Should Stack Exchanges sites with top-level domains have *.stackexchange.com redirects? For example:   stackoverflow.stackexchange.com serverfault.stackexchange.com superuser.stackexchange.com askubuntu.stackexchange.com seasonedadvice.stackexchange.com   (And also the meta.*.stackexchange.com versions of those too.)  It just seems like if someone hears about this Stack Exchange site Example that might help, they might try typing example.stackexchange.com instead of example.com.


"Sorry, Ubuntu 12.04 has experienced an internal error."

I have recently upgraded to Precise and had some errors. It seems to be quite random and with differences in the error reports. I have duly sent the reports hoping the system will have found the problem and sorted itself out. After the second error I am following the wizards (software...) advice and seeking help. The 1st time it happened I jotted down the following:  ExecutablePath /usr/lib/tracker/tracker-extract LaunchPad bug 950765 AMD64   The second time the following:  ExecutablePath /usr/share/appart/appart-gpu-error-intel.py "Possible GPU hang........" sandybridge-m-gt2 LaunchPad bug 981261   If there is anyone that can help it is much appreciated. I did not really want to upgrade at this stage, but was forced to due to the latest version of python-numpy in precise. You win some, you loose some....  Jacques   I am using a Pavilion dv6 notebook and 64bit ubuntu 12.04 LTS


Why are non-environment variables passed to the subshell invoqued by command substitution?

Bash manual says:     Command substitution, commands grouped with parentheses, and asynchronous commands are invoked in a subshell environment that is a duplicate of the shell environment,   except that traps caught by the shell are reset to the values that the shell inherited from its parent at invocation.   In this example,b isn't an environment variable, so b doesn't exist in the subshell created by command substitution. Then why is c assigned the value of b by command substituion? Is it because the parameter expansion happens for $b in the shell process before creating a subshell to execute echo 1?  $ b=1 $ c=$(echo $b) $ echo $c 1


The cover of my passport had deattached from the old passport. I am under F1 status in the US. can I still travel with it?

The cover of my passport had deattached from the old passport. I am under F1 status in the US. It happened at a layover and when the immigration officer checked he didn't say anything. Can I still travel with it?


How to create a new partition in Ubuntu 14.04?

I'm currently using Ubuntu 14.04. It's showing the whole hard drive as single partition. I need to split the drive into different partitions.  How can I accomplish this, preferably via the terminal?


I'm looking to read digital and analog pins on one arduino from another arduino. I believe that as long as they share a common ground connection this should work fine. I'm aware of I2C and I have used it for other projects, but for this I am more interested in just making the connections.  I was wondering   Has anyone had experience with this? Will I damage anything if I do this?


Why is $\lim_{n \to \infty}(1+1/n)^n$ not $1$?

I have the series $\sum_{i=1}^\infty n^n/n!$ in my math textbook, and it is used as an example for the ratio test. Completing the ratio test on this problem leads to having to take the limit of:  $$\lim_{n \to \infty}(1+1/n)^n$$  the textbook says that the answer is $e$, however when I take the limit I get  $$ (1+1/\infty)^\infty $$ which is just $1^\infty = 1$.     Am I missing something as to why this is not $1$? Does the variable $n$ behave different from other variables?


Finding specific implementation of generic interface on classpath

I bumped recently (twice) at following problem - is it possible to find on classpath specific implementation of generic interface? To visualize this please consider these snippets of code:    public interface Cleaner<T extends Room> {} public class KitchenCleaner implements Cleaner<Kitchen> {} public class BathroomCleaner implements Cleaner<Bathroom> {}   Now - Is it possible to have a following method ?:  public static <T extends Room> findCleanerServiceForRoomType(T room) {     return ??? }   returning KitchenCleaner for Kitchen class and BathroomCleaner for Bathroom class? Of course I would like to have it extensible so that when new Room and Service type is added this method still works... So no switches or ifs :)


Some of the more common symptoms of COVID-19 are fever and cough. There has been  of SARS-Cov-2 in feces. Do we have any further knowledge of the prevalence of GI symptoms among those with COVID-19?


How to remove file versions from the file source links in wp_head?

I observed the inside the wp_head function in the source links of every .css, .js files a ?ver=1 (or other number based on the file's/library version) is added. How can I overwrite them, to remove them?  This issue I think is causing problems on the cache manifest part.


java.lang.nullpointerexception for ImageIcons and optimization

so I'm working on a basic Slot Machine program for my school and I keep getting this exception. I understand what it means but I dont understand why it reads my image files as null.   Exception in thread "main" java.lang.NullPointerException at ui.UI.<init>(UI.java:22) at ui.Driver.<init>(Driver.java:27) at ui.Driver.main(Driver.java:39)   Any help is NEEDED!  I'm also not sure how optimal my code is so any tips on that would be great.  package ui; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.ArrayList; import java.util.Collections;  import javax.swing.*;   public class UI extends JPanel { private ArrayList<ImageIcon> images; private ArrayList<JLabel> labels; JPanel panel1; JButton a;  public UI() {     ImageIcon imageGreen = new ImageIcon("C:/Users/Liam/workspace/CSE115-Lab8a/Images/Green.png");     ImageIcon imagePurple = new ImageIcon("C:/Users/Liam/workspace/CSE115-Lab8a/Images/Purple.png");     ImageIcon imageRed = new ImageIcon("C:/Users/Liam/workspace/CSE115-Lab8a/Images/Red.png");      images.add(imageGreen);     images.add(imagePurple);     images.add(imageRed);     setLayout(new GridLayout(3, 2));       for(ImageIcon s : images) {         JLabel label = new JLabel(s);         labels.add(label);         add(label);      }     a = new JButton("SPIN");     add(a);      ActionListener click = new ActionListener() {         @Override         public void actionPerformed(ActionEvent e){             JLabel label = new JLabel();             removeAll();             updateUI();             Collections.shuffle(labels);             add(label);             updateUI();             }         };         a.addActionListener(click); } }   Driver  package ui; import javax.swing.*; import java.awt.*; import java.awt.Dimension;     public class Driver extends JFrame {  private static final long serialVersionUID = -3413552064004843029L; private JPanel panelMain; private UI panel;  public Driver() {     setLayout(new GridLayout(2, 1));     setPreferredSize(new Dimension(420, 90));     setResizable(false);     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);      panelMain = new JPanel();     panelMain.setBackground(Color.WHITE);     panelMain.setBounds(0, 0, 420, 90);     panelMain.setPreferredSize(new Dimension(200, 40));     add(panelMain);      panel = new UI();     panelMain.add(panel);     pack();       }  public static void main(String[] args) {     Driver frame = new Driver();     frame.setVisible(true);   }  }   THANKS!


How could i make a button behave like the back arrow key does?

I would like to know how to create a back button to move back through the characters of an input?  I got a backspace to work but am having trouble with moving back without deleting chars.    function setBack(){document.getElementById('someText').value = document.getElementById('someText').value.substring(0, document.getElementById('someText').value.length - 1);} function setOne(){ document.getElementById('someText').value += "A"; } function setTwo(){ document.getElementById('someText').value += "B"; } function moveBack(){document.getElementById('someText').value = document.getElementById('someText').value.substring(0, document.getElementById('someText').value.length - 1);} .inputUser{ width:55%; float:left;  margin-top:3%; border:0px; overflow-x:scroll; text-align:left; border:1px #000000 solid; } <input id="someText" class="inputUser" type="text" readonly dir="rtl">  <div> <button onclick="setOne();">A</button> <button onclick="setTwo();">B</button> <button onclick="setBack();">Backspace</button> <button onclick="moveBack();">back</button> </div>     No jQuery please. Thank You!


Copy all images in a directory to sub-directories in batches of 30

All of my images are in a single folder which are in excess of 1.6K. I want to make a batch of 30 images from the folder, and copy that batch over to its respective separate folder. The names of these folders can be anything, like folder1, folder2, fodler3, and so on. I have no idea how to approach the problem. I thought about writing a Python script to copy the files one by one and, as soon as the count reaches 30, change the folder. But I thought that maybe you guys have a better idea on how to do it with Bash.


I am trying to encourage my 5 1/2 year old son to try different activities but he often simply rejects them out of hand before trying them.  Recently I saw a groupon for ten Taekwondo lessons.  He did not participate in the first 3 lessons and said he didn't like it and wanted to stop.  I told him he had to do the 10 lessons because I paid for them.  After another few lessons he started liking it and now loves going to class and is doing well.  So by forcing him to go he found that he actually did like the activity.  I have been less forceful with regard to other activities because I don't want to be an overbearing father.  I bought him a soccer ball, basketball, bicycle, scooter, motorcycle, baseball and glove, ukelele, piano etc.  He says he doesn't want to do them.  Maybe he would like them if he tried them a few more times like his Taekwondo.  I want to expose him to as many things as I can and want him to find his passion (if he has one) but it seems he just doesn't want to try new things.  I see many other boys his age advancing in these activities while he wanders aimlessly.  He is a very active boy who runs a lot and is generally happy and I don't want to squash that demeanor.  I too took a long time to 'find myself' so I don't want to be too forceful but at the same time if I give up too early he might not find something he truly enjoys and might excel at.  I realize this is a somewhat open ended question with possibly no 'correct' answers but I would be happy to hear other parent's perspectives.


How do I find out which Windows 10 four-digit-version (not build number) am I running?

I currently face some problems with an update for Windows 10, and all guides, advice and troubleshoot sites out there start of by assuming you have specific versions of Windows 10 already running. But I am afraid I don't have those, since one of those numbers seems to be the update that gets stuck and doesn't finish correctly.  How do I see which version (not build number) of Windows 10 I'm actually running? All answers I've seen so far help you find which build number you have --since it seems more relevant for Windows apps developers--, but not the four-digit version number Microsoft is mentioning for troubleshooting the failed updates.  I've tried suggestions from a Windows 8.1 related question (); in particular I got some information with the following command line:  wmic os get Caption, Version, OperatingSystemSKU, OSProductSuite   but nothing of that seemed like the four digit number I see posted everywere (1511, 1607,...).  Also with msinfo32.exe and systeminfo.exe but still the same lack of 4-digit number.


Is there a limit as to how tall a building can theoretically* be? Why/Why not?   *By theoretically, I mean ignoring factors involving human discomfort (transportation, reduced air density affecting respiration, coldth etc), cost, material issues (Availability of substances etc).  I'm looking for purely physical answers with proper explanations.


My email attached to my Pokémon Go account will soon be deleted. How can I change it, so I can login with another email?


After Ubuntu boots, the tty1   Ctrl+Alt+F1 shows this:     Thegatorade-PC login: mountall: disconnected from Plymouth    mountall: Event failed   This happened after partitioning with gparted and happens every time I use Ubuntu.


How can I scp a file across two servers in one line?

I'm using Mac 10.9.5 and bash shell.  In our environment, we have to go through a proxy (a CentOS machine) to SSH properly into a destination machine (another CentOS machine).  What I would like to do is create a shortcut so that I can scp files quickly to the destination server, something like  scp localfile.txt davea@server:/home/davea   But right now, I have to do multiple commands to transfer the file …  scp localfile.txt davea@proxy:/home/davea ssh davea@proxy scp localfile.txt davea@server:/home/davea   Is it possible to condense the above into one line?


Creating shapefile of satellite image footprints?

I'm looking for a tool or a workflow to compute satellite image footprints, for a large number of images across directories, and produce a shapefile. Ideal work flow would be:   fire up tool point to a directory and provide file mask the tool browses directory and sub-directories and compute footprints the tool produces a shapefile with a polygon for each footprint and pre-selected attributes   It would preferably be Esri or ERDAS based, but not necessarily.


Already dual booting windows and ubuntu but want to install latest ubuntu on another hard drive

so currently I'm already dual booting windows and ubuntu. I've bought a new hard drive where I want to install the latest ubuntu but I want to keep my current setup whilst I make the transition to my new ubuntu installation. After that, I want to delete my ubuntu partition from the dual booting hard drive to just keep windows.  So essentially in the end, I'd end up with 1 hard drive with windows 7 and 1 hard drive with ubuntu. How would I go about doing this? How would I setup grub? I'm very new to this stuff, so any help appreciated.


Need help with old data and Ubuntu installation to replace Windows entirely

I have Windows Desktop which I am using from a very long time. I have been a regular Windows user since I have stepped in the computer world.  I have a plan to install Ubuntu on my desktop and want to remove the the Windows installation entirely. What I mean by this is I want to replace the whole windows 7 OS with the latest version of Ubuntu.  I have never used Linux before in my life at all but have started developing an interest in it.   My exact question is if in case I happen to install Ubuntu on my C: drive will I be able to access all my data on all the other drives as the data available on all other drives is extremely important for me and I cannot afford to loose it on any circumstances.  If not, then what are the steps to accomplish the same and an information if it is critical.  On the other hand I cannot backup the entire data as it happens to be about 1 TB.  Any help in this case is welcomed and appreciated.


I dont know if my question makes sense or not, but i am facing this problem   Case 1:  String fileLine  ="->->->6"; System.out.println(fileLine.split("\t").length);  output: 4   Case 2:  String fileLine  ="1->->->6"; System.out.println(fileLine.split("\t").length);  output: 4   The Problem Case:  String fileLine  ="1->6->->"; System.out.println(fileLine.split("\t").length);  output: 2   Can anyone tell me why is that and to capture this situation?  I want to capture the tabs in the end of the line as well even if the file end is empty  Thanks


What will happen to the hats when Winterbash is over?

Will there be a record of who had which?  Will the data be made available via the data.stackexchange site?


When I got the ps3 I had a different psn account then I do on my ps4. I want to remove the psn account from my ps3, but since I had loads of trophies(achievements) that I got before a psn account was added I want to be able to put a new psn account (the one on the ps4) on that profile and keep the trophies.


Compute $1 \cdot \frac {1}{2} + 2 \cdot \frac {1}{4} + 3 \cdot \frac {1}{8} + \cdots + n \cdot \frac {1}{2^n} + \cdots $

I have tried to compute the first few terms to try to find a pattern but I got  $$\frac{1}{2}+\frac{1}{2}+\frac{3}{8}+\frac{4}{16}+\frac{5}{32}+\frac{6}{64}$$  but I still don't see any obvious pattern(s). I also tried to look for a pattern in the question, but I cannot see any pattern (possibly because I'm overthinking it?) Please help me with this problem.


Could you please recommend should I carry all my lenses for a Safari Trip to Kruger Park in South Africa? I have the below lenses with Canon 80D Camera   Sigma 17-70mm f 2.8 - f4 OS HSM Tamron SP 70-200mm f2.8 VC USD Tamron SP 150-600mm f 5- f 6.3 VC USD Canon 50mm f 1.8   I am thinking should I carry both Tamrons or just the 150-600 and save up on weight on my shoulders? I am expecting there will be available light during the day to make sure 150-600 can shoot adequately.  Please help / advise should I carry an extra faster lens?


If $G/Z(G)$ is cyclic, then $G$ is abelian

Continuing my work through Dummit & Foote's "Abstract Algebra", 3.1.36 asks the following (which is exactly the same as exercise 5 in ):     Prove that if $G/Z(G)$ is cyclic, then $G$ is abelian. [If $G/Z(G)$ is cyclic with generator $xZ(G)$, show that every element of $G$ can be written in the form $x^az$ for some $a \in \mathbb{Z}$ and some element $z \in Z(G)$]      The hint is actually the hardest part for me, as the quotient groups are somewhat abstract. But once I have the hint, I can write:  $g, h \in G$ implies that $g = x^{a_1}z_1$ and $h = x^{a_2}z_2$, so \begin{align*}gh &= (x^{a_1}z_1)(x^{a_2}z_2)\\\  &= x^{a_1}x^{a_2}z_1z_2\\\ & = x^{a_1 + a_2}z_2z_1\\\ &= \ldots = (x^{a_2}z_2)(x^{a_1}z_1) = hg. \end{align*} Therefore, $G$ is abelian.  1) Is this right so far?  2) How can I prove the "hint"?


Proving that $\{0,1\}^\mathbb N$ and $\mathbb{N^N}$ have the same cardinality

Problem  Let $D$ be the set of all the functions $f\colon\mathbb N\to \mathbb N$ , where $\mathbb N$ is the set of natural numbers.   Let $E$ be the set of all functions $f\colon \mathbb N\to\{\,0,1\,\}$.  Prove both the sets have equal cardinality.   Attempt (failed)  $E$ is the set of all infinite binary sequences. By Cantor's second diagonal argument $E$ is uncountable. Since $E\subset D$, $D$ is also uncountable.  If i prove there exists injections from $D$ to $E$ and also from $E$ to $D$, then Schroeder-Bernstein theorem can be used.   Attempt 2  Consider two functions  $\alpha\colon D \to E$ and $\beta\colon E \to D $  Consider a function $f \in E$ is a function from $\mathbb N$ to $\{\,0,1\,\}$. $\beta(f) $ is a function that assigns to $n$ the $f(n)+1$ . This is a injective function .   I have difficulty finding $\alpha$.  Any hint or help will be appreciated.


What was Data's joke about clowns and Ferengi in gorilla suits?

In , Data remembers a joke and finds it funny. He only reveals the joke's punchline:     The clown can stay, but the Ferengi in the gorilla suit has to go.   What was the complete joke? Is it mentioned anywhere?


Why was this bounty awarded by the Community user?

I accepted an answer to this question:    but the bounty was awarded by Community ♦ to another answer. Why did this happen?


Center of the group algebra of the symmetric group

How to prove that the center of the group algebra of the symmetric group is generated by 1-cycle conjugacy classes? I mean, that the center (consisting on class functions) is multiplicatively generated by classes of cycle permutations.


Increasing the FOV on Borderlands (Steam version)

Aight, I've read up on the five other posts here and managed to "brick" my game... of sorts. The current FOV gives me a headache when dealing with anything nearby. I put the line:  Bindings=(Name="F1",Command="FOV1 00",Control=False,Shift=False,Alt=False)    in my steamapps\common\Borderlands\WillowGame\Config\DefaultInput.ini file, and the game has absolutely no input except for my F1 binding (which zooms out to a decent FOV, but then nothing else works).  I had some other keys bound to lower FOV's but they did not work, and they do not pull this out of the wider view.  Everything here seems to be outdated or not for the Steam version, and there's .ini's everywhere. I tried tweaking some others, but they did nothing.  Any ideas? Thanks in advance!


How can instantaneously extract text from a screen area using OCR tools?

In Ubuntu 12.10, if I type  gnome-screenshot -a | tesseract output   it returns:  ** Message: Unable to use GNOME Shell's builtin screenshot interface, resorting to fallback X11.   How can I select a text from the screen and convert it to text (clipboard or document)?  Thank you!


When a druid wild shapes to a beast that has double proficiency with a skill, should the druid's proficiency bonus be doubled with that skill?

When a druid uses its  feature:     Your game statistics are replaced by the statistics of the beast, but   you retain your alignment, personality, and Intelligence, Wisdom, and   Charisma scores. You also retain all of your skill and saving throw   proficiencies, in addition to gaining those of the creature. If the   creature has the same proficiency as you and the bonus in its stat   block is higher than yours, use the creature's bonus instead of yours.   Consider the example of a Circle of the Moon druid, who does not have proficiency in Stealth, taking the form of a . A saber-toothed tiger's statblock states that it has a +6 modifier to Stealth. Since the beast's Dexterity modifier is +2, and a CR 2 beast has a proficiency bonus of +2 (), the saber-toothed tiger must have double proficiency in Stealth.  Should the druid therefore double their proficiency bonus and add it to the saber-tooth tiger's Dexterity modifier, resulting in the wild-shaped druid having +8 to Stealth at level 6, +10 to Stealth at level 9, etc.?


How much time does Google take to display rich snippet of a web page?

I have put some Event rich snippet on the , and Google has already crawled this page(as I knew it from the Google Cached Timing of this page), but Google is now showing the Event Rich Snippet.  Although when I have tested this page on , I found no error there.  So, I want to know that does Google take some time to display the rich snippet after crawling a web page?  Could anybody help me to find out what is the problem with this page, so that the Rich Snippet is not being displayed properly on Google Search.


I use Ubuntu 14.04 at work. It's the first major use of Linux that I've had. I have gotten used to it so much that I prefer using it instead of Windows for all work, particularly in a command line; I am a software developer so perhaps this might not surprise you.  I am considering installing Ubuntu in a new personal laptop.  However, I would want to completely remove Dash. I am absolutely not interested in searching my computer through a GUI (I use find). I've had Ubuntu 14.04 for two years and haven't used Dash a single time. It's intrusive to my workflow. I do not want to pay the cost of a background application indexing my machine. I do not want to pay the cost of the indexed database storage on my machine.  I want, instead, a more Windows XP style prompt. It should have a hierarchy of directories which I manually created. I have that already on the filesystem, but a GUI navigation tree would be acceptable. However, having this menu is not as important to me as removing Dash.


Hello i have an asus s550cm and i have a 24gb Kingston ssd, i installed Windows 8 and i have a problema with junction links.  The only junction link i can make it´s users folder but when i try to remove  -ProgrData -Program files -Program files (x86)  I can´t even when i enter Command line after and before configuring Windows I use:  robocopy "c:/program files" "d:/program files" /E /COPYALL /XJ rmdir "C:/program files" mklink /J "c:/program files" "d:/program files"


Confidence intervals of positive parameters reaching into negatives

Suppose I want to estimate the proportion parameter for a binomial distribution, and my method for constructing a 95% confidence interval (e.g. MLE +- 1.96 SDs) gives an interval of let's say (-.1, .3). Then what is the standard practice? I mean it's not wrong by my understanding of what a confidence interval is, but on the other hand would it be better to truncate the interval? So if the normal approximation gives (a,b), the CI should be (max{a,0},min{b,1})


Best approach to parse the expression - Multiple variables

I have a situation where i need to parse multiple n number of related fields (Do not want to evaluate):      string exp1 = "10";     string exp2 = "20";     string exp3= "exp1 + exp2 + 30";     string exp4 = "exp5 - exp3";      string exp5 = "exp3 / 10";      Dictionary<string,string> expressions = new Dictionary<string,string>();     expressions.Add("exp1", exp1);     expressions.Add("exp2", exp2);     expressions.Add("exp3", exp3);     expressions.Add("exp4", exp3);     expressions.Add("exp5", exp5);   Now we want to loop through all the expression fields and parse the expression with the actual values (Bodmas should also be applied) .So, after parsing, We want below as output:  exp1 = "10"; exp2 = "20"; exp3= "10 + 20 + 30"; exp4 = "((10 + 20 + 30 )/10) - (10+ 20 + 30)"; exp5 = "(10 + 29 + 30)/ 10";   What would be the data structure I should use here to parse it using a generic way? Would it be Binary Tree, graphs, ExpressionTrees?


Hi i am new too latex environment. i configure the texstdio bibtex to biber. But My bibliography isn't displaying. It shows warning about empty bibliography and undefined references.  My main.tex file is  \documentclass[12pt]{report}  \usepackage{biblatex}  \addbibresource{lol.bib}  \begin{document}   Bibliography \cite{lol}.  \printbibliography  \end{document}   My lol.bib file is  @article{lol, author        = {B. B. CHAUDHURI* and U. PAL}, title         = {A COMPLETE PRINTED BANG¸A OCR SYSTEM}, journaltitle  = {Pattern Recognition Society}, year          = {1998}, volume        = {31}, number        = {5}, pages         = {531-549}, doi           = {10.1016/S0031-3203(97)00078-2} }   Output is  Bibliography [lol].  error is showing.    i am stuck for 3 hour. what should i do??


Can an Echo Knight fighter's Manifest Echo move through another creature's space?

I would like to know if an Echo, created by the Manifest Echo ability of an Echo Knight, can move through the space of another creatures (hostile or not)? I know characters cannot normally move through an enemy's space, and can move through an ally's space with some movement cost.  But based on multiple unofficial , an Echo itself is not considered a creature, and instead is listed as an "image" and an "object" . It is also worth noting that and Echo "...occupies its space", per the subclass description, and thus I'm not sure how to rule it. This question relates directly to, ""


When saving a webpage from Chrome on Android, where in the file manager can I locate the stored file?

I need to know where are the saved webpages of Google Chrome stored in Android.  I mean, I can access them from the browser itself but I need to know where its stored in the file manager.


Ubuntu 18.04.3 LTS Permanently disable on screen keyboard

Does anybody know how to get rid of the on screen keyboard for good please? It's disabled in the Universal Access but each time a text entry element is touched on the touch screen back it comes like a dose of STD. I have this on multiple devices running different flavours of 18.04.X and it's extremely undesirable.  Seems to go away if I plug a physical keyboard in but I don't want to do that.


Jquery return the same id,but i don't use the same id on two elements

I have a table and for this table i have an icon "plus" and for each row i have an icon "edit".  When i press "plus" it will create another tr with a select in it and an icon "edit".  This "edit" has an id that is equal with the number of the row,so the first "edit" icon will have id=1,the second id=2 and so on(i'm using an i++ for this).  My problem is that,when i press on "edit" icon i want to display in console the id of the icon(testing porpouse),but this will only work on the first icon.  I saw in another question that this will happen if you have the same id on more elements,but i don't.The code is this:  The main table,with just one row:

                                      <select class="form-control select-table" name="products[]" id="select-1" data-dep="">                         <?php foreach($products as $product):?>                             <option value="<?php echo $product['products_id'];?>"><?php echo $product['product_name'];?></option>                         <?php endforeach;?>                     </select>

   The jquery code where i add a new row:  var i = 1;     $('#plus-div').click(function(){         i++;         j++;         $('#dynamic').append('
<select  id="select-'+i+'" class="form-control select-table" name="products[]">' +             <?php foreach ($products as $product):?>'<option value="<?php echo $product['products_id'];?>"><?php echo $product['product_name'];?></option>' +             <?php endforeach; ?>             '</select>
');     });   The jquery code where i display the id:  $('.edit-div').click(function(){         console.log((this).id);     });


What will be my next step to install Ubuntu

I am totally new to Ubuntu,I have download the latest Ubuntu 12 64bit(ubuntu-12.04.4-desktop-amd64.iso) from the Ubuntu site,the file is approx 700mb.  I want to install it on my laptop(currently on windows 7 32bit) that's why i copied the file to my usb then paste it to the c: drive of my Windows platform,(the file is in rar format) that's why i extracted it and found that there is wubi.exe (which is the Ubuntu installer for windows).  Now what should I do, do I? Just click the wubi.exe and follow the process, will wubi.exe need any internet connection to download any other extra file or 700mb is enough.


Controling and getting feedback for robots in Blender

Is it possible to control, and get feedback for robots in Blender using the python API?   I'd like to have proxy objects in Blender, that I can control, that will control my reallife robot, but also will mirror the actions of the real life robots. I would like to use wifi to send the information, and the robot would use either an Arduino or Raspberry Pi.  Is it possible to do this in Blender using Python, and if so, how would I go about doing it?


How can I automount my hard disk partitions?

How can I auto-mount all my hard disk partitions?


Change the default application (for a file extension) via script/command line?

Is there a way to define the default application for a file extension via an Apple script, command line command (like defaults write [...]).  I know that you can change it manually via the information panel or by using  but as I have to setup many machines and user accounts I would like to find a way to automate the process.


Question: Does the sequence 144; 1,444; 14,444; 144,444; ... contain any squares besides 144 and 1,444?  One can easily see that $12^2=144$ and $38^2=1,444$, so I am wondering whether the sequence contains any further squares.  The number 14,444 is not a square, because it is strictly between $120^2=14,400$ and $121^2=14,641$ (found in row 4 in Pascal's triangle).  Similarly, the number 144,444 is not a square either, because it is strictly between $380^2=144,400$ and $381^2=145,161$.  More generally, as one might expect, the square root of one followed by an even number of fours begins with the digits one and two, while the square root of one followed by an odd number of fours begins with the digits three and eight.  Using modular arithmetic, one can easily show an integer whose square ends with a four in base ten must either end with a two or an eight in base ten.


How can I display images in terminal from a filename?

I use Ubuntu 18.04 and want to display images in terminal from a specified file name.I tried VIU and FIM, but they display the image in different windows. I want the image to displayed in the same window under some text.How can I do so?


How to find the type from database resultset in java

Hello I'm making an app in java!my program loads data from a database and we can make some changes (like deletion, import, etc.) through it. I'm at the point where I want to load the items into a JTable. I'm trying to get the type of the object but I get NullPointerException.   I'm sorry if I'm not understandable, it's just my first time I'm asking here.      @Override public Object getValueAt(int row,int col) {     Object retVal=null;     try{         rs.absolute(row + 1);         switch(col) {             case 0:                 if(rs.getString(c1) == null){                     retVal=String.valueOf(rs.getInt(c1));                     break;                 }                 else{                     retVal=rs.getString(c1);                     break;                 }             case 1:                 if(rs.getString(c2) == null){                     retVal=String.valueOf(rs.getInt(c2));                     break;                 }                 else{                     retVal=rs.getString(c2);                     break;                 }             case 2:                 if(rs.getString(c3) == null){                     retVal=String.valueOf(rs.getInt(c3));                     break;                 }                 else{                     retVal=rs.getString(c3);                     break;                 }             case 3:                 if(rs.getString(c4) == null){                     retVal=String.valueOf(rs.getInt(c4));                     break;                 }                    else{                     retVal=rs.getString(c4);                     break;                 }              case 4:                 if(rs.getString(c5) == null){                     retVal=String.valueOf(rs.getInt(c5));                       break;                 }                 else{                     retVal=rs.getString(c5);                     break;                 }             case 5:                 if(rs.getString(c6) == null){                     retVal=String.valueOf(rs.getInt(c6));                     break;                 }                 else{                     retVal=rs.getString(c6);                     break;                 }         }                } catch(SQLException e) {         System.out.println("getValueAt: " + e.getMessage());     }     return retVal; }


What's the difference between the "%s" in vim normal mode and regular GNU sed

I am quite new to regex, and thought markdown(custom/madeup format of maardown) to html conversion using regex would be a good way to get started. When I'm within Vim(8.1), say converting this line; +style #include <style.css> -style  to; <link rel="stylesheet" type="text/css" href="style.css">  I used this command in Vim; :%s/^+style$\n\(.*\)$\n^-style/<link rel="stylesheet" type="text\/css" href="\1">/g  And I get exactly what I was hopping for. However, when I ran the same command from my terminal using GNU sed, I get no change in output; sed 's/^+style$\n\(.*\)$\n^-style/<link rel="stylesheet" type="text\/css" href="\1">/g'  Also, including the -z flag doen't seem to be much of a help either, the output remains same as input. I wonder why that is.


Views exposed filter to search multiple fields

To my knowledge there hasn't been an option in drupal 7 to create a single exposed filter in a view which searches multiple fields, while in previous versions there existed modules to do just that.  Using the or operators is fine but then you get multiple fields in the form.  Add Global: Populate filters and you can have a single field but then the view never shows anything.  Is there any way or module that will make this work?  Edit: What I didn't notice was the field operators. For some reason the default operator for text fields in views is =, while a proper search function needs contains or has word. I've been looking for the reason I couldn't get it to work for almost 6 months now. Wow. What a pain. /facepalm


Attempt to invoke virtual method 'on a null object reference

package com.example.ben.droidmice2;   import android.hardware.Sensor;  import android.hardware.SensorEvent;  import android.hardware.SensorEventListener;  import android.hardware.SensorManager;  import android.support.v7.app.AppCompatActivity;  import android.os.Bundle;    import com.example.ben.droidmice2.net.NetworkTask;   public class MainActivity extends AppCompatActivity implements   SensorEventListener{      private long lastUpdate = 0;     private static final float TILT_THRESHOLD = 1.1f;      private SensorManager sensorManager;      //sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);     }      private void getAccelerometer(SensorEvent event) {         Sensor mySensor = event.sensor;          if (mySensor.getType() == Sensor.TYPE_ACCELEROMETER) {             float x = event.values[0];             float y = event.values[1];             //float z = event.values[2];             long curTime = System.currentTimeMillis();              if ((curTime - lastUpdate) > (1000/60)) {                 long diffTime = (curTime - lastUpdate);                 lastUpdate = curTime;                  if(Math.abs(x) > TILT_THRESHOLD || Math.abs(y) > TILT_THRESHOLD) {                     int dx = (int)(x  * diffTime);                     int dy = (int)(y  * diffTime);                      new NetworkTask().execute("MOVE " + dx + "," + dy);                 }             }         }     }       @Override     public void onSensorChanged(SensorEvent sensorEvent) {         if (sensorEvent.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {             getAccelerometer(sensorEvent);         }     }      @Override     public void onAccuracyChanged(Sensor sensor, int i) {         // Ignorable     }       protected void onPause() {         super.onPause();         sensorManager.unregisterListener(this);     }       @Override     public void onResume(){         super.onResume();         // register this class as a listener for the orientation and         // accelerometer sensors         sensorManager.registerListener(this,                 sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),                 SensorManager.SENSOR_DELAY_FASTEST);     }   }   I'm trying to make a app that move phones and let phone acts like a mouse  here's my code it tells me i have some problem on  Attempt to invoke virtual method 'android.hardware.Sensor android.hardware.SensorManager.getDefaultSensor(int)' on a null object reference for me there's no problem inside OnResume() here somebody help?


Upvote reputation was not added with my Account

See the above Image its my account .Two question upvote reputation not added with my account.But the answer reputation was added. Any body explain why? and Whats the reason?


Prove that $G$ graph contains prime cycle, which length is not less than $\delta(G) + 1$

Prove that if $G$ graph $\delta(G) \ge 2$, than the graph contains prime cycle, which length is not less than$\delta(G) + 1$  I have proved that for every graph with $\delta(G) \ge 2$, has a prime cycle, but I am stuck for the length.


Jean Baptiste Joseph Fourier (1798–1830) was a French mathematician who is most widely recognized for his development of what we now call Fourier Series.  In ABE425, we do not solve differential equations, but we use Fourier Series to analyze signals by creating frequency spectra.  Let's assume we have an interval $[0,2\pi]$ on which our signal (input function) is defined.  According to Fourier we can now write our input function $f(t)$ as the sum of a constant and a sum of cosine and sine functions of varying frequency $n$ (also known as basis functions) as follows   $$ f(t) = c_0 + \sum_{n=1}^{\infty} a_n \cos(nt) + b_n\sin(nt) \tag{11.1} $$   According to a textbook that my professor wrote, it is defined as shown above.  But I wanted a more specific/deeper explanation of what exactly this "basis function" is. Can someone explain what basis function is with examples if possible and why it is applicable in Fourier series?


I know it's much better to use \[ \] over $$ $$ when typesetting math equations on their own line (I believe this is called display math?) But is it also inappropriate to use $ $ for in-line math over \( \)? If so, what are the reasons? I find the latter much more cumbersome to type, so I'd only like to use it if there's a good reason.


XeLaTeX not giving priority to .cbx files in local texmf tree

I just installed MacTeX on a new machine. I'm running into a difficulty I hadn't had before.   I have a .cbx file inside ~/Library/texmf/tex/latex/biblatex/cbx/ that has the same name as another .cbx file inside /usr/local/texlive/2017/texmf-dist/tex/xelatex.   If I run LaTeX on a file calling the corresponding citation style (\usepackage[citestyle=name-of-cbx-file]{biblatex}) the .cbx file inside the texmf tree inside ~/Library is given priority. If I run xelatex on the same file, however, the one that is inside texmf-dist is given priority.   This is the output of kpsewhich -expand-var='$TEXINPUTS':  .:{{}/Users/apc/Library/texlive/2017/texmf-config,/Users/apc/Library/texlive/2017/texmf-var,/Users/apc/Library/texmf,!!/usr/local/texlive/texmf-local,!!/usr/local/texlive/2017/texmf-config,!!/usr/local/texlive/2017/texmf-var,!!/usr/local/texlive/2017/texmf-dist}/tex/{kpsewhich,generic,}//   Shouldn't xelatex and latex be searching for biblatex style files in the same way? If so, why is xelatex not finding the files?


How do I stop my second monitor from cutting off top and bottom?

My Samsung SyncMaster 913v (henceforth "913v") outputs VGA. Thus I need a VGA-to-HDMI adapter to connect it to my Lenovo Ideapad Y700.   In Dec 2016, I bought . In Sep 2018, it failed, and then I bought , but the 913v's top and bottom were cut off. Thus in Oct 2018, I tried another adapter: . But the cutoffs remain:


How does Ethernet know how long a frame is?

Looking at the  entry on Wikipedia, I can't figure out how it's indicated how long the Ethernet frame is.  The EtherType/Length header field apparently can indicate either a frame type or an explicit length, and I'm guessing that in the case of a frame type, it has to do some other logic to figure out how long the packet is.  For example, if the EtherType field is 0x0800, that indicates an IPv4 payload, and so the receiving NIC would have to examine the first 32 bits of the payload to find the length of the IP packet, and therefore to figure out the total length of the Ethernet frame, and know when to look for the end-of-frame checksum and interframe gap.  Does this sound correct?  I also looked at the  for Ethernet (part 1, anyway) which seems to corroborate this, but it's pretty opaque.


I am self learning abstract algebra. I am using the book Algebra by Serge Lang. The book has different definitions for some algebraic structures. (For example, according to that book rings are defined to have multiplicative identities. Also modules are defined slightly differently....etc) Given that I like the book, is it OK to keep reading this book or should I get another one?  Thank you


I want to automatically disable my touchpad when I use a mouse. I have tried touchpad indicator which didn't work (error message, couldn't install) and configuration using synaptics driver but it's too complicated for me :(   Any ideas?  Another thing, if I don't use a mouse I would like to configure the touchpad settings, because "disable touchpad while typing" doesn't help and it is really impossible to type right now.   Is there any easy way to change the settings for the touchpad?  Thank you!


What's the code for “evaluated at” line with separate limits?

I want the limits separated, like in the second one here:   TOO CLOSE: $\int_{a}^{b}$ RIGHT: $\int\limits_{a}^{b}$   How to I do the same thing with the vertical line "evaluated at"-limits?   TOO CLOSE: $|_{a}^{b}$ then the limits are too close; I want them more separated. RIGHT: ???


How to Prove with Mathematical Induction $3^n > n^2$

How do I prove that $3^n > n^2$ with mathematical induction? I thought I had the correct answer but my teacher says its wrong.  I let $n=1$ for the initial case and it works. I then assumed $n=k$ works and went onto the $n=k+1$ case, but after that it goes a little awry. Thanks in advance!


Find the value of the double integral: $\int\limits_0^{2a}\int\limits_0^{\sqrt{2ax-x^2}}\frac{\phi'(y)(x^2+y^2)xdxdy}{\sqrt{4a^2x^2-(x^2+y^2)^2}}$

Evaluate $$\int_0^{2a}\int_0^{\sqrt{2ax-x^2}}\frac{\phi'(y)(x^2+y^2)xdxdy}{\sqrt{4a^2x^2-(x^2+y^2)^2}}$$  Here I changed the order of integration but after that I am not able to think of the relevant substitution to proceed with the integration.  I have tried to substitute it with polar co-ordinates but didn't succeed in solving that either.  I have checked the solution provided here  , but this solution is very lengthy.  I am looking for a shorter way of solving this question which is more obvious to hit during exam and also considers the space constraint.  If someone could suggest what substitutions to make to solve it in lesser steps.


How to modify an existing part in an installed integrated library in Altium designer?

I'm new to PCB design, I'm using Altium to design a PCB. I have installed a few useful libraries. Sometimes in my design I find that a part is not exactly what I want, it needs some modifications. Is it possible to make changes to the library and then immediately use it? When I open the integrated library It asks me to extract it, then I compile it and reinstall the library! I'm sure I'm doing it the wrong way.


How to solve this inequality question: $\sqrt{\frac{a}{a+8}} + \sqrt{\frac{b}{b+8}} + \sqrt{\frac{c}{c+8}} \ge 1$ for $abc=1$?

$abc=1$ where $a$, $b$, $c$ are positive reals. Prove that $$\sqrt{\frac{a}{a+8}} + \sqrt{\frac{b}{b+8}} + \sqrt{\frac{c}{c+8}} \ge 1$$


How to enlarge font of street names while printing in QGIS?

I have to print some Municipality shots and I use OpenStreetMaps or Google Maps but when I print the streets names are too little and is is not possible to read them. On screen names are perfectly legible and the size is right. How can I solve?  I use OpenLayerPlugin v1.4.1


I've got a swap partition, but the System Monitor in Linux Mint says, 'Swap not available'. I guess I've forgot to set 'Use as: swap' on install.  How to fix this?


How can i ignore a space in file name using if condition

I tried:  for item in * do  if [ -d  ${item} ] then  echo "$item"  fi done   and when a file name with space is read it prints error:   line 11: [: too many arguments


It appears that Winter Bash just went down.   now redirects to  exchange.com/promos.  Additionally, the snowflake and my hats have disappeared from my view.  Is this a bug?


Everyone I speak to says that a 50mm lens is the best and beats them all as an all-rounder. I was wondering whether to get myself a decent, fast 50mm as well. However I'm still not 100% sure whether I really need such a lens.  I use a Pentax K10D and mainly shoot people (kids, portraits, some street shots). The lens I love and use most is the DA 70mm f/2.4 Limited. I often also use a DA 40mm f/2.8 Limited. They are great little lenses that produce very high quality images but they could be a bit faster.  Is is worth spending 400 quid on a Sigma 50mm f/1.4 in my situation? It seems like a good compromise between the 40mm and 70mm and much faster (in fact, 2 f-stops faster than the DA 70mm f/2.8!). On the other hand would the lens be sufficiently different from my current lenses?


Windows Update doesn't work and consumes 100% of CPU

I have a fresh installed computer with Windows 7, 64-bit, Service Pack 1.  After a few minutes after startup, svchost.exe is consuming 100% of one cpu core.  I know there are many threads which are dealing with this problem, but none of them helped me.  I installed this updates: KB3050265 and KB3065987  I used this "Microsoft Fix it"-Tools: MicrosoftFixit50123 and MicrosoftFixit50362  I installed the current Windows Update Agent:   I tried to remove the SoftwareDistribution directory:  net stop wuauserv net stop bits rd /s /q %windir%\softwaredistribution net start bits net start wuauserv wuauclt.exe /detectnow   And I tried to connect the computer with my home network over a usb/ethernet-adapter, and I tried to disable IPv6.  For diagnostic, I post here the WindowsUpdate.log file (after removing the SoftwareDistribution Directory, waiting until the service is hanging on 100%):


Phd program @Harvard when my '''education''' didn't go beyond highschool?

Would I be accepted at a Phd Program @Harvard when my '''education''' didn't go beyond high-school? I have however done lot of self-study after graduating from high-school by studying:   Electrodynamics. General Relativity. Quantum Mechanics ...   and all the maths that is related to those physics areas. So do I have any chance?


What's the difference between "speak" and "talk", grammatically speaking?

There are a number of questions e.g.  and  that deal with the slightly different connotations of the words "speak" and "talk". However, there also seem to be some grammatical differences between the two words. This question is about whether there's a way to formally pin down these differences, or whether they're just contingent features of the two words having different histories.  Some examples of grammatical differences are as follows:   be talkative ... be speakative speak French ... talk French give a talk ... give a speech (as opposed to a speak) speak up ... talk up (the meanings of the two phrases being completely different, with "up" being a preposition only in the latter case) speaking of which ... talking of which grammatically speaking ... grammatically talking   On the other hand, many other constructions work just as well with either (though they might have subtly different meanings), for example   speak to ... talk to speak with ... talk with speak about ... talk about   I'm interested in whether there's a way to pin down these differences (e.g. are the two words classified as different types of verb in some way?), or whether they're essentially just arbitrary. I'm also interested in why we have these two different words with subtly different meanings. Is the distinction between “speak” and “talk” a feature of many languages, or is it just a peculiarity of English?  Etymologically, both words are from Germanic origins. “Talk” seems to have been formed from the Middle English tale, even though “speak” already existed in the English language by then (as far as I can tell). This makes it even more mysterious: Why did we form a new word as a synonym of one that was already established? Or were the meanings different at that time?


How to merge coordinates into one value and return it?

As above, any tricky methods to do so? Since you cannot pass an array, I wonder how to return coordinates (x/column and y/row) to the calling object. Regards.


Install Win10 Pro 64 bit on Laptop Dell Vostro 3580 AFTER Ubuntu 18 desktop

I have just bought a DELL Laptop Vostro 3580 Intel Core I5-8265U having dedicated Ubuntu 18 already installed (customized for Dell laptop)  I'd like to ask you two questions,please:  1) Is it possible to install Windows 10 Pro 64 bit from a "regular"- off the shelf-  stick/DVD distribution as the second OS, keeping the already installed UBUNTU as the first OS and having dual boot ?  2) I believe that UBUNTU 18 is desktop version, not server version.  Is it possible to install LAMP suite on my laptop ?  I'd like to start programming in PHP and MySQL.  Thank you very much !  Best regards, Paul


Why is the variance of a binomial distribution n*p*(1-p)?

I don’t understand why this is the formula for variance for binomial distribution. The 1-p especially confuses me. The variance in the square of the standard deviation which I don’t get how this gives us a deviation.


unpacking lists inside another list python

Assume you have a list :  mylist=[[1,2,3,4],[2,3,4,5],[3,4,5,6]]   any pythonic(2.x) way to unpack the inner lists so that new list should look like ?:  mylist_n=[1,2,3,4,2,3,4,5,3,4,5,6]


I have the following random data in sheet one  A  orange D  yellow C  yellow B  orange B  orange C  blue A  yellow D  blue C  orange C  blue   In sheet two I use the following query function:  A1=UNIQUE(QUERY(Sheet1!A1:B10,"select A, B order by A asc")) C1=sumproduct(Sheet1!A:A=A1,Sheet1!B:B=B1) C2=sumproduct(Sheet1!A:A=A2,Sheet1!B:B=B2) C3=sumproduct(Sheet1!A:A=A3,Sheet1!B:B=B3) . . .   Which returns the following:  A   orange 1 A   yellow 1 B   orange 2 C   yellow 1 C   blue   2 C   orange 1 D   yellow 1 D   blue   1   Instead of using sum product in each row, I want arrayformula to expand automatically.  When I use E1=ArrayFormula(sumproduct(A1:A10=C1:C,B1:B10=D1:D)) I get     Error: Array arguments to EQ are of different size.   Please help me out.


How should I phrase a question that must be answered with an ordinal number (e.g., the third prime)?

I want to make a question having an answer as follows:     5 is the third prime number.   The bold part is the answer. How to phrase the question?


The Earth is spinning, so why don't we jump and land on a different location?

I know there are similar questions on StackExchange but I think it is different and detailed.  The earth is spinning 465 meters/second so why don't we jump and land on a different location?  I googled about this question and I got some answers:   When we jump, we (and the atmosphere itself) also spin along with the earth so we don't land at a different location. (But why we are also spinning along with earth ?) The earth is so big and we are very small relative to earth so the tiny jump won't make any difference.   But according to answer 1, We are also spinning with the earth. But the question is, "why are we also spinning along with earth" ??  Regarding the answer 2, it won't make any difference but logically it doesn't make sense or I just don't understand it.  Here is the followup question,   "When we jump why don't we thrown out of earth due to centrifugal force of the spinning earth ??"  Please provide some detailed answer to these questions. With logic if possible.   This phenomenon is not possible I know, but even if it exists, then traveling will be so easy, we just have to hang on space (with help of helicopter etc.. ) and we can travel the whole world in 24 hours :D


I got a MS SQL table for translation of my webpagel, when I change my language to german there are words what are not shows properly an example in DB:  EL_ID   TEXT_EN TEXT_DE el10    Reset   Löschen   but when I use in my html/php page it is not showing properly:  [10] => Array         (             [0] => el10             [1] => L�schen         )   in my webpage I got activated:  <!DOCTYPE html> <HTML>   <HEAD>     <meta charset="UTF-8">     <TITLE>     </TITLE> ...   It is the data what is carried out from the DB or the HTML presentation the issue?


Most elegant way for a switch case as in C

In order to parse some args via cmd line, I've a "switch case" written with if .. elif  if arg == 1:     ..something... elif arg >= 2 and arg < 4:     ..something else ... elif arg < 6:     ..something else ... else:     ..something else ...   above, elif arg < 6: could be replaced by:    elif arg == 4 or arg == 5:  this get's a bit messy when there are more argument values to check.  What could be the most efficient and easy way to read the code?


I want to animate water splash.  All I want is to splash water from bottle to paper towel. Which method should I use ?    Thanks,


How can I handle two extremely different brightnesses in the same picture?

I am the fresh owner of my first DSLR (a Canon EOS 600D, as far as I know called Rebel T3i in the USA). I'm a total newbie, and the camera is a lot smarter than me most of the time. But I'm trying to learn how to choose the settings for certain situations myself (in particular when it comes to lighting) instead of leaving stuff to the electronics.  Now, I understand the theoretical basics of the influence of exposure time, ISO, and aperture size on the resulting image, but knowing the theoretical basics of a combustion engine doesn't enable me to drive in the Indy 500.  So I'm trying to take pictures here and there and looking at results etc., and now I have a situation where I have no idea what to do. The example is probably silly; this is more a "I'd love to know how it works" than a "this is an actual problem I need solved".  I have a ceiling lamp (essentially a tinted glass ball) that has a very nice structure to it and gives the (white) ceiling above it a nice orangy-red glow. Capturing the structure is doable:   (f/5.6, 1/500s, ISO100)  Getting the nice glow is probably possible as well, by finding something between these two and adjusting the white balance:   (1: f/5.6, 1/125s, ISO 800; 2: f/5.6, 1/60s, ISO 3200)  (yes, the aperture is identical among all three images; I also tried slower ones, but didn't get any noticably different results).  So usually I'd say "well yeah, it's impossible; you have a glass structure with a bright light bulb behind it, and a dimly lit ceiling; no way you're getting those two nicely into a single image". But over the past few days since I started trying to learn about photography, I've read up on so many ways to play with how light reaches the sensor, that I wouldn't be too surpised to learn I can actually achieve both.  Can I?  Note that I'm interested in doing this in one shot; I can obviously combine two different images during post-processing, but I'm interested to learn "tricks" to achieve this in a single shot.


I am facing difficulty in passing parameters to apex method from test method. In apex method, I am getting parameters from my VF page. Example of Apex Method: public PageReference create_contact()  {         String callfrom = System.currentPageReference().getParameters().get('callfrom');                  Contact newCon = new Contact(lastname = 'Anonymous', phone = callfrom);           insert newCon;                  return null; }  My Test method: static testMethod void testmatchingcontactController() {         test.startTest();         matching_contacts mc = new matching_contacts();         mc.create_contact();         test.stopTest(); }  On running test method, I get an error that "Argument cannot be null" because the parameter callfrom in apex code is provided by Visualforce page in application. I don't know how can I pass it from test method. Please help if you know solution to this problem.


How to detect which Malware has affected my system

My system is showing advertisements of all sorts popping everywhere and I cant use my system properly. Someone suggested it is a malware issue but what are my options how to detect which malware and how to cure it.


What is a term for using a large word that the speaker/writer clearly thinks means something other than what it does?

A lot of times I'll hear a politician or see a  where they clearly think the meaning of one or more words they use is something other than the real meaning. Is there a term for this type of "near miss?"


how to install Ubuntu Phone OS on my samsung galaxy s3?

Is there an guide or way to install the Ubuntu phone OS on other devices and is it safe?  I saw  but they are saying that is not stable yet. I'm asking about  "Ubuntu Phone OS"  and I need an installation Guide as well or preferably a step by step installation guide.  If any thing happens will I be able to but android on my phone again ?  thank you .


Prove that $e^x \gt 0$ for $x \in \mathbb{R}$

This is a consequence of the exponential rule, but how do I actually prove it to be true?


Plot a data/Table from Mathematica using `pgfplots`

I use data1 = Table[] in Mathematica 9 (M9) to generate a table of values. The thing is that when I read the data file, there's only one column! How can I plot this data file in LaTeX using pgfplots? Here's a ME  \documentclass[border=1]{standalone} \usepackage{pgfplots} \pgfplotsset{compat=1.5} \begin{document} \begin{tikzpicture}     \begin{axis}             \addplot table {TestTable.csv};      \end{axis} \end{tikzpicture} \end{document}   I also tried TestTable.txt instead of .csv but without any success.  TestTable.csv is generated in M9 with the following code   Export[NotebookDirectory[] <> "TestTable.csv", data1]  where data1 is defined earlier in M9 is some data e.g. numerical integration or similar. A smaller version of data1 in textform (i.e. TestTable.txt) looks like this   1.1 2.3 3.0 4.1 5.3 6.2 7.3 8.4 9.6 10.3


Except when we use right to denote direction, what is the difference between these two terms?  Also, which one is the preferred construction between these two     Am I right?   or     Am I correct?


Why was this question protected when no one answered? There are no 'thanks' 'me too' answers and my answer was posted today.


When to use Interface and when to use Abstract class

Folks can you explain me in which condition I should go with Interface and at which condition should I prefer Abstract class ... ? keep in mind I am not asking difference between Interface and Abstract class.


How can I add a "C" wire to my thermostat?

So, the spiffy new wi-fi thermostats want power on the C wire from thermostat, but the old thermostat doesn't have a C wire at it.  What's the easiest way to add the C wire/24 volt to the thermostat location?


I am learning C++ and I want to know what is more efficient for debugging;  Is std::cout << "Test\n"; more efficient than std::cout << "Test" << std::endl?  What I am trying to say here is, is "<string>\n" more efficent then <string> << std::end;?


How to solve modular equivalence with polynomial

I'm finding the solutions for the modular equation $x^2 -3x+2 \equiv 0\pmod{14}$. This is what I've done so far:  \begin{align} 0 & \equiv x^2 -3x+2 \pmod{14}\\ & \equiv (x-1)(x-2) \pmod{14} \\ \end{align} This implies that two of the solutions are the polynomial's usual roots: 1, 2.  This is where I get lost. I realize I should be using the following fact to find the other solutions, but don't know how to approach it.$$(x-1)(x-2) \overset{14}{\equiv} 0 \Leftrightarrow 14|(x-1)(x-2)$$ The provided answer says that 8,9 are the other solutions. How would I go about finding these?


Measuring distance from observations to coastline

I am looking for a way to use a computer software to measure distances from observation points to the coast of Iceland. I have over 51,000 observations as a points layer and I have the coastline of Iceland as a polygon. Is it possible to do this calculation in QGIS and add a column (Distance) to the attributes table of the points layer? I've found no instructional YouTube video to solve this particular exercise, though I've found many that explain how to measure distances between points. I've also found one thread where the same question was asked here last year, but the only answer was that using a different program would be the only way. The person asking that question has the same problem I do: I don't know how to code, so PostGIS is not a viable option.


What Is the best long term, Fragmenting LAMP or beefing up hardware

I currently have a VPS with apache, php and mysql running on it (got other stuff too, but they arent related to the web server). It has 8gb ram, 4 core intel atom (dont know the clock speed) and 100gb disk space. This has run fine for a while, but im hitting limits with the processing speed and disk space. I have maxed this server package out so i have to move somewhere else. The concern i have at the moment is everything is currently running off the 1 CPU. When a request is made the 1 CPU has to handle everything. Fine on a small scale, but im starting to hit limits and i need to decide where to go from here. I have 2 solutions and i dont know which is the best long term solution. I want to make this server change now and be well setup for the future. I know cloud is good and all for addon, but i need to know what i should do to best deal with my concerns.   Option 1) Upgrade to a fully dedicated server. Brings me from 8gb ram to 32gb, atom CPU to Intel  Xeon D D-1520 (4 core, 2,2ghz) and 4TB storage. This is great, but expensive and it sticks to the same model i have now where everything is running off the one machine.   Option 2) Fragment the system so that mysql is on its own server with 100% of the computers resources and then have a separate file system that contains all of the files. This way when a reqest is made 1 server can handle all of the files and the other deal with the sql. My concern here is that the fragmentation will mean longer request times. calling localhost is a lot faster than an external http request.   What is the best direction for me to go?


The same pronunciation but spelled differently

What do we call words that sound (pronunciation) similar but have different spellings?  Just for example :     come - kom   you  - u      I've already seen this  but that does not comply with the examples I have shown.  Are there any words like that?


Is there no scope for asking opinion-based questions on Stack Exchange?

I'm a frequent user of Math SE, and I think the SE community has people who have similar interests as me (in math) and are overall very insightful: so naturally, when I have "softer" questions about math (perhaps bordering on opinion-based), I wonder what people on the SE community have to say about it; yet, a lot of times these get put on hold because of being opinion based. While I understand that Stack Exchange is meant for productive and to-the-point questions on things relevant to an area, is there no scope for talking about questions requiring insight as opposed to a strict answer to a problem?   Examples include: asking Math SE for views on how the ideal math class should be structured, asking History SE about the "good things" done by people regarded as evil rulers, etc. These are all productive and constructive things to discuss among people interested in math or history, but are usually struck down. Is there any way to frame these questions to fit SE guidelines, or is there no place for such questions on SE?


How to uninstall Ubuntu 14.04 and install Windows 7 without dual boot?

How can I install Windows 7 and remove Ubuntu 14.04? I do not have dual boot or anything, when I first installed Ubuntu on my "experiment desktop", I formated my entire harddrive.  Any help with this is very much appreciated, the answers I found so far by searching for it, almost everybody mentioned how to do it by dual boot.


Prove that there is an irrational number $a$ such that $a^{\sqrt3}$ is rational.

the problem at hand is:  Prove that there is an irrational number $a$ such that $a{^\sqrt{3}}$ is rational.  Hint: Consider $\sqrt[3]{2}^\sqrt{3}$ and argue by cases.  Any help on this problem would be greatly appreciated!


How to replace form with other when javascript is enabled?

Below is a form which would appear no matter javascript is enabled or disabled.  <?php if (logged_in()) { echo "     <form method='post' name='form' action='' class='oldform'>         <textarea  name='content' id='content' ></textarea>         <input type='submit' value='post' name='submit'/>     </form>";   }   ?>   Now I want to replace the above form with another form when javascript is enabled complying with the logged_in php code. I think code below will hide old form and display new form but I am not able to get how to put script in echo so when javascript is enabled <script> replaces old form with new.  <script>     <style>      .oldform{display:none;}      </style>      <form name="newform">     </form> <script>


Cardinality of the basis for $\mathbb{R}$ over $\mathbb{Q}$?

This question came up as a discussion I had with a friend. Clearly, the basis is not of finite cardinality since that would imply the set $\mathbb{R}$ has the cardinality $\aleph_{0}$ which is false. Therefore the basis clearly has to be infinite. However, the question that came up was that is the basis countably infinite or uncountably infinite. So I'd like to know the cardinality of the basis and also appreciate some pointers to the proof.  Thanks in advance. :)


.bashrc and bash.bashrc include:  [ -z "${debian_chroot:-}" ]  Bash manpage states the following on parameter expansions of the following form: ${parameter:-word}  If parameter is unset or null,  the  expansion of word is substituted. Otherwise, the value of parameter is substituted. Why write   "${debian_chroot:-}"   and not simply  "${debian_chroot}"   ?   Answer I'm going with:


Reconstruction of original dataset through loadings in PCA

I am very new to PCA and I was trying, just as excercize, to reconstruct original dataset from loadings.  Let's suppose I have a matrix A corresponding to the original dataset and C that is the z-score of matrix A. What I want to do is to get back matrix A starting from loadings and C as A=C L' where L is the matrix of loadings (as described here: ). So after doing the PCA I calculated the loading matrix L by multiplying each column of the eigenvectors matrix for its eigenvalue square root (i.e. first column by first sqrt eigenvalue, second column by second sqrt eigenvalue...). However when I calculated C L' I got a new matrix different from A.  Where do I go wrong? Tried to search around but could not find anything.


Is there any way to play a video as a screensaver?


How do you programmatically set a custom title via a Views display using PHP?

I'm trying to set a custom title for my Views display by programmatically doing a drupal_set_title() within the Global PHP footer. But it seems that its not firing as I think its firing before the page is rendered.   How can I programmatically set the title of the page using Global PHP within the footer? I want to tap into the results data to create a custom title using drupal_set_title().


Why is there constructor in abstract method when abstract method cant me instantiated?It is confusing me..  Code from tutorialspoint.com  public abstract class Employee  {    private String name;    private String address;    private int number;    public Employee(String name, String address, int number)     {       System.out.println("Constructing an Employee");       this.name = name;       this.address = address;       this.number = number;    }    public double computePay()    {      System.out.println("Inside Employee computePay");      return 0.0;    }    public void mailCheck()    {       System.out.println("Mailing a check to " + this.name        + " " + this.address);    }     public String toString()    {       return name + " " + address + " " + number;    }    public String getName()    {       return name;    }    public String getAddress()    {       return address;    }    public void setAddress(String newAddress)    {       address = newAddress;    }    public int getNumber()    {      return number;    } }   Now you can try to instantiate the Employee class as shown below:     * File name : AbstractDemo.java */ public class AbstractDemo     {        public static void main(String [] args)        {   /* Following is not allowed and would raise error */       Employee e = new Employee("George W.", "Houston, TX", 43);        System.out.println("\n Call mailCheck using Employee reference--");       e.mailCheck();     } }   When you compile the above class, it gives you the following error:     Employee.java:46: Employee is abstract; cannot be instantiated   Employee e = new Employee("George W.", "Houston, TX", 43);                ^ 1 error   What i m getting into trouble is if it has to show error why is their constructor in Abstract classes for what reason?


I'm making a trip back home (to the coast) shortly, and I would like to bring back sand from the beach with me as a keepsake or memento. It's just a short weekend trip, and I won't be checking any luggage, so I was wondering if it's even worth bothering trying to bring sand aboard the plane in my carry-on?  If so, what can I do to make the security screening as smooth as possible? I was planning on putting the sand in sandwich-sized plastic bags, enclosed in a larger quart- or gallon-sized bag.


A trick to make $\frac{1}{i} = i$ (contradicting $\frac{1}{i} = -i)$

Bizarrely came up with this while asleep ...  $$ \tag{1} \frac{1}{-1} = \frac{-1}{1} $$ and $$ \tag{2} \sqrt{\frac{a}{b}} = \frac{\sqrt{a}}{\sqrt{b}} $$ Thus combining (1) and (2): $$ \tag{3} \sqrt{\frac{1}{-1}} = \sqrt{\frac{-1}{1}} $$ which using $\sqrt{-1}=i$ gives, $$ \tag{4} \frac{1}{i} = \frac{i}{1} $$ contrary to the property, $i^{-1} = -i$  Would it be correct to suggest that you cannot move the negative from top to bottom without crossing a branch-point in the square root?  If I have not made a mistake, I am incredibly surprised that I wasn't taught this as a rule at high-school!


Pre-1972 sci-fi short story or novel: alien(?) tunnel where people try new moves and get destroyed if they're not the correct ones

It might be a short story or it might be a novel. It must be before 1972 because I read it in my youth and I am OLD.  The following is very impressionistic.  There is a multidimensional/not of this Earth/alien artifact-like tunnel.   Picture a long, perhaps transparent, storm drain like structure sitting in a field but with an opening on only one end.  It is the subject of a lengthy investigation/exploration that has cost many lives. An instrumented investigator enters the "tunnel" and makes the exact movements that his predecessors have made, advancing until he must do something original at which point he survives and a new "move" is added to the list of correct moves or he is destroyed and a "move" is added to the list of things to be avoided at that point.  I remember absolutely nothing else about the work except that (I hope central) feature.


I have a .txt file with some words in it like "example". I also have the following code would be:  Name = open("file.txt", "r") print(name.read()) print("text") input()   Why is there a whitespace in the output like  "example  text"   And how do I stop that from happening?


How do I start and install Ubuntu from USB flash drive

I'm replacing Windows 10 with Ubuntu. I downloaded Rufus and put the Ubuntu IOS on a flash drive.  I've rebooted my computer and clicked into the Ubuntu file on the flash drive.   I find several files with names like ".disk," "boot" and "install."   From here, I cannot figure out how to install. I would appreciate any help you can offer. Thank you.   Todd


Credit utilization when large purchases are paid off mid-month?

Here's a situation I've always wondered:   Suppose Alice has a $1500 Credit Card and wants to buy a $2000 trinket from Bob. Bob agrees to allow Alice to make 2 $1000 installments on a NET 30 term. Alice buys the trinket, making the first payment. She waits for the transaction to post then pays it immediately. The following week, she makes the second payment, then pays that off immediately. She doesn't pay any of her other expenses on the card until the end of the month when she gets her statement (suppose at the end of the month it's $500)  What is her CC utilization for the month in this scenario?   Is it    33% (500/1500, her unpaid expenses as of the statement date)    or   167% (2500/1500, the total amount she put on her card that month divided by her limit)?


I'm trying to install Ubuntu 18.04 on my Win10 notebook. I have alredy booted my stick and did everything right. When Im booting I try to run the version 18.04 and it appears the black screen of ubuntu loading, but after a few seconds its appears the message of the title: "Booting kernel failed: Invalid Argument". I tried other suggestions that I searched but no one has fixed my problem. My stick is formatted with FAT and has the 18.04 ubuntu. Please, could someone help me?


Are these the correct constructions?   Do any of the students write well? Does anyone write well?


If an $H\le G$ has an irreducible representation of dimension $d$, then show $G$ has an irreducible representation of at least dimension $d$.

Let $H$ be a subgroup of a group $G$, and let $\rho :H\to GL(V)$ be an irreducible representation of dimension $d$. Prove that there is an irreducible representation of $G$ whose dimension is at least $d$.  This is a homework problem I would appreciate it if someone could give me a hint on how to begin. I am assuming I have to apply properties of induced representation, but I am not sure where to begin.  It should be noted we have covered both Frobineus reciprocity and Mackey's irreducibility criterion.  I tried taking the induced representation of $\rho$, since that is all I can do. But the problem is that it may not be irreducible. I want to use Mackey, but I don't feel like I have enough information to apply it. Again any help would be great.


Cloning hard disk partition to smaller SSD on laptop

On my linux laptop, I currently have a 250 gb hd that has a 100gb partition but only 50 gb of it is used.  I would like to change to upgrade my system to a 64 gb SSD.    I read about Clonezilla and the dd command but this apparently clones the whole partition.  This would not work because the partition is 100 gb and my new SSD is only 64 gb.    I also read that I could resize the 100 gb partition to a smaller size than the 64 gb SSD but won't that destroy data that is currently on my hd partition?  And if I can do this without losing data, how to I then copy it to the new 64 gb SSD? (I start a live CD version of Ubuntu, then dd the old disk to an external usb drive.  After that I physically remove the old HD, put in the new SSD and dd the partition back from the USB to the new SSD.  If I do that, won't I have to also create a partition to my external usb hd?)


The following solution, provided here:  does not work anymore. Only the DI part of the author name appears in smallcaps (while it needs to be all in smallcaps).  \documentclass[a4paper]{scrartcl} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage{ebgaramond} \usepackage{filecontents} \begin{filecontents}{biblio.bib} @Book{Aristosseno,   Title = {Armonikon Stoikeion},   Author = {Aristosseno di Taranto},   Keywords = {antico} } \end{filecontents}   \usepackage{polyglossia}  \setdefaultlanguage{italian} \usepackage[backend=biber, style=authortitle, sorting=nyt]{biblatex} \usepackage{xpatch} \let\mkbibnamelast\textsc% \let\mkbibnamefirst\textsc% \let\mkbibnameprefix\textsc% \let\mkbibnameaffix\textsc \renewcommand*{\newunitpunct}{\addcomma\space} \xpatchbibmacro{publisher+location+date}{\setunit*{\addcolon\space}}% {\setunit*{\addcomma\space}}{}{} \DeclareNameAlias{sortname}{first-last}  \addbibresource{biblio.bib}  \begin{document} \section{Sezione} This is a test.\nocite{Aristosseno}  \printbibliography  \end{document}      It happened after updating to Ubuntu 16: a bug uninstalled biber, which had to be reinstalled from source.  Any help or any workaround suggestion? Thank you,


How to define $x^a$ for arbitrary real numbers $x$ and $a$

Questions like , which asks to solve $$x^{\frac43} = \frac{16}{81}$$  confuse me. The solution for real $x$ is $\pm \frac8{27}$.  The question would presumably be a bit different to solve  $$x^{\frac42} = \frac{16}{81}$$  Because on the one hand $\frac42 = 2$ so the answer is $\pm\sqrt{\frac{16}{81}} = \pm\frac49$.  But on the other hand $x^{\frac{4}{2}} = x^{{\frac12}\cdot{4}}$ which, as a function of $x$, is not equal to $(x^{\frac12})^4$.  This is fine, but it raises the question, what is the proper way to define $x^{\frac{4}{3}}$? We have seen we cannot just arbitrarily factor the exponent and apply the multiplication rule. But that's the only way I can think to define $x^{4/3}$ without first defining $x^a$ for all real numbers probably by way of $\ln$.  This tends to come up for  and similar questions on the site. It might be harder than first appears.  More precisely I am asking how to define $x^a$ for as general real $x$ and $a$ as possible, in the context of precalculus, or how to define it at any level of mathematics and adapt it to a precalculus or at least $\mathbb R$ concept.


I think this is a duplicate of an old question without a good answer:  My child was doing schoolwork on her school-issued Macbook Air. Suddenly lighter greys are totally white. This generally gives the images on the screen a vague feeling of being "off", and pixellates all curved edges. The biggest problem is that text on some of her sites is unreadable. I've checked the following:  Color profiles - it looked like it was using the default, but a cycled through a few built-ins. I could see noticeable changes to color balance, but the light greys remained the same as white. Also deleted contents of ~/Library/ColorSync/. Accessibility - my child has accidentally inverted colors before, this isn't that. No other accessibility settings seemed related to color. Display settings - Modifying brightness was also fruitless. The screen overall got brighter or darker, but still couldn't distinguish between light grey and white Rebooting - colors look fine until shortly after logging in - seems connected to user profile somehow.  Here are some images to demonstrate the issue. This is a generic color test image:  On the Mac, it looks like this (simulated with photoshop):  Any solution would be appreciated, but if there is a keyboard shortcut that can cause this, it would be the most likely explanation (8 year old says they "might have rested their arms on the keyboard" during a class meeting)


what's goes on inside the recursive function

I'm currently learning Python and recursive function. I'm just stuck with it that do not actually know what happened after the recursive step is executed. I have an example such # sum of list def my_sum(L):    # this step is just print out current list     # at each level    print(L)    if not L:       return 0    else:       return L[0] + my_sum(L[1:])  and the result for the above function is [1,2,3,4,5] [2,3,4,5] [3,4,5] [4,5] [5] [] 15  I've read a few articles about recursion and understood a bit. However, in this case, I don't see that size of L is decreased at all, so how can the list is growing smaller like that? Could someone figure this out for me? Thank you!


I have a Postfix server with authentication running. However I recently found out, that anyone authenticated may send mail from any account. Meaning user1 is logging in and may send the e-mail from user2@domain.com  Is there a way to "bind" user1 only to send mail from user1@domain.com (and his assigned account alias)? Thank you.


Is there a way to return a Double AND a String from a single method in java?

I have a method which calculates the square root of only negative numbers  (which is sqrt(x)=sqrt(-x) +"*i" , where x is a double and "*i" is a string)  the problem I have is that this method returns a double and a string which are two different variable types, so the question is how do I make this method return both?:  public static **(what goes here?)** myFunction(double x){      return(sqrt(x)+"*i");  }   this code is wrong but I do not know how to fix it, any tips?


Show graph of references inside a document

I have quite a lot of labels and references (around 250 labels, 600 references to those) in my document. As I need to re-arrange parts of the document, I'd like to know which labels are referenced from which parts (and, transitively, which are referenced by the referenced label etc.). In other words, I'd like to have a graphical representation of my document which only shows the names/numbers of the environments (proofs, lemmas, etc.) and the corresponding labels and references.  Example:   Lemma 2 -> Proof A, Proof B, Lemma 1 Proof B -> Proof C Lemma 3 -> Lemma 2   How can I generate such a graph? I am only interested in the information conveyed by the graph, the graph itself will not be published and does not need to look nice.


Why is my external monitor put to sleep on lid close?

I just edited /etc/systemd/logind.conf to ignore lid close, as opposed to suspend, which seems to have worked. But now when I close the lid my external monitor goes to sleep. The system is still running though - if I move the mouse the monitor wakes up immediately.  Why is this happening?


How can I show that  $$ \sum_{i=1}^{n-1}i=\binom{n}{2}? $$  This is what I have tried, but I do not know if it is correct:  Proof.  Let $n=2$. Then,  $$ \begin{align} \sum_{i=1}^{1}i&=1\text{, and}\\ \binom{2}{2}&=1. \end{align} $$  Hence, it holds. Assume that this is true for $k$. Then, we show that it is also true for $k+1$:  $$ \begin{align} \sum_{i=1}^{k}i=k+\sum_{i=1}^{k-1}i&=k+\binom{k}{2}\\ &=k+\frac{k!}{2(k-2)!}\\ &=k+\frac{k(k-1)}{2}\\ &=\frac{k(k+1)}{2}\\ &=\frac{(k+1)!}{2!(k-1)!}=\binom{k+1}{2}.\square \end{align} $$  Also, proofs by induction are confusing to write. Is there a standard "skeleton" for them I can use?


Books recommended as requisites for understanding general relativity to the fullest?

Saw some questions here which asks for what a student should know but couldn't find a complete list of recommended books for the maths and physics one needs to know. The answers can serve as a journey to a college fresher where to start from and how to go ahead.


I am including a formula in a LaTeX document that includes subscript that consists of more than one character: N sub t0 and N sub tmax  I managed to get LaTeX to do this using this syntax:  \[   \vec{V} = \vec{N_t_0} * M \cdots \vec{N_t_m_a_x} * M \]   This syntax throws multiple Double subscript errors.  Although it produced the intended results despite these errors, eventually these errors cause weird behaviors in the document, such as the bibliography dropping references, etc.  What is the correct syntax to produce the result I need without throwing errors?


I tried the commands suggested for the person with the Brother computer who has the same problem and I got an error message:  $ apt-get purge cups E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?   running a printer shouldn't consume 2 people an entire fruitless morning. Yes, we're clueless.


Pretty much the same question as   The answer is from 2014 and says an update then would fix this, but I can't find anything related to this. Does anyone know if an update released anything regarding this? I couldn't find anything in the manual


One of my questions was recently "removed" and I don't know why

I was wondering this morning why I was 3 rep less and then I tracked it down to this recent activity:  -3  10 hours ago    removed     Using Kendo upload to extract txt file data and record to a database   There was no downvote or any explanation provided, just that the question was "removed". Not only did I lose the reputation I had earned from this question, but last I remember, I was still interested in an answer for future reference.  Can someone please explain what happened and why my question was deleted?


Is there a boxplot variant for Poisson distributed data?

I'd like to know if there is a boxplot variant adapted to Poisson distributed data (or possibly other distributions)?  With a Gaussian distribution, whiskers placed at L = Q1 - 1.5 IQR and U = Q3 + 1.5 IQR, the boxplot has the property that there will be roughly as many low outliers (points below L) as there are high outliers (points above U).  If the data is Poisson distributed however, this does not hold anymore because of the positive skewness we get Pr(X<L) < Pr(X>U). Is there an alternate way to place the whiskers such that it would 'fit' a Poisson distribution?


iPhone SDK: what is the difference between loadView and viewDidLoad?

When working with views and view controllers in an iPhone app, can anyone explain the difference between loadView and viewDidLoad?    My personal context, is that I build all my views from code, I do not and will not use Interface Builder, should that make any difference.  I've found that often when I add init code to loadView, I end up with an infinite stack trace, so I typically do all my child-view building in viewDidLoad...but it's really unclear to me when each gets executed, and what is the more appropriate place to put init code.  What would be perfect, is a simple diagram of the initialization calls.  Thanks!


Installing .deb packages with Ubuntu Software

I cannot seem to install any downloaded .deb package by clicking on it (I am on Ubuntu 16.04):   they open with the "Ubuntu Software" GUI, with a button "Install"; clicking on this button seems to do something (as in, a progress-bar appears), but the software is not installed afterwards.   I can install them from the console using sudo apt install /path/to/foo.deb, but I would like to know why the graphical way of doing things doesn't work.  Note: I know I can also install gdebi to install .deb packages, but that's not really the point of my question :)


Non-Static Method cannot be called from Non-Static Method in Android Studio

Of course I know that a Non-Static Method needs to be called from a Non-Static Context.  And am I missing something when I think that  public void methodName(int i) { ... }   is Non-Static ?  Because Android Studio 2.3.2 flaged it as a Static Context so I can't call the following statement from the Method     Method:  public void deleteCard(int id){     for(int i = 0; i < cards.size(); i++){         if(cards.get(i).id == id){             cards.remove(i);             notifyItemRemoved(i);             notifyItemRangeChanged(i, cards.size());         }     } }


Why there's an "Android" folder in my phone's storage?

I'm just wanted to know why there's an Android folder. As we all know that the data which apps stores for itself stores in root directory which is "data/data" but why there's an Android folder? Please let me know.


Appending to macro name in a metacommand

I'm trying to build a macro that in-turn generates a couple related commands. Here's a really simplistic example:  \documentclass{article}  \newcommand{\myabbv}[3]{%   \newcommand{#1}{#3}   \newcommand{#1full}{#2} }  \myabbv{\alky}{Alcoholics Anonymous}{AA}  \begin{document} \alkyfull is a place for people that go to \alky \end{document}   This chokes though, complaining I already defined \alky when I run the command to make the other commands. It seems like TeX doesn't concatenate the argument with my suffix; is there a fix?


How do you delete your account at Area 51?

It was quite simple to delete many accounts by clicking on 'help', but I cannot find such a   possibility at Area51.  Can someone tell me how to delete that account?


Question about $a_n=\sum_{k=1}^n \frac{n}{n^2+k}\ $for $ n \in\mathbb{N}$

Please help me solve this. Please try to give some details also.  Let $a_n=\sum_{k=1}^n  \frac{n}{n^2+k}\ $for $ n \in\mathbb{N}$ then the sequence $\{a_n\}$ is (choose the correct option):     Convergent   Bounded but not convergent   Diverges to infinity   Neither bounded nor diverges to infinity     My thoughts : I tried doing it by testing if it is monotonic with help of $a_{n+1} -a_n$ and checking if its +ve or -ve but, the the terms dont simplyfy by cancelling each other...


Fundamental group of $S^2\cup\{xyz = 0\}$

We want to compute the fundamental group of $S^2 \cup \{xyz=0\}$. It is easy to see that it retracts to a sphere joined with three disks. How can I show that its fundamental group is trivial?


I have following do while code, where I am trying to end the loop when the text entered is Stop. However even though when I type Stop in the console, it doesn't work. I tried to debug it and see it tries to compare the Stop text but doesn't stops it. I don't understand what is the problem. This is a java code running in eclipse.     import java.util.Scanner;  public class Application8_Switch {   public static void main(String[] args) {     Scanner input = new Scanner(System.in);     System.out.println("Enter a string to match the output");     String text;     do {       text = input.nextLine();       switch (text) {          case "start":           System.out.println("Machine started");           break;          case "end":           System.out.println("This Machine stopped");           break;          default:           System.out.println("Command not recognized");           break;       }      } while (text != "Stop");     } }


I just started learning decorator pattern and I'm confused in when can I use Decorator pattern, or why is it different than just calling super, w/o using a pointer to a super class.  "...is a design pattern that allows behavior to be added to an individual object, either statically or dynamically, without affecting the behavior of other objects from the same class."  Isn't it the same as just subclassing or am I missing something?  public class Foo {      protected void doSomething() { } }   //using decorator pattern public class Bar extends Foo {     private foo;     public Bar(Foo foo) {         this.foo = foo;     }     public void doSomething() {         foo.doSomething();         // extra code     } }  //using super  public class Bar extends Foo {     @Overide     public void doSomething() {         super.doSomething();         // extra code     } }


How to prevent flickering in ListView when updating a single ListViewItem's text?

All I want is to update an ListViewItem's text whithout seeing any flickering.  This is my code for updating (called several times):  listView.BeginUpdate(); listViewItem.SubItems[0].Text = state.ToString();    // update the state listViewItem.SubItems[1].Text = progress.ToString(); // update the progress listView.EndUpdate();   I've seen some solutions that involve overriding the component's WndProc():  protected override void WndProc(ref Message m) {     if (m.Msg == (int)WM.WM_ERASEBKGND)     {         m.Msg = (int)IntPtr.Zero;     }     base.WndProc(ref m); }   They say it solves the problem, but in my case It didn't. I believe this is because I'm using icons on every item.


How to do the loop which can check the process by the bat file

Im a newbie in the cmd, and if you can just help me to do the batch while for Windows. This program must check the process while script is opened. If it doesn`t launched it will be open. If you can help me, just show me a code and explain how it works, please.


Missing parentheses around close vote count

The problem can be easily found while using the Android app and mobile web. Just find a question with a close vote on it and you will see this:       close 1   is what it says there. Can we fix it so we can have the parentheses around the close vote count so it can look like the way it is supposed to look?:     close (1)


Define $\triangle$ as $A\triangle B = (A\cup B - A\cap B )$, show associativity of $\triangle$

We define $\triangle$ as $A\triangle B = (A\cup B - A\cap B )$ and want to prove axiom G1 for the group (G, $\triangle)$.     We want to show that $(A\triangle B)\triangle C = A\triangle (B\triangle C)$   $(A\triangle B)\triangle C = ((A\cup B - A\cap B)\cup C) - ((A\cup B - A\cap B)\cap C) = $ $(A\cup B \cup C - A \cap B) - ((A\cup B)\cap C) + A\cap B = $  $A\cup B \cup C - (A\cup B)\cap C$  $A\triangle (B\triangle C) = (A\cup (B\cup C - B\cap C)) - (A\cap (B\cup C - B\cap C)) = $ $(A\cup B \cup C - B \cap C) - (A\cap (B\cup C)) + B\cap C = $  $A\cup B \cup C  - (B\cup C)\cap A$   The problem I'm running into now is that I believe that $A\cap (B\cup C) \neq (A\cup B)\cap C$ in general. I'm not sure if I'm taking wrong steps in my derivation (probably). Does anyone know what steps are wrong, or if there's a better way to prove this?


Text is english, citation style is in another language

My LaTeX document is English but when I cite multiple authors     Teyseyre und Campo   occurs instead of      Teyseyre and Campo   I set \selectlanguage{english} and for every single entry I added language = {english}.   I also tried adding the following which I found in another thread:  \usepackage{babelbib}  \selectbiblanguage{english}  \renewcommand\betweenauthors{and} \providecommand\harvardand{} \renewcommand\harvardand{and}   Tt still displays the German "und".  Can someone help me getting rid of it?


Element may not have 2-sided inverse in infinite ring

Suppose you have a ring R with 1. If this ring is finite, I think I can prove that any element with a 1-sided inverse also has a two-sided inverse. The question asks for a counter-example when the ring is infinite. I'm having trouble coming up with one.


Is there a simple way to fill in a grungy font to make it solid?

I'm looking to make the entire letter solid. I want to complete the grungy white space and fill it out with solid black. Is there a simple way to do this?


what is difference between console.time() vs Date.now() in javascript and which one is better performance

I have written some nodejs code and I am logging api call response timing. console.time() and Date.now() but I am not sure which one is better in performance and right to use.