint:unchecked to javac to get more details.        Unchecked call to 'ArrayList(Collection)' as a member of   raw type 'java.util.ArrayList' less... (Ctrl+F1)  Signals places where   an unchecked warning is issued by the compiler, for example:      void f(HashMap map) {       map.put("key", "value");   }    Hint: Pass -Xlint:unchecked to javac to get more details.     private void readItems() {     File filesDir = getFilesDir();     File todoFile = new File(filesDir, "todo.txt");     try {         items = new ArrayList<>(FileUtils.readLines(todoFile));     } catch (IOException e) {         items = new ArrayList<>();     } }


Let $C$ be a certain set of pairwise co-prime balanced rectangles in a plane. need to prove that C is a Countable set. The meaning of balanced rectangles is a set of the next form: $$B=<x,y>\in \mathbb{R}^2:a\le x\le b, c\le y\le d$$ for $a,b,c,d$ such that: $a<b \ and \ c<d$.  I need to use the density of $\mathbb{Q} \ in \ (\mathbb{R},\le)$.   I don't know how to even start proving. Therefore, I will be happy to get some help.


Maintain different set of extensions in Chrome, on different PCs

I use my GMail account both at home, and in the office, to sign in to Chrome. In my PC at home, I have a set of Extensions that I use a lot, like YouTube Actions, AdBlocker, HoverZoom, etc. But on my Mac in the office, I'd like to maintain a different set of Extensions like JSONParser, Any.Do, etc.  Is there a way to keep them differentiated?


So with the final releases of Python 3.0 (and now 3.1), a lot of people are facing the worry of how to upgrade without losing half their codebase due to backwards incompatibility.  What are people's best tips for avoiding the many pitfalls that will almost-inevitably result from switching to the next-generation of python?  Probably a good place to start is "use 2to3 to convert your python 2.x code to 3.x" :-)


I'm working on a 2D game, so most of the graphics are sprites. However, some elements are drawn using trianglestrips in Orthographic projection. The thing is that I can't do a 3D projection because the coordinates of the vertices have to line up with some of the sprites in the game.  I'm running into a problem trying to texture these triangles.  I understand how the texturing works, so I understand that the interpolation causes the effect:    For now I have no idea where to start. I Googled and looked for similar questions, but all seem to deal with fixing this in OpenGL.  I have no clue how to apply it to Monogame/DirectX. I also don't know how to start with a shader, as I don't really grasp how to interpolate across two triangles.  If it makes the issue easier, I don't care for accurate perspective, just that the texture is correctly stretched over the two triangles.  So far I have only used a BasicEffect like this:          checkered = Content.Load<Texture2D>("checkered");          basicEffect = new BasicEffect(GraphicsDevice);         basicEffect.VertexColorEnabled = true;         basicEffect.TextureEnabled = true;         basicEffect.Texture = checkered;         basicEffect.Projection = Matrix.CreateOrthographicOffCenter         (0, GraphicsDevice.Viewport.Width,     // left, right         GraphicsDevice.Viewport.Height, 0,    // bottom, top         0, 1);   The draw function is like this (nothing special):          GraphicsDevice.Clear(Color.Green);          basicEffect.CurrentTechnique.Passes[0].Apply();          VertexPositionColorTexture[] vertices = new VertexPositionColorTexture[4];          vertices[0].Position = new Vector3(100,50, 0);         vertices[1].Position = new Vector3(200, 50, 0);         vertices[2].Position = new Vector3(50,200, 0);         vertices[3].Position = new Vector3(250, 200, 0);          Color color = Color.White;         vertices[0].Color = color;         vertices[1].Color = color;         vertices[2].Color = color;         vertices[3].Color = color;          vertices[0].TextureCoordinate = new Vector2(1, 0);         vertices[1].TextureCoordinate = new Vector2(0, 0);         vertices[2].TextureCoordinate = new Vector2(1, 1);         vertices[3].TextureCoordinate = new Vector2(0, 1);          GraphicsDevice.DrawUserPrimitives<VertexPositionColorTexture>(PrimitiveType.TriangleStrip, vertices, 0, 2);


Ways to speed up render of same scene multiple time with different textures?

I've recently come back to Blender after not using it for a while and I'm trying to reacquaint myself with everything.  I've been working on a model of a product to be used on a company's website. It's fairly simple, they supply boxes of different drinks to bars, restaurants etc. So the model is just a box which will have different labels on for each flavour.   There are around 50 variations and the render time takes around 25 - 30 minutes each.  Because the only thing that is changing is the textures for the labels I was wondering if there is anyway to either keep the parts of the scene that don't change pre-rendered, or to only render the areas around the labels and then layer those on top of a blank render of the box (in Blender itself or with Photoshop)?  I'm using Cycles if that makes a difference.


Does apps installed via "snap" has man page?

Just installed kubectl via snap:    sudo snap install kubectl  But, man kubectl shows:     No manual entry for kubectl   See 'man 7 undocumented' for help when manual pages are not available.   Wondering does apps installed via snap have man page by default? If yes, how to see it?


How to center three divs horizontally within a parent div?

I know this question has been frequently asked but I can never seem to get it to work. Can you tell me what's wrong?  I have three divs within a #container div, which I want to centre side by side. The #container is 1000px wide (I want to keep it that way). Here is my code:    #container {   margin-top: 500px;   position: absolute;   width: 1000px; } .related-article {   background-color: #D6A400;   display: inline-block;   width: 230px;   height: 300px;   border-radius: 30px;   margin-bottom: 0px; } .related-article > img {   width: 200px;   height: 150px;   border-radius: 15px;   margin-top: 15px; } .related-article > h3 {   font-size: 15px;   width: 180px;   text-align: justify;   margin-left: auto;   margin-right: auto;   color: #f1f1f1;   font-family: Abel, serif;   margin-bottom: none; } a {   text-decoration: none; } #right {   float: right; } #left {   float: left; } #center {   margin-left: 385px;   margin-right: 385px; }

Here's what you'll do!

Constructing amazing fossils you never even dreamed of

Studying ancient marine biology

Uncovering the world's greatest mysteries

     All help would be gladly appreciated.


What antivirus programs are available for Ubuntu?  We previously used Symantec Endpoint Protection but it does not work in Ubuntu.


Is it unwise to run replication on same physical server?

I'm contemplating setting up a Master-Slave replication for my database. The slave server will be used for redundancy and possibly a reports server. However, one of the biggest issues I'm running into is that we're already maxed out on power at our datacenter. So adding another physical server is not an option.  Our existing database server is fairly under-utilized as far as cpu (load averages never really get above 1 on a quad-core). So the leading idea is to toss in some new drives and double the memory (from 8GB to 16) and run a second mysql instance on the same physical machine. Each instance would have separate disks for the database.   Is there anything wrong with this idea?  Edit (more info): I've (luckily) never had anything bad enough happen to take down the server, but am trying to plan ahead. We of course have nightly backups that we could recover from. But I figured having the redundant data on separate disks would provide a quicker solution if the master server's drives failed (obviously not if the entire machine goes out).   As for the reporting aspect, any tables we would report off of are MyIsam. So doing expensive reads on the same tables that are being written to can bog down the server. My assumption was having a slave server to report off of wouldn't affect the main server as long as we threw enough RAM at it (since cpu load hasn't been an issue yet).


What are the conditions for one-one and onto of a given liner transformation?

Let $T:\Bbb R^4\longrightarrow\Bbb R^4$ be a linear transformation satisfying $T^3+3T^2=4I$, where $I$ is the identity transformation. Then the linear transformations $S=T^4+3T^3-4I$ is a). one-one but not onto. b). onto but not one-one. c). Invertible. d). Non-invertible.  on solving i get $S=4T-4I$, but how does this suggest invertibilty? Also, Logically thinking option $a,b$, and $d$ are interlinked. So if only one choice is correct then i could simply say that yes option $c$ is correct. But can someone give the general aproach?


Why does Data have to use a computer in Star Trek?

In the earlier episodes of The Next Generation is where I noticed it, and I realise he could be inputting commands into the command terminal, but why isn't his positronic brain interfaced with the command console in that case?   I can't remember the exact example but there are episodes where he goes to the computer to look things up despite having encyclopedic knowledge of everything which could be known by the computer. Any explanation?


What is the possessive pronoun for a person whose gender we don't know?

If I speak about a neutral sex person, what can I say to exprime a possession ?  Example: The student will use his or her pen to write.  Is it better to write every time his or her or is there a correct sentence about it ?


Proof of AM-GM Inequality (setting $a_n$ in the last step)

I have been reading  and , but I don't understand how one of the steps works.     Let $a_n=\frac{a_1+a_2+\cdots+a_{n-1}}{n-1}.$   How do you set $a_n$ to meet certain criteria and not lose generality?


How do big companies like Youtube load balance traffic with only one IP?

Examining the A records for youtube.com (for example), I see only one IP address.  How can this be possible, given the volume of traffic they handle?  Do they use anycast with load balancers behind it?


Relation between divisions $\Bbb Z$ and $K[t]$

Let K be a field and a,b $\in \Bbb N$ Show that   $$a\text{ divides } b \text{ in } \Bbb Z \iff t^a-1\text{ divides } t^b-1 \text{ in }  K[t] $$   My attempt at this:  I found a formula (speculation) for the polynomial division. It states as follows  $$(t^b-1):(t^a-1)=\sum_{i=1}^{\frac{b}{a}}t^{b-ia}$$ of course this is only defined as long as $\frac{b}{a}$ is a natural number, which is only the case when a divides b. So (I think) it's sufficient to show that this formula is true.    I try to show this by induction over $\frac{b}{a}$ as follows.  $\frac{b}{a}=1$  $\Rightarrow a = b$, so $(t^a-1):(t^a-1) = 1$ and $\sum_{1}^{1}t^{b-a} = 1$  $\frac{b}{a} \to \frac{b}{a}+1$ We have  $\frac{b}{a}+1=\frac{b+a}{a}$ So  $(t^{b+a}-1):(t^a-1) = 1$ and $\sum_{i=1}^{\frac{b+a}{a}}t^{b-ia+a}$ (we have to prove this equality holds)  $\iff t^b(t^a-1):(t^a-1)=\sum_{i=1}^{\frac{b}{a}}t^{b-ia+a} + 1 $ Now susing the induction hypothesis we get  $\iff t^b\sum_{i=1}^{\frac{b}{a}}t^{b-ia} =\sum_{i=1}^{\frac{b}{a}}t^{b-ia}t^a + 1 $  I am stuck here. Thanks in advance


Hi I want to start learning multi variable calculus specifically for learning electrodynamics. What are some good text books?


Is it a good practice to always scale/normalize data for machine learning?

My understanding is that when some features have different ranges in their values (for example, imagine one feature being the age of a person and another one being their salary in USD) will affect negatively algorithms because the feature with bigger values will take more influence, is it a good practice to simply ALWAYS scale/normalize the data?  It looks to me that if the values are already similar among then, then normalizing them will have little effect, but if the values are very different normalization will help, however it feels too simple to be true :)  Am I missing something? Are there situations/algorithms were actually it is desirable to let some features to deliberately outweigh others?


Why is the amount of photos that fit on one card dependent on ISO?

I have a Canon 550D with a 16GB SD card. I noticed that, when in P-mode, if I choose an ISO of 100 I can shoot 595 raw files on an empty card. If I choose an ISO of 200 this is 590. And if I choose 400 this number decreases to 583. Here below is the rest of the ISO vs. space     ISO  __ | __  Amount of raw files that fit on 16GB   800  __ | __ 569   1600 _ | __ 556   3200 _ | __ 539   6400 _ | __ 510   12800_| __ 477     Does anybody know, why the filesize of one raw photo increases with the ISO?


How can do you install Ubuntu onto a blank Computer using a USB?

I wiped my computer and need to install an OS. Unfortunately my computer does not have a CD drive so I need to boot from a USB. How do you do this?


Why are PhDs the most common doctoral degree?

I have heard many people say they have a PhD in a certain area.  For nearly all of my life,  I thought a PhD was simply a doctorate,  and I didn't know that it had anything to do with philosophy.   There are many doctoral degrees, why are PhD's the most popular doctoral degrees by a long shot?


The accepted answer is factually incorrect; one can simply call  row.Table.Columns.Contains(name);   What should be done?


Can I apply for and receive a US visa when residing in country other than my own?

I'm currently residing in a country other than my own, and am planning a business trip to the USA for a week. Being a Bulgarian citizen, I do not qualify for the ESTA visa waiver program, unlike other EU countries.  The US embassy in Sofia lists a  which they inexplicably describe as "really quite easy". Unfortunately, some of the steps involved would be a major inconvenience for me, as I'm not residing in the country currently, particularly the interview and the visa/passport delivery.  I was hoping it could be possible to apply for a visa from the country of current residence rather than my own, but I wasn't able to find any information on the US embassy's webpages concerning this.


Canoical vs robots disallow for sorted content

I have a web page that displays 5 items (each with a headline, image and short content like in a microblog).  Item 1 Item 2 ... Item 5   Based on the query parameter in the URL, I will be sorting the items by date, votes, etc.   I in a dilemma to choose from one of the below solutions to avoid duplicate content issues.    Should I stick with a rel canonical tag to point to the original page from all the pages with query parameters (for sort)?  Or will it be better to disallow robots when query parameters are present in the URL?


Dust patterns inside electronic product - what causes this?

(Note: another similar question from a few years ago yielded nought but speculation. I have at provided some detailed observations in the hope that the community can come up with something rigorous as an explanation...) We disassembled an electronic product and found this interesting pattern of dust on the plastic (ABS, HDPE or similar material)...  Observations:  The dust is easily wiped off. There is no cooling fan in the product and it was situated in an unventilated cupboard.  Any airflow would be a result of thermal convection for the most part. It's an old broadband/DSL router which ran from a 12V wall wart ("double insulated" so no Earth-ground connection). The patterns seem to congregate around some of the minor injection-moulding features (known as "ejector marks", the 4 small circular features are almost co-planar with the main surface surrounding them, they are extremely shallow and have a slightly different surface finish to the rest of the plastic). The appearance of the features ("lightning" springs to mind) suggests to my mind that this is some sort of electromagnetic / electrostatic effect. The plastic is not coated with any kind of electrically conductive EMC coating. The circuitry housed within doesn't seem to indicate any particular correlation between the placement of electronic components and the locations of the dust patterns.  The features of the plastic case seem to be a more significant catalyst for the formations.  Questions:  How do these interesting patterns form? What is the composition of the dust likely to be (e.g. metallic or something else?). Why does the shape of the plastic seem to catalyse these weird shapes? Why the lightning / fractalline appearance?


If $\sum_{n=1}^\infty{a_n}$ and $\sum_{n=1}^\infty{b_n}$ converge then If $\sum_{n=1}^\infty{a_n*b_n}$ converge

My attempt;   Since $a_n$ converges then its sequence of partial sums $(x_n)$ converges to a limit x. Also, since $b_n$ converges then its sequence of partial sums $(y_n)$ converges to a limit y. Observe that by using the multiplication limit theorem: If $x_n \to x$ and $y_n \to y$ then $x_n*y_n \to x*y$. We know that the product of its partials sums converge, thus the product of the series converges.$  Is this correct? Any guidance is appreciated !


"24 hours' notice" or "24 hours notice"?

Which one is correct?  1: Well, you canceled on Tuesday and our policy is 24 hours' notice for all cancellations. 2: Well, you canceled on Tuesday and our policy is 24 hours notice for all cancellations.  To me personally, the first one makes more sense grammatically. But I've also heard that the second version is how they typically write it on paper forms at hospitals (that's what native speakers say). Could you please clarify my confusion?


MS SQL Concatenate multiple values into a single column

I currently have the following table;  Invoice   Client   Purchase Order 1000      A1       1234 1000      A1       1235 1001      B2       1236 1001      B2       1237 1002      B2       1238   and I'm looking for a quick way to get to;  Invoice   Client   Purchase Orders 1000      A1       1234 1235 1001      B2       1236 1237 1002      B2       1238   Any help would be appreciated!


How can I proof that $\lim\limits_{n\to\infty} \dfrac{n^b}{a^n}= 0\;,\;$ when $\;a > 1,\; b > 0\;.$

I am having a hard time with this problem: I tried by using the sandwich theorem but I failed. $\lim\limits_{n\to\infty} \dfrac{n^b}{a^n}= 0\;,\;$ when $\;a > 1,\; b > 0\;.$ Could anyone please help me?


Does anyone know how many suits of power armor I can leave at red rocket truck stop before I should worry that they will spawn away. Note that none have fusion cores in them as I took them out when I store them there. I'm looking at 9 suits of power armor there now


Suppose that $f:\Bbb R\to \Bbb R$ is continuous and that $f(x)\to 0$ as $x\to \pm\infty.$Prove that $f$ is uniformly continuous.

Suppose that $f:\Bbb R\to \Bbb R$ is continuous and that $f(x)\to 0$ as $x\to \pm\infty$. Prove that $f$ is uniformly continuous.   Since $f(x)\to 0$ as $x\to \pm\infty$ we have $|f(x)|<\epsilon $ whenever $x<-K$ and $x>K$ where $K>0$.  Also $f$ is uniformly continuous on $[-K,K]$ as the domain is compact.  Hence $f$ is uniformly continuous in $(-\infty,-K)\cup [-K,K]\cup (K,\infty)$.  But how to conclude that $f$ is uniformly continuous on $\Bbb R$ from above as I may chose $x\in (-\infty,-K);y\in [-K,K]$ ,how to conclude that $|f(x)-f(y)|<\epsilon $ from above for a given $\epsilon$?  Please suggest the edits required.


What exactly is the origin of the orange ring around M$87$?  I understand that the image was not taken in the visible light range. The colors are therefore artificial.   I also read that the image shows the shadow of the black hole on a brighter region of space which is "glowing" gas. Still I wonder about the following:   Why is the bright region circularly shaped and centered around the black hole? Is the bright region at the same distance as the black hole or much further away?


Centering header image div in whole page / not browser window size

I'd like to center my header image to be in the center of the whole page - not the center of the browser window base on what size it is. Site is www.anathema.me  Here's the css.   #wrapper {  margin: 0 auto;    }   #header {  margin: 0 auto;  background: #FFFFFF;  text-align: center;   }     #header img {  max-width: 40%;  height: auto;   }


Does Ubuntu One effected by NSA according what Edward Snowden published?

It is very important for me to keep my files in a safe Host. I use ubuntu one because of ease of using in Ubuntu. You think is it safe enough of spying ?


How to convert/format a date from vb.net to JavaScript?

In JavaScript, I have dates in an array ( named aLabels) that looks like:  /Date(1485703380827)/,/Date(1485703410233)/,.... to 96 entries.  How to I convert/ format them so I can use them in a label?  I tried:  Looping through the array to try to format each date. But for each iteration, before I am able to modify it, I get: Invalid Date.            // Create a holding array.           var formatttedDateTime = new Array();            // Loop thru the label array to format each entry into a formatted data/time.           for (i = 0; i < aLabels.length; i++)           {               var utcDateVal = new Date(aLabels[i]);                // For testing.               alert("original date " + utcDateVal);                var actualDate = new Date(utcDateVal.getTime() + (utcDateVal.getTimezoneOffset() * 60 * 1000))               // Load the formatted date/time array.              formatttedDateTime[i] = actualDate;           }


Custom shortcut Ctrl + Shift + Esc doesn't fire the event

For some reason my custom shortcut for the System Monitor that I created according to this instruction does not work.   When I press it, it just does nothing. Any ideas?  My shortcut is ctrl+shift+esc.  Here is a screenshot:


Is it legal to write and publish a novel based on a pre-existing campaign or setting?

I have read over the OGL and researched copyright laws, but I still am not sure how much of what I want to do is legal. What if someone wanted to write a story about a pre-existing campaign, such as The Temple of Elemental Evil or The Village of Hommlet? If descriptions and specific names were changed enough, would it be legal? How does one go about getting the rights to use material like that, or is it simply infringement?


This is a problem in my graph theory class and I'm unsure about how to solve it..  Let $X$ be the set $\{1,2,\dots,mn\}$. Suppose we partition $X$ into $m$ sets $P_1,\dots,P_m$, each of size $n$. Suppose we choose another partition $Q_1,\dots,Q_m$, each of size $n$. Show that the sets $P_i$ can be renumbered so that $P_i \cap Q_i$ is non-empty for every $i$.  Thanks in advance! Edit: I'm attempting to use Hall's Marriage theorem to solve this but I'm struggling with formulating the solution in a way that would get me to my answer.


Presheaf image of a monomorphism of sheaves is a sheaf

EDIT: The original version regarding coker is false.  Consider a morphism of sheaves of abelian groups $\Phi:\mathscr{F}\to\mathscr{G}$.   It is not in general true that Im$_{pre}\Phi$ is a sheaf. However, if $\Phi$ is a monomorphism, then $\Phi_U$ is a monomorphism on open sets and Im$_{pre}\Phi$ seems to be a sheaf. Consider the explicit construction of Im$_{pre}\Phi$ where $$\text{Im}_{pre} \Phi(U) := \text{Im}\; \Phi_U \subset \mathscr{G}(U)$$  since we are dealing with sheaves of abelian groups, this seems to be a sheaf.    Is this true? What if we are dealing with a monomorphism $\Phi:\mathscr{F}\to\mathscr{G}$ of sheaves of some unknown abelian category, is it still true that Im$_{pre} \Phi$ is a sheaf? And if so what is a purely abstract argument?


authentication is required when I try having an access to the google play store

I am not able to install my favourite games such as ZOMBIES KILLER 3D. Whenever i ha ve tried installing this games the pla store send me a message and that is "authentication is required you need to sign in your google account" I am kindly requesting you solving my problem.


Are $10\times 10$ matrices spanned by powers of a single matrix?

I don't know how to answer this question:     Is there a $10 \times 10$ matrix $A$ such that $$M_{10}(\mathbb{F})=\text{span}\{I,A,A^2,\ldots, A^{100}\}\textrm{,}$$ where $M_{10}(\mathbb{F})$ is the vector space of $10 \times 10$ matrices over $\mathbb{F}$?   I think there is a connection to Jordan normal form.


Including python matplotlib plots in LaTeX documents and inheriting document font properties

I am trying to get a standardised method to import plots from matplotlib into my LaTeX document, borrowing text formatting from the main document (so I want to avoid pure PDF). I am currently exporting the figure as  PGF. When I save the figure as a PGF the settings (linewidths, markersizes, annotation text sizes, etc.) do carry over properly, but the font is not inherited from the document. MWE: Create the figure in python: import matplotlib.pyplot as plt import numpy as np  plt.rcParams.update({'text.usetex': True})  x = np.random.random(10) y = np.random.random(10)  plt.figure() plt.plot(x, y, 'o') plt.xlabel('my xlabel') plt.ylabel('my ylabel')  plt.savefig('D:/_Current Work/fig.pgf')  LaTeX: \documentclass{article} \usepackage{pgf} \usepackage{pgfplots}  \renewcommand\familydefault{\sfdefault}  \begin{document}  \input{"D:/_Current Work/fig.pgf"}  \end{document}  The figure created will not change the font used in the tick labels and axes labels regardless of whether I include or omit the \renewcommand\familydefault{\sfdefault} to change the font to sans-serif. I've read many other posts on the forum about these two tools but it seems like this should work without any problems so I assume I am missing something basic. EDIT A few users suggested this question is a duplicate of . My problem seems to be the exact opposite of the question in the link: my math is being renderred according to the global math font correctly, but the normal text is not.


Comment edit button still enabled/available after edit period elapsed

Right now, for 5 minutes, you're able to edit any comment:    Even after the 5 minute grace period, this edit button still works/is enabled:    The user is mislead to believing they can edit their comment, and spend time improving/updating their comment, only to recieve this message:   For larger comments, this can be quite frustrating. I'd like to recommend some client side checks that when the comment reaches 5 minutes old, the edit button is removed from the client side (Or as soon as they hit the button, if it's more than 5 minutes old, display the error message). Additionally, if the user hits the edit button before the 5 minute period, I recommend a server side grace period (Somewhere between 1-5 more minutes) to allow the user some additional time to finish their edit.  While the duplicate mentions part of what I'm proposing, it does not going into detail about server side grace periods, nor how the edit button should work at 5 minutes (I offer a few different solutions). I find it difficult to justify editing the other post to add my suggestions to that post in order to make it resemble an exact duplicate (As stated in my comment below)


Indirect return of all elements in an array

The Bash man page describes use of ${!a} to return the contents of the variable whose name is the contents of a (a level of indirection).  I'd like to know how to return all elements in an array using this, i.e.,  a=(one two three) echo ${a[*]}   returns  one two three   I would like for:  b=a echo ${!b[*]}   to return the same.  Unfortunately, it doesn't, but returns 0 instead.  Update  Given the replies, I now realise that my example was too simple, since of course, something like:  b=("${a[@]}")   Will achieve exactly what I said I needed.  So, here's what I was trying to do:  LIST_lys=(lys1 lys2) LIST_diaspar=(diaspar1 diaspar2)  whichone=$1   # 'lys' or 'diaspar'  _LIST=LIST_$whichone LIST=${!_LIST[*]}   Of course, carefully reading the Bash man page shows that this won't work as expected because the last line simply returns the indices of the "array" $_LIST (not an array at all).  In any case, the following should do the job (as pointed out):  LIST=($(eval echo \${$_LIST[*]}))   or ... (the route that I went, eventually):  LIST_lys="lys1 lys2" ... LIST=(${!_LIST})   Assuming, of course, that elements don't contain whitespace.