Ways to optimize run-time of _view_layer_update calls?

I've been working on an Add On project for a while to generate buildings/terrain procedurally out of "primitive" Blender objects as elements. As you might expect, one of the most common operations the Add On performs is to duplicate an object (and its children, as 'primitive' is interpreted somewhat loosely here, to allow for multiple objects related through parenting to serve as a single modular building block). Recently, I've been trying to optimize the Add On's run-time a bit, and noticed that it seems to spend almost all of its time -- if I am understanding this cProfiler () output correctly -- updating the view layer:    Ordered by: cumulative time     ncalls  tottime  percall  cumtime  percall filename:lineno(function)         1    4.202    4.202  116.476  116.476 make_building.py:32(makeBuilding)       260    0.078    0.000  107.959    0.415 util.py:68(blDuplicate)       260    0.005    0.000  106.569    0.410 ops.py:184(__call__)       520  105.985    0.204  105.985    0.204 ops.py:155(_view_layer_update)        1    0.002    0.002   56.751   56.751 make_building.py:132(generateFloorsWallsHallways)        1    0.006    0.006   43.853   43.853 make_building.py:287(addCeilingTiles)  (pstats output truncated, but sorted on cumtime so I think this is sufficient to get the idea) To be a bit more confident about this, I also setup this minimal example, run from inside a Blender Console inside a running Blender session: >>> def dup(): ...     bpy.ops.object.duplicate() >>> import cProfile >>> p = cProfile.Profile() >>> p.runcall(dup, *[], **{}) >>> p.dump_stats(bpy.path.abspath("//") + "turkey_baster.dump")  This, similarly, seems to indicate that view layer updating is taking most of the time: >>> ps.strip_dirs().sort_stats('cumulative').print_stats() Sun Feb  7 12:00:42 2021    <filepath removed + "turkey_baster.dump">           13 function calls in 0.233 seconds     Ordered by: cumulative time     ncalls  tottime  percall  cumtime  percall filename:lineno(function)         1    0.000    0.000    0.233    0.233 <blender_console>:1(dup)         1    0.000    0.000    0.233    0.233 ops.py:184(__call__)         2    0.232    0.116    0.232    0.116 ops.py:155(_view_layer_update)         1    0.002    0.002    0.002    0.002 {built-in method _bpy.ops.call}         1    0.000    0.000    0.000    0.000 ops.py:40(__getattr__)         1    0.000    0.000    0.000    0.000 ops.py:82(__getattr__)         1    0.000    0.000    0.000    0.000 ops.py:180(idname_py)         2    0.000    0.000    0.000    0.000 {method 'startswith' of 'str' objects}         1    0.000    0.000    0.000    0.000 ops.py:79(__init__)         1    0.000    0.000    0.000    0.000 ops.py:168(__init__)         1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}  I haven't yet tried to look up ops.py in the Blender source to try to read what _view_layer_update is doing, but in short am wondering if there's much room from the Blender Python API to optimize this operation, or if I just have to accept this cost. I don't really have any idea what view_layer_update does right now, so I'm not sure whether there's much opportunity to reduce its cost. (EDIT: in case it is pertinent, note that I'm working in Blender v2.83.2; I've been upgrading versions only slowly to avoid having to accommodate any assumptions I've made that the version upgrade would break) EDIT2: I notice the layer update percall time is very small (0.001) on a brand-new scene, and I seem to be able to cut it down from 0.116 to 0.07 or so by disabling every single collection (except the Master Collection) from the scene. Maybe I could cut that down further by disabling or deleting still other data structures in the file (e.g., Materials)? I am not sure how practical that is as solutions go, but it seems like relevant evidence, at least.


I've created a building model with a architecture software (Sweet Home 3D) and on the generated .obj object I have this problem: the flat walls are divided around windows and doors and look curved or angled. It appears that the 3D is flat though, so maybe it is a lighting or a normal problem?   Does anyone know how to solve this in blender so the walls look flat? Many thanks Thomas.


Why is the closed $\operatorname{im} T$ in the definition of Fredholm Operator redundant?

, it's stated that the condition of $\operatorname{im} T$ being closed in the definition of Fredholm Operator is redundant. Why is that?  Edit: Most proofs use the existence of a closed $N$ such that $T:X\rightarrow Y$, $Y=imT\oplus N$. However, why does such a $N$ exist?


How to change sharepoint outgoing email body

our company decide to use sharepoint 2013 my site feature.  i should change the content of email body which automatically send to users.  for example there shouldn't be SharePoint word in this mail.  how can i change the content of email body. i couldn't find in resx file.    thanks for redirection. however i don't think so that i ask for this.  I don't want to change or make a new mail template. I want to change the content of mail body.  as i mention the first part, it should't be written a word like "SharePoint" on mail body. because my customer don't know what is "sharepoint".


What is the proper behavior when someone abuses the close-vote superpowers?

I got  in the re-open vote queue.  I noticed it is marked as a duplicate of a question titled Complete and utter nonsense, which was a bit suspicious. So I looked at the bottom of that question and found out it was closed as duplicate by a single user with the new close-vote superpowers.  When going to the duplicate question (the one titled ), I noticed that the same user with the superpowers changed the title of that question and edited the only answer to say If you're reading this, you've posted a question that makes no sense what so ever !.  While this is quite funny, and perhaps both of the questions are low quality and don't make sense (I don't have a gold badge on the relevant tag, so who am I to say), this behavior seems to abuse both the new superpower (since if the new question makes no sense, it shouldn't be closed as a duplicate of a non related question, it should be closed as off topic or unclear) and the edit privileges (what was done to the older question looks like vandalism to me).  This is definitely not a behavior I expect from a 100k+ rep user.  What do you think should be done in this case?


I have two system   A: Ubuntu 14.04 with internet  B: Ubuntu 14.04 without internet   I have customized and installed missing files and packages on A. Now I  need to enable  to play .mp3 files on B  How do I do that? overall I want to know    How to install missing packages, in some zip or any package system? How do I distribute the packege  or it will done by single command?   UPDATE  I run below command from   dpkg -l | grep "^ii"| awk ' {print $2} ' | xargs sudo apt-get -y install --reinstall --download-only   now what to do?  Please help.


If statement not responding to a scanner input?

Okay, so I'm currently working on a Computer Science project and I'm coming across an error. Whenever I run these two classes, I get an error where it doesn't read the input and just does nothing after my Scanner gives it a value. I'd appreciate some clarification on what I'm doing wrong. Thanks.   public Recipe(String Directions, String RecipeName, int CalorieCount, MethodOfCook H){      directions = Directions;      recipeName = RecipeName;      calorieCount = CalorieCount;      hi = H;  }  public static void RecipeDisplay(){     for(int i = 0; i <= Ingred.size(); i++){         if (Ingred != null){             Recipe.DisplayHelper();             System.out.println("===============================");             System.out.println(recipeName);             System.out.println("===============================");             System.out.println("Directions; " + directions);             System.out.println("Calories; " + calorieCount);             System.out.println("Cooking Method; " + hi );         }     } }  public static void DisplayHelper(){     int index = 0;     System.out.println("Would you like to add a recipe?(Type YES or NO)");     Scanner wantTo = new Scanner(System.in);     String bad = wantTo.nextLine();      if(bad == "YES"){         index++;         System.out.println("First we'll start with Ingrediants, Input as many as you like");         Recipe.addIngrediants();         Recipe.editIngrediants();         Recipe.removeIngrediants();          System.out.println("Great, now lets name your Recipe;");         Scanner nameDude = new Scanner(System.in);         String yesName = nameDude.nextLine();         yesName = recipeName;          System.out.println("Moving on, Input your Directions;");         Scanner inputDude = new Scanner(System.in);         String bud = inputDude.nextLine();         bud = directions;          System.out.println("Now input a Calorie Count (Numbers Only!)");         Scanner numberMan = new Scanner(System.in);         int jman = numberMan.nextInt();         jman = calorieCount;          System.out.println("Now select an Enum Method;");         System.out.println("Remember your values are;");         Scanner sc = new Scanner(System.in);         MethodOfCook bu = hi;         for (MethodOfCook bum : bu.values())             System.out.println(bum);          // read strings from Scanner - display Algorithm value or   throw exception         while(true){             try             {                 System.out.print ("Enter value  ");                 System.out.println("Great, your value is" + bu.valueOf(sc.next()));                 Recipe ji = new Recipe(bud, yesName, jman, bu);                 System.out.println(ji);             }             catch (IllegalArgumentException m){                 System.out.println("  Error: " + m);             }             }      }      else{         System.out.println("Okay thanks.");      } }   The error is mainly in my DisplayHelper I believe, also I'm trying to link the scanner inputs to my recipe class, so that I can build an ArrayList of recipes in a separate class, thanks in advance! (Sorry for the strange format, it doesn't seem t want to work.)


If $ \frac {x^2}{a^2} + \frac {y^2}{b^2} = r^2$ is an ellipse, with the parameterization $x(θ)≔r(a \cos θ,b \sin θ ),$ I have to find the value of $θ$ giving the minimum distance from $P(p,q)$ (not on the ellipse) to the ellipse is given by a quartic in $t= \tan( \frac {θ}{2}).$ A necessary condition for $x$ to be the closest point to $P$ is that $P-x$ is perpendicular to the tangent vector in $x ,$ i.e. $(P-x(θ) ). x' (θ)=0$  I can't handle the above condition to make an fuction (e.g. $f(θ)$) to find the minimum value by calculating the rerivative $f'(θ)=0$ for example. Then I have to prove that rational, non-zero values of $a, b, p, q$ can be found such that the quartic factorises as the product of two quadratics with rational coefficients. Any help? Thank you


Could pp Collisions in the LHC produce Gravitons?

Could proton-proton Collisions in the LHC produce Gravitons?


What is the dispel CL of a crafted Pearl of Power?

I asked something similar and didn't get the clarity I was seeking, so I will be more concise. If I craft a 1st level Pearl of Power at CL 1, and it gets hit with a targeted , what is it's caster level for the check? Is it 1, as that was the chosen CL at time of crafting, or is it 17, the listed CL for a Pearl of Power of any level?


Average area of a triangle on the inside of a circle

So the other day I was looking at a list of hard putnam questions, as you do, and I stumbled across a problem "What is the probablity that four points chosen randomly and uniformly form a convex quadrilateral" - I quickly reduced the problem to the average area of a triangle inside a circle with the observation that if a quadrilateral is concave, one angle is over 180 degrees and so one of the points lies inside of a triangle formed by the other three. Now here is the issue, I barely know calculus with one variable, so I cant solve this as I'm pretty sure this will require a multivariable integral, so help me out pls.


What rule does this violate?  I know that it's wrong, but what is this tense or of what tense is it not a proper form? I hear these a lot: we are needing or we are wanting instead of we need or we want.


Add Twitter status to StackOverflow maintenance page

The StackOverflow maintenance page states:     Routine maintenance usually takes less than an hour. If this turns   into an extended outage, we will post details on the .     Would it be worthwhile to add a latest tweet(s) from  on this page as well?  As we saw today, the outage was short enough to not merit a blog post, but caused enough of an impact to post a tweet about.  It could be done either via the  or using the embed code (as provided by Twitter):  Tweets by @StackStatus


Is there any way to capture all the places in a String, where there are punctuation marks like '.,:;!?'      Basically, am looking for a regex that captures all the above.


How do I use MySQL from the CLI?  When I use the terminal, I get:  Darrens-MacBook-Pro:~ thufir$  Darrens-MacBook-Pro:~ thufir$ mysql -bash: mysql: command not found Darrens-MacBook-Pro:~ thufir$    As you can see, MySQL is installed and running:    this system:  System Software Overview:    System Version:   OS X 10.10.2 (14C1510)   Kernel Version:   Darwin 14.1.0   Boot Volume:  Mac OSx   Boot Mode:    Normal   Computer Name:    A MacBook Pro   User Name:    thufir (thufir)   Secure Virtual Memory:    Enabled   Time since boot:  2:08


Probability: finding the expectation of "overlapping events"

Suppose there are 666 coins with 6 different colors in a non-transparent box. 111 of them are white coins. 111 of them are black coins. 111 of them are yellow coins. 111 of them are red coins. 111 of them are green coins. 111 of them are blue coins. You are going to repeatedly randomly take out one coin from the box, record its color and put it back to the original box. Assume that each time after you put the previous coin back and before you take out one coin, all 666 coins in the box have been “shuffled” thoroughly and all coins are the same in any other physical attributes except for their colors.  What is the expected number of coins needed until you have seen all types of coins?  I've been stuck on this question for hours, can someone explain it?


How to evaluate $\lim\limits_{x \to \infty}\dfrac{\ln{\left(1+e^x\right)}}{x}$ without using L'Hôpital's rule?

The given limit is from an exercise from the book Differential and Integral Calculus by Piskunov: $$\lim\limits_{x \to \infty}\dfrac{\ln{\left(1+e^x\right)}}{x}$$ The answer in the book is $1$ as $x \to +\infty$ but $0$ as $x \to -\infty$.


How do I display an image in Java with no errors?

I have tried a million different things, but Java just gives me errors or straight up doesn't work when I tell it to display an image. I have to use the default "Graphics" coordinate grid because this will result in a playable game. Please tell me (ASAP - As Simply As Possible) how to get the code below working.  import java.awt.Container; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException;  import javax.imageio.ImageIO; import javax.swing.ImageIcon; import javax.swing.JFrame; import javax.swing.JLabel;  public class main extends JFrame {      static JFrame frame = new JFrame();     static Container pane = frame.getContentPane();     static Graphics graphics;      static ImageIcon background = new ImageIcon("background.png");     static JLabel backgroundLabel = new JLabel(background);      static File titleFile = new File("title.png");     static BufferedImage title;      public static void main(String[] args0) {          frame.add(backgroundLabel);         backgroundLabel.setVisible(true);         frame.setContentPane(backgroundLabel);          frame.setVisible(true);         frame.setTitle("Fastball");         frame.setDefaultCloseOperation(EXIT_ON_CLOSE);         frame.setResizable(false);         frame.pack();          try{              title = ImageIO.read(titleFile);          } catch (IOException e) {              System.out.println(e);          }finally{          };          if(title != null) {              graphics.drawImage(title, 15, 15, 440, 112, null);          }     } }   With this code, I am getting the error Exception in thread "main" java.lang.NullPointerException at main.main(main.java:60) and I don't know exactly what it's refering to...


Where does the 12 come from in the denominator of the variance formula in the Wilcoxon (Mann-Whitney U) test?


How to restrict access to view a block for a certain role?

I have some custom roles such as Premium Membership and I don't want to allow access to this category.  The authenticated role is included to Premium Membership or Moderator users because every registered user has this authenticated role assigned to them by default.  I want to hide a block and display only for authenticated users that do not have other roles assigned to them.  What can I do?


Announcing the Stack Exchange Time Machine

We are living in the gold age of user-generated content. Anyone can post a joke before breakfast, become a meme by lunch and be fired for the joke at the end of business. Ok, it's more like the " age", but still a unique moment in human history. Here at Stack Exchange, we're doing our part by hosting some of the very best content produced entirely by individual users at scale. I think it's fair to say we are the  of Q&A.  It all started back in . Even so, it achieved some popularity within the developer community. The network first expanded to fairly technical topics, but very quickly  for just about every form of human knowledge including an endless variety of  and  schemes. In the days BSE (Before Stack Exchange) it was certainly possible to share knowledge. There were podcasts and blogs and forums and . You could post on  or  or . And of course there were  and  sites with alien mascots. But none of them capitalized on the simple genius of the question and answers format quite like Stack Exchange.  The  and we got to thinking it's too bad Stack Exchange sites have only been part of a third of that history. What, we pondered, would the world be like if Stack Exchange had started back in  1998? Relieving you of the need to imagine it, we are proud to announce a new Time Machine feature that lets you experience Stack Exchange before its time.    What's that? It says "WELCOME TO STACKOVERFLOW" you say? I asked our designers about that and they tell me dank fonts don't need lower case. Oh, you mean why isn't it STACKEXCHANGE? That's a bit of a time travel paradox. We set the baseline at 2008, but the Stack Exchange brand didn't really show up until . We have our crack quantum mechanics working on it. Once they patch the timeline, we won't have any way of knowing.  As you explore the Stack Exchange off-ramp of the Information Superhighway keep your eyes peeled for content that could only exist in the '90s such as:     Funny        Feel free to note especially appropriate examples in the answers below, but please don't .


Null pointer exception while creating excel file in Java with apache poi on the line rowHeading.getCell(i).setCellStyle(stylerowHeading);

I am going through POI Excel tutorial on you tube. when I executed following code I get NullPointer exception. Plz suggest the ans.  Thanku.  package main;  import entities.*; import dao.*; import java.util.*; import org.apache.poi.hssf.usermodel.*; import org.apache.poi.hssf.util.*; import org.apache.poi.ss.usermodel.*; import org.apache.poi.ss.util.*; import java.io.*;   public class Main {      public static void main(String[] args) {         // TODO Auto-generated method stub         try{             ProductModel pmodel = new ProductModel();             HSSFWorkbook workbook= new HSSFWorkbook();             HSSFSheet sheet=workbook.createSheet("List Products");             //create heading             Row rowHeading = sheet.createRow(0);             rowHeading.createCell(1).setCellValue("Id");             rowHeading.createCell(2).setCellValue("Name");             rowHeading.createCell(3).setCellValue("Creation Date");             rowHeading.createCell(4).setCellValue("Price");             rowHeading.createCell(5).setCellValue("Sub Total");              for(int i=0;i<6;i++)             {                 CellStyle stylerowHeading= workbook.createCellStyle();                 Font font = workbook.createFont();                 font.setBold(true);                 font.setFontName(HSSFFont.FONT_ARIAL);                 font.setFontHeightInPoints((short)11);                 stylerowHeading.setFont(font);                 stylerowHeading.setVerticalAlignment(CellStyle.ALIGN_CENTER);                 rowHeading.getCell(i).setCellStyle(stylerowHeading);              }              //save to excel             FileOutputStream out =                       new FileOutputStream("D:\\AVIATE\\excel\\listproducts.xls");             workbook.write(out);             out.close();             System.out.println("Excel written successfully........");          }catch(Exception e){             System.out.println("exception");             e.printStackTrace();         }     }  }


What is the categorical diagram for the tensor product?

The title says it all: what is the diagram that defines a tensor product?  (I'm using the term diagram here in the  it has in category theory.)  Edit: This question was motivated by the following statement:  "...all limits and colimits are initial objects somewhere, and we can even sort of take the view that all universal properties are initial objects somewhere", from  (@~9:15)  Thanks!


Is there a word for when a statement is technically true but misleading?

The statement that inspired the question was "Newton was wrong [about the laws that govern movement]". Although some exceptions have been found to Newton's laws since he discovered them and thus the statement is true, the laws are still taught and used, making the statement misleading.  Another example would be "I've never lost at chess" when the speaker has never played a game of chess.


Ubuntu Gnome 16.04 - Power button action "Interactive" doesn't work

I want the confirm dialog when I press the power button. It worked in 15.10. I tried tweaks tool and dconf editor, neither work. In dconf there are 2 entries one doesn't work, the other doesn't have an option for "interactive". Tweaks tool has the option, but it doesn't work.  Ubuntu Gnome 16.04 LTS on Asus zenbook ux305  Thank you


How many times per rest cycle can a cleric cast their domain spells? And at what level are they cast?

The description for Domain Spells is vague.  Once a cleric gains access to a domain, can they cast the domain spells as often as they wish (like a cantrip) or only a certain number of times per rest cycle?  Also, at what level are these spells cast as some of them have greater effects as they are cast at higher level?


Currently selected indicator's colour in flag summary and help pages, can be the same as the site's colour code

Some of the Stack Exchange sites has it's own colour code. Like Meta Stack Exchange has #17a7db, ELU has #AE3737, Travel has #277789 for the currently selected item's indicators in main page and the user activity page. But in the flag summary section and help pages of those sites, the indicator has the colour of #F48024 which is same as the Stack Overflow site's colour code. So instead of applying the Stack Overflow's colour code to all the sites, shall we apply the site's specific colour code in flag summary and help pages too. Selected indicator in flag summary section of MSE, ELU and Travel:      Selected indicator in help page:


How to search an element in ArrayList in java?

I need to find car element in ArrayList. The ArrayList data like this { [1,mobile,5000]    [2,car,50000]    [3,bike,20000] }  and classes are  //pro.java import java.util.*;   public class Pro{  private int id; private String name; private int price;  public String toString(){   return id+" "+name+" "+price;   }  //getter & setter methods }   and the search code is like this  //Product.java System.out.println("enter name you want to search"); name = scanner.next(); Iterator it=al.iterator(); while(it.hasNext()){  if(it.next() == name){  System.out.println("Yes found");  }  else{  System.out.println("Not Found");  } }   it is the iterator reference object and al is the ArrayList reference object.  the search is always return Not found but the element what I find is exist. How to fix it in order to return FOUND? Please help me with the appropriate code Thank's.


what is the differene between "class" and "struct"?

When writing C++ code, what is the difference between using class and struct?  class Foo final { };   vs.  struct Bar final { };   When should I prefer one over the other?  Is this merely a choice of programming/coding style?


ul list disappears when not using overflow:hidden

In this example, the list disappears when not using the overflow property with the hidden value.Can some one explain why ?    ul {   list-style-type: none;   margin: 0;   padding: 0;   overflow: hidden;   background-color: #333333; }  li {   float: left; }  li a {   display: block;   color: white;   text-align: center;   padding: 16px;   text-decoration: none; }  li a:hover {   background-color: #111111; }

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     Here's a link to the tutorial:


$A$ = $\{X\subseteq \mathbb N : |X| = \aleph_0\land |\bar X| \lt\aleph_0  \} $   I need to find the cardinality of group A.  As I understood, I need to find a function that helps me determine the cardinality.  Any ideas?


check whether if two squares are intersecting with each other

I would like to check if two square are intersecting with each other. My idea is this  for (i = 0; i < 4; i++)    for (j = 0; j < 4; j++) {        bool x = check line(i) of first square intersect with         line (j) of the second square        if (x) return;    }   any idea to optimize this code?


How can sunlight be white , but pictures of the sun be orange?

I was thinking about elementary physics today and realised: We learned and proved that sunlight is white. But i don't understand why when you look at a picture of a satellite orbiting the sun , it(the sun) seems yellow-orrange. How could this be? It is like there is a red light bulb in the room but what you see is green.


How to find SQL Server database is in use or not?

What query do I need to write to know if the database is in use or not? I tried following query  SELECT     name  FROM      sys.databases  WHERE      state != 0;   but it is not working.  I want to check there should not have a open connection with that database and should not executing a query against that DB


How do I setup a Lan between two notebooks with a single ethernet cable?

I want to connect two Acer notebooks with a single ethernet cable between them for lan gaming.   Connecting them to a router or a switch is not an option due to distance. I found a couple of tutorials by searching for it, but all of them depended on the already extinct Workgoup function on Windows, thus I can't confidently follow the tutorial.   So I would appreciate any help with this, because it doesn't seem as simple as plug the cables in the notebooks.


I'm creating an installation script for an application that I'm developing and need to create databases dynamically from within PHP. I've got it to create the database but now I need to load in several .sql files. I had planned to open the file and mysql_query it a line at a time - until I looked at the schema files and realised they aren't just one query per line.  So, how do I load an sql file from within PHP (as phpMyAdmin does with its import command)?


For a finite group of order $2n$ does there exist $x$ such that $x\ast x=e$?

Let $ (G,\ast)$ be a group with identity $e$ and cardinality $2n$ for some $n\in\omega$. Then, does there exist $x\in G$ such that $x\ast x=e$ and $x\neq e$?


Do we understand why mass, charge or magnetic moment appear as quantized quantities?

There are two similar questions as the comment notified:   I could see two points there:  compactness of the space limited by potential.  symmetry requirement such as angular symmetry of atom, Lorentz symmetry, etc.   But I don't see the explanation of why there arise the quantized quantities such as mass, charge, and magnetic moment I explained below. (If I missed the answer, guide me please.) The free electrons are not in the compact space and not in the symmetry requirement except the translation. Lorentz invariance would not be the point as we can talk of a non-relativistic electron. But we can observe the quantized charge and mass. So I think my question is still not answered.  When I was a physics student, I remember to solve the Schrodinger equation with the well potential. And because of the boundary condition which the equation has to satisfy, only the solutions resonating with the well can survive. And this leads to the quantization of energy level even though Hilbert space is continuous in terms of energy level. I also remember a similar logic when I was introduced into the quantum field theory. One of my teachers explained the quantization with the resonance. He starts with the finite box and increases the box size infinite to get the quantization of free particle. However, how about the electric charge? The electric charge of electrons can exist as the multiples of a unit charge only(I remember some particles with different charge units though.). Also, the mass of fundamental particles are fixed and can exist as the multiples of unit mass. And there is spin whose size is fixed as giving rise to the multiples of the unit magnetic moment. In the view of classical mechanics, those quantities (mass, charge, and magnetic moment) are assumed to be the continuous number. Do we understand the origin of these quantized quantities? If we do, could you explain the reason for the layman?


finer control of Preview anti-aliasing (font smoothing)?

I have just updated to Yosemite and something must have changed in the way Preview renders fonts.   I find that Preview display of text in PDF files is rather sloppy, I am pretty sure it used to be much sharper in Mavericks. At the very least now Preview is significantly less sharp than Acrobat Reader, you can check out a screen-shot to convince yourself of what I am talking about.  In the rest of the UI I am quite happy with how fonts are displayed. So I was wondering if there are ways to control the anti-aliasing of Preview. In the preferences of Preview I can find only a global switch for anti-aliasing, but I would like to play around with the strength of the anti-aliasing so to find the optimal setting.   I am looking into defaults of com.apple.Preview but in my current values there seem to be no setting about Font Smoothing or anything evocative of anti-aliasing. Any suggestion about possible values to edit here?  Thanks for your suggestions, Roberto


How to download all required Ubuntu drivers

Is there a package of Ubuntu drivers as driver pack solution? I tried to search for it, but I did not find it. If there is, how can I easily get it?


I have column with dates in column U. I changed them to "ddd" format, so now they are Mon, Tue etc.   I am trying to count how many times Mon is in cells between cell U2 and U1048576. I tried =COUNTIF(U2:U1048576,Mon) and =COUNTIF(U2:U1048576,"Mon"). Result is always 0. I tried same thing but searching for a number and it works. How do I do same thing for weekdays ?


Rolling question rate limits are now network-wide

When you think of Q&A sites, you think of a place where you come to get answers to your questions. But, where do those answers come from? What doesn't immediately stand out for many folks is that it's not our software that's giving them answers, it's other people that are taking the time to share what they know. Our engine is a vehicle that you use to arrive at an answer to your question, and vehicles are things that takes a bit of time to learn how to use.  If you have a driver's license, you probably went through some kind of program where someone else taught you how to operate a car properly. It was most likely a special kind of car, where the instructor had a brake pedal just in case someone had to slam on the brakes and you weren't doing it. After all, things go bad when you don't hit the brakes in time, especially when you're going too fast.    A while back, we  when it comes to asking questions. The single most common mistake that folks were making was in fact going way too fast; some would ask three or even five questions initially and none of them did well. The system didn't have that extra brake pedal and many users sped, you guessed it, .  We did what we always do, research:    Turns out, slowing folks down just a little when it looks like they're getting off on the wrong foot is the most effective way to help potentially great users become great users. We don't go from 100 km/h straight into a wall any longer, . Additional just-in-time help (triggered while writing a question) is in the works.   New users who aren't doing so well initially will be shown the additional guidance and will be asked to wait anywhere from one to seven days before asking their next question, depending on how they've done recently.   The system is also pretty smart, and takes the following things into consideration:   How many substantive edits you've made to your own posts recently How many good answers you've written recently How long you tend to wait between asking questions   The more acclimated you become, the sooner the system will get out of your way entirely. Yes, it is still possible to encounter a much longer-term block on some larger sites, but you'd need to ignore a lot of help before hitting it.  Testing on Stack Overflow and several other large sites has gone very well, so we've enabled this throughout the network. Most users on smaller sites probably won't see these kick in, and that's fine - but they're in place for those that can really benefit from them, just like those brave souls that teach folks how to drive.  This feature came out of the SE Quality Project ( | ) and is one of several initiatives we're putting in place to help maintain the overall quality of our sites while providing new users with a better experience.


What is the difference between "coefficient of determination" and "mean squared error"?

For regression problem, I have seen people use "coefficient of determination" (a.k.a R squared)  to perform model selection, e.g., finding the appropriate penalty coefficient for regularization.   However, it is also common to use "mean squared error" or "root mean squared error" as a measure of regression accuracy.  So what is the main difference between these two? Could they be used interchangeably for "regularization" and "regression" tasks?  And what are the main usage of each in practice, such as in machine learning, data mining tasks?


So I'm trying to use four $2$'s to make the number $7$. I can use parenthesis, addition, subtraction, indicies, addition, division, multiplication   edit: also have the same problem with $9$ but I'll try that myself if someone could help with $7$


BACKGROUND: I went to oracle.com and I downloaded the JDK. I moved the file to /usr/local/java. Afterwards, I set the path variable and JAVA_HOME in /etc/environment.  PROBLEM: I have a jar file in my downloads directory. Although I can go to terminal and use "java -jar" and it works, I want to be able to double click and execute the jar file.


Clear column on a double column document

How do I clear a column in a double column document? I have two floats, and I want each to occupy a different column.  \clearpage before the second float puts it on a new page, while \pagebreak does nothing (puts the two floats on the same column).  MWE  \documentclass[twocolumn,english]{article} \begin{document}  \begin{figure} \caption{} \end{figure}  \newpage{}  \begin{figure} \caption{} \end{figure}  \end{document}


Is there a way to preserve a weapon in Magicka within a saved multiplayer game

In Magicka, you and your "wizard bros" have a saved, progressed multiplayer game.  You have the M60 from chapter 3 (I think, just got into this game) and when you come back, the players are wiped from the game instance (IP game / private). Is there anyway to spawn this item? Somehow with a Steam update we lost character data in our game. We still had all the usual robes we were always accessible to - however our host lost his sword, I lost my beloved M60 (best item in the game IMHO) and another player lost their off hand.  We crossed a chapter point then "called it a night because we're all married old men". However, I'm a child when it comes to my M60.  Any thoughts / suggestions?


How to downgrade java (jre) the ubuntu way

Background of the question is that I have tried (in vain) to set up my newly installed box with Java 9 together with Eclipse Oxygen.  Those won't work together (there are multiple questions about this, and it looks like every problem is a special case with a different cause).  The direct reason seams to be that Eclipse (eclipse.ini) cannot start the JVM, and the popup with the parameters is not even accessible to copy & paste.  So I did a sudo apt-get remove openjdk-9-jdk-headless, but after that java -version still told me it's 1.9.  Next try was sudo apt-get remove openjdk-9-jre-headless. Now the shell can't find any Java at all. Fine, so far, as I deliberately removed it.  Now I tried to install JRE 8 with sudo apt-get install openjdk-8-jre-headless (and I really wonder if that headless is kind of an omen).  I get  Reading package lists... Done Building dependency tree        Reading state information... Done openjdk-8-jre-headless is already the newest version (8u151-b12-0ubuntu0.16.04.2). openjdk-8-jre-headless set to manually installed. The following packages were automatically installed and are no longer required:   ant ant-optional aspectj default-jdk default-jdk-headless   eclipse-platform-data eclipse-rcp fastjar gconf2 jarwrapper junit junit4   libapache-pom-java libart-2.0-2 libasm3-java libasm4-java libaspectj-java   libbonobo2-0 libbonobo2-common libbonoboui2-0 libbonoboui2-common   libcanberra0 libcglib3-java libcommons-beanutils-java libcommons-cli-java   libcommons-codec-java libcommons-collections3-java libcommons-compress-java   libcommons-dbcp-java libcommons-digester-java libcommons-httpclient-java   libcommons-logging-java libcommons-parent-java libcommons-pool-java   libdb-java libdb-je-java libdb5.3-java libdb5.3-java-jni libeasymock-java   libecj-java libequinox-osgi-java libfelix-bundlerepository-java   libfelix-gogo-command-java libfelix-gogo-runtime-java   libfelix-gogo-shell-java libfelix-osgi-obr-java libfelix-shell-java   libfelix-utils-java libgail18 libgeronimo-jpa-2.0-spec-java   libgeronimo-osgi-support-java libglade2-0 libgnome-2-0   libgnome-keyring-common libgnome-keyring0 libgnome2-0 libgnome2-bin   libgnome2-common libgnomecanvas2-0 libgnomecanvas2-common libgnomeui-0   libgnomeui-common libgnomevfs2-0 libgnomevfs2-common libhamcrest-java   libice-dev libicu4j-49-java libicu4j-java libjetty8-java libjline-java   libjsch-java libjtidy-java libkxml2-java liblucene2-java libobjenesis-java   liborbit-2-0 libosgi-annotation-java libosgi-compendium-java   libosgi-core-java libosgi-foundation-ee-java libpthread-stubs0-dev   libregexp-java libservlet3.0-java libservlet3.1-java libsm-dev   libswt-cairo-gtk-3-jni libswt-glx-gtk-3-jni libswt-gnome-gtk-3-jni   libswt-gtk-3-java libswt-gtk-3-jni libswt-webkit-gtk-3-jni libtdb1   libtomcat7-java libx11-dev libx11-doc libxau-dev libxcb1-dev libxdmcp-dev   libxt-dev openjdk-8-jdk sat4j sound-theme-freedesktop x11proto-core-dev   x11proto-input-dev x11proto-kb-dev xorg-sgml-doctools xtrans-dev Use 'sudo apt autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 6 not upgraded.   OK, I can read and write, so I did that proposed autoremove and repeated the install command, but still have no Java:  Reading package lists... Done Building dependency tree        Reading state information... Done openjdk-8-jre-headless is already the newest version (8u151-b12-0ubuntu0.16.04.2). 0 upgraded, 0 newly installed, 0 to remove and 5 not upgraded.   What is happening, and how can I fix it?


mySql database doesn't read UTF-8 properly

I have an application working fine with special characters, except on firefox and when the app is online.  I'm using AngularJs as front-end and php/mysql to control my dataBase. When I insert new values to data-base, it convert special characters to something like this     São paulo -> SÃ£o Paulo   The problem is, only in firefox and only when I'm testing it online, the output on the screen is show as SÃ£o Paulo instead of São Paulo. In chrome it works fine.  I already tried a bunch of things to correct this.   Table in mysql to use utf-8 instead of latin1; mysql:host=$host;dbname=$db;charset=utf8; Convert data when going from AngularJs to php to utf-8;   But none of the solutions have worked to fix this problem.  Any ideas?


Scale on map requires correction coefficient. But why?

I am computing the distance of a map I am getting from ArcGIS' REST services by using a calculator as provided by . In a nutshell, it uses a GeodeticCalculator for distance computation based on latitude and longitude.  I then use the distance and my display width to compute a scale. My display is currently 362*230 (custom display hence the off measurements). When comparing the distances on screen to the distances as given by Google maps, the measurement always overestimated. However, it did so by a factor of roughly 1.2. I not use this as a correction coefficient and am accurate to about 1m in 1 km.  While this solution works (for now), I would like to know where this offset could come from. Below is a bit of code to show how the computation is done. Note that scale is a field of the class this method resides in.  /** Relevant fields */ private GeodeticCalculator calculator = new GeodeticCalculator(CRS.decode("EPSG:3857")); private static final double CORRECTION = 1.2;  /** More code left out for reasons of brevity. */  public double computeScale(double latMin, double latMax, double lonMin, double lonMax) {                calculator.setStartingPosition(new DirectPosition2D(latMin, lonMin));     calculator.setDestinationPosition(new DirectPosition2D(latMax, lonMax));             double distance = calculator.getOrthodromicDistance();     scale = distance / (Calibration.getTableWidth() / 10) / CORRECTION;     return distance; }


Failed to build in android studio. Can't find why it's not working

at first when I started the app the error sad "unable to delete directory" so i delete that file. The virtual devices started but the app keep stopping and I can't find why.     Process: com.example.library, PID: 10926     java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.library/com.example.library.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)         at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)         at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)         at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)         at android.os.Handler.dispatchMessage(Handler.java:106)         at android.os.Looper.loop(Looper.java:223)         at android.app.ActivityThread.main(ActivityThread.java:7656)         at java.lang.reflect.Method.invoke(Native Method)         at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)      Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference         at com.example.library.MainActivity.onCreate(MainActivity.java:20)         at android.app.Activity.performCreate(Activity.java:8000)         at android.app.Activity.performCreate(Activity.java:7984)         at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)          at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)          at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)          at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)          at android.os.Handler.dispatchMessage(Handler.java:106)          at android.os.Looper.loop(Looper.java:223)          at android.app.ActivityThread.main(ActivityThread.java:7656)          at java.lang.reflect.Method.invoke(Native Method)          at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)  this is the error when i start the app


Is it worth unsplitting my fusion drive?

I was messing around with my iMac and got to a point where I had to reinstall the OS, but it turned out the Fusion Drive had split into a 1 TB hard drive and a 24 GB flash drive. After looking around I found that you can unsplit the Fusion Drive with a Terminal Command in Recovery Mode but that would involve reinstalling macOS afterwards. There doesn't seem to be a way to fix the split fusion drive without losing my data (or rather, having to restore it from a backup which in my experience is not only a tedious process but also doesn't restore everything...). So I was wondering if you guys think it would be worth it to fix the fusion drive and reinstall the OS or if a split fusion drive is not necessarily a problem. What are the drawbacks/benefits of having a split fusion drive? I have a 2017 iMac 27-inch currently running macOS 10.15.6 Beta.


My travel plans have changed after Schengen visa issued. What do I do?

I planned to travel on my German-issued Schengen visa to Berlin for 7 days by myself and my tourist multiple entry visa got approved. However, now it looks like I will not be able to go to Germany during those dates due to work commitments.   Can I do the following instead:   Can I travel to Germany at another time during the validity of my visa for 7 days? Can I travel during my initial intended period of travel to some other Schengen country? If so, my port of entry will change to another country. However, given my travel to Germany later on, Germany will still be the country I spend my most time in overall.  Do I need to let the German embassy know of my change in travel plans?   From comment:     So original plan: 7 days Berlin and that's it. New plan: 4 days probably Greece or Hungary during the same week as the original plan as I have to work some of the days now and the flight tickets are too expensive for the days I want to go. Following this trip, another trip to Frankfurt for 9 days in October. All for tourism purposes, and change only due to work commitments and flight prices going up.


I tried removing Ubuntu and now I can't boot into windows

I am brand new to all of this. I had a dual boot system going on. Everything was going pretty well for a while and I was really enjoying everything. I was having some serious issues and there didn't seem to be an easy fix. I decided to pretty much get rid of Ubuntu. Grub didn't like that and now I can't get back into windows. I need some help!


HP laptop running Ubuntu 18.04 facing booting problem after kernel update

I'm using an HP laptop running Ubuntu 18.0. Recently I tried to update the kernel by running sudo apt-get dist-upgrade, but after that I was unable to boot into my laptop. I'm getting this error: Failed to start udev Kernel Device Manager. A photo of the screen is attached here. I can't upload a log or a screenshot as I can't access the laptop anymore. I did some googling, but I couldn't find anything that helped. Also I have some important data that I don't want to lose, so I don't want to reinstall. Is there any way to fix this without losing data?


Is it legal to use car manufacturers' names in a game?   For example:   to describe Audi's quattro drive system? to display a rendering of an Audi? to include a photo (to which I have rights) of an Audi?


Is it ok to remake a 2D game into first person and then releasing it for free?

I saw a video online where someone made a first person version of flappy bird, so I was wondering...  If I were to remake a 2D game into a 3D game and change the perspective to first person, and then proceed to release it online (like on itch.io) for free, would there be any repercussions?  The game concept and gameplay would be nearly identical with maybe a few changes, and while the art would be very similar, they'll still be original 3D models that I made myself, and differ from the actual assets used in the original game. All the code is original.  And could I just name it "First person (+ game name)" outright or is it better to name it something original?


I have two rasters Ras1 and Ras2.  I want to change the Ras1.  In Ras1, there are few areas, lines, points I am interested having nodata cells and wrong data cells.(limited to interested areas only not talking about the entire Ras1 image)  For those interested areas of Ras1 having nodata cells and wrong data cells, I want to replace cell values with Ras2.  I have seen few tools replace values, but those are value specific ( ie. Replacing all "10" value cells with "56" in entire image) and conditon tools in arcgis, deals with null/no data values.  Is there any way, I can do Replacing Raster Values in Ras1 with Ras2 of my chosen area in the image?? Is there any way I can use arcgis / envi / erdas for this? Please guide me.


Script to auto-detect features to track using Python

I am attempting to make these GUI steps into a script. When I follow this process manually, I get a tracking error under 1 and I get some great matches. This is far better than autotrack. import bpy  Step 1 - Set tracking settings extra correlation to .99: bpy.data.movieclips["Name.png"].(null) = 0.99  Step 2 - Loop through 1000 times When in loop, it loops but only tracks one frame forward: for loopv in range (1000):  Step 3 - Detect Features bpy.ops.clip.detect_features(ctx)  Step 4 - Track Features 1 Frame bpy.ops.clip.track_markers(ctx,backwards=False, sequence=False)  Step 5 - Deselect all features bpy.ops.clip.select_all(ctx,action='TOGGLE')  or bpy.ops.object.select_all(ctx,action='DESELECT')  Step 6 - End Indentation of loop and Return to Step 2 This is my current code. I have to hit Run Script. over and over, for it to work and go through all the frames of the clip. import bpy import random  #for loopv in range (1000): ctx = bpy.context.copy() for area in bpy.context.screen.areas:    if area.type == 'CLIP_EDITOR':    ctx['area'] = area  bpy.ops.clip.select_all(ctx,action='DESELECT') bpy.ops.clip.detect_features(ctx) bpy.ops.clip.track_markers(ctx,backwards=False, sequence=False)


Double increment from negative to positive in for loop


Where can I put a user-defined shell function?

I am planning to create a function that would simplify things for me. The function  would be something like  function lazymode() { echo "Hello World!"; }   so that when I use the command lazymode in the shell , it will output the Hello World!.  What file should I put the user-defined function?


Question: Find all functions $f:\mathbb{N}\rightarrow\mathbb{N}$ such that $yf(x)+xf(y)=(x+y)f(x^2+y^2)$ for positive integers $x, y$.  My attempt at a proof is the following:  (1) As well if $x=y$ we have $$2xf(x)=2xf(2x^2)\Rightarrow f(x)=f(2x^2)$$ (2) Now observe if $f(x)=f(y)$ we have wlog $$(x+y)f(x)=(x+y)f(x^2+y^2)\Rightarrow f(x)=f(x^2+y^2)$$ That's all I've got for now, and I'm out of ideas.  Edit: I forgot to add I'm relatively certain the only function which works is the constant function as playing around with pythagorean triples yields a lot of cases where $f(1)=f(x)$  Edit: Removed lemmas made under the incorrect assumption that 0 is included in $\mathbb{N}$ this case.


How can I use (sed|awk) to mask an e-mail address with asterisks like

How can I mask a list of e-mail addresses like:  John Doe <john.doe@gmail.com> John Doe <johndoe@hotmail.net> Jane Doe <j.doe@outlook.org>   ... with sed (or awk) into something like:  John Doe <j******e@g***l.com> John Doe <j*****e@h*****l.net> Jane Doe <j***e@o*****k.org>   In other words: replace most of the e-mail address with asterisks but make it somehow recognizable by users who know the actual e-mail address.


Delete duplicate items in multidimensional array

This is my array:  Array (     [0] => Sos, Ser     [1] => Sos, Ser, Pieczarki     [2] => Sos, Ser, Szynka     [3] => Sos, Ser, Salami     [4] => Sos, Ser, Szynka, Pieczarki     [5] => Sos, Ser, Szynka, Ananas     [6] => Sos, Ser, Salami, Pieczarki     [7] => Sos, Ser, Tunczyk, Cebula )   I want to delete duplicates. array_unique() doesn't work. Desired result:  $result = array('Sos', 'Ser', 'Pieczarki', 'Szynka', 'Salami', 'Ananas','Tunczyk','Cebula');


Update: To be clear, I've got 3 commands, and I want 1 of the 3 to execute, effectively on loop.  I've got a couple command blocks, each with some commands, and I want them to execute at random intervals.  My strategy so far is to use chickens that wonder in a pen stepping on pressure plates, but they don't move often enough and I'd rather not just resort to duplicting commands:    I've tried a lot of ideas with the chickens, (speed effects, spawning an entity holding seeds), but I think I'll need something better.  Any ideas?


Is it possible to use a RegEx to validate, or sanitize Base64 data?  That's the simple question, but the factors that drive this question are what make it difficult.  I have a Base64 decoder that can not fully rely on the input data to follow the RFC specs.  So, the issues I face are issues like perhaps Base64 data that may not be broken up into 78 (I think it's 78, I'd have to double check the RFC, so don't ding me if the exact number is wrong) character lines, or that the lines may not end in CRLF; in that it may have only a CR, or LF, or maybe neither.  So, I've had a hell of a time parsing Base64 data formatted as such.  Due to this, examples like the following become impossible to decode reliably.  I will only display partial MIME headers for brevity.  Content-Transfer-Encoding: base64  VGhpcyBpcyBzaW1wbGUgQVNDSUkgQmFzZTY0IGZvciBTdGFja092ZXJmbG93IGV4YW1wbGUu   Ok, so parsing that is no problem, and is exactly the result we would expect.    And in 99% of the cases, using any code to at least verify that each char in the buffer is a valid base64 char, works perfectly.  But, the next example throws a wrench into the mix.  Content-Transfer-Encoding: base64  http://www.stackoverflow.com VGhpcyBpcyBzaW1wbGUgQVNDSUkgQmFzZTY0IGZvciBTdGFja092ZXJmbG93IGV4YW1wbGUu   This a version of Base64 encoding that I have seen in some viruses and other things that attempt to take advantage of some mail readers desire to parse mime at all costs, versus ones that go strictly by the book, or rather RFC; if you will.  My Base64 decoder decodes the second example to the following data stream.  And keep in mind here, the original stream is all ASCII data!  [0x]86DB69FFFC30C2CB5A724A2F7AB7E5A307289951A1A5CC81A5CC81CDA5B5C1B19481054D0D 2524810985CD94D8D08199BDC8814DD1858DAD3DD995C999B1BDDC8195E1B585C1B194B8   Anyone have a good way to solve both problems at once?  I'm not sure it's even possible, outside of doing two transforms on the data with different rules applied, and comparing the results.  However if you took that approach, which output do you trust?  It seems that ASCII heuristics is about the best solution, but how much more code, execution time, and complexity would that add to something as complicated as a virus scanner, which this code is actually involved in?  How would you train the heuristics engine to learn what is acceptable Base64, and what isn't?    UPDATE:  Do to the number of views this question continues to get, I've decided to post the simple RegEx that I've been using in a C# application for 3 years now, with hundreds of thousands of transactions.  Honestly, I like the answer given by  the best, which is why I picked it as the selected answer.  But to anyone using C#, and looking for a very quick way to at least detect whether a string, or byte[] contains valid Base64 data or not, I've found the following to work very well for me.  [^-A-Za-z0-9+/=]|=[^=]|={3,}$   And yes, this is just for a STRING of Base64 data, NOT a properly formatted  message.  So, if you are dealing with data of this type, please take that into account before attempting to use the above RegEx.  If you are dealing with Base16, Base32, Radix or even Base64 for other purposes (URLs, file names, XML Encoding, etc.), then it is highly recommend that you read  that  mentioned in his answer as you need to be well aware of the charset and terminators used by the implementation before attempting to use the suggestions in this question/answer set.


Show that the curve $x^2+y^2-3=0$ has no rational points, that is, no points $(x,y)$ with $x,y\in \mathbb{Q}$.   Update: Thanks for all the input! I've done my best to incorporate your suggestions and write up the proof. My explanation of why $\gcd(a,b,q)=1$ is a bit verbose, but I couldn't figure out how to put it more concisely with clear notation.  Proof: Suppose for the sake of contradiction that there exists a point $P=(x,y)$, such that $x^2+y^2-3=0$, with $x,y\in\mathbb{Q}$. Then we can express $x$ and $y$ as irreducible fractions and write $(\frac{n_x}{d_x})^2+(\frac{n_y}{d_y})^2-3=0$, with $n_x, d_x, n_y, d_y\in\mathbb{Z}$, and $\gcd(n_x,d_x)=\gcd(n_y,d_y)=1$.  Let $q$ equal the lowest common multiple of $d_x$ and $d_y$. So $q=d_xc_x$ and $q=d_yc_y$ for the mutually prime integers $c_x$ and $c_y$ (if they weren't mutually prime, then $q$ wouldn't be the lowest common multiple). If we set $a=n_xc_x$ and $b=n_yc_y$, we can write the original equation as $(a/q)^2+(b/q^2)-3=0$, and equivalently, $a^2+b^2=3q^2$.  In order to determine the greatest common divisor shared by $a$, $b$, and $q$, we first consider the prime factors of $a$. Since $a=n_xc_x$, we can group them into the factors of $n_x$ and those of $c_x$. Similarly, $b$'s prime factors can be separated into those of $n_y$ and those of $c_y$. We know that $c_x$ and $c_y$ don't share any factors, as they're mutually prime, so any shared factor of $a$ and $b$ must be a factor of $n_x$ and $n_y$.  Furthermore, $q=d_xc_x=d_yc_y$, so it's prime factors can either be grouped  into those of $d_x$ and those of $c_x$, or those of $d_y$ and those of $c_y$. As we've already eliminated $c_x$ and $c_y$ as sources of shared factors, we know that any shared factor of $a$, $b$, and $q$ must be a factor of $n_x$, $n_y$, and either $d_x$ or $d_y$. But since $n_x/d_x$ is an irreducible fraction, $n_x$ and $d_x$ share no prime factors. Similarly, $n_y$ and $d_y$ share no prime factors. Thus $a$, $b$, and $q$ share no prime factors, and their greatest common divisor must be $1$.  Now consider an integer $m$ such that $3\nmid m$. Then, either $m\equiv 1\pmod{3}$, or $m\equiv 2\pmod{3}$. If $m\equiv 1\pmod{3}$, then $m=3k+1$ for some integer $k$, and $m^2=9k^2+6k+1=3(3k^2+2k)+1\equiv 1\pmod{3}$. Similarly, if $m\equiv 2\pmod{3}$, then $m^2=3(3k^2+4k+1)+1\equiv 1\pmod{3}$. Since that exhausts all cases, we see that $3\nmid m \implies m^2\equiv 1\pmod{3}$ for $m\in\mathbb{Z}$.  Notice that $a^2+b^2=3q^2$ implies that $3\mid (a^2+b^2)$. If $3$ doesn't divide both of $a$ and $b$, then $(a^2+b^2)$ will be either $1\pmod{3}$ or $2\pmod{3}$, and thus not divisible by $3$. So we can deduce that both $a$ and $b$ must be divisible by $3$.  We can therefore write $a=3u$ $\land$ $b=3v$ for some integers $u$ and $v$. Thus, $9u^2+9v^2=3q^2$, and equivalently, $3(u^2+v^2)=q^2$. So $3$ divides $q^2$, and must therefore divide $q$ as well. Thus, $3$ is a factor of $a,b,$ and $q$, but this contradicts the fact that $\gcd(a,b,q)=1$, and falsifies our supposition that such a point $P=(x,y)$ exists.


How do I obtain crash-data from my Android application?

How can I get crash data (stack traces at least) from my Android application? At least when working on my own device being retrieved by cable, but ideally from any instance of my application running on the wild so that I can improve it and make it more solid.


When using unicode-math, how do I get the original calligraphic alphabet back?

I am happy with the great majority of what unicode-math does. But at times I find that I prefer a symbol the way it was before. With \varnothing and \complement, for example. In those cases I was able to save them under a different name before loading unicode-math, but this doesn't always work.  Right now I'm trying to access the \mathcal alphabet from plain LaTeX. How might I accomplish this?    Additional Question  I've been looking through unicode-math, trying to figure out where exactly the original \mathcal alphabet gets discarded, but I eventually gave up.  It would be interesting if someone could explain:   how/where the original \mathcal font is defined anyway, and what kind of 'switch' is thrown by unicode-math that makes it unavailable.


Can I ask (and where should I) a question about a public speaking manual I cannot find anymore?

I am new to SE so please bear with me if this is not the right place for such a question. I have already looked and found  but I do not think it is what I am looking for. My question is, can I ask the below question (and where should I)?  A couple of months ago I found a book (not the pdf; on an e-commerce site) regarding public speaking that I deemed very interesting. I was looking for something more or less directly applicable to politics/political speeches, and I came across this book (quite recent, published not many years ago really) by a French author. The book was also translated into Italian, which was actually the version I had found. Now, I have been looking for it in the past few days, but since the only things that I remember are the very few details above, I was not able to find it (or at least I did not recognize it among the one that I had found). I remember that the author was a man and the Italian translator probably a woman, but I am not 100% sure of this. I also remember that the cover had a white background (but it was not completely white). Honestly I really need only the name of the author, but I have no idea what else I can do. Does anyone know anything about such a book?  So basically I am looking for either the title of the book (does not matter the language) or the name of the author, but I do not have much information. Also, what tags should I add (depending on the site where I should post this)?


permutations-why do we need to return copy of the list from local function?

I'm writing a permutation function as below, what I'm confused is if we return "res.append(nums[:])", it works perfectly, but if we return just "res.append(nums)", it'll only return the original nums value, without storing the new nums after my manipulation... But not sure about the theory behind it, could anybody explain? Thanks!   class Solution(object):     def permute(self, nums):         """         :type nums: List[int]         :rtype: List[List[int]]         """         if len(nums)==0:             return [[]]         res=[]                   def get_permute(n):             if n==0:                 res.append(nums[:]) ##<----here if we do res.append(nums) it'll be wrong, but why?                 return             for i in range(n+1):                 nums[i], nums[n]=nums[n], nums[i]                 get_permute(n-1)                 nums[n], nums[i]=nums[i], nums[n]              get_permute(len(nums)-1)         return res


Given an ordinal $(\alpha,\in)$, how do I find a subset of rationals which is isomorphic to it?

How do I find a subset $E$ of the rationals such that $(E,<) \cong (\alpha,\in)$ where $<$ is the usual ordering of the rationals and $\alpha$ is an ordinal?  $(E,<) \cong (\alpha,\in)$ means that there is a bijective map $f: E \rightarrow \alpha$ such that $a<b \Leftrightarrow f(a) \in f(b)$.  If this question is too general, consider the following special cases:  (a) $\alpha=\omega + 2$  (b) $\alpha=\omega \cdot 3$  (c) $\alpha=\omega \cdot \omega$  (d) $\alpha=\omega^\omega$  $\omega$ is the set of all natural numbers which is an ordinal.


Integration of $e^{ax}\cos bx$ and $e^{ax}\sin bx$

I am curious about the proof of these two integrations. It would be great if you could point me in the right direction : $ \int{e^{ax}\cos({bx})dx}= \dfrac{e^{ax}}{a^{2}+b^{2}}[a\cos(bx)+b\sin(bx)] + C $ & $ \int{e^{ax}\sin({bx})dx}= \dfrac{e^{ax}}{a^{2}+b^{2}}[a\sin(bx)-b\cos(bx)] + C $


Column Space of AA' is equal to column of A.

This is my question. How to show that the column space of matrix A is just equal to the column space of AA'?.. A' represents the transpose of A. I know that the column space of AA' is a subset of the column space of A which is just trivial. But the other way around I still used inclusion  but it seemed that it is going nowhere. Maybe it can be done by some manipulation or the barbaric way of doing this. I just want to obtain a simple proof. Anyone?


I have a problem that dual boot system did not set a date and time as usual when I set that date and time every time I login.


Find $\lim\limits_{n \to +\infty} np^n\sum\limits_{k=n}^{\infty} \frac{1}{k} \binom{k-1}{n-1}(1-p)^{k-n}$.

This is very likely to be a probabilitic problem，just noting that  $$E[1/X]=\sum_{k=n}^{\infty} \frac{1}{k}\binom{k-1}{n-1}p^n(1-p)^{k-n},$$ where $X$ is the random variable of Negative-Binomial Distribution. Thus the present limit is the very $$\lim_{n \to \infty} nE[1/X].$$ How to go on from here? Can it be solved just by calculus without probability?


In short term C type visa Overstay is the allowed duration a six month stay or the visa expiry date?  Because the duration of stay is 180 days. I entered UK at September 27; my visa will be expire 12 October. How Long I can stay in UK in this case?  If I stay after 12 October is it overstay or I can stay maximum 180 days from the date of entry even if the visa expires. What is over stay in this case please let me know .


Writing above and below a symbol simultaneously

I'd like to have a "=" symbol with some text over it, and an equation below it. I know that \stackrel{\frac{0}{0}}{=} can handle my demand on the equation part, however I don't know how to write something more below my "=" sign at the same time.


In the book "Beginning JavaScript" by Jeremy McPeak and Paul Wilton  there's a do-while loop example.   var userAge; do {    userAge = prompt("Please enter your age","") } while (isNaN(userAge) == true);   and below the author repeats one more time:     userAge = prompt ("Please enter your age","")   There's no semicolon at the end of the statement inside the do {} block.  As far as I can remember the author stated that it's considered best to always end any statement with a semicolon although it's not a must in most cases.   Was the omission of ; intentional? It seems so considering that in both the 4th and 5th editions there's no semicolon.  And there's also a repetition of that line below which doesn't contain a semicolon either.  Of course, one might say that it's not even a mistake. What I want to understand is whether the omission of a semicolon is more likely to be a typo or (which is worse) rather was done intentionally. If the latter is true, isn't that a sign of inconsistency?


Shouldn’t the word bird in the first sentence be birds’ as it’s a nest for more than one?


80’s Sci-fi anime with an outside force attacking the planet resulting in space battles

Anime film or series from the 80's. There is this hostile extraterrestrial force that attacks the planet. Action takes place in space near the planet and with spaceship battles. The planet sea level is rising (because of global warming?). At some point, someone compares the estimated landmasses with the attackers' planet resulting in a similar area, suggesting that they come from the future.


How to calculate Beta and coefficient of determination ($R^2$) from unstandardized coefficients in OLS regression?

I have a table in which the multiple linear regression results is provided. If I have unstandardized coefficients and standard error for each independent variable, is it possible to calculate standardized coefficient (Beta) and coefficient of determination ($R^2$) from these data.   My friend provided $R^2=0.41$  for these data, but I doubt if the results are reliable. I brought the table in the following, would you please compute Beta and R-squared for me to compare with the original table?    the descriptive statistics is the following table:


Exit Shell Script Based on Process Exit Code

I have a shell script that executes a number of commands. How do I make the shell script exit if any of the commands exit with a non-zero exit code?


I have the following theorem:  If $a = p^{n_1}_1 p^{n_2}_2$ ... $p^{n_k}_k, b = p^{m_1}_1 p^{m_2}_2$ ... $p^{m_k}_k$, then  $gcd(a, b) = p^{min(n_1, m_1)}_1 ... p^{min(n_k, m_k)}_k$  How can I prove it? Any solution or hint?


only last row is inserting in table when having "instead of insert" trigger on that table

I have this trigger   CREATE TRIGGER [dbo].[intrigger] ON [dbo].[test]  instead of insert AS begin declare @name nvarchar (50),@city nvarchar (11), @tdate datetime , @fid int,@fopd datetime; select @name =i.name from inserted i; select @city =i.city from inserted i; select @tdate =i.date from inserted i; select @fid =i.fid from inserted i; select @fopd = Faculty.fopd from Faculty      where fid= @fid; if (@fopd > @tdate ) begin     RAISERROR('Cannot insert ',16,1);     ROLLBACK TRANSACTION     RETURN;     -- stop on error end insert into test values (@name,@city,@tdate,@fid);  end   and the insert :  insert into test values('a','h','2014-10-13',1), ('s','h','2014-10-14',2), ('y','d','2014-10-15',2), ('s','h','2014-10-18',1), ('m','a','2014-10-20',1), ('a','h','2014-10-28',2)   then I select * from test .. only the last values are inserted ('a','h','2014-10-28',2)  I have to do one insert at a time !   I used for trigger .. all lines were inserted BUT in another test it accepted the wrong values :  insert into test values('a','h','2014-10-13',1), ('s','h','2014-10-14',2), ('y','d','2014-10-15',2), ('s','h','1990-10-18',1), -- this is wrong must not be inserted or stop all  ('m','a','2014-10-20',1), ('a','h','2014-10-28',2)   what went wrong !?


Why doesn't memory id change when there are no references to it?

>>> x = 5 >>> id(x) 40186104 >>> x += 6 >>> id(x) 40185960 >>> z = 5 >>> id(z) 40186104   Python deletes all objects once there are no more references to it.   Here when x is bound to 11, there are no more references to 5. So I suppose it is deleted. Then why does its id remain the same after reallocation?   The other possibility is that 5 is not deleted at all. If so, then why?


Python regex unable to remove content between [%~ abcd ~%]

I have raw HTML and am trying to remove this whole block like this [%~ as..abcd ~%] from the output string. Using re library of python  teststring = "Check the direction . [%~ MACRO wdwDate(date) BLOCK;                  SET tmpdate = date.clone();                  END ~%] Determine if both directions." cleanM = re.compile('\[\%\~ .*? \~\%\]') scleantext = re.sub(cleanM,'', teststring)   what is wrong in the code ?


Where can I find reference images for building modeling?

I am looking into modeling some realistic houses/buildings as a collection.  This is also one of the few times google images has failed me.  I can't seem to find helpful reference images and building plans. Anyone know of a good place to find these? www.the-blueprints.com/ sadly has no category for buildings.  Thanks


Google won't let me sign up without providing my phone number

Google says I need to “verify” my account. I don’t want to give up my phone number to Google. Are there any ways to bypass this? I’ve already tried changing my IP address.  It doesn’t matter how I register with Google, through Gmail, or from an Android device. They still ask for phone verification. Nothing works. I tried throwaway numbers, but apparently Google made sure to blacklist all numbers from VOIP services.


Should I round my uncertainty to nearest hundred?

I was doing some exercises on error propagation when I came across this problem:  $4\pi^2/(0,034 \pm 0,004 \space s^2/cm)$  I calculated my uncertainty to be $\Delta$ = 136 $cm/s^2$  And so the hole thing gives me: $(1200 \pm 136) \space cm/s^2$.  Now going into my question I rounded $4\pi^2/0,034 = 1161.12993$ to $1200$ which makes sense since my uncertainty is 136 but in the solution to this problem $136$ is rounded to $100$ and that's not making much sense to me.  So should I always round my uncertainty to the nearest hundred (assuming my uncertainty has 3 digits)?


ESTA: "Is your travel to the US occurring in transit to another country?" when going on a cruise

We're going on a cruise leaving from Texas in a couple of months, and I'm not sure what to respond to this question with - we're arriving and then staying in a hotel for one night before departing on the cruise and visiting 3 other countries before eventually returning and flying home.  Should we say "yes" to this question and enter the hotel we're staying at in Texas for one night as the point of contact?  Thanks


MySQL select all tags that are share common relationship with another entity

I have the following table structure:  tags            image_tags          image ------------    ----------------    --------------- id  tag         tag_id  image_id    id    etc... ------------    ----------------    --------------- 1   apple       1       1           1   image_1.jpg 2   banana      2       1           2   image_2.jpg 3   cherry      2       2                 3       2   Tags are joined to images through a many-to-many relationship.  I want to get a list of tags that appear together in at least one image.  Something like:  ----------------- a        b ----------------- apple    banana banana   cherry  etc..   Each tag pair should only appear once, and the order of the pair doesn't matter.  We'll be using this data to create a .dot file for a network graph.  I'm not sure exactly how to structure a query like this.


Summing pixel values within polygon zone in ArcGIS Desktop?

My question is the same as  but I'm working with ArcGIS and not QGIS.  I have a raster data set with values of type float.       And a polygon shapefile        I want to calculate mean of all raster cell values that are completely within the shapefile  In order to do so, I have used Extract by mask tool and now I have the following raster with NULL values for cells that are outside the polygon layer.        But there are 3 problems:     All parts of each masked pixel is not within the shapefile.       I want to mask just the pixels that are completely within polygon shapefile.     I don't know how to sum up all cell values in a masked raster?   I don't know how to count the number of such cells and calculate the mean?


Below is my object in JavaScript, how can i calculate the length of it.   var treeObj = {             1: ['96636736','10'],             2 : ['96636734','20'],             3 : ['96636731','45']               };       treeObj .length is not working. any help would be appreciated. Thanks.


Provide a way to exclude tags from display

I wish it were possible to exclude questions from  based on tags (the opposite of favorite tags). For example, I don't own an iPhone, a Mac or an Android device, and I will not develop for, buy nor use any of them for a few years at least. So, I don't want questions tagged ,  or  to appear on my "interesting" tab (because they are not interesting to me).


I want to know about the quantization of mass

Is mass quantized? If yes, then why do we see all amounts of mass? Well , can it be said quantized just for smaller masses?


Can I morph dimensionful physical constants meaningfully?

Discussions in the literature (e.g. ) say in no uncertain terms that it is meaningless to consider time variations of fundamental dimensionful parameters such as c, G, ... If one must consider this type of thing, one must use dimensionless parameters. Fine, the arguments seem reasonable.  But what if one wishes to investigate a theory where a (nearly)classical theory morphs through time continuously into a fully relativistic theory. The naive way to approach it would be to make c vary with time, starting with some very large value and decreasing. But that is not permitted.   Is this because such a theory is physically unrealizable?   Similar question: is it meaningful to say that two universes in the multiverse differ in their value of a dimensionful parameter, say, hbar, and that this difference has anthropic consequences?  Last similar question: Can a theorist predict roughly the properties of a model of the universe where hbar is replaced by hbar/2? I assume the answer to this is YES.  I do not feel that this is a duplicate. The referenced discussion (which an excellent link) is relevant (and mentions the same paper that I identify) but my problem is really - how does one interpret the paper. Can I predict different physics for separate universes, for example? Can I have a weakly relativistic universe that morphs into a strongly relativistic one? Or a completely nonrelativistic that changes into relativistic?


I'm a university student studying statistics by 'Discovering statistics using ibm spss 4th edition'  I don't understand what 'content-validity' means even though I read the explanation from the book again and again...


Cannot install Kubuntu 12.04.3 with wubi

Im trying to install kubuntu 12 with wubi, but I get      Cannot download the metalink and therefore the ISO   everytime I try to install.  My ISO name is      kubuntu-12.04.3-desktop-i386   Im running Windows 7 x86, I also tried the parameter "--32bit" but nothing works.  The last lines of my log:     err=[Errno 14] HTTP Error 404: Not Found 10-14 21:50 DEBUG    downloader: downloading              C:\ubuntu\install 10-14 21:51 ERROR  CommonBackend: Cannot download metalink file2          err=[Errno 14] HTTP Error 404: Not Found 10-14 21:51 DEBUG  TaskList:          Finished get_metalink 10-14 21:51 ERROR  TaskList: Cannot download the metalink and therefore the ISO Traceback (most recent call last):         File "\lib\wubi\backends\common\tasklist.py", line 197, in call   File "\lib\wubi\backends\common\backend.py", line 595, in get_iso   File "\lib\wubi\backends\common\backend.py", line 406, in download_iso   Exception: Cannot download the metalink and therefore the ISO 10-14   21:51 DEBUG  TaskList: # Cancelling tasklist 10-14 21:51 DEBUG    TaskList: # Finished tasklist 10-14 21:51 ERROR  root: Cannot download   the metalink and therefore the ISO Traceback (most recent call last):    File "\lib\wubi\application.py", line 58, in run   File   "\lib\wubi\application.py", line 132, in select_task   File   "\lib\wubi\application.py", line 158, in run_installer   File   "\lib\wubi\backends\common\tasklist.py", line 197, in call   File   "\lib\wubi\backends\common\backend.py", line 595, in get_iso   File   "\lib\wubi\backends\common\backend.py", line 406, in download_iso   Exception: Cannot download the metalink and therefore the ISO


Density and distribution functions of X + Y

Two numbers $x$ and $y$ are randomly and independently selected in the interval $[0,1]$. Find the density and distribution functions of the random variable $X+Y$.  I have doubts about how to approach this exercise, because I do not know if the variables satisfy a uniform distribution, although I have not until the moment very clear the concept of convolution to find what is required. Any contribution would be appreciated, thank you very much!  Not a duplicate. Uniform distribution is not mentioned in the case of this question


What type of spellcasting bonus do I use as a multiclassed bard/cleric?

I'm fairly new to D&D, and I'm going to multiclass for the first time - Bard/Cleric, to be specific.  What kind of spellcasting bonus do I use for spells like Healing Word which is bard and cleric? Do I have to choose between 1d4+Wis and 1d4+Cha?


Clear some doubts and questions about the Witch-king of Angmar

I recently found out about the war between Arnor and Angmar, and was pretty shocked to learn that the Witch-king basically wiped the floor with the Dúnedain kingdom... I mean he's basically the sole reason Aragorn wanders around like a homeless person.  So with which army did the Witch-king defeat Arnor? Orcs? Men? Sorcery? Did he ever go to battle himself? Did he do this for laughs or by Sauron's orders?   How powerful was the Witch-king at this point, compared to in the Fellowship of the Ring and Return of the King? Were the other Nazgul with him in this war?   And it doesn't even matter to me if all of the eight Nazgul were with him, even if they all had their Rings of Power, and even if they had the largest of armies of Orcs, Men, Elves, Dwarves or even dragons (yes I'm exaggerating at this point), but just how do you defeat a kingdom full of Dúnedain?   We have all seen what Aragorn is capable of doing, so how do you defeat a kingdom worth of Aragorns?   And if it is not much to ask, does anyone know where I can read all about this war and more about the Witch-king? so far all I read about it was from the Internet, wikis, forums and alike, I'd like to read it from the source.


How to exclude specific file types in Déjà Dup backup

I want to take regular backups of my web development project files but would like to ignore not so important files like images, vendor files, etc. There is a way to exclude folders but how to exclude by file type?


How to make variable show the count of records from a dynamic soql query

I have a custom controller with a variable 'count.' I want this to update on the page every time the account list updates. Right now it's static. It just displays the original number of records in the list. How do I make it dynamically update on the page?   public class AccountSearchController{   private String soql {get;set;}   public List<Account> Accounts {get;set;}       public integer count{         get{             count = Accounts.size();             return count;         }         set;     }     public AccountSearchController() {      soql = 'select Name,BillingState,Rollout_Group__c,Rollout_Status__c,SD_RD__c,Business_Launch_Date__c,Franchise_Email__c,X800_Number__c,Franchise_ID__c from Account where Status__c = \'Active\'';     runQuery();     count = Accounts.size();   }    public void runQuery() {      try {       Accounts = Database.query(soql + ' order by ' + sortField + ' ' + sortDir + ' limit 20');     } catch (Exception e) {       ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.ERROR, 'Ooops!'));     }   }   Visualforce Page:   <apex:pageBlockTable value="{!Count}" var="c">    <apex:column>{!c}</apex:column> </apex:pageBlockTable>


How to keep the console window open in Visual C++?

I'm starting out in Visual C++ and I'd like to know how to keep the console window.  For instance this would be a typical "hello world" application:   int _tmain(int argc, _TCHAR* argv[]) {     cout << "Hello World";     return 0; }   What's the line I'm missing?


I have the following chart yet the blue bar doesn't display correct:   \begin{tikzpicture}   \begin{semilogyaxis}[ybar,   xticklabels={{2}, {10}, {28}, {112}, {224}, {392}}, xtick = {2, 4, 6, 8, 10, 12},          width = 0.45*\textwidth,          xtick style={draw=none},          ymajorgrids=true,          ylabel={Transmission Speed (kbps)},           xlabel={Message Size}, xticklabel style={rotate=90},] \addplot [draw=blue,pattern color = blue, pattern = north west lines]                 coordinates {(2, 473000)}; \addplot [draw=red,pattern color = red, pattern = north west lines]                 coordinates {(4, 88500)}; \addplot [draw=green,pattern color = green, pattern = north west lines]                 coordinates {(6, 2320)}; \addplot [draw=yellow,pattern color = yellow, pattern = north west lines]                 coordinates {(8, 1160)}; \addplot [draw=black,pattern color = black, pattern = north west lines]                 coordinates {(10, 251)}; \addplot [draw=black,pattern color = black, pattern = north east lines]                 coordinates {(12, 164)};    \end{semilogyaxis} \end{tikzpicture}   I can't see why the 2, 473000 coordinates are missing.


Safe to Shrink Database in this Scenario?

For years I've had it drilled in to me:      Never ever shrink a database file.   I understand why of course, and I never do, mainly because I never need to.  Now though, I have a database with an .mdf file that is 800GB. It was a system designed to collect data over a certain amount of time, with no retention period.  A retention period of 90 days was recently placed on this data, and as such the developer has cleared about 3 years worth of data from the tables. Data and Indexes now total roughly 70GB, so now I have an .mdf file which is grossly over-sized.  I want to shrink it to reclaim some of that valuable disk space.  I'm planning to perform a shrink prior to rebuilding indexes and updating statistics (i.e the weekly maint. plan)  I'm not breaking any DBA laws here am I? I assume this is an acceptable scenario in which to perform a SHRINK as it is a true one off?  Thanks


Captcha is missing in Data Explorer when connected over HTTPS

When I tried to run , I got the below screen:    The captcha is missing!  I tried in other browsers too.    Update:  From @Oded's comments, I changed to HTTP and it was working perfectly.  Out of curiosity I would like to know why the captcha isn't working when accessing Data Explorer over HTTPS.


Find out what application prevents renaming a directory

Sometimes the update process of our application fails to rename a directory on the user's machine. Is it possible to easily find out with a standard Windows command line tool (no GUI application) which process has "open" a certain directory or file below the very directory, so we can tell the user to close that process?


Excel How to make Text Qualifier editable or add a new entry in the existing list?

I have a CSV file which is not properly formatted because one of the columns contains HTML code which use the same character as the Text Qualifier: the double quote.  Example:  "col1","col2","col3" "01","text","<html><tag attrib="true">"   I decided to use another character as text qualifier, the backtick ` which is never present in my original file.  My data are like this now:   `col1`,`col2`,`col3` `01`,`text`,`<html><tag attrib="true">`   Now my CSV is totally valid, but in Excel (2013) I cannot just change the Text Qualifier, it allows me only ", ' or {none}  Is there any way to edit this list to add a new text qualifier?  I finally found another way to import it but I am just wondering why the Text Qualifier box is not editable.


$\ell^{\infty}(\mathbb N)$ is not a separable space

I have to prove that $\ell^{\infty}(\mathbb N)$ is not separable.  My attempt  Consider a SUBSET $V$ of $\ell^{\infty}(\mathbb N)$ consisting of bounded sequences that have only $0$, $1$ entries, e.g. $(0,1,1,0,0,0,0,1,0,0,\dots)$  Now assume that this SUBSET is uncountable.  If we take a radius $r=1/4$ then balls with origins that are elements of $V$ would be disjoint and because any base of  $\ell^{\infty}(\mathbb N)$ must contain a subset of each element of the set of these balls, base of  $\ell^{\infty}(\mathbb N)$ can't be countable so it doesnt satisfy the second axiom fo countability and thus is not separable (since  $\ell^{\infty}(\mathbb N)$ is a metric space).  Could someone check this? And I still need to prove that $V$ is uncountable...


$\sin( a\arcsin(x))$ in terms of rational functions and radicals

By letting $$ \theta = a \arcsin(x) \, , $$ $$ x = \sin\left(\frac{\theta}{a}\right)$$ If $\theta / a$ is the angle in a right triangle then the hypotenuse of length $1$, and the opposite side $x$. I want to find $\sin(\theta)$ as $ \theta = a \arcsin(x)$. For $a = 2$ and $a = 4$ this is quite simple. When $a = 2$: $$\sin(\theta) = 2 \sin\left(\frac{\theta}{2}\right)\cos\left(\frac{\theta}{2}\right)$$ As $\theta/2$ is the angle in our triangle we can simply substitute this in terms of $x$ So $$ \sin(\theta) = \sin(2 \arcsin(x)) = 2x\sqrt{1 -x^2}$$ repeating this process for $a = 4$ $$ \sin(\theta) = 2 \sin\left(\frac{\theta}{2}\right)\cos\left(\frac{\theta}{2}\right) = 4 \sin\left(\frac{\theta}{4}\right)\cos\left(\frac{\theta}{4}\right)\left( 2 \cos^2\left(\frac{\theta}{4}\right) -a\right)$$ In other terms $$\sin(4 \arcsin(x)) =4x\sqrt{1- x^2} (1-2x^2) $$ How can I attempt to generalise this at least for even values of $a$, thanks.


How to load input elements by the load function ? jquery

here is my code :  <script>     $(document).ready(function(){         $(".checkbox").change(function(){             alert("test")         });          $(".loadInto").load("test.php");     } </script>  <td id="loadInto" > </td>   test.php script return this code :  <input type="checkbox" class='checkbox'/>   I succeed to load the input checkbox but when I press on the checkbox, I didn't get alert. why ?


Why does a multiplicative subgroup of a field have to be cyclic?

The book "A First Course in Abstract Algebra" by Fraleigh says      If $G$ is a finite subgroup of the multiplicative group $\langle F^*,\cdot\rangle$ of a field $F$, then $G$ is cyclic. In particular, the multiplicative group of all nonzero elements of a finite field is cyclic.    I wonder why that is. Take $a,b\in F$ such that $a^2=b^2=1$. Then $\{1,a,b,ab\}$ is a non-cyclic subgroup of $F$. Where am I going wrong?  Thanks in advance!


Can a ring without a unit element have a subring with a unit element?

A ring need not have a unit element, e.g. even numbers.      Can someone give me an example of a ring which doesn't have a unit element but it's subring does have a unit element.


Why does Windows only show about 3.5 GB of my 4 GB of RAM?

I recently upgraded my computer's RAM to 4 GB. My 32-bit Windows installation shows only 3574 MB of the memory. How can I make Windows use the full amount of RAM?


How to calculate the number of non decreasing functions between two finite sets?

I want to know how to calculate number of non decreasing functions from one set to another set.  Let $A=\{1,2,3,\ldots,10\}$ and $B=\{1,2,3,\ldots,25\}$  Please tell me an easy method to calculate the number of non decreasing functions from set $A$ to $B$.  I can understand permutations and combinations, but I need an explanation which sticks to a basic level.


Which program on XP can I use to open the Lubuntu image I've downloaded?

I want rid of XP and as my laptop is 7 years old I thought Lubuntu would fit the bill. I've downloaded it but I can't find a program on XP to open it.


I'm looking for a word that is the opposite of "adaptable." I would like to say "unadaptable,"  but that's not a real word according to my dictionary. So, what's the best word out there for not-able-to-change?  Update: I'm embarrassed to admit I was accidentally searching the Mac's built-in thesaurus, not dictionary, when I checked to see if unadaptable was a word. My bad! I'll still award Jasper the answer for pointing out my obvious oversight.  Update 2:  To respond to the various calls for clarification, I'm specifically using this word in a report talking about the development of certain kinds of subdivisions, especially very homogenous single-family subdivisions in outer ring suburban areas. In my report I'm referring to a neighborhood that can change at the micro-level, ie. it can improve or deteriorate, but it cannot change what it is: ie. the infrastructure pattern is not capable of supporting a different land use, and it is not economically feasible to retrofit the infrastructure, therefore the nature of the subdivision cannot be changed, while the condition of the subdivision (if it is deteriorating) may cause people to wish that it could be changed.   So, with that in mind:   Why not immutable?" Immutable is a great word, but I understand it's connotation to mean "permanent, unchanging", in the sense that something simply is not subject to change, not that it might like to change but cannot.  Why not "inflexible?" Inflexible connotes being "unwilling" to change, or perhaps being able to be changed (or reshaped / bent) but only slowly and with much resistance.   So, in this situation I am looking for an adjective that describes an inability to adapt to changing market conditions by shifting from one land use to another. In this case I specifically use the word "adaptable" in many places to describe the opposite, and given the context I think "unadaptable" will be better understood than any of the other suggestions, even though I am aware of (and agree with) the comments about it's status as a rarely used and therefore imperfect choice.  Thank you all for the feedback!


I see following code in a script:  OLD_IFS="$IFS" IFS='something-special' # code that needs the special IFS # ... IFS="$OLD_IFS"   If the IFS is not set before the script fragment then the script sets it to an empty string and the empty IFS and undefined IFS are different.  The script probably assume the IFS is always set. Is it safe to make such assumption?


Why was my edit to someone's question automatically rejected?

I spent some time fixing up the formatting for  and it was automatically rejected.  Is it because the question has several downvotes?


How to interpret variable declarations with right to left rule while typedef is included?

I am having trouble when using right to left rule to interpret variable declarations when typedef is involved.  In the C++ primer 5th edition book I saw the following code:    typedef char *pstring; const pstring cstr = 0; // cstr is a constant pointer to char const pstring *ps; // ps is a pointer to a constant pointer to char   If I replace the pstring with char * then it stands like this:const char *cstrSo I expect cstr to be a pointer to a const char. But the comments in the book states the pointer itself is constant. My question is what's wrong with my way of thinking.


How to pass elisp function or command into function parameters?

I want to write a custom function to do bellowing work:  (defun my-org-agenda-switch-or-build ()   "Switch to *Org Agenda* buffer, if not available, then build it."   (interactive)   (if (get-buffer "*Org Agenda*")       (switch-to-buffer "*Org Agenda*")     (command-execute 'org-agenda-list)     (bury-buffer)     (switch-to-buffer "*Org Agenda*")     ))  ;;; start Org Agenda at Emacs startup, and put in end of buffer list: ;; (add-hook 'emacs-startup-hook 'my-eshell-start-or-switch) (define-key my-org-prefix-map (kbd "o") 'my-org-agenda-switch-or-build)   And here is my demo code, but it does not work. Do you have better idea about this?  (defun my-func/open-and-switch-to-buffer (the-command the-buffer-name &optional whether-switch-to-buffer)   "Open a `COMMAND', and switch to that `BUFFER' depend on `OPTION'."   ;; (interactive)   (if (get-buffer the-buffer-name)       (progn         (,the-command)         (bury-buffer))     (let (whether-switch-to-buffer (and t whether-switch-to-buffer))       (and whether-switch-to-buffer (switch-to-buffer the-buffer-name))))) (define-key my-org-prefix-map (kbd "o") (my-func/open-and-switch-to-buffer 'org-agenda-list "*Org Agenda*" t))


h1-h6 tags: would I be penalised by Google for SEO for making content smaller than browser default?

There are several reasons to use h1-h6 tags:   Creates a hierarchy of title sizes from h1 (main title) downwards Provides a standardised size for titles Improves SEO   But if I change the size of an h1-6 tag's content from its default, will I be SEO-penalised by Google?    I have searched for an answer but cannot find one.


Closure of a Ball is Contained in Closed Ball (usual metric)

Let $\overline{B_d (x, r)}$ be the closure of an open ball, and let $\hat B_d (x, r)$ be a closed ball. Show that in any metric space $(X, d)$, $\overline{B_d (x, r)} \subseteq \hat B_d (x, r)$ for all $x \in X$ and $r > 0$.    I used the definition of closure: $\overline{B}$ = $B \bigcup B'$. If $x \in \overline{B}$, then $x \in B$ or $x \in \overline{B}$, or both. If $x \in B$, then clearly $x \in \hat B$ since $B \subseteq \hat B$. But, if $x \in B'$, then $x$ is an accumulation point. Since $\hat B$ is closed, it contains all accumulation points of $B$. Thus, $x \in \hat B$.  Is this approach correct, or at least in the right direction? Should I be using the closure definition, or try another one? Thank you.


Check string value isblank or null in lightning Component's controller

In Lightning Component controller checking blank and undefined for a string variable.   var AccAsset = component.find("AccountAsset").get("v.value");   if(String.isBlank(AccAsset) || AccAsset == 'undefined'){         component.set("v.hasError", true);   }   This is throwing an error      "String.isBlank is not a function"


How can I configure /etc/syslog.conf file in order to save log information about iptables in a specific file.  I want to save these information separately, so I can extract what I want easily and rapidly.