How do I include math mode in a bibliography entry with ieee style?

I just spent a while identifying that this one reference in my bib file was preventing compilation after running bib mwe.  I get the error: ! Extra }, or forgotten $.. I found that it would compile when I changed the style to certain ones but not ieee nor phys.  The problem is the greek character \lambda in the title.  How can I get this citation to work with these biblatex styles?  \begin{filecontents}{\jobname.bib} @article{qiu_saltdependent_2011,   title = {Salt-Dependent DNA-DNA Spacings in Intact Bacteriophage $\ensuremath{\lambda}$ Reflect Relative Importance of DNA Self-Repulsion and Bending Energies}, % ieee does not like math mode commands   % title = {Salt-Dependent DNA DNA Spacings in Intact Bacteriophage lambda Reflect Relative Importance of DNA Self Repulsion and Bending Energies}, % runs fine   author = {Qiu, Xiangyun and Rau, Donald C. and Parsegian, V. Adrian and Fang, Li Tai and Knobler, Charles M. and Gelbart, William M.},   journal = {Phys. Rev. Lett.},   volume = {106},   issue = {2},   pages = {028102},   numpages = {4},   year = {2011},   month = {Jan},   publisher = {American Physical Society},   doi = {10.1103/PhysRevLett.106.028102},   url = {http://link.aps.org/doi/10.1103/PhysRevLett.106.028102} } \end{filecontents}  \documentclass{article}  \usepackage[ %  style=phys,       % ! Extra }, or forgotten $.   style=ieee,       % ! Extra }, or forgotten $. %  style=chem-acs,   % this one works %  style=science,    % this one works %  style=nejm,       % this one works %  style=nature,     % this one works %  style=chem-rsc,   % this one works %  style=chem-angew, % this one works   backend=biber ]{biblatex}  \addbibresource{\jobname.bib}  \begin{document}  test text here \cite{qiu_saltdependent_2011}.  \printbibliography  \end{document}   I compile this using the commands:  rm *.blg *.bib *.bbl *.aux -f && pdflatex mwe.tex && biber mwe && pdflatex mwe.tex


I want the entries in the TOC for the indices to align with the Chapter entries. I can do this with \addcontents. \printindex also puts an entry in the TOC but it is aligned with the section entries.   So I want to:    change how printindex makes its entry into the TOC or  to eliminate printindex entry.   MWE:  \documentclass{book} \usepackage{multind}        % create the indices \makeindex{names}            \makeindex{subject} \newcommand{\Ndx}[1] { \index{names}{#1} }     % define the type of entry \newcommand{\Sdx}[1] { \index{subject}{#1} }   % to the indices \usepackage[headings]{fullpage}         % 8-1/2, 11 page with 1" margins \usepackage{fancyhdr} \pagestyle{fancy} \begin{document} \fancyhead{} \fancyfoot{} \renewcommand{\sectionmark}[1]{\markright{\thesection.\ #1}} \fancyhead[LE,RO]{\rightmark} \fancyhead[RE,LO]{\thepage} \tableofcontents        % put table of contents here  \chapter{\bf Logic, Plausibility, and Probability} \label{Ch:Logic} \section{Logical Arguments and Reasoning } It is obvious that logical arguments are essential to the judicial system. The logic must be able to treat syllogisms\Sdx{syllogism} that range from deductive\Sdx{syllogism!deductive} to abductive\Sdx{syllogism!abductive}, that is from strong to weak syllogisms \Sdx{syllogism!weak}\Sdx{syllogism!strong} as illustrated in the table taken from Author \Ndx{Author} \Ndx{Cohen} \Sdx{Cohen on probability} \clearpage \addcontentsline{toc}{chapter}{Subject Index} \printindex{subject}{Subject Index} \addcontentsline{toc}{chapter}{Name Index} \printindex{names}{Name Index} \end{document}


The smallest infinity and the axiom of choice

The short version of this question is: which (natural) axiom should be added to ZF so that the statement "$\aleph_{0}$ is the smallest infinity" becomes true?  A set $A$ is called infinite if it can be put in bijection with a proper subset of itself, or, equivalently, if there exists an injection $\phi \colon A \hookrightarrow A$ that is not a bijection. Consider the following proof that the cardinality of the natural numbers, $\aleph_{0}$, is the 'smallest' infinity.  It is enough to show that for every infinite set $A$ there is an injection $\mathbb{N} \hookrightarrow A$. It is simple to prove that if $A$ is in bijection with a set $B$, then $B$ is also infinite. Define $A_{0} = A$, and let $\phi_{0} \colon A_{0} \rightarrow A_{0}$ be an injection that is not a bijection. Denote $A_{1} = \phi(A_{0})$, and $B_{1} = A_{0} - A_{1}$. By definition of $\phi_{0}$, we have $B_{1} \ne \emptyset$. Since $A_{1}$ is also infinite (as $\phi$ restricts to a bijection between $A_{0}$ and $A_{1}$), we can repeat this process with a non-bijective injection $\phi_{1} \colon A_{1} \rightarrow A_{1}$, and define  $A_{2} = \phi_{1}(A_{1})$ and $B_{2} = A_{1} - A_{2}$, with $B_{2} \ne \emptyset$.  Continuing in this manner we obtain an infinite descending chain of proper subsets $$A_{0} \supsetneq A_{1} \supsetneq A_{2} \supsetneq A_{3} \supsetneq A_{4} \supsetneq \cdots$$ and a countably infinite family $\{B_{n}\}_{n \in \mathbb{N}}$ of mutually disjoint subsets of $A$. Choosing a $b_{i}$ from each $B_{i}$, we obtain an infinite sequence of elements of $A$ without repetitions $$b_{1}, b_{2}, b_{3}, b_{4}, \dots,$$ which is exactly an injection $\mathbb{N} \hookrightarrow A$.  It seems clear to me that the above argument uses the axiom of choice in choosing the sequence $\{ b_{n} \}_{n \in \mathbb{N}}$. It also seems clear that without something like AC one cannot guarantee that $\aleph_{0}$ is the smallest infinity. However I've also been told that people often mistakenly use the axiom of choice, or use the full axiom when a weaker variant would do. Since here I have an ordered, countably infinite collection of sets to make a choice from, it seems like this might be the case.  I am no set theorist, so I don't know how to answer these questions (and maybe even how to ask them), but roughly: are there commonly used axioms that imply '$\aleph_{0}$ is the smallest infinity', but are weaker than AC? Is there a minimal such axiom? Can one adopt '$\aleph_{0}$ is the smallest infinity' as an axiom, or would this cause problems?  EDIT: I am informed below that no version of the axiom of choice is necessary with this definition of 'infinite set'. So what about when we use the 'usual' definition of an infinite set: a set that is not in bijection with any natural number.  Supplementary question: why is the 'usual' definition preferable to the 'bijective with proper subset' definition? The latter seems more natural to me, seeing as it only mentions sets and doesn't require numbers to be defined.


Using Virtual Box, how can I install an OS to a secondary, physical disk, and boot it in both (at separate times) Virtual Box, and as a typical secondary OS install?


clipboard operation between LibreOffice and other application

When I want to copy text from LibreOffice to an gmail in the Chrome browser, the clipboard does not work unless I keep the text document of LibreOffice open.  How can I fix this limitation or is it just a matter of waiting for improvements?


C++: Which API is recommended for implementing threading model in a windows application

I have a C++ application which needs to be multi-threaded in windows platform. After browsing some forums, I gave CreateThread API a try.  is the link giving details regarding its signature.  But, it always throws Access violation error and after going through some more forums, I got a bit confused when they said that this API has always had some problems. Some have recommended to use BeginThreadEx.  What is your recommendation for threading model implementation? Also, give reasons for your recommendation.


The set of continuous functions on $[0,1]$ is a vector space.

I'm a beginner in the course of Linear Algebra; please bear with me if the question seems too trivial.   The set of all continuous functions on interval $[0,1]$ is a vector space.   I have trouble in understanding this.  What does a continuous function on $[0,1]$ mean? That the range lies within $[0,1]$?  For it to be a vector space, it needs to satisfy vector additivity.   Say, we take a vector with continuous function $f(t)=0.9$ which belongs to $V$.  Another vector belonging to $V$ has continuous function $g(t)=0.8$.  For vector additivity, we add the elements of vector (in this case I'm considering only 1 element in the vector). Here the new vector would give us $0.8+0.9$ which us not in $[0,1]$.  And yet this is a valid vector space.  I'm sure I'm missing something. I'm probably not able to understand what the question demands.


Unexplained step in the proof of uniqueness of solution in chinese remainder theorem

In the book Introduction to Analytic Number Theory written by Tom M. Apostol, there is a step in the proof of Theorem 5.26 (Chinese remainder theorem) that I am unable to understand. In the proof, we assume $ m_1, \dots, m_r $ to be positive integers relatively prime in pairs and $ M = m_1 \cdots m_r $. There is a step that proves the uniqueness of solution that I cannot understand. Here it is:  But it is easy to show that the system has only one solution mod M. In fact, if $x$ and $y$ are two solutions of the system we have $x \equiv y \pmod{m_k}$ for each $k$ and, since the $m_k$ are relatively prime in pairs, we also have $x \equiv y \pmod{M}$.  The author does not explain why must $x \equiv y \pmod{m_k}$ for each $k$ imply that $x \equiv y \pmod{M}$? I know we can show this ourselves. When $gcd(a,b) = 1$, $a|n$ and $b|n$ implies $ab|n$. There are numerous proofs of this available online. This is equivalent to stating that $ n \equiv 0 \pmod{a}$  and $n \equiv 0 \pmod{b}$ implies $n \equiv 0 \pmod{ab}$ when $gcd(a,b)=1$. But is this so obvious that it does not require a proof of its own in the book? So what I am asking here is how do we justify this step from the preceding material in the book:  we have $x \equiv y \pmod{m_k}$ for each $k$ and, since the $m_k$ are relatively prime in pairs, we also have $x \equiv y \pmod M$  Does the book explain why this should be true somewhere earlier? I could not find anything. If you have read this book and you found the necessary groundwork for this in the preceding material, please share it here. If the book does not explain it somewhere earlier, does this step not require a proof of its own?


help, I just installed linux but when I reboot, windows 10 starts instead of grub. I try to selected a diffrent boot by pressing esc, but I could only chooice windows boot system, of my cd/dvd player.  secure boot is disabled (the answer of )   I am prety new to linux, So I hope somebody can help me with this? It was already hard to install linux at the first place.  Thanks a lot!


Using “used to” vs "would" when expressing something done in the past

I understand how the phrase "used to" can describe something that was done in the past:  When I was growing up, my parents used to read to me at bedtime. My dad used to take the family out for ice cream on Sundays in the summertime.  Although these sound fine in conversation, when I see this construct in writing, I often find the word "used" tripping me up. When I'm proofreading my own work, I find myself expecting "used" to be the past tense of the verb use (meaning, "to wield or to utilize"). In other words, when I initially read the word "used," my brain is expecting the word to be used differently – something like:  When I was growing up, my parents used... (a pair of pliers to open pickle jars). My dad used... (his old t-shirts to wax the car).  So, I'll sometimes reword the original, to eliminate the "used to":  When I was growing up, my parents would read to me at bedtime. My dad took the family out for ice cream on Sundays in the summertime.  I realize that the construct is plenty common; when I type "my parents use" into Google – both in a web search, and a book search – I find more instances of:  my parents used [to do something]  than:  my parents used [something].  So, my questions:  Is it worthwhile to make such edits? Might others occasionally stumble momentarily as they run across the word used used in that context while reading? (Or maybe that's just me?)  Finally, is there a reason why (or a context where):    My brother used to loan money to his friends.  would be considered better than:  My brother would often loan money to his friends.  I'd be especially interested in answers from both native and non-native speakers of English.


What is the difference between Unity vs c++?

What could be the difference between using SDK like UNITY/xamarin and (native development programming language + c++) for multi platform? It seems UNITY/xamarin, is pretty cheap compared to having to learn new languages. It seems though, big companies use the native language and c++. What are the FACTUAL benefits and setbacks in terms of SPEED?


I am looking for an expression that uniquely determines the following set: $S$ is the set of binary strings such that each block of $0$'s is congruent modulo $3$ to the length of block of $1$'s that follows it (if it exists)...that is,  (length of $0$) = (length of $1$) mod $3$. I am thinking to start from $0^*(\{1\}\{1\}^*\{0\}\{0\}^*)^*1^*$, but soon I realize that, the length of block of $1$ is arbitrary, then I got stuck....Could you please give me some hints?


Algorithm/Steps for solving a congruence with small numbers

Below is text from the book Joseph H. Silverman: A Friendly Introduction to Number Theory, 4th Edition, chapter 8, page 56.  To solve $4x\equiv 3 \pmod{19}$ we will multiply both sides by $5$. This gives $20x\equiv 15 \pmod{19}$ But $20\equiv 1\pmod{19}$, so $20x\equiv x\pmod{19}$ Thus the solution is $x\equiv 15\pmod{19}$  I was wondering if I can document the steps on how this is done to solve a generic congruence - I know this can be done only for solving congruences with small numbers To solve $Ax\equiv B \pmod{m}$ Find P & Q such that they satisfy the following conditions  Q = A * n P = B * n $Q \equiv 1 \pmod{m}$  Once you do this - you can easily solve the congruence.  I have 2 questions  Is this correct - i.e. my description of the steps of how the example in the book was solved?  This seems to work when gcd(A, m) = 1. Will this work if the gcd is not 1.


SE login OpenID redirect blocked in Chrome Canary

It is not possible for me to logon to SE using Chrome Canary. I have to use Canary, because a recent bug prevents flash from loading at all in Chrome for some sites.  Canary seems to adopt security BCPs that are incompatible with what SE does. The following errors are displayed after clicking "StackExchange Account" on the login page:    The login works in Chrome stable. If I manually follow the OpenID auth link, the login completes successfully.


What approaches are there to blending multiple terrain types?

So for my university final assignment I'm doing a procedural world generator in unity. The idea is that different types of terrain are generated such as ocean, swamp, hills etc. I have the different biomes generating as chunks with different colours at the moment and the next step for me is to smoothly transition between them rather than drop off from one terrain type to another. To do this I'm going to need to adjust the heightmap so that the edges join together rather than having gaps between them. The noise is continuous so biomes of the same type connect seamlessly. However with different biomes the height generated from any given noise is different, that way my mountains stick up without my ocean chunks being weird shapes. The result is like I said earlier, there are seams between my chunks that I need to stitch. So my real question is what approaches are there currently to blend from one height map to another?


Is the speed limit as light speed just based on what we see?

I know, the title makes no sense, generally. Let me explain. I am just asking a question for which I found an answer nowhere (not even here). i think similar questions has been asked before and, no perfect answer is got(at least to what I ask).  The question is simple, why is light speed the limit for speed of particle? From many sources, I heard the answer, if we travel faster than light, we will reach somewhere before light reaches there and we will see and be in the past.   My question is, if we travel faster than light, surely we will be able to see the past. It is just because photons reach there later. We will see photons from a time before we started the journey, and probably the past. Of course it make sense. We are just seeing the past. Now we are seeing the past of sun since it take time for photons to reach here. In the same manner, we will see (and just see) the past of earth when we travel faster than light. That doesn't mean we are at the past. If we return back, we will reach the very normal time we would have felt if we neither went or returned.   I don't know if it makes any sense or not. I am not a graduate in physics. I am just 16.


I've been working with the Fermat numbers recently, but this problem has really tripped me up. If the Fermat theorem is set as $f_a=2^{2^a}+1$, then how can we say that for an integer $b<a$, the $\gcd(f_b,f_a)=1$?


Find " extra" dot in filename and remove it

I have some files inside a directory structure with multiple folders that have more than one dot. For example, "x.y.jpg" or "x.yz.01.jpg". How can I   list all files with more than one dots in their names in the directory structure and delete the extra dots except the one before the extension?   Please note the extensions vary among one, two and three letters.  I was hoping I could do this with a windows script.


How to add a PNG-File-Array to an ArrayList - Java

I have this method:  private ArrayList<Image> imageArray(File files[]) {      ArrayList<Image> images = null;      for(int x = 0; files.length > x; x++) {          //I want to add each PNG-File to the Image-Array          try {             images.add(x, ImageIO.read(files[x])); //Demo.imageArray(Demo.java:23)         }catch(IOException | ArrayIndexOutOfBoundsException exception) {             exception.printStackTrace();         }          //Now I scale each Image, so it fits the screenSize          int newWidth = (int) screenSize.getWidth(),             newHeight = newWidth * images.get(x).getHeight(null) / images.get(x).getWidth(null);          if(newHeight > screenSize.getHeight()) {              newHeight = (int) screenSize.getHeight();             newWidth = newHeight * images.get(x).getWidth(null) / images.get(x).getHeight(null);         }          images.set(x, images.get(x).getScaledInstance(newWidth, newHeight, Image.SCALE_SMOOTH));     }      return images; }   which causes this Exception :  Exception in thread "main" java.lang.NullPointerException     at Demo.imageArray(Demo.java:23) //I've marked the position in the code!     at Demo.main(Demo.java:47) // Just, when I want to use the method anywhere   Why do I get that Error and how can I work around it? I have added a parameter, when I wanted to use the method, which looks like this :  imageArray(new File[] {new File("filePath to PNG-Image"),             new File("filePath to PNG-Image")})


How can Dumbledore cast a spell on Harry while Harry was under the invisibility cloak? Is this a plot mistake of JKR?

It was clearly mentioned in Deathly Hallows that you can't curse someone under the Invisibility cloak,  since it is one of the Deathly Hallows and Death has given immunity. Even if Dumbledore was the most powerful wizard alive, how did he overcome the power of the Cloak of Death himself; that, too in such a weakened state? Here is the excerpt from the 6th book Harry Potter and the Half-Blood Prince, Chapter 27, page 584... So did i actually find a mistake in the book or is there a proper explanation?     Harry hurried over to the door leading to the spiral staircase, but   his hand had only just closed upon the iron ring of the door when   he heard running footsteps on the other side. He looked around at   Dumbledore, who gestured him to retreat. Harry backed away,   drawing his wand as he did so.   The door burst open and somebody erupted through it and   shouted, “Expelliarmus!”   Harry’s body became instantly rigid and immobile, and he felt   himself fall back against the tower wall, propped like an unsteady   statue, unable to move or speak. He could not understand how it   had happened — Expelliarmus was not a Freezing Charm —   Then, by the light of the Mark, he saw Dumbledore’s wand flying   in an arc over the edge of the ramparts and understood. . . .   Dumbledore had wordlessly immobilized Harry, and the second he   had taken to perform the spell had cost him the chance of defending   himself.   This was while Harry was under the Invisibility Cloak.


It is considered very useful to utilize youtube-dl software for downloading youtubes.  A message is seen and it stopped working, which is following.  ERROR: Signature extraction failed: Traceback (most recent call last):   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 479, in _decrypt_signature     video_id, player_url, s   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 383, in _extract_signature_function     res = self._parse_sig_js(code)   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 454, in _parse_sig_js     u'Initial JS player signature function name')   File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/common.py", line 391, in _search_regex     raise RegexNotFoundError(u'Unable to extract %s' % _name) RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Be sure to call youtube-dl with the --verbose flag and include its complete output. Make sure you are using the latest version; type  youtube-dl -U  to update. ; please report this issue on https://yt-dl.org/bug . Be sure to call youtube-dl with the --verbose flag and include its complete output. Make sure you are using the latest version; type  youtube-dl -U  to update.   What should I do to proceed?


Jquery click event after after creating div

hello people here is my ajax output...  $(function(){     //after ajax request     success:function(data){         $('#inbox').html('
'+data+'

')     } })   Div is creating successfully,so Iam very sure no issues with ajax code....but now i have to give click event to class .inbox_user ,,,its not working with no error message on console... click event for #inbox works fine.....  any idea to fix this??  i am trying in normal way $('.inbox_user').click(function(){})


I work on a project in Java for school, and I have a problem with JOptionPane.showInputDialog().  My question is: What does JOptionPane.showInputDialog() return if I enter nothing into the field and then hit "OK"?  I tried to find it out by myself with this test-code:  public static void main(String[] args) {     String test = JOptionPane.showInputDialog("Please enter:");     if (test==""){         System.out.println("Found it");     }else{         System.out.println(test);     } }   This doesn't work, as I said. It will print out the variable test, instead of the string "Found it".  What must I enter in the if-query in case I enter nothing in the field and then hit 'OK'?  Excuse my English, I'm Swiss.


I found a lot of people figuring out why instruction similar to this :   Put X to your ~/.bashrc and you can do Y    don't work.  It always turns out that Mac OS X's bash's startup files (or Mac's Bash itself) doesn't source ~/.bashrc file, either in the login shell, or in a shell spawned from window system - like Terminal app in Mac OS X)  Why is this, when all other Unix-like systems with Bash I've worked with before have done this?  PS:  I found what Bash itself says about startup files (which could be helpful) :     When Bash is invoked as an interactive login shell, or as a   non-interactive shell with the --login option, it first reads and   executes commands from the file /etc/profile, if that file exists.   After reading that file, it looks for ~/.bash_profile, ~/.bash_login,   and ~/.profile, in that order, and reads and executes commands from   the first one that exists and is readable. The --noprofile option may   be used when the shell is started to inhibit this behavior.   Source :


Equations inside enumerate aligned on item's number

If I type    \begin{enumerate}         \item        \begin{align*}         eqn 1         eqn 2       \end{align*}   \end{enumerate}   the label will appear on the first lines and the equations will appear on subsequent lines. How do I make it so that the equations begin on the same line as the enumerate label? Obviosly, I could manually adjust the location using \vspace and \rule, but is there a better way?


I have the following test code for a class:  /**  * Test Class  */ public class GeneratorTestTest {     private Generator generator;     private static BufferedImage testImage;     private BufferedImage rotatedImageTestResult;      @Before     public void setUp() throws Exception {         generator = new Generator(null, 0);          File inputFile = new File("src/test/resource/picture.jpg");          testImage = ImageIO.read(inputFile);     }      /**      * Test method      */     @Test     public void testRotateImageRotateImage() {         //Line 39         rotatedImageTestResult = generator.rotateImage(testImage, 0);         assertTrue(imageEquals(testImage, rotatedImageTestResult));     }   I am get a NullPointerException on the Test method when I try to run it. How can I pass the Junit test?  Here is a full log of the Exception:     line 39 is "rotatedImageTestResult = generator.rotateImage(testImage, 0);


How to travel as a crew member on a ship?

Is there a feasible way to take a one year break from a IT job and work as a crew member on a big ship? How can one go about this? I am a recreational sailor and know intermediate sailing, coastal navigation, radio handling and all that stuff. I think this could be the experience of a life time. Where should  I look? I imagine getting it would be hard since obviously this is a lucrative job.


How can I execute a single command as non-root user while the rest of the script runs with root privileges?

I have a script that checks if Java version 8 is installed on my system. If not, the script installs it. Also once it makes sure that correct java version is installed it checks if $JAVA_HOME variable is set properly.   I am doing this by adding  JAVA_HOME path to my /etc/environment file. Everything till here works.   In the next step however, when I try to reload the /etc/environment file using source command, it does not load the new file.   I believe this is due to user running the script. I am running the script as root user. However I need to run source /etc/environment as non-root user and the have rest of the commands run as root.  I have tried sudo with the -u and su with -u -c commands, however this has not worked for me. Any pointers to how this could be done would be great help. Thanks


Why do divisions like 1/98 and 1/998 give us numbers continuously being multiplied by two each time in decimal form?

For example, when I divided $1$ by $98$, I got an amazing result of $0.0102040816326530612244897...$ where so many numbers get multiplied by two every time in the right pattern with some carrying.  Also, when I divided $1$ by $998$, I got an amazing result of $0.0010020040080160320641282...$.  I have a longer result from my cool memory, which is $0.001002004008016032064128256513026052104208517034068136272545090180360721442885...$What explains why this doubling thing is happening?  I love it when I see it!  Also I don't know if it repeats (I'm talking about 1/998).  I think it does because I looked it up and it said 498 numbers repeat every time, so it's rational.  I mean seriously, how does this doubling happen?  I hope I can receive good information from you!


Why haven't I earned the Electorate badge yet?

I have ~700 votes, and am sure that a lot more than 25% are on questions.  What could be the problem?


I'm porting C code where there are direct __asm__ calls from Linux to Windows. Those calls are not supported by the Visual Studio compiler so I'm looking for a Windows version of the following GCC call:  __asm__("bswapl %0" : "=r" (val) : "0" (val))  Could someone help me? Thanks!


I'm probably missing something obvious here but why is it possible for comments to be deleted?  I was recently engaged in a discussion on Stack Overflow and the other party later selectively deleted some of their comments. The context of the discussion thread then became somewhat ambiguous.   If a comment is deleted is a reason provided? Is the process of comment deletion peer reviewed? I appreciate it could be useful for good house-cleaning but it can also lead to disjointed conversations.  I know that commenting is intended to annotate rather than chatter, but there's still some back and forth involved.  Sorry for the newbie question and please signpost me if this has been covered elsewhere.


Vector Union function performance in QGIS and ArcGIS DEsktop

I am trying to find the union of two vector layers (both spatial indexed) - one land use polygons and another grid. In QGIS it is running since 4 days ago, but in ArcGIS Desktop it took less than 10 min.  Does anyone know if ArcGIS Desktop pre-processes vector(s) before actual union function?  The time difference cannot be this drastic!


For all square matrices $A$ and $B$ of the same size, it is true that $(A+B)^2 = A^2 + 2AB + B^2$?

The below statement is a true/false exercise.  Statement: For all square matrices A and B of the same size, it is true that $(A + B)2 = A^2 + 2AB + B^2$.  My thought process: Since it is not a proof, I figure I can show by example and come to a valid conclusion based on such example.  My work:  Come up with a square matrix A and B let both be a 2 by 2 matrix(rows and cols must be same).  Matrix $A$:  $A = \begin{array}{ccc} 3 & 5 \\ 4 & 6 \\ \end{array} $  Matrix $B$:  $B =  \begin{array}{ccc} 5 & 8 \\ 9 & 4 \\ \end{array} $  $A + B =  \begin{array}{ccc} 8 & 13 \\ 13 & 10 \\ \end{array}$  $(A + B)^2 =  \begin{array}{ccc} 233 & 234 \\ 234 & 264 \\ \end{array}$  $A^2 =  \begin{array}{ccc} 29 & 45 \\ 36 & 56 \\ \end{array}$  $(AB) =  \begin{array}{ccc} 60 & 44 \\ 74 & 56 \\ \end{array}$  $2(AB) =  \begin{array}{ccc} 120 & 88 \\ 234 & 112 \\ \end{array}$  $B^2 =  \begin{array}{ccc} 97 & 72 \\ 81 & 88 \\ \end{array}$  $A^2 + 2AB + B^2 =  \begin{array}{ccc} 246 & 205 \\ 265 & 256 \\ \end{array}$  Based my above work, the answer is false.   Is there another way to approach the problem? It seems like a lot of work needed to be done for a true/false question which raised my suspicion about whether there is a better way to look at the problem.


Who do you have to contact to obtain a license to stream manga?

I am curious to know who the copyright holder to a manga is: is it the mangaka, or the publisher (such as Kodansha, Shonen Jump, etc)?  Who do you have to contact to obtain a license for streaming it?


I was wondering if there is a way to recover photos and things alike from a MacBook after reinstalling the OS X.  Like when you reinstall Windows there is the "Windows.old" folder and you can recover some of the data from there.


How are ETF prices calculated after the market is closed

For example:  Because the NASDAQ: DAX is tracking the index INDEXDB: DAX should its trading value be completely flat when the market the markets are open in the US, but closed in Germany? I'm not seeing that artifact in any of the charts I can find.


Using Java's replaceAll to replace the whole string

I am trying to use following code to replace the whole string:  Code:  String a = "Hello"; String b = a.replaceAll("(?s).*", "US");  Output:  USUS   Question: Why is the string "US" repeated twice? How can I replace the whole string using replaceAll function, making use of regular expression?  Why I need to do this: I need to pick up replace patterns specified in a json file with the values given there. In this model, I wanted to give independence to the user(json configurer) to define a pattern such that entire string may be replaced, without me having to code special handling of string replacement.


I'm wondering what prepositions to use after "assist someone." It seems there is a choice between "in" and "with," but I don't know if they are freely interchangeable. If they are interchangeable in particular sentences, is there any subtle difference?   You will be employed to assist in/with the development of new equipment.     Two men are assisting the police in/with their enquiries.     We are looking for people who would be willing to assist in/with the group's work.     Another doctor assisted him in/with the operation.     A senior academic would assist him in/with his work.     The cream assists in/with the prevention of skin cancer.   Could it be that "in" followwed by a noun (phrase) suggests that work of a more general nature is involved, whereas "with" suggests more specificity, tied to a paritcular task?


How to get Python multiprocessing module working on windows?

I am trying to run a script within Blender that utilizes multiprocessing module. According to documentation it is possible to use it ( see note at the end of  ).     Pythons threads only allow co-currency and won’t speed up your scripts on multi-processor systems, the subprocess and multiprocess modules can be used with Blender and make use of multiple CPU’s too..   So I tried running below script within Blender:  from multiprocessing import Pool  def test( v ):     print(v)     return v  p = Pool(2)  print( p.map(test, range(5) ) )   This however spawns as many new Blender instances (with separate windows) as there are workers in p (in my case 2). Also it spews in System Console :  Can't read file: "C:\Program Files\Blender Foundation\Blender\-c", Unable to open the file. Can't read file: "C:\Program Files\Blender Foundation\Blender\from multiprocessing.forking import main; main()", Unable to open the file. Can't read file: "C:\Program Files\Blender Foundation\Blender\--multiprocessing-fork", Unable to open the file. Can't read file: "C:\Program Files\Blender Foundation\Blender\2888", Unable to open the file.   I also thought about using os.fork() to do the same thing, but sadly Windows does not support that.  I've been looking all over Internet, but so far I was not able to find even one example proving that documentation is correct.  The only thing I found was , but it is locked and with no responses.    Update: This is a windows spesific limitation in the multiprocessing module. ~ideasman42.


Why are my country's banks buying their own shares now?

In light of the Covid-19 crisis, my country's banks have seen their shares' prices drop. Last week, the banks announced that they will doing a share buyback, and this week, the prices of the shares have increased...  Is there any reason why the banks are buying their own shares at a crisis like this?


One lily pad, doubling in size every day, covers a pond in 30 days. How long would it take eight lily pads to cover the pond?

A lily pad sits on a pond. It doubles in size every day. It takes 30   days for it to cover the pond. If you start with 8 lily pads instead,   how many days does it take to cover the pond?   I think that the answer is $27$, but I don't really think that makes sense intuitively. I think that, intuitively, the answer should be less than $30/4$ since it is increasing at an exponential rate.


Files hidden on USB hard disk because of virus, how to clean?

I have 1 GB hard drive with files hidden on it due to a virus. All of its contents were gone after a virus got in when I gave the drive to someone else. After research found that it was a virus may be.  I ran Nortan Anti-Virus and removed a certain virus. Then ran Malwarebytes, now Ad-Aware and AVG 2011 Anti-Virus.  After that, I could see the files on my other computer. But now I have hooked this to my new MacBook Pro—which is running Windows—I can’t see the files. The Anti-Virus finds all the files and Mac OS X wrote a 400 MB directory there which I can see but nothing else.  How to fix this? Which program will fix it?


The vertex-first parallel projection of the tesseract into three-dimensional space has a rhombic dodecahedral envelope. What is the four-dimensional projection of the five-cube? By analogy, its envelope should be a four-dimensional polytope that dissects into 5 congruent "rhombic" tesseracts in two possible ways.  What's the name of this object?


Most people say $0 ^ 0$ is indeterminate, but that's in the context of limits. I mean $0 ^ 0$ when the zeros are absolute.   I've seen that one way to define exponentiation of natural numbers is saying that $a ^ 0 = 1$ for any natural $a$ (including zero), and $a^{1+n} = a * a ^ n$  Under this definition there is no problem, but my concern arises because in the construction of natural numbers, as in Von Neumann's using sets, natural are not the same non-negative integers. Integers are constructed as pairs of natural numbers.  So what would be the value of this expression $0 ^ 0 + (-4)$? You can not just replace $0 ^ 0$ by $1$ using definition above and say the result is $-3$, because you can not operate a natural with an integer. They are different structures. For this expression been properly defined it is needed to be a definition of exponentiation in integers where $0 ^ 0 = 1$  Or perhaps it is not correct to define exponentiation in integers, since it would not be closed. But it would be closed in the complex numbers. What is the definition of exponentiation in the complex, using set theory?  Is it possible that $0 ^ 0$ is equal to $1$ only with natural zeros but not with the zeros of other numerical sets?


Why is the var type still str in Case 1?. Shouldn't it be int? In Case 2 when I'm not using the function it changes to int.  #CASE 1 num1=str()  def suma():      num1=int(7)  suma()  print(type(num1)) # <class 'str'>  #CASE 2 num1=str() num1=7  print(type(num1)) # <class 'int'>


Serializing Object to XML without [xmlns=""]

The Manual of Jackson XML write Object like this   <Simple>   <x>1</x>   <y>2</y> </Simple>   in  but in my code,it has [xmlns="" ],and it can't be in my business.  My code:  public class Sample {     private int id=1;     private String name="abc";      public String getName() {         return name;     }      public void setName(String name) {         this.name = name;     }      public int getId() {         return id;     }      public void setId(int id) {         this.id = id;     }     public static void main(String[] args) throws Exception {         XmlMapper mapper = new XmlMapper();         System.out.println(mapper.writeValueAsString(new Sample()));        //<Sample xmlns=""><id>1</id><name>abc</name></Sample>     } }


After rebooting and choose to boot from DVD that contain Ubuntu ISO. Then the ubuntu logo appear and when total black and nothing happen. Is there any solution for this problem? I wanted to make dual boot and currently using windows 8.1.


Why MySQL Repository Key suddenly expired?

Why is this happening? I've updated my machine last week.  W: GPG error: http://repo.mysql.com trusty InRelease: The following signatures were invalid: KEYEXPIRED 1487236823 KEYEXPIRED 1487236823 KEYEXPIRED 1487236823


Excel copy-paste: always match destination formatting

I use Excel to crunch numbers, so I usually don't want to copy the formatting along with the text. But this is the default. Is there a way to default to always match destination formatting when pasting into Excel?


Nested arrays - how to add a row of elements to nested JavaScript array

I want to add the row      ['2008',777,333]   to var fun and maintain the structure:  var fun = [     ['Year', 'Sales', 'Expenses'],     ['2004',  1000,      400],     ['2005',  1170,      460],     ['2006',  660,       1120],     ['2007',  1030,      540]          ];   Using push or concat seems to destroy the structure.  Can this be done?


How to perform frequency analysis of a substitution cipher using a Base64 alphabet

Let's imagine a cipher that works like the following:   Plaintext is encoded to Base64. The characters in the encoded plaintext are substituted with a randomly shuffled character set(A-z, 0-9, -, _, =).  The shuffled alphabet is, in essence, the key.   Not particularly complex or even secure.  But...  What if I wanted to do frequency analysis?  For example, "RUNFORYOURLIFE" when encoded in Base64 is:  UlVORk9SWU9VUkxJRkU=  When the character set is shuffled, the final cryptext can look something like this:  xv24DYG9qxG2xYg6DYxf  The key being:   yhAc5bTOWeYvBXCpVuoMJLdg8P1jHN3ZIsi67SrK4E_D9-x2qRQmnlkwUaFt0G=zf  Which is a shuffled version of:  abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_=  Let's also assume that the character set in subsequent messages is in the same order(ie the key is re-used).  Since the bytes are basically split up resulting in different character units that may or may not correspond, is frequency analysis still feasible?  Does encoding plaintext this way before encryption add any form of security?  My question mostly pertains to longer messages, as my example may be too short for any sort of real analysis.


I am just wondering if it is possible to have a public static array that can be accessed and edited by all classes.  To see if it works I have tried to access it but I just get an error.  public class FileManager {     public static String[][] cassetteArray = new String[10][6]; }   The command I use to check if it works is;  FileManager.cassetteArray[0][1].length();   Instead I get the following error;  Exception in thread "main" java.lang.NullPointerException at AssignmentStage1.UserInterface.userMenu(UserInterface.java:35)


How can I download LaTeX, PGF, TikZ, and get them to work?

The most I have ever done with software is clicking the download button for something like Adobe and then clicking through the installer. I am way over my head here. I am trying to download and use PGF and TikZ on my Windows 10 system, and I've followed instructions to download MiKTeX console and added PGF, TikZ, and xcolor to the root directory. I can use MiKTeX fine, but I don't know how to create diagrams. Please advise, and please use instructions that a dim-witted five-year-old could follow.  This is not my forte.


Does leaning (banking) help cause turning on a bicycle?

I think it's clear enough that if you turn your bicycle's steering wheel left, while moving, and you don't lean left, the bike will fall over (to the right) as you turn. I figure this is because the bike's momentum keeps it moving in the direction you were going, and since your wheels have friction against the ground, the top of the bike moves forward relative to the bottom of the wheels. The top of the bike going north while the bottom of the wheels go northwest will understandably cause you to topple. So to counteract this and keep you from falling over, leaning into the turn is necessary. But is there also a direct causal relationship -- that leaning will cause the bike to start to turn? If I start leaning left, I will turn left... but maybe that's because I know that if I don't turn the steering wheel left, the bike will fall over (to the left). I experimented with unruly turns of the steering wheel when I was a kid, and got my scrapes and bruises. Now that I'm a cautious and sedate adult I'm not anxious to experiment that way. :-) (I also want to ask why airplanes bank into a turn... they don't have the same issues as a bike, i.e. the bottom part has no special friction against the ground. But that would probably make the question too broad.)


Probability that iid uniform random variables equal the natural numbers

I have random variables $X_1 , X_2 \ldots $ that $X_n\sim \text{Unif}\{ 1, \ldots , n\}$, and I want to calculate  $$\Bbb P ( \{ X_1 , X_2 , \ldots \} = \Bbb N )$$  My intuition is that this means each $X_n = n$, which occurs with probability $\frac 1 n$.  Does this seem correct?


I am studying number theory for cryptography and I've got confused by the log notation that they used. In one video, prof Jonathan Kat refers to the length of a number as the number of bits that are needed to represent that number. To denote the length of a number two vertical bars surrounding the number are used and that is considered to be equal to the logarithm of the number magnitude. See below the expression: $$\|a\|=O(\log a); a=2^{\|a\|} $$ My question is regarding the notation used for that logarithm. I have always thought that when a log appears without subscript was referring to $\log_{10}$, however in the above example is referring to $\log_{2}$.  Then I googled and I found the following:  $x = \log y$  often means  $x = \log_e y$  in mathematics texts. $x = \log y$  often means  $x = \log_{10} y$  in science and engineering texts. $x = \log y$  often means  $x = \log_2 y$  in computer science texts.  How often the above statement are met and why the use of different notation between fields?


I have a folder that consists of other folders (whose names are unknown), .tar archives and JPEG images. How can I remove everything except .jpeg files?


Difference between specific time and current time

Well i have a time in UNIX format. i need to find the difference between a specific time and current time. if difference is 5 minutes. do something.  $sp_time = 1400325952;//Specific time $currentTime = //current time in UNIX format  $difference = $currentTime - $sp_time; if($difference >= 5)//if difference is less than or equal to 5minutes {     //DO SOME STUFF }   EDIT : How to find the difference in minutes and how to get currenttime?


I need your help with the following task. I am in possession of a list as follows: a=[1,2,3,4,5,6,7,8,9]  I would now like to extract a total of 3 numbers for each run, e.g. with the help of a for-loop. For this I want to use the indices. The For-loop should start at the index 0 and go to 2 and then pack it into a and pass it on a total of three times... for i in a[0:9:3]:  In the output according to my example above, it would then have to make as many passes as possible and output the following: 1 2 3 ----------------------- 4 5 6 ---------------------- 7 8 9


How to run .sh script in python script and use the output in Python

The .sh script contains all the paths and variables which I might need in my python script. I do not want to create a .py file and export it in my program as that will require lot of changes. I tried using subprocess module but not sure how to get the variables for using in py script. Is there any way or I will ultimately have to import a new .py file containing all declarations.  Thanks in advance.


Prove that if $A$ is a square matrix with integer entries and $\det(A) = \pm 1$, then $A^{-1}$ contains all integer entries.  I'm really thrown off by this one, its unlike all the examples I've seen.. I just dont know where to start... how can I begin to prove this?


Can you have a negative base for a logarithm? If the answer is no, why can you not? Isn't the answer to the above just $2$?  Similarly, is $-3$ also a solution to the equation $\log _{x}\left( 9 \right)\; =\; 2$ (I know one solution is obviously 3).


Truth table and the meaning of $\oplus$ in propositional logic

Could someone show me the truth table for this proposition? I think I have the last two down, but I'm not sure what the symbol in the following one is: $$p\oplus (p\wedge q)$$


Using reference name of cited source instead of number in text and bibliography

By default biber simply numbers the entries in my bibliography. How can I change the style to reflect the citation reference names I choose instead?  Example:  @book{myownreferencename,   author    = {Abcd Somebody},    title     = {some title},   publisher = {some publisher},   year      = 1990,   volume    = 2 }     % no additional configuration of biblography \bibliography{references} % ... \MakeBibliography      Hey this is a source \cite{myownreference} that should show up.     Result: Hey this is a source[myownreference] that should show up.


How to find $\ \lim_{n \to \infty} \frac{\log n}{\sqrt n}$?

Find the limit of the following expression:      $$\lim_{n \to \infty} \frac{\log n}{\sqrt n}$$   As I plot this function, it seems that this goes to $1$. Is it correct?


Filling triangle doesn't seem to work with PGF/TikZ


Best way to create an  link with empty href

I want to create a link , and to force the link anchor using javaScript, i tried the following:-  <a id="ServerSort" href="#" style="text-decoration:underline">   it worked well but the page will loose its current position after clicking on the <a> link.   I need the link to have an href, because i need need the mouse to change the cursor when going over it ?  can anyone advice ?


Why do we get this formula for the action for Maxwell theory?

I have a question on the variational formulation of electromagnetism.   I read that the action is given by   $\mathcal{S}_{EM} = \int d^4x\  F_{\alpha \beta} F^{\alpha \beta}$ (1)  and the source term is given by   $\mathcal{S}_{source} = \int d^4x\  A_{\alpha} J^{\mu}$ (2)  My question is on how one obtains the above two actions. Here is the explanation that I read.   A.) For expression (1), by the Lorentz invariant of electromagnetism, the Lagrangian must be of the form   $c_1 F_{\alpha \beta} F^{\alpha \beta} + c_2(F_{\alpha \beta} F^{\alpha \beta})^2 + c_3(F_{\alpha \beta} F^{\alpha \beta})(F_{\sigma \tau} F^{\sigma \tau})+...$ (3)  Furthermore, we assert that the higher order terms (i.e. the terms including and after the second term) are all small, experimentally. (Alternatively, we can assert that they are small when we work in Plank units.) Therefore, we are left with the form of the action as in equation (1).    B.) We get equation (2) as follows. We want $\mathcal{S}_{EM} + \mathcal{S}_{source}$ to be invariant under the gauge transformation $A_{\alpha} \to A_{\alpha} + \partial \Lambda$ for any smooth scalar function $\Lambda$. Furthermore, under this gauge transformation, we get $\delta A_{\mu} = \partial_{\mu} \Lambda$, so   $\delta(\mathcal{S}_{source}) = -\int d^4x\ \Lambda \partial_{\mu} J^{\mu} + \text{boundary terms}$  We get gauge invariance if $\partial_{\mu} J^{\mu} = 0$ holds, i.e. if the charge conservation holds. Thus, we get equation (2).   In summary, equation (1) follows from Lorentz invariance and experimental evidence. Equation (2) follows from gauge invariance and conservation of charge.   The above formulation seems unsatisfying to me for the following reasons.    Argument A.) relies on experimental evidence which seems to not follow from general principles. Is there a way of coming up with this using only knowledge in, say Purcell?  All argument B.) seems to do is check whether equation (2) satisfies gauge invariance and charge conservation, and in particular, it does not help us come up with equation (2).    My question: is there a more intuitive way of "seeing" equation (1) and (2)? (For instance, in classical mechanics, the Lagrangian of a system is fairly easy to see since we can just take the difference of the kinetic and potential energies which in turn follows from undergraduate Newtonian mechanics.)   What I have tried: I noticed that $F_{\alpha\beta}F^{\alpha\beta} = \frac{1}{2}(\mathbf{E}^2 - \mathbf{B}^2)$, and I also recalled that the energy density of an electromagnetic field is $\frac{1}{2}(\mathbf{E}^2 + \mathbf{B}^2)$.  This seems to be analogous to $L=T-V$ and $E = T+V$ from classical mechanics. I am not sure if this analogy is just a coincidence.    I tried Googling all of the above of course, but I could not find anything that satisfied me.


For years URLs nesting did matter. Structures like category/subcategory/article were useful to send signal to Google - these things are related.  Then some of big players overcome to flat structures, like    example.com/category1,  example.com/category2,  example.com/category1-article1,  example.com/category2-article2   In such flat structures the only signal of topical relation is an internal linking.  Q   How are your experiences at the moment?  Do you feel any boost of nesting? Specially in non-straight ecommerce environments (content projects and/or lead generation)   There are indeed some questions about the same topic - but they are seven respective four years old - my question is about your current experience (still matter)


Install both BIOS and UEFI bootloaders with kickstart

I am trying to build a . To do so you specify a kickstart file to be used. Since QEMU is spawning a BIOS VM, my kickstart is doing only BIOS related stuff.  My issue here is that I want this image to run on UEFI-only machines as well. How could I accomplish that with just one kickstart file? Bear in mind building always happens in a BIOS machine, so my idea is whether it is possible to "install both bootloaders" for both BIOS and UEFI so this image can run on every machine no matter what it uses.  This is the Kickstart file I am using:  (...) ignoredisk --only-use=vda # System bootloader configuration bootloader --append="console=ttyS0,115200 console=tty0 inst.gpt" --location=mbr --timeout=5 --boot-drive=vda # Clear the Master Boot Record zerombr # Partition clearing information clearpart --all --disklabel gpt  part biosboot --fstype=biosboot --size=1 --ondisk=vda partition /boot/efi --fstype=efi --label EFI  --size=200 partition /         --fstype=xfs --ondisk=vda --label ROOT --size=2800 --mkfsoptions="-n ftype=1"  (...)  /usr/sbin/grub2-mkconfig -o /boot/grub2/grub.cfg /usr/sbin/grub2-mkconfig --o /etc/grub2-efi.cfg # We are installing bootloader with the bootloader command, but this only adds bios compatible, so we force both: https://unix.stackexchange.com/questions/273329/can-i-install-grub2-on-a-flash-drive-to-boot-both-bios-and-uefi # Should not be necessary to add --directory=/usr/lib/grub/x86_64-efi/ /dev/vda /usr/sbin/grub2-install --target x86_64-efi /usr/sbin/grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg


Is it legal to copy stats and abilities of characters from another game?.Please note that my game does have a similar gameplay to the game I am copying. My characters will look different of course.


I would like to show that ring of order $p^2$ is commutative.   Taking $G=(R, +)$ as group, we have two possible isomorphism classes $\mathbb Z /p^2\mathbb Z$ and $\mathbb Z/ p\mathbb Z \times \mathbb Z /p\mathbb Z$.   Since characterstic must divide the size of the group then we have two possibilities $p$ and $p^2$.   Now IU don't understand how can I reason to say that the multiplication is commutative and how can I conclude for the case when characterstic is $p$?


The time to submit this optional question has passed but I'm curious as to what the answer is. We haven't learned what a metric is yet, which is why its a challenge question.  Show that the function $d$ is a metric where  $$d(x,y) = \frac{\left|x-y\right|}{1+\left|x-y\right|}$$


Why are extensions often hidden on URLs?

Many times I see that URL extensions are hidden (e.g. .html, .php), but not all websites do this.  Why do webmasters hide the extension? Is it for security, for the URL to look cleaner, or for some other purpose?


Is there a name or reference in a published journal/book for the following variance formula?

Variance can be combined as  $$v=\frac{1}{n-1}\left(\sum_{i = 1}^{numGroups}n_{i}(m_{i}-m)^2+ \sum_{i = 1}^{numGroups}(n_{i}-1)v_{i}\right)$$  where $v$ is the combined variance, $n$ is the total sample size, $n_i$ is the number of points in group $i$, $numGroups$ is the total number of groups, $m_i$ is the mean of group $i$, $m$ is the combined mean, $v_i$ is the variance of the $i^{th}$ group  Is there a name for this formula or any reference to it?


How does the Adam method of stochastic gradient descent work?

I'm familiar with basic gradient descent algorithms for training neural networks. I've read the paper proposing Adam: .  While I've definitely got some insights (at least), the paper seems to be too high level for me overall. For example, a cost function $J(\theta)$ is often a sum of many different functions, therefore a vast amount of calculations have to be made to optimize its value; stochastic gradient descents - as far as I'm understanding the topic - calculate the optimization only for a subset of the these functions. To me it is unclear, how Adam does this and why this results in a decreased training error for the whole of $J(\theta)$.  I think Adam updates its gradient by taking into account the previous gradient. They call it something like utilizing the momentum? What exactly is this momentum? According to the algorithm on page two in the paper, it is some kind of moving average, like some estimates of the first and second moments of the "regular" gradient?  Practically, I would suspect that Adam enables one to use larger effective step sizes for decreasing the gradient and therefore the training error in combination with the stochastic approximation. Thus, the resulting update vector should "jump" around more in spatial dimensions, rather describing some curve like normal gradient descent algorithms would do.  Can someone de-mystify how Adam works? Especially how it converges, specifically why Adam's method work and what exactly the benefit is?


Negating a raising verb vs its complement infinitive

Consider the sentence:      I don't seem to have enough time.   Theoretically, it could be rephrased:     I seem to not have enough time.   It seems to be grammatically correct, but it sounds a bit off. What is the problem with the rephrased version?


Instead of numbers, symbols are showing up in the references using biblatex

I am using biblatex for creating a poster.I made a small example with all the packages I am using.       \documentclass[]{beamer} \usepackage[orientation=portrait,size=a0,scale=1,debug]{beamerposter} \usepackage[utf8]{inputenc} \usepackage[english]{babel} \usepackage{amsmath} \usepackage{csquotes} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{textcomp} \usepackage[style=numeric-comp,maxcitenames=3,backend=bibtex,url=false,doi=false,isbn=false,hyperref=false,bibencoding=ascii]{biblatex} \addbibresource{library.bib} \usepackage{wasysym} \usepackage{graphicx} \usepackage{multirow} \usepackage[document]{ragged2e} \usepackage[version=3]{mhchem} \usepackage{multicol} \usepackage{fancyhdr} \usepackage{tikz} \usepackage{lmodern} \usepackage[version=3]{mhchem} \usepackage[lf]{venturis} \usepackage[version-1-compatibility]{siunitx} \renewcommand*{\bibfont}{\scriptsize} \DeclareSIUnit\Molar{\textsc{m}} \setbeamertemplate{caption}[numbered]   \begin{document}  tedhjfshsofhewihewi\cite{Meyer1996a}nfoeeghraeoghru  \begin{minipage}{0.98\columnwidth}     \begin{multicols}{3}          \noindent              %\scriptsize                          %\setbeamertemplate{bibliography item}[text]                 %\bibliographystyle{abbrv}                 %\bibliography{library}                 \printbibliography                 %\vspace{3em}         \end{multicols}              \end{minipage}  \end{document}   In principle everything is fine. No error messages and no bibtex related warnings. I get the (1) in the text.  However in the reference list, instead of      (1) Author1, Title1, Journal1...   I get       Author1, Title1,   Journal1   Any ideas?  Thanks for your help.


Integrate $\int_0^{2 \pi } \frac{1}{(a+b \cos^2 (x))^2} \, \mathrm{d}x$

I'm having a trouble with this integral expression:  $$\int_0^{2 \pi } \frac{1}{(a+b \cos^2 (x))^2} \, \mathrm{d}x$$ I want to solve to using residue but it seems hard.


I have never used Ubuntu before.  I am currently running Windows 8 and have installed Ubuntu 12.10 using the wubi install kit.    My comp. will not recognize a DVD drive for now.    I want to destroy Windows 8, while keeping personal files, and make Ubuntu my only OS.    How do I do this?     The problem being that I cannot create a disk... So I am looking to accomplish a full install with only the use of wubi


I am trying to figure out the best title for a section of a technical document. I wish to mean tables with 12 columns. Should I write: 12-Column Grid or 12-Columns Grid ? Which is correct?


In the help center under the moderator tools privilege, there is an interesting screenshot.    I assume that this picture was taken while logged in as Jeff Atwood on Meta Stack Overflow.  In this picture, I can see "print" and "transmogrify" buttons beneath the question. It's pretty obvious what "print" means, but what about "transmogrify?" And what privilege levels do you need to see these buttons?


Do circular polarizer gels for creating left and right handed polarized light exist?

I am looking for a polarizer gel for our lights, but specifically one for creating left or right handed circular polarization.  I can find linear gels all over the place. I can even find circular filters for the camera. But no circular gels.  Does this even exist or is it something that isn't possible to do in a gel?  Edit since there are so many questions and links to other questions:  Quick high level explanation for what I am attempting to experiment with:  On set I will have multiple light sources. I want one set to be Right-handed and the other will be Left-handed.  Then 2 cameras will shoot the same scene, one with a Right-handed filter and the other with a Left-handed filter.  Why circular and not linear? If you are using linear polarized light and linear polarized filters then your filter has to be correctly aligned to properly work. Rotating the filter will change what polarization it filters out. Also, linear polarization can change it's direction easily when bouncing off different surfaces.  Think of a 3D movie that uses this tech. 2 projectors use left and right handed polarization. Your glasses filter out each one almost perfectly AND you can tilt your head without screwing with what light is being filtered through.  I'm not an expert on this topic but I do believe I know enough to know what I need. I found in another thread that in photography terminology on this topic is a bit "messed up" and may have different meanings to different people.


My son is a freshman this year.  We live in and he attends school in California.  We pulled out the first $ from our Utah 529 plan.  I had the money deposited in my account since I paid the registration and dorm & meal plan.  Our friend has a son a year ahead and he has the exact same 529 plan.  He warned me that he got hit with a small tax penalty when he withdrew the money to his account and not to an account in his son's name.  I called the 529 administrator and they said it shouldn't matter either way.  Other online blogs agree.  They say the only difference is that my son would get the tax forms and have to file if it went to his account. Nevertheless, my friend did get a penalty.  Any clarity would be appreciated!


In C++, I can use the following code to implement the functions.  char result=0; for(char c:s)    result^=c;   However, when I try to implement this in Ruby, it fails.  result=0 s.chars.each do |c|    result^=c end   How should I XOR each char in a string in Ruby? Thanks very much!


I can't install or remove any software from software center?

I can't install or remove any software and the Ubuntu software center shows me this message when I install software:  Software can't be installed or removed because the authentication service is not available.  (org.freedesktop.PolicyKit.Error.Failed: ('system-bus-name', {'name':  ':1.88'}):  org.debian.apt.install-or-remove-packages    and after I press ok, a second massage appears:  org.freedesktop.PolicyKit.Error.Failed: ('system-bus-name', {'name': ':1.88'}):  org.debian.apt.install-or-remove-packages   Can anyone help me?


I was told by my professor that homeomorphisms are continuous maps with continuous inverse, but do those conditions also imply that the map is bijective?


Ubuntu 20.04: keyboard and mousepad not working after installation

I've been following a lot of issues here that relates to this one - so it might be a possible duplicate, however since I didn't see it for 20.04 version, I think it's a new one. The issue is:  I have installed (via USB that contained a downloaded version from Official website) the Ubuntu 20.04 new OS. - Please note this is a fresh installation. After rebooting, the keyboard and mousepad are just not working. They are working if I am getting to tty (for example) / BIOS, however not in the login page / in the OS.  I have followed each and any guide here about installing / updating xserver-xorg-input-all again and again, however this isn't seems to solve the issue. Hardware: Architecture:        x86_64     product: Inspiron 7348 (0675)        product: 067RT2           product: Intel(R) Core(TM) i7-5500U CPU @ 2.40GHz              product: HMT41GS6BFR8A-PB           product: Broadwell-U Host Bridge -OPI              product: HD Graphics 5500              product: Broadwell-U Audio Controller              product: Broadwell-U Processor Thermal Subsystem              product: Wildcat Point-LP USB xHCI Controller                 product: xHCI Host Controller                    product: USB Receiver                    product: ST_SENSOR_HUB                    product: Integrated_Webcam_HD                    product: Touchscreen                 product: xHCI Host Controller              product: Wildcat Point-LP MEI Controller #1              product: Wildcat Point-LP High Definition Audio Controller              product: Wildcat Point-LP PCI Express Root Port #3                 product: Wireless 7265              product: Wildcat Point-LP USB EHCI Controller                 product: EHCI Host Controller             product: Wildcat Point-LP LPC Controller              product: Wildcat Point-LP SATA Controller [AHCI Mode]                 product: LITEONIT LCS-256              product: Wildcat Point-LP SMBus Controller              product: Wildcat Point-LP Thermal Management Controller           product: PnP device PNP0c02           product: PnP device PNP0b00           product: PnP device INT3f0d           product: PnP device PNP0c02           product: PnP device PNP0303           product: PnP device DLL065a           product: PnP device PNP0c02           product: PnP device PNP0c02        product: DELL 0WF28498        product: OEM Define 5  My questions:  Did anyone else suffer from this problem? Where you reboot - install the xserver using an external (for example) keyboard and mouse - then it works. Then after another reboot - it does not work? Specifically after upgrading to 20.04!  How can I solve it? Please assist as it is a critical issue!


I have been told that the way I am grabbing the post, and then passing it to the query so that it can be stored is very unsafe, and unsecure, and I would like to know ways I could strenghen it. I am quite novince at this, so please bear with me.      $course_price_final = $_POST['priceFinal'];     $course_provider = $_POST['courseProvider'];     $user_email = $_POST['userEmail'];     $crs_title = $_POST['courseTitle'];     $course_date1 = $_POST['courseDate'];     $course_token = $_POST['courseToken'];     $card_name =  $_POST['cardName'];      $course_delivery = $_POST['courseDelivery'];     $order_date = date("Y-m-d");     $insert_c = "insert into orders (course_title,course_price_final,course_provider,user_email,course_date,course_delivery,order_date,course_token)               values ('$crs_title','$course_price_final','$course_provider','$user_email','$course_date1','$course_delivery','$order_date','$course_token')";     $run_c = mysqli_query($con, $insert_c);


I need my pendrive to boot into Ubuntu, how to correct this and boot from the HDD?

I installed Ubuntu through USB. Instillation was successful.  But when I restarted my laptop it didn't boot. So planed install it again when started selected install from USB. it booted my previous installed Ubuntu. So after went Ubuntu boots no need of that pen drive, so in short, every time I want to start my pc I need that pen drive to boot.


Infinite Series Convergence Verification

I'm currently tackling the following infinite series in order to determine if it converges or not:  $$\sum_{n=1}^\infty \frac{\sqrt{n+1}-\sqrt{n}}{n}$$  What I've done is rearranged this to make use of the comparison test, shown below:  $$= \frac{\sqrt{n+1}-\sqrt{n}}{n} * (\frac{\sqrt{n+1}+\sqrt{n}}{\sqrt{n+1}+\sqrt{n}})$$  $$= \frac{(n+1)-(n)}{n(\sqrt{n+1}+\sqrt{n})}$$  $$= \frac{1}{n(\sqrt{n+1}+\sqrt{n})}$$  $$= \frac{1}{n^{3/2}+\sqrt{n+1}} < \frac{1}{\sqrt{n+1}} < \frac{1}{\sqrt{n}} $$  However, $\frac{1}{n}$ is smaller than $\frac{1}{\sqrt{n}}$, therefore:  $$  \frac{1}{n}   < \frac{1}{\sqrt{n}}$$   This implies divergence by the comparison test due to the fact $\frac{1}{n}$ diverges, and if a smaller series diverges any larger series must as well.  Is this right? If I've made any mistakes in any part, please tell me!


Shared ground between two different circuits?

I have a 240 circuit that i am trying to split into 2 120 circuits.  I have only 3 wires available, red/white/black.  I have another circuit a few inches away (both in junction boxes),  Can I share the GROUND wire with the two circuits to avoid having to run all the way back to the panel or getting only one circuit from the 3 wires.  I know how to split the circuit, breakers, etc.  My only question is the shared ground.  All 3 circuits will be 20A.  It is the GROUND I am asking about, not the neutral wire.


I'm trying to compare the result of a command substitution to a string, like this:  if [$(ping $1)=="ping: unknown host localhosts"] then   echo "no"; else   echo "yes"; fi   What am I doing wrong here?


I'm working on a new version of a corporate website. As it stands, it has about 6 different sections. Each of those sections have between 3 to 6 sub-pages. My nav is at the top of the page and looks a bit like the wireframe below:         – Wireframes created with   I have made some simple dropdowns with js to handle the desktop side of things. For tablets and mobile devices I have gone with the standard right aligned hamburger menu button. The more I look at the site on a tablet, the more I like the lack of clutter at the top.  Apart from potentially confusing some users, what are the downsides of going with the hamburger menu for all devices?    and a number of other sites do this already.


Fraleigh Section 23 12.Give an example to show that a factor ring of an integral domain may be a field 13.Give an example to show that a factor ring of an integral domain may have divisors of $0$ 14.Give an example to show that a factor ring of a ring with divisors of 0 may be an integral domain.  For 12, $Z/2Z$ works For 13, $Z/4Z$ works For 14, $4Z/8Z$ ( isomorphic to Z$_2$?) works. -> I just figured out 4Z is not a ring with divisors of 0... I'm unsure about my answer for 14. Is it correct? And any other examples for 12,13,14?


Show that $B(X)$ is semisimple for a Banach space $X$

Show that $B(X)$ is a semisimple Banach algebra, where $X$ is a Banach space. That is, to show that rad $B(X)=\{0\}$, or equivalently, to show $\sigma(AT)={0} \, \forall T\in B(X)\Rightarrow A=0$.  I have been trying to find a simple proof of the following without using the more general result that for a Banach space $X$, $\sigma(AT)=\sigma(BT) \, \forall T\in B(X)\Rightarrow A=B$.


Google Search Console: existing sitemap not found

Google search console (at Crawl -> Sitemaps) gives me General HTTP error: 404 not found errors after I upload the sitemap.xml to my website. When I click the link generated in the search console, it opens the file, but Search console still gives me 404 error.


Will adding more RAM speed up my computer?

Apparently, you can speed up your computer by adding more RAM. Is the amount of ram to be added is directly or indirectly related to the amount of hard-disk  space, processor speed, Motherboard etc... Can the memory of a RAM be compared with Virtual Memory and Cache Memory?  Note: About my PC Configuration: Intel core i5 processor, Motherboard DP55WB 4GB RAM, 700 GB Hard-disk space.


Recently, I installed , and ever since then, both resizing and dragging windows does not behave as it used to; I simply get a placeholder, and the window does not resize in real-time:    How can I fix this?  Windows 8.1 x64.


Why should already negative sentences have 'no' in them again ?

I encountered a couple of sentences, mostly in American movies, that I wondered why they have something I call ' Double negatives', for example:  Don't go no further (why not Don't go further) We can't grow no crops without no water I don't see no friends (why not I don't see any friends / I see no friends)  What's the structure of these sentences, are these considered informal? Are there any other correct alternatives to them?


How to create a python object that be passed to be open as a file

I have some lines in Python that I want to pass a function that for some reason only accepts inputs as filepaths. For the example, let's call this function func.read(). Since func.read() only knows how to reads files, not strings directly, I'm being forced to write my text into an auxiliary file and then pass the file path to func.read(): text="""some random text""" fout = open("aux","wt") fout.write(text) fout.close() func.read("aux")  But this is a hassle, and I'd like to avoid relying on writing external files. I could modify the function to take a string or list of strings, but this is a last case scenario (for some other reasons I can't go into detail here). Is there a way I can "trick" this function by creating an object that behaves like a path to a file? Essentially an object that can be passed to open() I'd say. Cheers


I have the following code:  #include<stdio.h> int main(int argc, char const *argv[]) {     float min, max, step;     min = -0.85, max = 0.85, step = 0.002;     int rank = 3, total = 4;     float step1 = min + (max - min) * rank / total; // should be 0.425     printf("%f %.7g\n", step1, step1); // 0.425000 0.4250001     float step2 = min + (max - min) * (rank + 1) / total - step; //should be 0.848     printf("%f %.7g\n", step2, step2); // 0.848000 0.848     float noc = (step2 - step1 + step) / step; //should be 212,5     printf("%f %.7g\n", noc, noc); // 212.499985 212.5     int nol = 1200;     int result = (int)nol * noc; //should be 255000     printf("%d\n", result); // 254999     return 0; }   This is a fragment of code isolated from a project I have to do. The final result should be 255000, but for some causes, it shows 254999. Can someone please explain me what happens in the process? I have read somewhere that multiplying a floating number with 10^k and then dividing back solves such problems, but in this case, due to the variable step varying from 0.000001 to 0.1, I can't actually use that (in the same way, I can't use a defined EPSILON). What else can I do?   Thanks in advance!  P.S.: I have used double and long double as well, but with same problems, only this time error propagates from a further decimal. I am using gcc 4.8.2, under Ubuntu 14.04.1.


$R^2$ for mixed models with multiple fixed and random effects

I have a mixed model with three random effects and many fixed effects.  I set aside some of my data to validate my final model and now I would like to compute the $R^2$ on the validation set, in R.    I found some code for a mixed model with one random effect but not for a model with more than one random. Does anyone know a package or some code to compute $R^2$ for mixed models with more than one random effect?  If this isn't possible, does anyone have a good suggestion for comparing model fits?


What are the minimum specs for Ubuntu server to host a subversion repository?

I need to build an server (Ubuntu 9.10 server) to host source control (subversion) from my house.  What are the minimum specs (processor and RAM) to do this with good performance?  I'll need to buy some new parts from newegg and just need enough to get by.  It may also serve as a file server for other things in the future, but nothing intensive like media streaming.  I only need about a 1GB repository, and 2 or 3 users.


Cycles Render Is in Low Quality But The Viewport Looks Great

I have a Blender file which consists of an ocean plane and a sky node. The render view looks great through the viewport and it even looks great through the camera view when I lock the view to the camera square. Why does it look extremely low res when I render an image? Btw I'm using Blender 2.92 on Windows 10 and I'm trying to render with Cycles Supported on my GPU which is a 3070. This is a screenshot of the viewport. Notice how good it looks.  This is a rendered image. Notice that it looks really bad and low res.  Also here is the actual file.


Windows 7 lowers applications' volume automatically

Every time I run some of my games, if the media player is open and playing, Windows 7 lowers the volume of both applications (the game and the player). All other applications are not affected. I tried foobar and Winamp, combined with several games, and it happened every time, which makes me think it’s a Windows 7 thing.  The volume goes down to inaudible levels (usually 3 or 4), and I’m forced to alt+tab, open the volume mixer, and increase both volumes manually every time.  This also doesn’t look like a bug, but some kind of feature. When it happens, the little bar in the volume mixer that shows each application’s volume level gets a little transparent (but stays in it’s regular position), while a new one appears and tells the new volume.  Anyone know what’s causing this?  (The games ran from steam, in case it matters)


The intersection of a closure with an open set

I have been stuck on this problem :   Prove :If $A$ is Open , then $A\cap \overline B \subset \overline {A \cap B}$.I have tried to use the previously proven fact that $\overline {A \cap B}\subset \overline{A} \cap \overline{B}$ , but I cannot seem to get anywhere ...In particular, I do not see how A being open is relevant here..........


Can't install Ubuntu 18.10 on XPS 15 - EFI\BOOT\mmx64.efi not found

I tried to install Ubuntu 18.10 on my XPS 15 9570 earlier. Everything was working fine until I got to the partition selection part of the installation. That's when the installer crashed and I had to shut down my machine. I think it's because I had my SATA configuration set to RAID ON instead of AHCI, which is now fixed.  Now when I try to run the installer from my bootable USB I get the following error  Failed to open \EFI\BOOT\mmx64.efi - Not Found Failed to load image \EFI\BOOT\mmx64.efi: Not Found Failed to start MokManager: Not Fond Something has gone seriously wrong: import_mok_state() failed   Hoping someone might have some idea as to what is going on


What types of industry positions favor PhD over a masters?

I'm coming from a biomedical engineering background, and I'm noticing that almost all job postings ask for either an MS or a PhD, and from speaking with my friends with masters it seems that masters are often favored, because they demand less pay. In fact, the only positions that specifically seek out PhDs seem to be research positions in industry.  Based on that, I'm curious to see if this exists beyond just engineering. Are there any non-research industry positions that actively seek to hire PhDs over masters students?


Finding units and zero divisors of the ring $\mathbb Z_6 \times \mathbb Z_8$

As stated in the title, I wish to find all the units and zero divisors of the ring $\mathbb Z_6 \times \mathbb Z_8$.   What I have so far:  The units of $\mathbb Z_6$ are $\{1,5\}$, and the units of $\mathbb Z_8$ are $\{1,7\}$, so the units of $\mathbb Z_6 \times \mathbb Z_8$ are $\{(1,1), (1,7), (5,1), (5,7)\}$. Is that correct?  The zero-divisors of $\mathbb Z_6$ are $\{2, 3, 4\}$, and the zero-divisors of $\mathbb Z_8$ are $\{0, 2, 4, 6\}$. I am not sure how to proceed, however. Thoughts?  I am new to math.stackexchange so please let me know if any part of my question is unclear. Thanks!


How to know the corresponding face of an object in UV view?

Just a quick question here. I want to know the corresponding face(s) of the object I've selected in the UV view. But all faces of the object are selected so I'm unable to do that. Any help is appreciated :)


Prove the complex Inequality $|z_1 + z_2| \le |z_1| + |z_2|$.

I have to be prove the following inequality, where $z_1$ and $z_2$ are two complex numbers. $$|z_1 + z_2| \le |z_1| + |z_2|$$  I know I can substitute Z as 'x + iy' and open both sides but I am confused about the inequality. Any help would be appreciated.


Simple Windows deployment to multiple PCs

I purchased 3 PCs with identical hardware that have Windows 8.1 installed.  I purchased 3 licenses for Windows 8.1 Pro retail/full version.  I want them to be configured identically initially, including the administrator account and password.  I will be spending considerable effort to configure a PC, and I would rather not have to do it 3 times.  I don't do IT for a living, and I would rather not go through that learning curve for a one-time deployment.  I saw , but it is for Windows 7 and the answer looks like more learning and effort than what it would take me to manually configure 2 PCs.  Referencing , will the following scenarios work?  Scenario A   Install Windows 8.1 Pro on the 1st PC, with the 1st Product Key Install updates, drivers, common apps, change settings, etc. Open a Command Prompt window as an administrator Move to the %WINDIR%\system32\sysprep directory. Enter command: Sysprep /generalize /shutdown /oobe Use disk backup software to take an image of the drive Restore the image to the 2nd and 3rd PCs At the next boot for all 3 PCs, enter the Product Key as part of the OOBE Activate Windows on all 3 PCs   Scenario B   Install Windows 8.1 Pro on the 1st PC, with the 1st Product Key Activate 1st PC Install updates, drivers, common apps, change settings, etc. Use disk backup software to take an image of the drive (1st-PC specific) Open a Command Prompt window as an administrator Move to the %WINDIR%\system32\sysprep directory. Enter command: Sysprep /generalize /shutdown /oobe Use disk backup software to take an image of the drive (generalized) Restore the 1st-PC-specific image to the 1st PC Restore the generalized image to the 2nd and 3rd PCs At the next boot for the 2nd and 3rd PCs, enter the Product Key as part of the OOBE Activate Windows on the 2nd and 3rd PCs


Need help calculating resistance for transistor base

I have 3 12VDC/40A automotive relays () that I want to use with my Arduino. Based on the tutorial I am following () I need transistor, resistor, and diode. I am not an electrical engineer therefore I am unsure about the parts and calculations I made. For the start, relay coil resistance is 90+-10% Ohm per datasheet. So I proceed by calculating the current flow.  Voltage=Resistance*Current Current=Voltage/Resistance Current=12V/90 Ohm Current = 133mA  For the transistor I can get 2N3904 or 2N4401. At this point I have to calculate resistance for the base of transistor. In tutorial its as following  hfe = Ic / Ib Ib = Ic / hfe Ib = 0.03 A / 75 Ib = 0.0004 A => 0.4 mA R1 = U / Ib R1 = 5V / 0.0004 A R1 = 12500 Ohm  2N3904 datasheet states the H(fe) is 30-300 when lc = 100mA (mine is 130mA) and Vce = 1V. At this point I have no clue what is going on, thus I need help. Edit: Here is what I ended up with. RLY1 in the picture is 12VDC/40A ()


Can I fly to (board) Turkey without passport?

I am a French citizen and I want to go Turkey. As I see in their Ministry of Foreign Affairs page, I can go to Turkey with my national ID. My passport is expired 3 years ago. And again, as I see in their Ministry of Foreign Affairs page, I can go to Turkey with an expired passport (5 years most) Looks like it's ok but when I am boarding the plane, will staff ask my passport? Or when I am going to gates, will the passport police ask my passport in the passport check point?


I was getting No space left on device, so I removed some of the files. But again when I try to update my folder with svn update I am getting the same error. Is this the problem with space left?  When I run df -k I get     and when I run df -i , I get     It seems like the system has ran out of inode space as you suggested even though I have the space left in my disk. How do I fix this?


Create Sub-bibliography file from a main bibliography

Say, I have a main (large) bibliography file, Large.bib, I include in TeX as  \bibliography{Large.bib}   how do I crate another sub-bibliography file, SubBib.bib that contains the entries which are being cited in the main TeX?


Question -  Example 1.30. Let $p \geq 7$ be a prime. Prove that the number $ \underbrace{11 \ldots 1}_{(p-1) \mathrm{l}^{\prime} \mathrm{s}} $ is divisible by $p$  Proof: We have $ \underbrace{11 \ldots 1}_{p-1^{\prime} \mathrm{s}}=\frac{10^{p-1}-1}{9} $ and the conclusion follows from Fermat's little theorem.   But by FLT we get ${10^{p-1}-1} \equiv 0 \pmod{p}$ how we will get that $\frac{10^{p-1}-1}{9} \equiv 0 \pmod{p}$?


Humanoid Rigify help: I tried everything but still getting: Warning: Bone Heat Weighting

I know this is a duplicate issue, but could someone help me to understand why I'm getting this Bone Heat Weighting Failure.  I've gone through the forums and youtube and tried around 8 or so different suggest fixes, but no luck.  I'm fine with the module being one mesh. I've tried loosening vertices and I noticed it broke the mesh into parts with the finger and toe-nails separate. I'm not sure if this has anything to do with the issue but I'm certainly fine with that all being one mesh.  Here's a couple different links to download my latest file post fix attempts:    or   or the same via google drive:   Also, if it's helpful, here is a blender file with the metarig before I generated the rig:   If it turns out the issue has something to do with the fact that I deleted the meshes for the eyes and inside of the mouth. Here's the original model I was using:   I simply deleted all the extra meshes to try and simplify my issue. Ideally I want to work with those other meshes and rigify, but I'm starting out simple.


What resources should I use to learn LaTeX

I'm new to LaTeX. When I'm learning how to use it, I'm always having trouble searching the meaning of some commands, such as \thechapter, \chaptertitlename... I think these must be basic commands in LaTeX but I cannot figure out what EXACTLY they are used for. Someone suggest me to check texdoc, however I didn't find the explanation of what I want either(I searched for the commands name in the doc). Is there some other resource that I can refer to? Or am I using wrong way of reading texdocs?


Find $$\sin\left(\frac{2π}{7}\right)+\sin\left(\frac{4π}{7}\right)+\sin\left(\frac{8π}{7}\right).$$  I already know of two methods. The first is in which we let $2π=7\theta$ and proceed as such- $\begin{align} 2\pi-3\theta=4\theta\\ \implies\sin(3\theta)+\sin(4\theta)=0\\ \implies-4\sin^3\theta+3\sin\theta+ 4\sin\theta\cos\theta(1-2\sin^2\theta)=0 \end{align}$ On solving further we get a cubic polynomial in $\sin^2\theta$. We can then find the required sum from the sum of roots and some algebra. I also know of the method that involves complex numbers and the roots of unity. What I am interested in is a method involving trigonometric identities. I tried a few things. In particular I noticed one fact that might be of significance, that is the sum of the angles $\frac{2π}7, \frac{4π}7$ and $\frac{8π}7$ is precisely $=2π$. However, I was not able to make much progress. Can someone please help me with this?


My iPhone 5 runs out of power very quickly. First it was 50%. Then it was 60%, then 70%, and now 80%. At 80%, the phone will shut down like it would when the power gets to 0%. When it powers back on, it says 80%. It's almost like the limit of when to shut the phone off was, and still is getting to a higher percentage.   However, the phone is unusable. Not only does it run out of power quickly, it also drains power at a ridiculous rate. In half an hour, with wifi enabled and the screen off, it takes about half an hour to turn off. When I'm using it, it takes 10-15 minutes after a full charge to die. What's the cause of this issue, and how can I fix it?


"going to come down" vs "going to have to come down"

What is the difference between the following sentences?        This fence is going to come down.   This fence is going to have to come down.      I have doubt that when you are saying fence is going to have to come down, that is enough to say it right? but why I hear in movies saying fence is going to have to come down, is there a difference between them?


Let $a,b,c$ are positive real numbers such that $abc=1,$  prove that $$a^2+b^2+c^2 \geq a+b+c$$  i was thinking of using AM GM  inequlaity.but donot have idea on which pairs to apply it.   any hint....


Remove keyboard shortcuts of the Dock's applications (Gnome 3.26.2, Ubuntu 17.04)

When hitting Win+1, the first application of the dock is launched. Same for Win+2 to second application, etc.  Is it possible to disable this feature? (personally, it interferes with my desktop selection shortcuts)


okay so basically I've played with friends while im at their house. Well if we live in the same city but far away is it possible to just do as you normally do and open lan then type in the IP, etc. Hahah I'm rlly stupid


Why doesn't this integral yield the area of the sphere?

Here's how my book derives the formula for the volume of the sphere:     A sphere can be thought of as the solid of revolution generated by   revolving a semicircle about its diameter (see the figure below). If   the equation of the semi-circle is $x^2+y^2=a^2$, then the element of   volume is $dV=\pi y^2dx=\pi(a^2-x^2)dx$ and the volume of the sphere   is given by  $$V=2\int_0^a{\pi(a^2-x^2)dx}=\frac{4}{3}\pi a^3$$   So I thought: well, I know that the 'lateral' surface area of the element of volume $dV$ is just the circumference times a little change in $x$, so by the same reasoning the area of the sphere should be given by  $$2\int_0^a{2\pi\sqrt{a^2-x^2}dx}$$  That way we should be able to cover the whole surface of the sphere. Sure, there would still be an extra "peeling" around the outside of the strip, but as the book says, just as in the calculation of the volume, "this slight apparent error - due to using disks instead of actual slices - disappears as a consequence of the limit process that is part of the meaning of the integral sign.".   It turns out, however, that that integral does not equal $4\pi a^2$. So, what is wrong with my reasoning? Thanks in advance.


Looking for Analog story: Aliens come to force-field imprisoned earth looking for ally again evil alien empire.

This story I am sure was in Analog. A confederation of aliens come to earth and are able to break through a force field enclosing earth. The field was put there by aliens since they were not able to break earth's defenses in an older war. Earthlings appear completely non-technological, and the good aliens think they may at least be able to dress them up to be scary. One alien falls in shaft through hundreds of stories of tech before being saved. They bring down the force field and earth celebrates. Even the horses and dogs have conversations about it. Earth has not been idle during their imprisonment. They take on challenging the evil alien empire by moving the earth into space, and they take the moon along. I remember a cute seen where the human says he is making ice cream, but he is not sure he has enough for a large alien. The alien tries to hunch up, but it not sure if "ice cream" is something good or if it is used to remove reluctant teeth. A really great story.


Indicator changes to "2 hours ago" no matter when it was actually posted

Whenever I look at a question on Stack Overflow, once I spend maybe 30 seconds on that page, or sometimes even if I click edit, the box where it says "posted 10 minutes ago", will automatically switch to "posted 2 hours ago", no matter when it was actually posted.  It seems to happen rather randomly, but it happens on both my laptop and my desktop, which both use Google Chrome.  Is anybody else experiencing something like this?    This actually happened to this question right as I was about to add another comment.  Another Edit: Now when I refresh the page, it says "asked 14 minutes ago"


How do I edit the list of music library locations in Rhythmbox?

I previously set Rhythmbox to include a few different locations. Now following changes to my directory structure, I'd like to reflect these changes in Rhythmbox. But when I go to "Library Location", I see "Multiple locations Set" and I can only add to the list; no way to edit/remove.  I Googled this problem and the only relevant results I get date back to 2006, probably referring to a previous version of Rhythmbox and specifying components/locations that I can't find on my system.  Give a look at the documentation...kind of minimal.  Any clues?  Ubuntu 12.04 Rhythmbox 2.96


The official website of our company is no where to be found on google. How can we put it to the top position among other search results?

We have just built the official website for our company, but it is not listed in the results returned by google even if users input the full name of our company. Instead,the search results are all news reports about our company from other media outlets and very dated.


Command line move file with long directory path without repeating directory path

Is there any way of executing a mv command without typing the full path in the second argument?  Example:  mv my/file/that/has/a/really/long/path/foo.bar some_magic_operator_that_means_the_same_directory/foo.baz


Report coefficients of a factor in a GLM

I have a GLM and my explanatory variables are a factor of 9 levels (X1) and a numeric variable (X2). If I have to report the formula: $Y = B_0 + B_1X_1 + B_2X_2$ I have 1 coefficient for the intercept and 1 coefficient for the numeric variable, that's ok, but I have 8 coefficients for the factor, how do I report them? I mean, Bo is one number, B2 is one number, but B1? do I sum the eight numbers? or I report the mean of the 8 numbers, or I have to report the formula with the eight numbers?


Can someone please explain the bounty system?  I answered a question that featured a 50 rep bounty that no one else answered and I received nothing,   The other day  that featured a 500 rep bounty and got 3 upvotes. Before the bounty ended someone posted another answer and also got 3 upvotes. He got 250 points when the bounty ended but I didn't.   Why is that? and if there is no automatic split system that provides half of the bounty isn't that going to make some people to abuse it?


If I have a list with 600,000 elements  The list I have is quite complicated, and has nothing to do with sequence or order, but let's use this one with 600,000 elements as an example:  main_list = list(range(0,1200000,2)   and if I want to to create a list that slices the main_list into a new list likes this:  sub_list =  [main_list[0:100], main_list[100:200], main_list[200:300], main_list[300:400], ...]   How can I do it?


How to (re)define margins for sectioning commands?

I'm currently trying to adjust my document to the baseline grid and for that I want to change all margins of \chapter, \section, \subsection (and floats) etc. to multiples of the \baselineskip. I found that \titlespacing can do that, but it seems to generate errors.  \documentclass[paper=a5,pagesize]{scrreprt} \usepackage{titlesec} \titlespacing{\section}{0em}{2\baselineskip}{\baselineskip}  \begin{document}     \section{Test} % Missing number, treated as zero. \section{Test}                    % Illegal unit of measure (pt inserted). \section{Test}     Test \end{document}   I'm not sure what's happening here. I'm also getting Non standard sectioning command \section(titlesec) detected. Using default spacing and no format. warnings for all commands which suggests the packet might be incompatible with my class.  Is there any other way to do this?


Isn't the word "experience" wrongly used in this context?

Friend: Have you ever flirted with a female cop?      Me: Nope.      Friend: I have done that experience.   I think experience is the wrong word here. What else should he have said?


I can't boot into a usable system after updates. What should I do?

Since some system updates, my machine can no longer boot properly. I am no Ubuntu guru. I do not have a week to spare diagnosing the issue. I just want to retrieve important data from this machine's hard drive and get a working computer again ASAP.  What should I do?


Adding Direction and Distance into Attribute table

I just want to add direction (Bearing: i.e N 25 35 E) and Distance (Length: 125 meters) as my new field in polyline/line data. Is there a Plugin to generate these fields? I tried to used "Export/Add geometry columns" in my line data, but only "Length" value was added.


What do curly braces in Java mean by themselves?

I have some Java code that uses curly braces in two ways  // Curly braces attached to an 'if' statement: if(node.getId() != null) {     node.getId().apply(this); }  // Curly braces by themselves: {     List<PExp> copy = new ArrayList<PExp>(node.getArgs());     for(PExp e : copy)     {         e.apply(this);     } } outAMethodExp(node);   What do those stand-alone curly braces after the first if statement mean?


How to find the dimensions of a rectangle given a) the area and the diagonal or b) the perimeter and the diagonal

I need to write concise formulas of these two:$\space \space \space$ $(1)$ finding the dimensions of a rectangle given the Area and the diagonal $\space \space \space$$(2)$ finding the dimensions of a rectangle given the Perimeter and the diagonal  Searching on google I can only find examples using number (eg. “Let’s assume the diagonal is $5$ and the area is $25$”etc) but I’m having trouble writing down formulas that use variables (so that I can use them in my code).  Would appreciate if someone could show me how to formulate the formulas (no pun intended) for these two. Thank you!


Let A and B be two fixed points on a straight line. Two circles touch this line at A and B respectively and the tangent to each other at M, when the circles vary the locus of M is?  This question has already been asked , but I could not comprehend that answer properly, also I am not allowed to comment on that answer as I don't have 50+ reputation. I have only drawn the rough sketch but not able to go any further.