copying file from a server to a local drive - what could slow the access to get file?

I have an application which accesses files on the intranet. The users can copy the files from the server located on the network to their local PCs. I have encoutered a problem with initial connection. i.e. when the application is started. The user searches for the file in the database. When he finds a file he wants to download he clicks on the name and the application downloads it.  The first time download operation takes about 8-12 seconds just to initial the download and see the progress bar. The next downloads are almost instant. The file size varies between 1 MB to 15 MB.   Here is my code:   const  projectFilesURL = '\\IntranetServer\Directory\filesLocation\';      procedure form1.GetSelectedFile(const fileName: string);     var     sourceFile: string;     begin     { \\IntranetServer\Directory\filesLocation\userSelectedFile.zip}     sourceFile := projectFilesURL + fileName;            if FileExists(sourceFile) then       begin         fileCopy(fileName);        lblSearching.Hide;        AnimSearching.Hide;        end   else   MessageDlg(     'The file was not found on the server'       , mtInformation, [mbCancel], 0);  end;  end; procedure form1.fileCopy(const sourceFile: string);  var    SourceF, DestF: file;    Buf: array [0 .. 1023] of byte;    NumRead, FSize, BytesCopied: Integer;    destinationPathandFile: string; begin   destinationPathandFile := ExtractFilePath(ParamStr(0))     + exportPath + sourceFile; try   AssignFile(SourceF, projectFilesURL + sourceFile);   AssignFile(DestF, destinationPathandFile);   FileMode := 0;   Reset(SourceF, 1);   Rewrite(DestF, 1);   FSize := FileSize(SourceF);   BytesCopied := 0;   fileCopyProgress.Percent := 0;   while not Eof(SourceF) do   begin     BlockRead(SourceF, Buf, SIZEOF(Buf), NumRead);     BlockWrite(DestF, Buf, NumRead);     Inc(BytesCopied, NumRead);     fileCopyProgress.Percent := (BytesCopied * 100) div FSize;    Application.ProcessMessages; end; CloseFile(SourceF); CloseFile(DestF);  except   on E: Exception do   begin   raise Exception.Create('Error occured while copying a file');    Exit; end;  end;   I am not sure where could be a choking point...maybe fileExists is not necessary. Since a file is on the server or not...maybe to throw exception is better... I appreciate any suggestions.  Thanks,


Will a larger or smaller body of water lose heat faster?

Say you fill a bucket full of hot water, and you fill another bucket half full of hot water. The water is the same temperature and the room conditions are the same. Which one loses heat first?  Apologies if this question has been asked before and/or is obvious, but I wasn't able to find any answers, and I have no knowledge of physics to attempt to answer this question myself.


Nikon Speedlight: Slave mode and built-in flash/commander light

I'm thinking about getting a speedlight to use for off-camera lighting, perhaps the SB700, but I don't understand its different wireless triggers,  says:     For off camera use, the SB700 can be controlled (1) via Nikon’s wireless AWL mode using TTL or manual mode, (2)... or (3) with the simple optical “SU-4″ slave mode.   If I it understand correctly, AWL is not radio, right? so is it necessary to fire the built-in flash to control it, what if I don't want the light from the built-in flash, do I have to use an  or is there any other to turn off its light only?  I'm also concerned about the optical receiver on the speedlight, apparently it is on right side of the SB700′s body, then how can I position the flash in right side of camera?  can the optical receiver still receive the command if it's not positioned in line with camera?


Reassigning element of a list inside a list


Ok so i tried to reset my password using these instructions    Hold shift during start menu to open up the ubuntu menu Hit enter on recovery mode Hit enter on root After that this appeared like it was supposed to root@vera-hp-g62-pc: or something like that and i put in the code "passwd" (dont add the apostraphe's) and than my user name  Immediatly fallowing that it asked me to enter a new password only problem was that i couldnt type and had to use the "exit" comand (again no apostraphe)  P.S. I ignored the fact that the characters werent visible and entered my would be password but an error messege showed up


Finding nth power of a 4 state Markov Chain Matrix

I am required to find P$_{ij}^{(n)}$ for the P matrix of a 4 state Markov chain with states 0,1,2,3 as given below  $\begin{matrix} 1-p&&p&&0&&0\\0&&1-p&&p&&0\\0&&0&&1-p&&p\\0&&0&&0&&1\end{matrix}$  There were two options. One was to solve it by finding eigenvalues and then left and right eigenvectors...etc. Second choice was to use method of generating function   P(s) = I+sP+s$^2$P$^2$+s$^3$P$^3$...........  I chose to use the second method and got the  (I-sP)$^{-1}$ as under:  \begin{matrix}\frac{1}{ps-s+1}&&\frac{-ps}{(ps-s+1)^2}&&\frac{p^2s^2}{(ps-s+1)^3}&&\frac{p^3s^3}{(s-1)(ps-s+1)^3}\\0&&\frac{1}{ps-s+1}&&\frac{-ps}{(ps-s+1)^2}&&\frac{-p^2s^2}{(s-1)(ps-s+1)^2}\\0&&0&&\frac{1}{ps-s+1}&&\frac{ps}{(s-1)(ps-s+1)}\\0&&0&&0&&\frac{-1}{(s-1)}\end{matrix}  Now to gather the coefficients of $s^n$ in each of the terms, I could do it for all terms of the inverse matrix except terms $a_{14}$, $a_{24}$ and $a_{34}$.    (a)    Could I please get guidance to do this?  (b)   Is there any other easier method to calculate the P$_{ij}^{(n)}$?


For which natural n is $3^n+5^n$ divisible by $3^{n-1}+5^{n-1}$? I only got that $3^n+5^n=8k$ when $n$ is odd. How to solve this one?


How to open two separate tabs in same google chrome window using webdriver and python?

I need to test interacting with two tabs in Chrome. I've written a test in Python using Webdriver where I open Chrome with one tab.  I need to open a second tab (similarly to using Ctrl+t) so I can interact with both tabs. My plan is to copy text from Tab 1 and paste it into one of the fields on Tab 2, and vice versa.  How do I use Python and WebDriver to open a new tab and switch between tabs?


I'm a new student and basically just got into the topic threading.  What I have to do seems rather simple. I have to make a combobox, but I need to fill it using a different thread. And thats where I ran into trouble, cause;  Additional information: Cross-thread operation not valid: Control 'ComboBox' accessed from a thread other than the thread it was created on.  So I did some research, and it seems you cant fill UI elements outside the main thread. So I'm sitting here scratching my head thinking what would be the best thing to do.   Help would be appreciated.  Oh btw, its C# and in windows forms.           public Customer()     {         InitializeComponent();         Thread red = new Thread(Fill);         red.Start();     }     public void Fill()     {         Thread.Sleep(5000);         ComboBox1.Items.Add(1);         ComboBox1.Items.Add(2);         ComboBox1.Items.Add(3);         ComboBox1.Items.Add(4);         ComboBox1.Items.Add(5);         ComboBox1.Items.Add(6);         ComboBox1.Items.Add(7);     }


Why can snap files not be modified in any way?

I have been trying for a long time to change Blender's icon, but no matter what I do, I am not allowed to edit anything in /snap/blender-tpaw/3/.  Here's what I tried:   Editing the files from nautilus without sudo. Editing the files from nautilus with sudo (sudo nautilus in terminal ). Using terminal commands such as cp or rm without sudo. Using terminal commands with sudo (such as sudo cp <source> /snap/blender-tpaw/3/ or sudo rm /snap/blender-tpaw/3/<filename.ext>) Doing everything above in a root terminal (using sudo -i)   In every case I get the following error:  cannot remove/copy '/snap/blender-tpaw/3/filename.ext': Read-only file system   where filename is the file and .ext is its extension.  This also applies to other snaps' files, not only Blender.  Am I doing something wrong here? Or is it just impossible to change those files? Although I don't think it is impossible because everything here from Ubuntu to Blender is open-source, so they have no reason to block us from modifying those files.  EDIT:  I used Main Menu (alacarte) to change the icon, but I still want to know why I cannot modify any snap file.


Are the foods in the Star Wars Universe the same as ours'? Do they have strawberries or potatoes or something? I know that they might have some food other than the food that we also have, but I'm wondering if they have any food like ours'.


Show that $\sum_{k=1}^{\frac{n}{2}}k\dbinom{n}{\frac{n}{2}+k}=\frac{1}{4}\left ( n+2 \right )\dbinom{n}{\frac{n}{2}+1}$

$n$ is assumed to be even. I assume I have to use the fact that $\dbinom{n}{\frac{n}{2}+k}=\dbinom{n}{\frac{n}{2}-k}$ for all $0 \leq k \leq \frac{n}{2}$, but I keep going in circles.


Calculating time to reach certain velocity with drag force

I was given a problem for homework where we needed to calculate the time for a falling object to reach a certain velocity when accounting for drag force. I did it by setting up acceleration as a function of velocity and integrating (it was a differential equation).   However, this is an introductory physics course, with no knowledge of calculus required going in. We haven't even done derivatives yet, strictly speaking. I was fortunate enough to have taken calculus before, so I was able to recognize and solve the differential equation.   When I asked my classmates how they did it, they said they messed around with numbers until they got something that worked (it was online with no points deducted for wrong answers). For most of them, they just divided the terminal velocity by acceleration due to gravity, which makes no sense, since we weren't even asked for time taken to reach terminal velocity, but 63% of it. That method just happened to round to the same number as the correct one.   My question is, is there some way to find this value using elementary physics, or did my professor give us an unfair problem? The TAs weren't any help and I have class during her office hours.   The question itself is as follows:     The terminal velocity of a 4×10$^{-5}$ kg raindrop is about 9 m/s . Assuming a drag force $F_D=−bv$, determine the time required for such a drop, starting from rest, to reach 63% of terminal velocity.


I have a simple Window with a table. But if I add more than 4 objects to my model, I get various NullPointerExceptions. Here's the model code:  public class CarTableModel extends AbstractTableModel { public LinkedList<Car> cars=new LinkedList<Car>(); @Override public int getRowCount() {     return 4; }  @Override public int getColumnCount() {     return cars.size(); }  @Override public Object getValueAt(int row, int column){     if((row>cars.size()-1) || (column>3) ){         return null;     }     else {         Car targetCar=cars.get(row);         switch (column){             case 0: {return targetCar.brand;}             case 1: {return targetCar.year;}             case 2: { return targetCar.volume;}             case 3: {return targetCar.maxSpeed;}             default: {return null; }         }      } }  @Override public Class<?> getColumnClass(int columnIndex){     switch (columnIndex){         case 0: {return String.class;}         case 1: {return Integer.class;}         case 2: { return Double.class;}         case 3: {return Double.class;}         default: {return null; }     } } @Override public String getColumnName(int columnIndex){     switch (columnIndex){         case 0: {return "Brand";}         case 1: {return "Year";}         case 2: { return "Volume";}         case 3: {return "Max Speed";}         default: {return null; }     } } @Override public boolean isCellEditable(int rowIndex, int columnIndex){     return false; }  public void addRow(Car value){     cars.add(value);     }  }   Here comes the MainWindow class:  public class MainWindow extends JFrame { public MainWindow(CarTableModel model){         JTable table=new JTable(model);         table.getColumnModel().getColumn(0).setPreferredWidth(27);         table.getColumnModel().getColumn(1).setPreferredWidth(27);         JScrollPane scrollPane=new JScrollPane(table);         getContentPane().add(scrollPane); }  }   Here's the MainTest class, that I use to test the MainWindow:  public class MainTest { static CarTableModel model; public static void main(String[] args) {     model=new CarTableModel();     for(int i=0;i<10;i++) {         model.addRow(new Car("Volvo", 4, 4, 4));;     }      MainWindow window=new MainWindow(model);     window.setSize(300,400);     window.setVisible(true); }   }  And here I have the Car class to store information about the cars:  public class Car { String brand; int year; double volume; double maxSpeed;  public Car(String brand, int year, double volume, double maxSpeed){     this.brand=brand;     this.year=year;     this.volume=volume;     this.maxSpeed=maxSpeed;     } }   As an output, if I add more than 4 values to the model, I get a blank window and lots of exceptions. It's really hard to google the mistakes when it comes to GUI tasks, so if anyone has already come across with the same problem here, I'm sorry, please post a link.


Is there an flat unordered pairing function in ZFC?

Is there an unordered pairing function that does not increase rank whenever the max rank is infinite, in ZFC? An unordered pairing function is one such that $f(x,y)=f(z,w)$ iff $(x=z \wedge y=w) \vee (x=w \wedge y=z)$.


When you back up a database and scripts are running at the same time, at what point in time does the backup reflect?

If I run a SQL Server database backup via Management Studio and there are scripts running at the same time, does the backup reflect the point in time when the backup was started or when it ended? My db is about 10GB so the backup takes some time, meaning there's lots of things that could go on in the meantime.  I'm using SQL Server 2008 R2  I just posted  but think this is probably a better place for it?


I ran the auto.arima()command in R on a set of data and it chose the appropriate model to be ARIMA(0,1,0).  I know ARIMA(0,0,0) is just white noise, but what does ARIMA(0,1,0) mean?


How to run method determined on user input in c#

I want to do something like this: class Program {    static void Main(string[] args)    {       string userInput = Console.ReadLine();       Program.//userInput    }        static void A()    {       //code    }    static void B()    {       //code    } }  What method will run will depend on what the user inputs. So if the user will write "B" than method B will run and if he writes "A" method A will run. I tried to Google it but I didn't find anything understandable to me.


How Do You Programmatically Set the Hardware Clock on Linux?

Linux provides the stime(2) call to set the system time.  However, while this will update the system's time, it does not set the BIOS hardware clock to match the new system time.  Linux systems typically sync the hardware clock with the system time at shutdown and at periodic intervals.  However, if the machine gets power-cycled before one of these automatic syncs, the time will be incorrect when the machine restarts.  How do you ensure that the hardware clock gets updated when you set the system time?


zshrc file invisible in finder but present in terminal

When I give ls-a in my root folder I can actually see zshrc. but when I open my root folder in finder using the open . command, It's not visible. Actually many files are missing..As you can see the zshrc file is visible here. I can't find it in the finder.


What is the closed form of $\int e^{x^2} \, dx$?

How can I do a closed form expansion of $\int e^{x^2} \, dx$? Please be specific as to which method I must use.


Is there any US bank that does not charge for incoming wire transfers?

I use CurrencyFair to exchange currency between EUR and USD.  I was surprised to see a $10 wire transfer fee at the end of the chain when CurrencyFair transfered from their BofA account to my BofA account.  Is there any bank in the US that does not charge for incoming wire transfers (not ACH, wire transfer) ?


Special Relativity tells us - the faster things travel their time is slower relative to a stationary observer.  Do massless particles, like photons travelling at the speed of light, “experience” zero time and in their frame of reference travel "instantaneously". Putting it in a thought experiment. Imagine travelling to a distant star. On reaching the star, several decades have past as shown on the spaceship's clocks and on our aging bodies. Now consider doing the same journey but incredibly close to the speed of light (not possible in practice but not violating any physical laws) we would see the clocks have changes only by a few minutes and our bodies are unchanged. Wouldn't it be reasonable to extrapolate and predict that if we were to travel at a smidgen less than speed of light, it would appear (to us astronauts) to have taken close to zero time?


What are some good statistics resources?

A year ago, I took a statistics course at my university. The course was based on Rice's "Mathematical Statistics and Data Analysis". Apart from the fact that I did not find the book terribly good, I found that the lectures did not aid me a lot in understanding the material either. I did pass the course, but I didn't feel I really understood the material.   Fast forward a year. I have now come to realise that statistics can be a very interesting and useful subject, but I haven't done any statistics ever since the course I just mentioned. I'm thinking of doing some statistics courses for my Master's degree, though.   Question: do you know any good resources (video lectures, books, solved problems) which I can use to brush up my statistics knowledge? I like books that have a large number of solved problems and worked examples, so I can check whether I actually solved the problems correctly.


Is there any way to kill or end a process in "disk sleep"

I am running Linux Mint 18.2 with KDE Plasma. Recently I noticed that most of the times I copy large files to removable drives the process hangs just before finish.  I opened KSysGuard and saw that the process of file.so is in disk sleep. When this happens the process seems not receiving any kill or end signal. I decided to reboot, opened a terminal in Konsole and ran reboot command. But the reboot also got stuck in the middle! I had to press the power button and force shutdown my laptop.  Now I want to know is it impossible to kill or end a process that is in I/O Sleep state ?


I need to change default title of ToC. Is it possible with titlesec package? Here is my MWE:  \documentclass{book}  \usepackage{titlesec} \titleformat{\chapter}{\normalfont\Large\scshape}{\thechapter}{1em}{} \vspace{6pt}]  \usepackage{lipsum}   %-------------------------------------------------------------------------  \begin{document}   \newpage \thispagestyle{empty} \tableofcontents \thispagestyle{empty} \newpage \thispagestyle{empty}  \setcounter{footnote} {0}\chapter*{{\fontsize{11}{14}\selectfont\normalfont{Author1} \\ {\scshape\Large Title}}} \addcontentsline{toc}{chapter}{\normalsize\normalfont{Author1} \\ \normalfont\scshape{Title}} \thispagestyle{empty} \Author{Author1} \Title{Title} \lipsum \newpage \thispagestyle{empty}    \end{document}


Characterizing units in polynomial rings

I am trying to prove a result, for which I have got one part, but I am not able to get the converse part.  Theorem. Let $R$ be a commutative ring with $1$. Then $f(X)=a_{0}+a_{1}X+a_{2}X^{2} + \cdots + a_{n}X^{n}$ is a unit in $R[X]$ if and only if $a_{0}$ is a unit in $R$ and $a_{1},a_{2},\dots,a_{n}$ are all nilpotent in $R$.  Proof. Suppose $f(X)=a_{0}+a_{1}X+\cdots +a_{n}X^{n}$ is such that $a_{0}$ is a unit in $R$ and $a_{1},a_{2}, \dots,a_{r}$ are all nilpotent in $R$. Since $R$ is commutative, we get that $a_{1}X,a_{2}X^{2},\cdots,a_{n}X^{n}$ are all nilpotent and hence also their sum is nilpotent. Let $z = \sum a_{i}X^{i}$ then $a_{0}^{-1}z$ is nilpotent and so $1+a_{0}^{-1}z$ is a unit. Thus $f(X)=a_{0}+z=a_{0} \cdot (1+a_{0}^{-1}z)$ is a unit since product of two units in $R[X]$ is a unit.   I have not been able to get the converse part and would like to see the proof for the converse part.


What is the difference of using arrayName and arrayName[:] in Python?

I just had a problem with Python which I eventually fixed myself. Although I'm still wondering what's the difference of using   arrayName   and  arrayName[:]   even if they have the same values. Here's my code where I had the problem:  def quickSort(ar, start, end):     count = 0     if end - start >= 2:         p = ar[end-1]         pos = start         for i in range(start, end-1):             if ar[i] < p:                 if i != pos:                     ar[i], ar[pos] = ar[pos], ar[i]                 pos += 1                 count += 1         ar[pos], ar[end-1] = ar[end-1], ar[pos]         count += 1         count += quickSort(ar, start, pos)         count += quickSort(ar, pos+1, end)     return count  def insertion_sort(ar):     shift = 0     for i in range(1, len(ar)):         j = i-1          key = ar[i]         while (j > -1) and (ar[j] > key):             ar[j+1] = ar[j]             shift += 1             j -= 1         ar[j+1] = key     return shift  n = int(input()) ar = list(map(int, input().split())) print(insertion_sort(ar) - quickSort(ar, 0, n))   The above will print -18 but if I change the last line into  print(insertion_sort(ar[:]) - quickSort(ar[:], 0, n))   it will print 1 which is the correct (the return value of insertion_sort() is 9 and the return value of quickSort() is 8). Why is it returning a wrong value when I didn't use list slicing?


access jquery element after append function using jquery

How to get click event of the  tag using jquery when i access click event it is not accees please help.  This is my script to add data using append method   $.ajax({   type: "POST",   url: URL,   data: datastring }).done(function(data) {    var status = JSON.parse(data);   for (var i in status) {     $("#loadmystatus").append(       "
" +       "2:45 am 02/04/2016" +       "
" +       "<button class='iconsiz' id='dd-user-menu' type='button' data-toggle='dropdown' aria-haspopup='true' aria-expanded='false'>" +       "" +       "</button>" +       "
" +       "" +       "" +       "Make current status" +       "" +       "" +       "" +       "Remove" +       "" +       "
" +       "
" +       "
" +       "
" +       "
" +       "" + status[i].userstatus + "" +       "
" +       "
"     );   } });   this is my scritp to access  tag even did nt work


What is gravitational radiation (in association with gravitational waves)? Is it a form of energy/mass? Or is it just another word for gravitational waves?


CSS: Using text-align: center to centre a DIV using display: inline-block

Does anyone have any comments as to the legality of this CSS method to horizontally centre a DIV (with unknown width) inside a parent DIV. The inner DIV is set to 'display: inline-block;' and its containing DIV uses 'text-align: center;'. The 'display: inline-block;' allows the DIV to be considered as an inline element which allows the 'text-align: center;' to act upon it. The outer div is just a demo container. Any comments?


What is the "ConcurrentModificationException"?

This is my Bullets class  package mainPackage;  import java.awt.Graphics; import java.awt.image.BufferedImage;  public class Bullets {      private double x;     private double y;     private BufferedImage bulletImage;     Bullets(double x, double y){         this.x = x;         this.y = y;         ImageLoader loader = new ImageLoader();         SpriteSheet ss = new SpriteSheet(loader.loadImage("/Pics/TheSpriteSheet.png"));         bulletImage = ss.grabImage(2, 1, 32, 32);     }      public void render(Graphics g){         g.drawImage(bulletImage, (int)x, (int)y, null);     }     public void tick(){         y--;     }     public double getX(){         return x;     }     public double getY(){         return y;     } }   Then I made my BulletQualities class  package mainPackage;  import java.awt.Graphics; import java.util.LinkedList;  public class BulletQualities {     Bullets b;     private LinkedList<Bullets> bulletList = new LinkedList<Bullets>();      public void addBullet(Bullets b){         bulletList.add(b);     }     public void tick(){   I get an error on this next line          for(Bullets bullet:bulletList){                 if(bullet.getY() == 0)                 removeBullet(bullet);             bullet.tick();         }     }     public void render(Graphics g){         for(int x = 0;x < bulletList.size(); x++){             bulletList.get(x).render(g);         }     }     public void removeBullet(Bullets bullet){         bulletList.remove(bullet);     } }   This is my error message:   Exception in thread "Thread-4" java.util.ConcurrentModificationException     at java.util.LinkedList$ListItr.checkForComodification(Unknown Source)     at java.util.LinkedList$ListItr.next(Unknown Source)   Then it just showed the lines with errors. I have no idea why It's not working. Please help me. It would mean a lot. :-)  Oh, I almost forgot, this is my removeBullet method from my bulletQualities class:  public void removeBullet(Bullets bullet){     bulletList.remove(bullet); }


Ubuntu server 18.04 slow boot due to drm_kms_helper

I have installed Ubuntu Server 18.04 on an old notebook for home purposes (SAMBA, Transmission, etc...). When I open it, it shows me . It remains for about 2-3 minutes and it slows the boot process. How can I remove this screen?


Light Travels in straight line even in gravity

As we know light travels in straight line in normal circumstances but when exposed to gravity it bends. But does it actually bends?


linux + delete words from file that appear in another file

I have two files: in linux redhat version 6  list1.txt         - this files contain 34732 words  list2.txt         - this files contain 272 words  I want to remove all words from list1.txt that spears from list2.txt  what the best approach to do that ( both files include only one field )  more list1.txt  dweferf fr grgr gefyh fergtrg ggtgg fergth gtg . . .  more list2.txt  dweferf fr frgrgggb rggtgtrgrt fergtrg rfergrtg fwed4  . . .


I'm New to Blender. I found a model a few days ago, but when I realized that there wasn't an armature in this one, I made an armature for myself, but when I try to combine the model with Armatur, I encounter a problem called "Bone Heat Weighting: failed to find solution for one or more bones". I would be very grateful if you could help and explain what i should do.


If a creature is dropped on a monster, how much damage does each of them take?

If a character who was under the effect of a growth potion (double their height and eight times their weight) and weighed 2,400 lbs. was able to use Dimension Door to teleport 400 feet or more into the air, directly above a Huge-sized monster, and fell on it, how much damage would the falling creature - and the monster - take?  I would assume both would take the 20d6 max for the falling over 200 feet, but is there a estimation on additional damage for the falling creature's size?  According to the splat calculator, at 500 feet you'd be falling at 196 km/hr, and it would expend 1.6 million joules of energy, the equivalent of over 3,000 mid-sized cars hitting an object at 60 km/hr.  A 2,400-lb. barbarian falling 500 feet is like dropping a mid-sized Toyota Corolla off a 50 story building onto a monster - it should do some damage.


Ctrl-D signal confirmation to avoid exiting terminal

I sometimes accidentally press Ctrl-D while using a terminal, exiting the terminal or closing screen/tmux.  Can I avoid this by having a confirmation before exit like this?  Are you sure you want to quit? [Y/n]   or   Press Ctrl-D again to quit


Must or should you use a hyphen in *Turing-complete* and *Turing-completeness?*

's quite a good general answer of when and how to hyphenate. This makes me believe, that Turing-complete is correct, even though .  However, Turing-completeness seems to me to be an extension of Turing-complete—Turing-complete + ness. It's not the completeness of Mr. Turing.  Do I need to get my understanding supplemented here? How?  EDIT:  The answers to  don't answer this question.  Is the hyphen in Turing-completeness considered wrong, or not exactly wrong but totally unnecessary? It's hard to put into words, but this compound word has a flair that distinguishes it from a mere compound word that combines two nouns, and I feel urged to express this with a hyphen, just like in the compound word Turing-complete.


Is it safe to delete files in WinSxS with no hard-links under Vista?

The question is not a duplicate. It's specific for the case of Windows Vista where there's no OS-provided method for reducing the size of the WinSxS folder (as opposed to Windows 7 and later, where there is such a method). The question asks about a specific manual method of reducing that folder size. This is not addressed on other SU questions.    My Windows\Winsxs folder is currently about 20 GB in size and is full of files which where last accessed years ago.  Some files are hard-linked from some other folder in the system, but most of them have no hard links (hard link count = 1). They just seem to be taking space.  Is it safe to delete the files that have no hard links? I have no intentions of uninstalling Windows updates, so I don't want to keep old versions of everything.


Why package installed by compiling its source code does not appear in dpkg -l output?

I'm seeing a potentially problematic issues here when I use the command line:  dpkg -l | grep macchanger    It would list macchanger and the version with no problems.  I recently uninstalled this buggy version I had via:  apt-get remove macchanger   Then reinstalled it but I manually compiled and installed it from sources from GitHub.  Now when I use:  dpkg -l | grep macchanger    I get absolutely nothing and the issue is that I want to be able to keep track of the package.


Suppose $f: X \rightarrow Y$, and is one-to-one, and let $A \subseteq X$, prove that $f^{-1}[f[A]] = A$.  EDIT: Actually, this identity should hold even if $f$ is not one-to-one (injective), right?  This is completely intuitive and logical, but I can't think of a proof strategy to use to prove it? I'm familiar with induction and element chasing, but they don't seem to work here.  Here is the beginning of my element chasing proof to prove that $f^{-1}[f[A]] \subseteq A$.  Start with arbitrary element: $a \in f^{-1}[f[A]]$ \  Apply definition of preimage: $a \in \{x \in X | f(x) \in f[A] \}$ \  Simplify and convert to boolean expression: $a \in X \land f(a) \in f[A]$ \  Apply definition of image: $a \in X \land f(a) \in \{y \in Y | y = f(x), x \in A \}$ \  I'm stuck here...


Remove empty directory trees (removing as many directories as possible but no files)

Suppose I have a dir tree like this:  ROOTDIR     └--SUBDIR1         └----SUBDIR2             └----SUBDIR3   I am looking for a command such that when I input:  $ [unknown command] ROOTDIR   The whole dir tree can be deleted if there is no file but only dirs inside the whole tree. However, say if there is a file called hello.pdf under SUBDIR1:  ROOTDIR     └--SUBDIR1         └--hello.pdf         └----SUBDIR2             └----SUBDIR3   Then the command must only delete SUBDIR2 and below.


Best practice for managing AWS SSH .pem files within team

We are running a number of environments on EC2 using VPC. In each VPC we have a hardened bastion host configured which is used as the initial SSH entry point into the network.  To access hosts within our private VPC subnets, a user first SSH to the bastion host and then SSH to other hosts within the subnets. To do this the user forwards the SSH keys (downloaded as .pem files from AWS) when they make the initial SSH connection. For example:  ssh -A ec2-user@bastion-host.on.aws ssh ec2-user@app-server.on.aws   The whole purpose of the bastion host is to allow team members to securely access our environments providing they have both .pem keys. The team members are trusted and within a single organisation.  My question is: What is the best way for us to manage and distribute the .pem files within the team so that:   Team members can find the correct .pem files for the environment they wish to connect to The storage of the .pem files is secure We can explicitly authorise individual users to access the keys   Any suggestions most welcome.


Mount Windows share as guest from command line

So I'm at a friend and hooked up my external EXT4 HDD to his router and it recognises it and he can connect his entire family to it and everything works fine. However, on my Ubuntu machine I can:  Go to my File Manager (Nemo) File Connect to Server   and that works fine! but I cannot: sudo mount -t smbfs //192.168.1.1/Fab-EXT4 /media/MichelNAS/ mount: unknown filesystem type 'smbfs'  sudo mount -t cifs //192.168.1.1/Fab-EXT4 /media/MichelNAS/ Password for root@//192.168.1.1/Fab-EXT4:   sudo mount -t cifs -o guest //192.168.1.1/Fab-EXT4 /media/MichelNAS/ mount error(112): Host is down Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)  sudo mount -t cifs //192.168.1.1/Fab-EXT4 -o user=,password= /media/MichelNAS/  mount error(112): Host is down Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)  sudo mount -t cifs -o rw,noperm,sec=none //192.168.1.1/Fab-EXT4 /media/MichelNAS/ mount error(112): Host is down Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)  However: smbclient --list=192.168.1.1 --no-pass  works perfectly and has as output: WARNING: The "syslog" option is deprecated Domain=[HOME] OS=[Unix] Server=[Samba 3.0.24]      Sharename       Type      Comment     ---------       ----      -------     IPC$            IPC       IPC Service (mymodem Sharing Files)     Fab-EXT4        Disk      Share Fab-EXT4 directory Domain=[HOME] OS=[Unix] Server=[Samba 3.0.24]      Server               Comment     ---------            -------     MYMODEM              mymodem Sharing Files      Workgroup            Master     ---------            -------     HOME                   So I'm obviously missing something completely stupid here, but I'm stumped as to why I cannot mount this share from the command line???


Convergence in Distribution in Order Statistics

Let $X_1, X_2, \ldots$ be iid from Exp$(\theta)$ with density function $f(x) = \frac{1}{\theta}e^{-\frac{x}{\theta}}$. (a) Find the limiting distribution of $M_n = Y_1 - \theta\ln(n)$ and $T_n = nY_n$, where $Y_1$ and $Y_n$ represent the first and last order statistics (among $n$ observations) respectively. Answer: I have obtained the CDF of X to be: $$F_x(x) = 1 - e^{-\frac{x}{\theta}}$$ the CDF of $Y_1$ to be: $$F_{Y_1} = 1 = e^{-\frac{xn}{\theta}}$$ the CDF of $M_n$ to be: $$F_{M_n}(x) = \left[1 - \frac{1}{n}e^{-\frac{x}{\theta}}\right]^n$$ with limiting distribution $$e^{-e^{-\frac{x}{\theta}}}$$ the CDF of $T_n$ to be: $$F_{T_n}(x) = 1 - e^{-\frac{x}{\theta}}$$ which is also the limiting distribution. (b) Show that $M_n$ and $T_n$ are asymptotically independent. Answer: I've tried finding the joint PDF for ordered statistics by using the equation $$g_{ij}(y_i, y_j) = \frac{n!}{(i - 1)!(j - i - 1)!(n - j)!}[F(y_i)]^{i - 1}[F(y_j) - F(y_i)]^{j - i - 1}[1 - F(y_j)]^{n - j}f(y_i)f(y_j)$$ however, it is a mess based on my CDFs. Any suggestions on a different approach?


which is better to use Mysql or Mysqli and in what conditions? I want to start a project that requires a database just wanted to know which of the two is better


I have read that positional parameters start at $1 (for example: $1, $2, $3 and so on are positional parameters). But $0 is not a positional parameter.  But why $0 is not a positional parameter?  I think this could be a reason, but not sure:  Positional parameters only take their values when a script is executed. For example: if we do ./myScript Hello, then $1 will have the value Hello. But $0 can take its value on two occasions: when a script is executed (it would have the value of the script name), and when bash itself is executed without a script (it would have the value bash or -bash).


Proof of $a^n+b^n$ divisible by $a+b$ when $n$ is odd

I read somewhere that     $(a^n - b^n)$         It is always divisible by $a-b$.   When $n$ is even it is also divisible by $a+b$.   When $n$ is odd it is not divisible by $a+b$.      and     $(a^n + b^n)$         It is never divisible by $a-b$.   When $n$ is odd it is divisible by $a+b$.   When $n$ is even it is not divisible by $a+b$.      I wonder what's the proof for this.  First postulate is clear. $(a-b)$ would or would not be a factor. Any light on others?


Reasons four double undescores in standard library implementations

Is there any technical reason for standard library (C or C++) implementations to, IMO abuse, underscores the way they do (=prefix everything with two undescore + add a trailing underscore to denote that a variable is a member variable)?  I get that /.*__.*/ and  /_[A-Z].*/ (<= regexes) are reserved-by-implementation. But isn't that supposed to refer to the implementation of the compiler rather than a (standard) library?  Couldn't a standard library behave like any other library in terms of choosing its internal names?


Manually make it look like an object is going through the floor (of a real life photograph)

I have a picture of a room including the floor and I want it to look like there is, for example, a cube going through the floor. Is there a way to do this, maybe by making it go through a plane that is transparent to the photograph but not to the cube?  If anyone knows how to do this, as I'm not very good at doing things from text, would you be able to explain with pictures or something? Is there is a tutorial for this sort of thing?


The slogan, "i'm lovin' it" is grammatically wrong

My grammar book pointed out that when you use some verbs in the continuous tenses, it need to be something active, such as running, or eating. Verbs that do not imply an action, but instead refer to a state of affairs - for example, know, own, love, or feel -can not be used in the continuous tenses. If so, is there any verb list which I can not use in the continuous tenses? It makes me confuse and easily make mistake if I am not careful. So as native English speaking people.


In Python 2.5, the following code raises a TypeError:  >>> class X:       def a(self):         print "a"  >>> class Y(X):       def a(self):         super(Y,self).a()         print "b"  >>> c = Y() >>> c.a() Traceback (most recent call last):   File "<stdin>", line 1, in <module>   File "<stdin>", line 3, in a TypeError: super() argument 1 must be type, not classobj   If I replace the class X with class X(object), it will work. What's the explanation for this?


Should we avoid negative words when writing error messages?

Does the use of words such as 'fail', 'wrong', 'incorrect' and 'invalid' have a sufficiently negative impact on a users frame of mind to warrant the prohibition of their inclusion in the error messages generated by typical web forms?  i.e. Should we rephrase examples like these to just use positive words?  'date entered incorrectly'  or  'failed to complete registration, please see below for invalid field entries'  (PS, the examples are there to show use of the words in an error message, not to serve as examples of error messages I would use or things that need correcting in answers, I'm not looking for advice on how to write form error messages, but for information about the effect of certain words on a users frame of mind)


Suppose $A$ is a 4x4 matrix such that $\det(A)=\frac{1}{64}$

Suppose A is a 4x4 matrix such that $\det(A)=\frac{1}{64}$ then $\det(4A^{-1})^T$   I created a 2x2 matrix $B$ and transposed it both had the same determinant  I then found $\det(B)$ and $\det(B^{-1})$ the results were inverses of each other I then tried found the $\det(2B)$    but I cannot see what is the relationship between the determinant of a matrix and the determinant of that matrix multiplied by a constant?


After lethal first strike damage to an indestructible creature, will it still do damage?

If I were to attack with a 4/4 indestructible creature and it's blocked by a 4/2 creature with first strike, would my indestructible creature still attack during the second combat damage step, or would it just tap, not assigning any damage?


Changing the default numbering scheme in enumerate environment

Together with a colleague I'm writing a book (with the Springer template), and I am currently homogenizing the layout. I'd like to change the default numbering scheme in the enumerate environment globally in the beginning of the document so that I don't have to tack on the modifier at the end of every “\begin{enumerate}[(1)]” — and change it once my co-author decides he prefers (i), (ii), etc. or some other way to number lists. Is there any way to do this?


How can I calculate AUC using Gini coefficient?

In the Gini Coefficient's , it is defined as $G= 1 - \frac{\Sigma_{i=1}^n f(y_i)(S_{i-1}+S_i)}{S_n}$ for discrete variables, where $S_i= \Sigma_{j=1}^i f(y_i)y_i$ and $S_0=0$ ($y$ being the discrete variable that takes $n$ different values), and it says that $AUC= \frac{1}{2}(1+G).$. However, I don't quite understand how I can get the AUC from that.   Let's suppose that I have response variables $y_1,...,y_k \in \{0,1\}$ in some test set and probabilities $\hat{p_1},...,\hat{p_k}$ for these observations generated by a logistic regression. With that information, how can I obtain $G$ to subsequently calculate AUC?


How do I show that there exists variational/action principle for a given classical system?

We see variational principles coming into play in different places such as Classical Mechanics (Hamilton's principle which gives rise to the Euler-Lagrange equations), Optics (in the form of Fermat's principle) and even General Relativity (we get Einstein's equation from the Einstein-Hilbert action). However, how do we explain this very principle, i.e., more mathematically, I want to ask the following:      If I am given a set of generalized positions and velocities, say, $\{q_{i}, \dot{q}_{i}\}$, which describes a classical system with known dynamics (equations of motion), then, how do I rigorously show that there always exists an action functional $A$, where    $$A ~=~ \int L(q_{i}, \dot{q}_{i})dt,$$    such that $\delta A = 0$ gives the correct equations of motion and trajectory of the system?    I presume historically, the motivation came from Optics: i.e., light rays travel along a path where $S = \int_{A}^{B} n ds$ is minimized (or at least stationary). (Here, $ds$ is the differential element along the path). I don't mind some symplectic geometry talk if that is needed at all.


Let $G$ be a finite group, say a group with $n$ elements, and let $\emptyset \neq S \subseteq G$. Suppose $e \in S$, and that $S$ is closed with respect to multiplication. Prove that $S$ is a subgroup of $G$.    Let $G = \{a_1, \ldots, a_n\}.$ Let $a_i \in G.$ Then any number of $a_ia_1, a_ia_2, \ldots, a_ia_n \in S,$ since $S$ is closed under multiplication. One of those $a_ia_j$ is $e$ since $e \in S.$ Then either $a_i$ or $a_j$ is $a^{-1}.$ Would this argument work?


Proof of convergence with central limit theorem

I'm trying to solve some problems and this one showed up: Show that $$ e^{-n} \left(1 + n + \frac{n^2}{2!} + \dots + \frac{n^n}{n!}\right) \to \frac{1}{2} $$ as $n \to \infty$. The problem sugests to apply the Central Limit Theorem to a sequence of random variables with Poisson distribution. Can somebody help me with this? I don't know how to apply it correctly. And if someone knows some another way to prove this, I'll apreciate! Thanks in advance!


How to wrap around a figure in a theorem-like environment?

I want to illustrate my examples, which are set in a theorem-like environment. Is it possible to wrap the text and equations around the figures? I have read about several packages but I can't get them to work in a theorem. Am I doing something wrong?


I somehow enlarged jpeg wallpaper.  I cannot figure out how to return to original size. Any downloaded jpeg as wallpaper does the same thing.  I am new to Ubuntu and can only use it.  I have no tech training.


I am using field image to insert image into article. The image can't show in article body.   How do I insert the image into article?


disable save password bubble in chrome using Javascript

Is there a way to disable the save password bubble in Chrome using javascript?  I need to make sure no users are able to use that feature.  This is a Chrome specific problem.  works for Mozilla, but not for Chrome. I don't want the bubble or option to even show up. autocomplete=off does not work in Chrome.


$f: \Bbb R\to\Bbb R$ maps every open subsets to open subsets, then $f$ may not be continuous?

$f:\Bbb R\to\Bbb R$ maps every open subsets to open subsets, then $f$ may not be continuous?  How to construct such an example? what happens if $f$ has discontinuities?


How can the probability of each point be zero in continuous random variable?

I know this is duplicated but I think the question is a bit different and needs different answer.  How can CDF be continuous and have derivative at each point that is not equal to zero but the probability at each point is zero?   Why not say for example if you want to choose a real number between 0 and 1 that the probablity is 1/N? Where this is just infinitesimal. (Just an example to describe the situation.)  It can neither be finite nor zero  The difference is: Why not assign it an infinitesimal instead of zero and to say that an event with P = 0 can happen?


Why are there no conserved quantities with discrete symmetries?

After studying a bit of theoretical mechanics, I was a bit puzzled by why discrete symmetries do not allow for the existence of conserved quantities in general. What would be a fundamental explanation of why this happens? More accurately, what impedes the existence of analogues to Noether's theorems for the discrete case?


The polarization identity expresses a symmetric bilinear form on a vector space in terms of its associated quadratic form:  $$ \langle v,w\rangle = \frac{1}{2}(Q(v+w) - Q(v) - Q(w)),  $$ where $Q(v) = \langle v,v\rangle$. More generally (over fields of characteristic $0$), for any homogeneous polynomial  $h(x_1,\dots,x_n)$ of degree $d$ in $n$ variables, there is a unique symmetric $d$-multilinear polynomial $F({\mathbf x}_1,\dots,{\mathbf x}_d)$, where each ${\mathbf x}_i$ consists of $n$ indeterminates, such that $h(x_1,\dots,x_n) = F({\mathbf x},\dots,{\mathbf x})$, where ${\mathbf x} = (x_1,\dots,x_n)$. There is a formula which expresses $F({\mathbf x}_1,\dots,{\mathbf x}_d)$ in terms of $h$, generalizing the above formula for a bilinear form in terms of a quadratic form, and it is also called a polarization identity.  Where did the meaning of "polarization", in this context, come from? Weyl uses it in his book The classical groups (see pp. 5 and 6 on Google books) but I don't know if this is the first place it appeared. Jeff Miller's extensive math etymology website doesn't include this term. See .


Decision boundaries and Gaussian density functions

This is for my hw, and if anyone can solve the first part of the question it will be great. Here is the question:  Assume a two-class problem with equal a priori class probabilities and Gaussian class-conditional densities as follows:  $$p(x\mid w_1) = {\cal N}\left(\begin{bmatrix} 0 \\ 0 \end{bmatrix},\begin{bmatrix} a & c \\ c & b \end{bmatrix}\right)\quad\text{and}\quad p(x\mid w_2) =  {\cal N}\left(\begin{bmatrix} d \\ e \end{bmatrix},\begin{bmatrix} 1 & 0 \\ 0 & 1 \end{bmatrix}\right)$$  where $ab-c^2=1$.   Find the equation of the decision boundary between these two classes in terms of the given parameters, after choosing a logarithmic discriminant function. Determine the constraints on the values of a, b, c, d and e, such that the resulting discriminant function results with a linear decision boundary.


After running SVD, how do I project new data onto the lower-rank space?

Suppose I have a training data-set A which is m x n, with samples arranged as rows, and I use singular value decomposition to find k principal directions defining a lower-rank space, k < n.  The output of SVD, named by convention U, Σ, V gives me an approximation for my training set: A approximately equal to U Σ transpose(V)  Moreover, the product U Σ is m x k with each row representing a vector in the lower-rank space that approximates the corresponding row in the rank-n original space. From this "lossy" data, it is also possible to return to the rank-n space by right-multiplying with V.  All of this is fine and well but let's say I now train some learning system using U Σ as my training set instead of the original A. In order to later exploit the trained system, I would have to query it using vectors in the lower rank space.  Assuming I have a query vector Q which is 1 x n and not present in the training set. I want to find the 1 x k vector in the lower-rank space that most appropriately matches Q. How do I do this?  Or am I completely missing the point of SVD and misunderstanding how it is useful for dimensionality reduction?


Clipping and exporting sections of raster from multi-feature shapefile using ArcMap

I have a multi feature shapefile and a slope raster and I'm trying to export images (tif, png whatever) for each feature showing the feature boundary and the slope raster contained within it with a field from the shapefile as the filename. I am dealing with a lot of features (>100,000) so efficiency is key, I tried data driven pages and it failed every time.


This is also a question on my exam paper that i proved by using mathematical induction. However, my tutor tells me that it can be proved without using mathematical induction. I really want to know how to deal with in another way.  Show that for any positive integer n, $(3n)!/(3!)^n$ is an integer.


PHP: Sanitising inputs after migrating to mysqli from mysql

I've just converted my code from mysql to mysqli and I used Oracle's converter:    It was my understanding from various questions/answers on Stack Overflow that inputs do not need to be sanitised if you are using mysqli. However it appears this isn't the case - even though I'm on mysqli - i can still input something with an inverted comma e.g. what's and it returns the error as it will try to merge anything after the ' with the rest of my code.   Am I doing something wrong? If I still need to sanitise my input values after using mysqli how could I do it?  UPDATE  If I run a function like this on my inputs would that be enough?  function sanitise($str){   $string = htmlspecialchars($str);   $string = mysql_real_escape_string($str);   return $str; }


In The Alloy of Law, Miles Hundred-Lives is a double gold twinborn.  This means he can burn gold to see visions of his possible alternative past, (Allomancy) and tap/fill gold to retrieve/store health (Feruchemy).  Since he can burn the same metal he can tap/fill, he can use "Compounding" to gain massive amounts of health (thus making him heal almost instantly from anything)  How do the mechnics for doing this work?  My understanding is:   He wears gold (his gold-mind piecings etc),  and fills them with X minutes of healing  (ie the amound of healing as a he would normally do in X minutes - he could Tap it as fast as he wanted, and take as much time as he wanted to fill it (for a normal Feruchemist this would be >X minutes)) He removes his gold minds and aranges them into consumable form (cutting them down to size). He consumes them, and by Allomantically Burning them, gains additional healing equal to roughly 10*X. He does not see visions of his possible alternitive past. (Which means a filled gold mind can no longer be burnt normally by the person who did the filling, right?) He can use (some of) this extra health to repeat from step 1, and can easily fill the new minds with much more than X minutes of health, easily.   Have I got this right?


Strange behaviour of remote objects feature on different orgs

I run the same js call to retrieve cases and on 1st org it works and on the 2nd org it results in error like:  Error occurred while performing RETRIEVE operation on sobject: Case with data: {limit=5, offset=5, where={IsClosed={eq=false}}} (MALFORMED_QUERY:  createddate, casenumber, priority, _cid FROM Case WHERE IsClosed =                                   ^ ERROR at Row:1:Column:88 line 1:88 no viable alternative at character '_')    On the 2nd org RO feature automatically  append unknown field _cid to query and claims about this.  Beside this I cannot register any new dev edition as it reports that my any username(random) already exists. Some strange things happens...


Can every quadratic extension of $\mathbb{Q}$ be extended to a cyclic extension of degree 4?

Suppose $K$ is a quadratic extension of $\mathbb{Q}$. Does there exist a Galois extension $L/K$ such that $Gal(L/K)\cong\mathbb{Z}/4\mathbb{Z}$ ?


How to simulate bit-fields in Delphi records?

I would like to declare a record in Delphi that contains the same layout as it has in C.  For those interested : This record is part of a union in the Windows OS's LDT_ENTRY record. (I need to use this record in Delphi because I'm working on an Xbox emulator in Delphi - see project Dxbx on sourceforge).  Anyway, the record in question is defined as:      struct     {         DWORD   BaseMid : 8;         DWORD   Type : 5;         DWORD   Dpl : 2;         DWORD   Pres : 1;         DWORD   LimitHi : 4;         DWORD   Sys : 1;         DWORD   Reserved_0 : 1;         DWORD   Default_Big : 1;         DWORD   Granularity : 1;         DWORD   BaseHi : 8;     }     Bits;   As far as I know, there are no bit-fields possible in Delphi. I did try this:   Bits = record       BaseMid: Byte; // 8 bits       _Type: 0..31; // 5 bits       Dpl: 0..3; // 2 bits       Pres: Boolean; // 1 bit       LimitHi: 0..15; // 4 bits       Sys: Boolean; // 1 bit       Reserved_0: Boolean; // 1 bit       Default_Big: Boolean; // 1 bit       Granularity: Boolean; // 1 bit       BaseHi: Byte; // 8 bits   end;   But alas: it's size becomes 10 bytes, instead of the expected 4. I would like to know how I should declare the record, so that I get a record with the same layout, the same size, and the same members. Preferrably without loads of getter/setters.  TIA.


Do I need aTransit visa for UK to Sweden even if I have a USA and Australia visa

I am a Fiji national with a multiple entry schengen visa travelling to Sweden this weekend.I am travelling via Los Angeles with a USA visa and London to Sweden. I also have a multiple entry Australian visa.  Do i need a transit visa for the 7 hour layover in London travelling on the same British Airways airlines from Los Angeles to Sweden with the visas I already have.


TIL: the singular of Unicoins is Unicoins

I saw this on my home page just now.    In case I have misread it, I zoomed in to see the letters more clearly, only to discover that the singular of Unicoins is Unicoins.     I doubt this is not a grammar bug because Unicoins are/is a mythical monetary unit and it has power so mythological that I am still trying to comprehend.


Resizing matplotlib figure after initializing it

How do I resize a matplotlib figure, after I have created/initialized it?  fig, ax = plt.subplots(figsize=(4, 3)) pd.Series([1, 2, 3]).plot(ax=ax)     # which command to use to? below obviously does not work fig.set_figsize((6, 6))


Difference between continuity and uniform continuity

I understand the geometric differences between continuity and uniform continuity, but I don't quite see how the differences between those two are apparent from their definitions. For example, my book defines continuity as:  Definition 4.3.1. A function $f:A \to \mathbb R$ is continuous at a point $c \in A$ if, for all $\epsilon > 0$, there exists a $\delta > 0$ such that whenever $|x-c| < \delta$ (and $x \in A$) it follows that $|f(x)-f(c)| < \epsilon$.  Uniform continuity is defined as:  Definition 4.4.5. A function $f:A \to \mathbb R$ is uniformly continuous on $A$ if for every $\epsilon > 0$ there exists a $\delta > 0$ such that $|x-y| < \delta$ implies $|f(x)-f(y)| < \epsilon$.  I know that in Definition 4.3.1, $\delta$ can depend on $c$, while in definition 4.4.5, $\delta$ cannot depend on $x$ or $y$, but how is this apparent from the definition? From what appears to me, it just seems like the only difference between Definition 4.3.1 and Definition 4.4.5 is that the letter $c$ was changed to a $y$.   My guess is that the first definition treats $c$ as a fixed point and it is only $x$ that varies, so in this case, $\delta$ can depend on $c$ since $c$ doesn't change. Whereas for the second definition, neither $x$ or $y$ are fixed, rather they can take on values across the whole domain, $A$. In this case, if we set a $\delta$ such that it depended on $y$, then when we pick a different $y$, the same $\delta$ may not work anymore. Is this somewhat a correct interpretation?  Anymore clarifications, examples, would be appreciated.


How many times do you write the digit 4 when writing all the numbers from 10 to 100?   Is there a way of doing this without having to write down all the numbers?


Install Ubuntu 18.04 on Dell XPS 15 9570

I am trying to install Ubuntu 18.04 on my Dell XPS 15 9570.  I have followed the steps provided in the .  However, I have stumbled on an issue.   When I boot from USB I am immediately directed to the "Try Ubuntu" option. I do not manage to choose "Install Ubuntu"    I connect to WiFi here. And then open the Install Ubuntu 18.04 icon from the desktop.   I select the language and the keyboard   I then press "Continue" on the following window:  I get to the following window:    If I try to press "Install Now" it tells me:  When I try to press "change" or "+" the Install window closes.     I suspect the issue is that I need to change the drive to ACHI mode. But, I don't know why that would help and why can't it see the drive now.  I have create the bootable USB using Rufus 3.3 and then I have formatted it and tried again using UNetbootin. Same issue.


How to convince longtable to do a page break earlier

using the longtable package to typeset page spanning tables, I run into a nasty behaviour: only a dummy table head and the caption are put on the following page. The contents of the table is extracted from program sources. I don't have much influence here.  \documentclass[a4paper,twoside,DIV10,BCOR1.5cm]{scrbook} \usepackage{longtable} \newlength{\tablcol} \setlength{\tablcol}{4.7cm} \newlength{\tabrcol} \setlength{\tabrcol}{8.1cm} \itemsep0ex plus0.2ex % \begin{document} \begin{longtable}{p{\tablcol}p{\tabrcol}}% % \hline \multicolumn{1}{l}{{\bfseries Feld}} & \multicolumn{1}{l}{{\bfseries Beschreibung}}\\ \hline \endfirsthead % \hline \multicolumn{2}{l}% {{\small\slshape Fortsetzung der vorherigen Seite}}\\ \hline \multicolumn{1}{l}{{\bfseries Feld}} & \multicolumn{1}{l}{{\bfseries Beschreibung}}\\ \hline \endhead % \hline \multicolumn{2}{l}% {{\small\slshape Fortsetzung auf der n\"achsten Seite}}\\ \hline \endfoot % \hline \caption[show user output]{Beschreibung der Output-Struktur des show user Statements} \endlastfoot % \label{tucshowxuser}% {\scshape id} & Die Nummer des Repository Objektes \\ {\scshape name} & Der Name des Objektes \\ {\scshape creator} & Name des Benutzers der dieses Objekt angelegt hat \\ {\scshape create\_time} & Datum und Uhrzeit der Erstellung \\ {\scshape changer} & Name des Benutzers der dieses Objekt zuletzt ge\"andert hat \\ {\scshape change\_time} & Datum und Uhrzeit der letzten \"Anderung \\ {\scshape privs} & Zeichenkette die K\"urzel f\"ur die Benutzerrechte auf dieses Objekt enth\"alt \\ {\scshape commenttype} & Typ des Kommentars \\ {\scshape comment} & Kommentar zum Objekt, wenn vorhanden \\ {\scshape id} & Die Nummer des Repository Objektes \\ {\scshape name} & Der Name des Objektes \\ {\scshape creator} & Name des Benutzers der dieses Objekt angelegt hat \\ {\scshape create\_time} & Datum und Uhrzeit der Erstellung \\ {\scshape changer} & Name des Benutzers der dieses Objekt zuletzt ge\"andert hat \\ {\scshape change\_time} & Datum und Uhrzeit der letzten \"Anderung \\ {\scshape privs} & Zeichenkette die K\"urzel f\"ur die Benutzerrechte auf dieses Objekt enth\"alt \\ {\scshape commenttype} & Typ des Kommentars \\ {\scshape comment} & Kommentar zum Objekt, wenn vorhanden \\ {\scshape id} & Die Nummer des Repository Objektes \\ {\scshape name} & Der Name des Objektes \\ {\scshape creator} & Name des Benutzers der dieses Objekt angelegt hat \\ {\scshape create\_time} & Datum und Uhrzeit der Erstellung \\ {\scshape changer} & Name des Benutzers der dieses Objekt zuletzt ge\"andert hat \\ {\scshape change\_time} & Datum und Uhrzeit der letzten \"Anderung \\ {\scshape privs} & Zeichenkette die K\"urzel f\"ur die Benutzerrechte auf dieses Objekt enth\"alt \\ {\scshape commenttype} & Typ des Kommentars \\ {\scshape comment} & Kommentar zum Objekt, wenn vorhanden \\ {\scshape id} & Die Nummer des Repository Objektes \\ {\scshape name} & Der Name des Objektes \\ {\scshape creator} & Name des Benutzers der dieses Objekt angelegt hat \\ {\scshape create\_time} & Datum und Uhrzeit der Erstellung \\ \end{longtable}  \end{document}   The problem is that I don't find a method to force a page break earlier. A page that isn't filled entirely, followed by a page with the last part of a table is better than this.  I tried to add "\needspace{someLength}" at the beginning or end of the rows, but that doesn't work either. It simply makes the rows someLength high instead of forcing a page break if there's no more than someLength room left on the page.  I'd be more than grateful for some solution or even a good hint.  TIA


Find out which remote branch a local branch is tracking

See also:         How can I find out which remote branch a local branch is tracking?  Do I need to parse git config output, or is there a command that would do this for me?


Problem with option border of class standalone

I tested a MWE given in question . Following the documentation (page 9) I used the class option border={left right bottom top} with left=right=top=0pt and bottom=20pt (20pt only to show the effect here).  With the version 2012/09/15 v1.1b of standalone and the following MWE I get no 20 pt margin at the bottom of my picture.  What is the problem?  MWE:  \documentclass[% % border=1pt   border={0pt 0pt 20pt 0pt} %left right bottom top ]{standalone}% http://ctan.org/pkg/standalone \begin{document} $2^5 = x_5 \times y^8$ \end{document}


Is the Hilbert-Schmidt norm of a matrix induced from a vector norm?

A general way to get a matrix norm is inducing it from a vector norm.  The question is, can the Hilbert-Schmidt norm obtained this way?  As a norm general question, is every matrix norm obtained this way?  The crucial condition is $\|XY\| \leq \|X\|\,\|Y\|$.


What does "isomorphic" mean in linear algebra?

My professor keeps mentioning the word "isomorphic" in class, but has yet to define it... I've asked him and his response is that something that is isomorphic to something else means that they have the same vector structure. I'm not sure what that means, so I was hoping anyone could explain its meaning to me, using knowledge from elementary linear algebra only. He started discussing it in the current section of our textbook: General Vector Spaces.  I've also heard that this is an abstract algebra term, so I'm not sure if isomorphic means the same thing in both subjects, but I know absolutely no abstract algebra, so in your definition if you keep either keep abstract algebra out completely, or use very basic abstract algebra knowledge, that would be appreciated.


Bootstrapped confidence intervals: different values at every computation?

I am running an ANOVA and computing bootstrapped CIs for my effect sizes. I am using for this the Measures of Effect Size Toolbox for Matlab.  To my surprise, if I re-run the same line of code, i.e. compute the same thing for the same data, the lower&upper margins of the CI are slightly different each time.  I know that bootstrapped CIs are built from permutation analyses based on random generations of distributions. Still, I do not remeber reading anywhere this odd property of CIs of being never twice the same!


Can the closed interval [0, 1] be expressed as the union of a sequence of disjoint closed subintervals each of length smaller than 1? Explain.  I have been trying to figure out this problem, and I do not know where to even begin.


What exactly is a seed in a random number generator?

I tried some usual google search etc. but most of the answers I find are either somewhat ambiguous or language/library specific such as Python or C++ stdlib.h etc. I am looking for a language agnostic, mathematical answer, not the specifics of a library.   As an example, many say that the seed is a starting point of random number generator and the same seed always produces the same random number. What does it mean? Does it mean the output number is a deterministic function of a specific seed, and the randomness comes from the value of the seed? But if that is the case, then by supplying the seed, are not we, the programmers, creating the randomness instead of letting the machine do it?  Also, what does a starting point mean in this context? Is this a non-rigorous way of saying an element $x\in\mathfrak{X}$ of the domain of a map $f:\mathfrak{X}\rightarrow\mathfrak{Y}$? Or am I getting something wrong?


Can someone show me how to set-up an auto reply for one day a week every week? using Outlook 2010. Basically we have some employees that only work certain days of the week and I want them to have an out of office on those days every week.  EDIT: It is for one day every week.  answer is not what I am looking for as it doesn't allow for a specific day of the week every week. The rules that is. You can only have a date range and not one every Friday for example.


Please wrap the entire comment flag description in a `` (making the entire text clickable)

Currently, in the , when you want to select an option, you have to click either on the radio button, or on the top part of the description. This is because only the top part of the description is contained in a <label>.  This doesn’t match the behavior of the other older modals. I’d like the entire text to be clickable to select the corresponding radio button, instead of having to click on this rather thin strip.  This is a screenshot of the flag modal with the <label> being inspected. The bottom description should be part of the <label>, too, or perhaps in another <label> for the same radio button — whichever works best.    Other people requesting this feature   For older flag modals,  similar to this one has been proposed in 2014. Before I asked my question, this has been requested in this comment (which I overlooked at first):     [feature-request] Can you make the flag option's subtext clickable? (Like in all other flag dialogs) –    After my question, ’s  to the question  requested this feature.


In the  for quantum mechanics, the first postulate states that a quantum state is a vector in a separable Hilbert space. It means it is assumed the Hilbert space has a basis with at most infinite countable elements (cardinality). In other words, it states that the energy of an arbitrary system is discrete. Is it always true? If not, can you make an specific example in nature that its eigen-energies are uncountable?


Proof of an identity in probability theory

I want to prove the following :  $$E\lvert X \rvert^{\alpha}=\int_{0}^{\infty} P\left\{\lvert X \rvert^{\alpha}>x\right\} dx=\alpha \int_{0}^{\infty} x^{\alpha-1} P\left\{\lvert X \rvert>x\right\} dx$$  The first equality is easy to prove. I'm having trouble with the second one. It appears to be some differentiation technique has to be used but I don't have a clue on how to proceed. Any help would be much appreciated.


Orientation change while editing a comment

If the device fits an orientation change while I am editing a comment, the Post button and down arrow no longer respond to taps.   App Version: 1.0.85 Device Manufacturer: LGE Device Model: VS425PP   OS Version: 5.1.1 (161331805d4f5)


Where are all my favorite questions listed? I recently added one and I'll need to browse it later. How can I do it?


Do scalloped sides on a knife blade have any effect?

One of the first knives I was ever given was a .  Over my years of use, I've never put much thought into the cut-outs along the side of the blade (which appear to be variously referred to as "hollows", "scallops", or a "Granton edge") which many santoku-style knives seem to feature.  Just to be clear, I'm talking about the oval indentations, evenly spaced down the side of the knife face, as prominently shown on this similar model:    I idly noticed these the other day and started a bit of research into their function, but what I found wasn't exactly definitive.   make them sound like quite an advantage:     ...it's the enhanced slicing ability - without shredding, ease of cutting and better food release that makes this particular knife design so popular with professional chefs and home cooks alike.   I question this, as I never noticed any of the professional chefs I've worked with in the past using a scalloped-sided blade, and I personally have never noticed a significant performance difference between my santoku and other knives of similar thickness.  Likewise, there seems to be  about whether this feature is actually effective for its stated purpose.  Many users seem to think that there's no real difference.  So, my main question: has anyone conducted a comparison of scalloped vs. non-scalloped knife designs?  Was there any significant difference?  In addition, some follow-on questions that an ideal answer could address:   What's the principle that these cut-outs supposedly work on?  In other words, if they work: why? Does the prominence of the cut-outs matter?  They're fairly subtle and shallow on my Wusthof, but are they more effective if deeper/more prominent, like on ? Is there a particular method that makes the best use of these cut-outs?  For example, do they have more effect when using a slicing motion across the food, as opposed to a chopping motion straight down to the board?   EDIT: Let me clarify, I'm not asking about general knife preferences here.  There are tons of other answers on this site related to what to look for in a knife, and I'm experienced enough to know what I like, and what works well.  But, if I were faced with a choice between two knives, identical in every way except that only one had scallops, could I anticipate any noticeable difference in their performance?


Edited texture not replacing old texture in render

I was working on a tower and painted my own texture for it. I saved halfway though and took a break. When I returned to my little project, I could paint on the image and it shows up in the material view but not the render. I did everything in my power but still couldn't understand why?  I have used:   Nodes, including mapping and insert UV coordinates. Unwrap UVs Used lights Deleted and replace nodes Deleted and replace Mat Removed image and replace it Reload image Painted on mesh   Even though use blender, I am not a programmer. So I find it really helpful if someone could give me an answer.


Showing $\frac{x^3y}{x^4+y^2}$ is continuous at all points

The function in the title is also defined to be 0 at (0,0).  So the functon is obviously continuous at all points except (0,0), so I need to show that the limit of the function as (x,y) goes to (0,0) is 0.  I used inequalities, so what I did is  $0\le \frac{x^3y}{x^4+y^2} \le \frac{(x^4+y^2)x}{2(x^4+y^2)}=\frac{x}{2}=0$  where this is as (x,y) goes to (0,0).  My issue is that the above doesn't hold if x and y are different signs, because then it's not greater than 0.  Any way to fix this?  Thanks


Can I extend my stay in Kuala Lumpur (Malaysia) beyond 90 days by doing a visa run?

I am US citizen. We are allowed to  stay in Malaysia for 90 days.      Can I extend my 90 days if I cross over to Singapore and return to Kuala Lumpur the following day, hence getting another 90 days "extension" for my stay in Malaysia?    Can I repeat this just a few days before my next 90 day is up?


/etc/sudoers: why is there an entry for root?

We are distributing a standard sudoers file to our Linux servers.  From an historical point of view the line ..  root    ALL=(ALL)       ALL   has been removed or never added. The package default sudoers contains this line and some applications seem to require this line to work properly.  I need to argument with my team why this line needs to be present but I cannot really find an answer since root can do anything anyway.  So why is this line present ? does it really have a functionality/purpose ?


Links don't load content dynamically when pressed a second time

I have a site that displays (or that's the plan at least) content dynamically, but it has some problems. When I open the site for the first time and click on a link, it loads the content dynamically. When I go back and press a link again, it reloads the whole site. I feel like I'm missing something important, what can it be?  Ajax:  $(document).ready(function () {     var container = $('#content');      $('a').click(function (e) {         e.preventDefault();         var url = $(this).attr('href');         //$('#content').hide('fast');         history.pushState({path: url}, null, url);         container.load(url);         return false;     });      $(window).bind('popstate', function (event) {         var state = event.originalEvent.state;          if (state) {             container.load(state.path);         }     });      history.replaceState({path: window.location.href}, ''); });


youtube-dl not working signature algorithm

I am getting this error when I am trying to download a video from youtube via youtube-dl:  WARNING: Warning: Falling back to static signature algorithm ERROR: unable to download video data: HTTP Error 403: Forbidden


I am trying to find the conjugacy classes of the Dihedral group $D_{12}=\{e,a,a^2,a^3,a^4,a^5,b,ba,ba^2,ba^3,ba^4,ba^5\}$   where $a^6=b^2=e$ and $ab=ba^5$. I know that one of the conjugacy classes will be $C_e=\{e\}$ but I don't understand how you find the others. All help appreciated.


Older fantasy novel with alternate world and musical themes

I read a fantasy novel that was implied to be part of a series around 20 years ago (was part of my high school library, not certain how old it was then).  I don't remember the title or author, or admittedly large portions of the plot (or maybe it was just a disjointed book), and would like to request help here.    These are the elements I remember:   A young teenager (in what I believe is regular old Earth) receives a list of instructions from a composer friend of his.  By going through the composer's house and taking a convoluted path through the neighborhood, that starts changing on him as he goes, he arrives in another world entirely. The path ends in a hostile garden or hedge maze that is tended/guarded by a woman in a veil. The village he ends up in seems pretty repressed.  Something about another guardian woman nearby related to the first, but not immediately hostile. Desert or a wasteland nearby that contain monstrous or demonic children. The protagonist eventually learns some ability to leave shadows or decoys behind by breaking off pieces of his emotions, or psyche.  He ends up using this to cross the local wasteland. Climbs a mountain and sees his own face as an adult in a snow vision, although he doesn't realize it until he finally returns home to Earth and sees himself in a mirror again. Someone wants a "song of power" or words of power and traps our traveler for it.  The original composer friend is somehow related to this, but what the traveler ends up writing under duress is a trap, and magically blows the villain's home up.   That's what I got.  Any ideas?


Univariate Regression, expectation of x given y

Perhaps an easy question for some: Given I have a univariate regression setting... $$y = b_1*x + e$$ ... with $e$ being the normally distributed error (standard normal dist.). $x$ is also a random variable which follows a standard normal distribution. How do I find the conditional expectation of x given y? $$E(x|y)$$


Regex for capturing only till the first find of a char in a Java string

This piece of code    String Str = new String("${project_loc:A}/Foo.yaml;${project_loc:B}/Bar.yaml"); System.out.println(Str.replaceFirst("[$][{].*[}]/", ""));   prints   Bar.yaml   while what I am trying to achieve is:  Foo.yaml;${project_loc:B}/Bar.yaml   Why is it stopping at second closing braces i.e. }, not at first?   What regex exp can be passed to replaceFirst() to achieve the desired result?  FYI: I tried few things at  but couldn't find any success.


How to increase java heap size in ubuntu

I am running a ubuntu server and wants to increase java heap size from 1024 mb to 2048 mb how to do it??


Let $f:[0,1]\rightarrow [0,1]$ be a continuous function and $x_1\in [0,1]$. If $x_{n+1}= \frac{\sum_{i=1}^n f(x_i)}{n}$ then prove or disprove that $\{x_n\}$ is convergent. I have proved  If $f$ is constant then the limit exists.  $\{(n-1)x_n\}$ is monotonic.  By compactness $\{x_n\}$ has limit points   But I am unable to show whether the sequence is monotonic or not and it has one limit point or more than one limit points. I come to know that a similar question was discussed in the following link  But some steps in that solution are not clear to me


SQL Server login error while revalidating the login on the connection

Recently we started seeing the below error in our environment.     Failed to open the database ‘XXXX’ configured in the login object while revalidating the login on the connection.   Any suggestions?


Failed to Login : Invalid session (Try restarting your game) Minecraft Error

When I try to connect to servers or join up on lan worlds in Minecraft it says "Failed to Login : Invalid session (Try restarting your game)". Multiplayer used to work fine but now keeps coming up with this error. Can anybody help?


A proper definition of $i$, the imaginary unit

Back when I was in high school, which was a long time ago, I recall my math teacher telling me that the definition of $i$, the imaginary unit, is $\sqrt{-1}$. Knowing little, at the time, I accepted it without thinking twice.  Several years later when I was in my Complex Analysis class, one of my classmates asked for the distinction between defining $i$ in the normal way, i.e., $i=\sqrt{-1}$, and more ambiguous way, $i^2=-1$.  Now that I thought deeply about it, I have some suspicions about what my high school teacher taught me at the time.  Firstly, at least at the level of high school, one normally defines a square root of $x$, $\sqrt{x}$ as the positive quantity of either number that satisfies the property $\sqrt{x}\sqrt{x}=x$. Clearly, when $x<0$, such notion of sign makes no sense, so one cannot honestly talk about $\sqrt{-1}$ with the naive definition of the square root.  Fine, we are better than that, and we may say that $i$ is the principal root of the equation $x^2=-1$. We then just denote it by $\sqrt{-1}$. But this way of denoting $i$ brings with its convenience a litany of disasters, including the famous $1=-1$ fallacy.  Namely, one can show that $1=-1$ by $1=\sqrt{1}=\sqrt{(-1)(-1)}=\sqrt{-1}\sqrt{-1}=i^2=-1$.  Many a people have pointed out the haphazardness of assuming that the familiar law $\sqrt{x}\sqrt{y}=\sqrt{xy}$ holds when $x,y<0$. But at the same time we have no shame in writing $\sqrt{-5}$ as $\sqrt{5}i$ (in fact, I think this is the very reason of inventing the imaginary unit). Is it not terribly unnatural that the law holds for odd number of negative factors, and not so for the even ones? In fact, is there an example where this native rule (that when you have a negative radicand, you can pretty much apply the familiar laws of exponents)? (I guess it makes the first question.)  Secondly (so this officially marks the second, and the last question), which ought to be the definition of $i$, in your opinion? I believe that many people choose to write $i=\sqrt{-1}$ as it gives some illusion of determinancy, whereas $i^2=-1$ does not. But I still prefer the latter definition, and it seems to be the consensus of every complex analysis textbook that I've ever laid my hands on.  Better yet, I believe that the complex numbers shold be defined as the algebraic completion of reals or an isomorphic field to $\mathbb{R}\times\mathbb{R}$, with some special addition and multiplication rules, but I guess it is a little bit out of high school students' league (at least for most of them).  EDIT: Thank you all for your insightful responds, but there still one thing none of you has yet answered... Is there a conunter example to the law where we have $\sqrt{-A}$ for $A>0$, we have $\sqrt{A}i$?


How is $a_n=(1+1/n)^n$ monotonically increasing and bounded by $3$?

I was reading about how completeness is required for limits. And I came across this:     the sequence $a_n=(1+1/n)^n$ is monotonically increasing and bounded by 3 and so we expect it to converge, but that it does not converge within $\mathbb{Q}$. More generally it stands to reason that any sequence of real numbers which is increasing and bounded must converge to some real number. This is a consequence of completeness of $IR$   My question is: How is the mentioned sequence monotonically increasing and bounded by $3$ ?


Html.TextAreaFor ASP.MET MVC 5 Cursor Position

The code for my TextBoxAreaFor<> text area (for some reason) puts the cursor at the end of the text area and not at the start like a TextBoxFor<> does. How do I get the cursor to be placed at correct position i.e. At beginning of text area?
         @Html.LabelFor(model => model.IncidentDescription, new { @class = "control-label col-md-2" })
             @Html.TextAreaFor(model => model.IncidentDescription, new { @class = "control-label col-md-1" })             @Html.ValidationMessageFor(model => model.IncidentDescription)


I am using Kile to write latex documents. I want to include .svg picture in my document. After including   \usepackage{svg}    and compiling my document into pdf, I have an error:   "File 'svg.sty' not found. \usepackage "   So I downloaded package svg from ftp.tex.ac.uk but I don't know how to install it. I tried to use package manager, but it didn't see this as a package.  Can someone suggest me how can I do that?


Exist strictly increasing $f \colon \omega _1 \mapsto \mathbb{R}$

Does there exist a strictly increasing injective function $f \colon \omega _1 \mapsto \mathbb{R}$, where $\omega _1$ denotes the first uncountable ordinal?


How to integrate $\int \frac{v}{g-kv}dv$

How to integrate $$\int \frac{v}{g-kv}\,\mathrm dv$$ it's supposed to be equal to $$ -\frac{v}{k} -\frac{g}{k^2}\ln(g-kv)$$ but I can't get that, I tried a substitution $u=g-kv$ and got close but no right? Any help.


I tried to draw a  (Lebesgue curve) by using  example for Hilbert curves. But I don't see why it does not work.   \documentclass[12pt]{article}  \usepackage{tikz} \usepackage{ifthen}  \usepackage[position=top,labelformat=empty]{subfig} \usepackage{verbatim}  \newdimen\HilbertLastX \newdimen\HilbertLastY \newcounter{HilbertOrder}  \def\DrawToNext#1#2{%    \advance \HilbertLastX by #1    \advance \HilbertLastY by #2    \pgfpathlineto{\pgfqpoint{\HilbertLastX}{\HilbertLastY}} }  % \Hilbert[right_x,right_y,left_x,left_x,up_x,up_y,down_x,down_y] \def\Hilbert[#1,#2,#3,#4,#5,#6,#7,#8] {   \ifnum\value{HilbertOrder} > 0%      \addtocounter{HilbertOrder}{-1}      \Hilbert[#5,#6,#7,#8,#1,#2,#3,#4]      \Hilbert[#1,#2,#3,#4,#5,#6,#7,#8]      \DrawToNext {#1} {#5}      \Hilbert[#1,#2,#3,#4,#5,#6,#7,#8]      \DrawToNext {#3} {#3}      \Hilbert[#7,#8,#5,#6,#3,#4,#1,#2]      \DrawToNext {#1} {#5}      \addtocounter{HilbertOrder}{1}   \fi }  \def\hilbert((#1,#2),#3){%    \advance \HilbertLastX by #1    \advance \HilbertLastY by #2    \pgfpathmoveto{\pgfqpoint{\HilbertLastX}{\HilbertLastY}}    \setcounter{HilbertOrder}{#3}    \Hilbert[1mm,0mm,-1mm,0mm,0mm,1mm,0mm,-1mm]    \pgfusepath{stroke}% }  \begin{document} \begin{figure}%     \centering     \subfloat[$n=1$]{\tikz[scale=18] \hilbert((0mm,0mm),1);}~~     \subfloat[$n=2$]{\tikz[scale=6] \hilbert((0mm,0mm),2);}~~     \subfloat[$n=3$]{\tikz[scale=2.6] \hilbert((0mm,0mm),3);}~~     \subfloat[$n=4$]{\tikz[scale=1.2] \hilbert((0mm,0mm),4);}~~     \subfloat[$n=5$]{\tikz[scale=0.58] \hilbert((0mm,0mm),5);}% \end{figure}%  \end{document}   I get this result which is obviously wrong:    Any suggestions how to make it work? Thank you!


How open "man node" or other informational command line's output in a text editor?

I'm working with command line and sometime some informational - as manuals readMe and all - output are very large and hard to read in a one shot from the command's line.  I wonder how open it directly on a text editor ?  I have tried gedit man  node  but it does'nt work. If any have some hint, would be gr


So, I have a simple emission texture applied to a particle system and I was wondering, is there a way to make your particle emitter emit a random variety of colors?


Rotate marker symbols individually in QGIS

Is it possible to rotate marker symbols (e.g. a triangle) in QGIS individually with an attribute field like in ArcGIS?  Edit: I would like to rotate each marker symbol individually in category A with an attribute field X, where the angle is defined.  This is how it is done in ArcGIS: "To rotate marker symbols individually based on the value of a field in the point layer's attribute table click Layer Properties dialog box > Symbology tab > Advanced > Rotation. On the Rotate dialog box, the Rotate Points by Angle in this field specifies the field that holds angular values and the Rotation Style controls the origin and direction of rotation" (ESRI Help).


Reputation change counter doesn't take into account deleted downvotes

The network-wide counter on the top displayed the correct +9 value, but the activity page showed 8:


What is a good strategy to deal with lots of engineers turtling on the other team?

Now that the Engineer update has come, there will be lots of Engineers building up everywhere.  How should this best be handled?


how to enable automatic login in windows 8

I have disabled my windows 8 lock screen but i would like to disable logging in altogether so that windows 8 automatically logs me in. If it is possible to disable lock screen, see , then i'm sure there has to be a way of disabling logging in altogether but i don't just know how to. Can anyone help?


My Father bought A new brand Galaxy A71 this year (January) and He passed a way two weeks a go, I had to rest the phone for me to use and the phone is asking for previous email address the one my dad was using I don't Know. how can i bypass this security future called KNOX or should I keep in Dustbin.


I want to replace a white (granulated) sugar in a recipe with brown sugar.  Is this a one to one substitution?    The original recipe calls for 2 cups white sugar.  Can I replace with 2 cups brown sugar?  Packed or unpacked?


Is “It must be him with whom you enjoy doing your assignments, not me” correct?

I’d like all of you to please consider the following sentence:     It must be him with whom you enjoy doing your assignments, not me.   I have known that after 'to be' verb pronouns words take the subjective form. For example:     It is he who was absent yesterday.   So, can I say that the first sentence is erroneous? Would it be correct to write     It must be he with whom you enjoy doing your assignments, not I.


What is an equivalent to instanceof in C++?

How can I check the class type in c++? In Java I used instanceof.  I prefer not to use dynamic cast, but only classic c++. Is there any way?  Clarification: It isn't a duplicate of , since I asked how can I find it without using of dynamic_cast. In the other question, the answer was to use it. Please don't mark it as a duplicated.


Bibliography will not recognize one source

I have an issue with my .bib in LaTeX. I just started using it and can't figure out what's wrong. I am using the site Overleaf to create my documents. Basically, I have a bibliography like so:  @online{1234, author = "Lexikon der Physik", title = "Kompensationsmethode", url = "https://www.spektrum.de/lexikon/physik/kompensationsmethode/8214", addendum = "(Stand: 30.05.2019)", }   @online{anleitung,     author = "Elektrizitätslehre Institut für Angewandte Physik der Goethe-Universität Frankfurt am Main",     title = "Anleitung zu Versuch 5",     url = "http://www.uni-frankfurt.de/49295171/Generic_49295171.pdf",     addendum = "(Stand: 30.05.2019)", }   In total there are 6 sources. My subfile in which I am citing goes somewhat like this:  \subsection{Kompensationsmethode}  blablabla text \cite{1234} \cite{anleitung}. more text   Now, the 1234 one will not be recognized, I have tried naming it differently, moving it to a different position in the .bib file and it just will not find it. Instead it will give me the [1234] instead of the actual citation within the PDF.    The error message is:     I have absolutely no clue why one of my sources is being recognized, and the other one is not. Any help is apreciated.


How to convert this string as date object in Python?

(Python 3.5) I have this string: 2021-05-05T13:13:56+00:00  I want to transform it to date object to perform latter actions on it. I've tried the following: d= "2021-05-05T13:13:56+00:00" dt = datetime.strptime(d, '%Y-%m-%dT%H:%M:%S')  Which trows, as expected:  ValueError: unconverted data remains: +00:00  I do not know what are exactly these elements and, refering to , I do not find what it could refer to. How to convert this string as a date object ?


Can't copy to clipboard using Javascript

I'm trying to copy to clipboard a link ( the current link of the page ) using JS, but the console tells me that toCopy.select is not a function, why's that ? Here's the code :  HTML/PHP  <img src="<?php echo get_stylesheet_directory_uri(); ?>/img/icons/link.png" alt="link">      <textarea id="to-copy" style="display: none;"><?php echo $current_url; ?></textarea>   JS   var toCopy = document.getElementById('to-copy'),     btnCopy = document.getElementById('copy');  btnCopy.addEventListener('click', function () {     toCopy.select();     document.execCommand('copy');     return false; });   Can anyone tell me why ? Thanks !


How to update a column with another tables columns value?

I have two tables "basket_products" and "products". I want to update "products" table's "adet" column with "basket_products" "adet" column. And i want to update rows where basket_products.urun = products.urun. I want to use this code and getting error : "The multi-part identifier "basket_products.urun" could not be bound."  update products     set adet = adet - (         select basket_products.adet             from basket_products                 inner join products                on products.urun = basket_products.urun)     where products.urun = basket_products.urun   What's wrong?


Missing vtable: should virtual function be redeclared in header file?

I am getting error NOTE: a missing vtable usually means the first non-inline virtual member function has no definition. "vtable for Algorithm2A". I suppose the problem in my base class I declared the function as pure virtual, and then in the header .h of derived class I redeclared it, in order to be able to implement it in the implementation file .cpp.   IAlgorithm2.h -- that is my abstract class  #include "IAlgorithm1.h"  //! Algorithm2 interface class IAlgorithm2 {  public:      ~IAlgorithm2() {     }      virtual std::vector<int> calculateLCP(std::string BWT)=0; };   Now, I have the implementation of this in Algorithm2.h, andAlgorithm2.cpp.  Algorithm2A.hpp  class Algorithm2A : public IAlgorithm2 {  protected:     IAlgorithm1 &algorithm1;      std::vector<Interval> getIntervals(int i, int j) {         return algorithm1.getIntervals(i, j);     }  public:     Algorithm2A(IAlgorithm1 &a) : algorithm1(a) {     }      std::vector<int> calculateLCP(std::string BWT); };   Algorithm2A.cpp  #include "Algorithm2A.hpp"   std::vector<int> Algorithm2A::calculateLCP(std::string BWT) {     // implementation of this }   How should this be done? If I remove the definition from the Algorithm2A.h that it won't compile, and if I leave it there, than there is a vtable problem.  edit: this is not a matter of templates  IAlgorithm1.h  //! Algorithm1 interface class IAlgorithm1 {  protected:     virtual std::string uniqueCharsInInterval(int i, int j)=0;   public:      ~IAlgorithm1() {     }      virtual std::vector<Interval> getIntervals(int i, int j)=0; };  #endif /* Algorithm1_h */   Algorithm1A.h  #include "IAlgorithm1.h"  class Algorithm1A : public IAlgorithm1 {  protected:     IRank &rank;     OrderedAlphabet &alphabet;     std::map<symbol_type, occurence_type> &C;     std::string &BWT;  public:         Algorithm1A(IRank &r,                    OrderedAlphabet &a,                    std::map<symbol_type, occurence_type> &c,                    std::string &bwt):                    rank(r), alphabet(a), C(c), BWT(bwt) {         }  std::string uniqueCharsInInterval(int i, int j);   There is also an implementation file Algorithm1A.cpp


Why couldn’t Newt use ‘Accio’ to retrieve all his beasts? ‘Accio’ only works on inanimate objects. While people or creatures may be indirectly moved by ‘Accio-ing’ objects that they are wearing or holding, this carries all kinds of risks because of the likelihood of injury to the person or beast attached to an object travelling at close to the speed of light.   It says that Accio-ed objects travel at close to the speed of light. Why do such objects not wipe out mankind from the face of the Earth ()? I know that electricity doesn't work well near magic, but it can't explain the above scenario.


How does Windows 7 determine that a system was not shut down correctly (Kernel-Power Event ID 41)

I have a strange situation that Windows 7 thinks it was not shut down correctly, and gives me a warning in the system event log like this:    What the KB-article does not tell is how Windows actually determines that situation. Does it parse its own system event log after reboot? Or where does it get that information from?  I am currently investigating an issue where I believe the system fails to write the system event log correctly (it stops having entries, although other logs like the application event log still have entries), and after a reboot, Windows thinks it has not been shut down correctly.  Does anybody have any experience with this? And can you confirm that Windows determines the previous correct system shutdown by parsing its own system event log on start-up?


Deleting your own closed questions fails silently on the mobile site

There is some sort of delay for deletion of your own closed questions (2 days, I think) for non-mods. Now, when you try deleting a closed question on the desktop site, it nicely tells you "please wait xyz to allow for possible reopening" (in a box similar to the "please consider adding a comment explaining why you downvoted" thingy).  On mobile, it just reloads the page—there is no indicator that deletion is not allowed.  Either completely disable the delete button on mobile for closed questions, or give it a popup as well. Not letting the user know what's wrong is confusing.


It is generally courtesy to use the plural 'we' or 'our' in papers, even when the primary author was the only contributor. While using personal pronouns in academic papers is typically a very bad idea, I have seen them being used in theses. What gives? Technically a PhD thesis is only meant to be the candidate's work, but if this work features previously published work surely you'd expect to same rules to apply to the thesis as applied to the academic papers?  So in terms of professional appearance and etiquette what is the (typically) correct approach? Should personal pronouns be used in a thesis?


Prove that for all acute triangles $\triangle ABC$, $r_a + r_b + r_c \ge m_a + m_b + m_c$.

Let $r_b$ and $m_b$ respectively be the exradius of the excircle opposite $B$ and the median drawn from the midpoint of side $CA$ of acute triangles $\triangle ABC$. Prove that $$\large r_a + r_b + r_c \ge m_a + m_b + m_c$$   We have that $$[ABC] = \sqrt{\frac{r_a + r_b + r_c}{2} \cdot \prod_{cyc}\frac{r_a - r_b + r_c}{2}} = \frac{4}{3}\sqrt{\frac{m_a + m_b + m_c}{2} \cdot \prod_{cyc}\frac{m_a - m_b + m_c}{2}}$$  Let $r_a - r_b + r_c = r_b'$, $m_a - m_b + m_c = m_b'$ and so on, we have that $$\sum_{cyc}r_b' \cdot \prod_{cyc}r_b' \ge \frac{16}{9} \cdot \sum_{cyc}m_b' \cdot \prod_{cyc}m_b'$$  In order to prove that $r_a + r_b + r_c \ge m_a + m_b + m_c$, which could be rewritten as $$r_a' + r_b' + r_c' \ge m_a' + m_b' + m_c'$$, we need to prove that $r_a' \cdot r_b' \cdot r_c' \le \dfrac{16}{9} \cdot m_a' \cdot m_b' \cdot m_c'$.  You could do that preferentially... or let $p - a = a'$, $p - b = b'$, $p - c = c'$, we need to prove that $$\sqrt{(a' + b' + c') \cdot (a'b'c')} \cdot \left(\frac{1}{a'} + \frac{1}{b'} + \frac{1}{c'}\right)\ge \sum_{cyc}\sqrt{b'(a' + b' + c') + \frac{(c' - a')^2}{4}}$$  $\left(p = \dfrac{a + b + c}{2}\right)$ in which I don't know what to do next.


What are the default placement options for a floating figure in Latex?

The document  talks about the different ways to affect where a floating figure is placed [htbp]. But these arguments are optional ...  So how is the float placed if I don't enter any options? Is not entering any options equal to [htbp] or some other combination of placement demands? If so which?


Which one is the faster and will I get all the features of Ubuntu on them? I've done a little homework too on it, I think xfce will be the better option. My pc specs aren't good enough to handle Unity, as it hangs very often.


When does $V = \ker(f) \oplus \operatorname{im}(f)$?

For a vector space $V$ and a linear operator $f : V \to V$, under what conditions does $V = \ker(f) \oplus \operatorname{im}(f)$?  Is it always true, or only in special cases?  Edit: $V$ is finite dimensional.


I’m having a pool put in and the pool guys said they need a 20 amp breaker for the pool equipment. My outside panel says 100 amps (see picture). But my panel inside adds up well over 100 amps. Is this normal?  The breakers never trip even with the dryer, AC, and other appliances running.


I'd like to create an "answer blank" in a document.  It should basically look like an underline with nothing above it.  I found a question about it (  ), but that doesn't deal with the main problem I'm having, which is that I want the blank to wrap normally to the text width.  The solutions using \hspace or \rule cause the line to extend into the margin.  I'm looking for something that wraps just like normal text and so won't extend into the margin.  It should be an underlined blank that has a specified length, but that length might be wrapped across multiple lines in the output document.