Parameter on $\mathrm{SU}(4)$ and $\mathrm{SU}(2)$

From my reading, $\mathrm{SU}(4)$ has 15 parameters and $\mathrm{SU}(2)$ has 3 paramaters that range differently with certain parameter (rotation angle). And all the parameter is linearly independent to each other.  My question are:   What the characteristic of each of the parameter?   If I choose two of them, what is the reason behind  the theory?   Can anyone explain to me or suggest any book/paper to me to understand the parameter itself.


NullPointerException from random index for populated array list?

I am trying to pull a random string from an ArrayList. I make sure to populate it before pulling from it yet it still acts as if it empty. I even printed the list out after populating it and it is indeed populated, leaving me to believe the problem must be elsewhere in my code. Any ideas?  Oh, and yes, my code is hilarious. I'm creating a console game for fun about a gross dude who works in my office. (Might as well make practice fun, right?) Enjoy. :P  here is the object class  import java.util.ArrayList; import java.util.Random;  public class Meg {      private String name = "Meg";     private int weight = 300;     private int annoyanceLevel = 1000;      static ArrayList<String> randomBoringTopics = new ArrayList<String>();      public static void populateRandomBoringTopics(){     randomBoringTopics.add("women's underwear");     randomBoringTopics.add("men with backhair");     randomBoringTopics.add("tucked in shirts");     randomBoringTopics.add("shaving at one's desk");     randomBoringTopics.add("pot bellies");     }      public void Fart(){         System.out.println("Meg let's out a huge fart with zero consideration for who hears it");     }      public static void startBoringConversation(){         Random randomGenerator = null;         int index = randomGenerator.nextInt(randomBoringTopics.size());         String randomBoringTopic = randomBoringTopics.get(index);         System.out.println("Meg begins to talk to you about his thoughts regarding " + randomBoringTopic);       }      public void creep(){     System.out.println("Meg suddenly appears behind you, breathing heavily and rubbing his stomach while fingering his belly button");       }      public void interject(){     System.out.print("Meg hears you talking and butts into your conversation, making it instantly boring");      }      public void disappear(){     System.out.print("Meg leaves his desk and is gone for an extended period of time, relieving those in his row but "     + "tormenting the rest of the office");     }      public String getName() {         return name;     }      public void setName(String name) {         this.name = name;     }      public int getWeight() {         return weight;     }      public void setWeight(int weight) {         this.weight = weight;     }      public int getAnnoyanceLevel() {         return annoyanceLevel;     }      public void setAnnoyanceLevel(int annoyanceLevel) {         this.annoyanceLevel = annoyanceLevel;     }  }   And here is my main...  public class Main {      public static void main(String args[]){          Meg.populateRandomBoringTopics();         Meg.startBoringConversation();     } }


I have two EXACT same uvc unity cameras that have no serial number so I have abandoned mounting them via some unique attribute. Instead I specifically looking to mount it via the usb port I have plugged them into   Camera 1 PLUGS ONLY INTO USB Port 1 Camera 2 PLUGS ONLY INTO USB Port 2   I wrote the udev rule like so  SUBSYSTEM=="usb", KERNELS=="2-2.2", ATTR{idVendor}=="0000", ATTR{idProduct}=="0001", NAME="video0", MODE="0666", SYMLINK+="video0" SUBSYSTEM=="usb", KERNELS=="2-2.3", ATTR{idVendor}=="0000", ATTR{idProduct}=="0001", NAME="video1", MODE="0666", SYMLINK+="video1"   However, this still does not work they get crossed it only depends on which device gets recognized first


If gcd(a,b) = gcd(a,y) = gcd(b,x) = 1, then show that gcd(ax + by, ab) = 1.

I started with bezout's theorem and assumed gcd(ax+by,ab) = d. From this I proved that d divides $a^(2)x$ & also $b^(2)y$. I intend to prove that d divides both a & b, which would be sufficient. If there's any alternative solution, please do suggest.


What does this heart icon mean on my status bar?


Square root of inverse gamma distribution?

I asked this question on mathoverflow yesterday and got a suggestion to try it here. I apologize if this is an easy question, but I can't seem to find an answer anywhere.  I'm trying to duplicate a macroeconomic paper that uses MCMC analysis to derive time series and parameter values. For the variance of a white noise term the authors of the original paper choose an inverse gamma prior of mean 0.5 and having a 90% confidence interval between 0.21 and 0.79.  I'm using Dynare to run my estimation and Dynare only accepts these kinds of parameters in terms of standard error. Therefore, my question basically amounts to "how do I find the square root of an inverse gamma distribution"?  In case it's not clear what I'm asking, here's how the model equation appears in the paper:  $a_t=\rho_a\times{a_{t-1}}+\epsilon_a;\hspace{20 pt}\epsilon_a\sim{N}(0,\sigma_a)$   $a_t$ follows a simple AR(1) process and $\epsilon_a$ is meant to be white noise with mean 0 and variance $\sigma_a$. The prior for $\sigma_a$ is supposed to follow an inverse gamma distribution with the mean and confidence interval above. My question then is how can I find the "square root of the distribution" so I can write an expression for the standard error of $\epsilon_a$, instead of its variance?  If it's not possible to come up with a simple expression for this, would you have any suggestions for roughly equivalent specifications of the prior?  Thanks in advance


What I had already performed are:  sudo /etc/init.d/mysql stop /usr/sbin/mysqld --skip-grant-tables --skip-networking &    After this I am getting:  [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release.   Please use the full name instead.  150929 11:48:31[Note] /usr/sbin/mysqld (mysqld ....)starting as process 3633 ...   And its not processed further.  What to do?


I'm making a presentation using the beamer, and some slides contains some details which can be shown using a click-on button to a slide which will be in the appendix. I want this slide to be shown only when I click on that button.    Is it possible to hide the appendix from the presentation slides but keeping the ability to click on that button and show the wanted slide.  As an example:  (I want the slide named by "More Details" to be hidden from the presentation pdf file)  \documentclass{beamer} \usetheme{Boadilla}  \begin{document} \begin{frame}[label=slide1]    text1     show more details   \hyperlink{more-details}{\beamerbutton{show more details}}  \end{frame}  \begin{frame}    text2 \end{frame}  \begin{frame}    text3 \end{frame}  %%%%%%%%%%%%%%%  \appendix       \begin{frame}[label=more-details,noframenumbering]{More Details}  Details  \hyperlink{slide1}{\beamerbutton{Back}} \end{frame}  \end{document}


The installation window don't show a root file system for choose in the installation of Ubuntu, the manual didn't help me

First of all, I have a new laptop Acer Aspire A315-53-386P with Windows 10. I was starting to install Ubuntu in the computer and then    I didn't understand the problem, so I investigated and I erased the secure boot and nothing. I want to erase Windows and install Ubuntu.  I read many sites, included , but they didn't helped me, all of them say me about a step 4, but my step 4 is this:    You must know that I am some beginner so really, any idea is useful.


I am trying to flash 4.4.3 to my Nexus 5.  When I enter this   cd desktop/android   I get this:  bash: cd: desktop/android: No such file or directory   I am looking right at the folder on my desktop named android. I tried the same command with other folders and I get the same error. Can anyone tell me why or what I am doing wrong?   Also, here is .


How to check if the value of the String passed as parameter of a function is null or not?

Why am I getting this "java.lang.String cannot be converted in Boolean" error when I have already declared a string with same value in the main function just below it?   I tried keeping it to null but I get the same error message.  1.public class test 2.    { 3.        public static String n(String t) 4.        { 5.            if(t = "") 6.            { 7.                 8.                return(t);             9.            } 10.        }  11.         12.        public static void main(String[] args) 13.        { 14.            String lan = ""; 15.            System.out.println(lan); 16.        } 17.    }  Error: line 5 "incompatible types: java.lang.String cannot be converted to boolean."


How to random every number we assign into a 2D Arrays in java?

I am trying to assign numbers randomly. I understand that Math.random() only goes between 0 and 1, and tried to multiply it by 10, and it still does not show any random numbers:   0 0 0 0 0  0 0 0 0 0  0 0 0 0 0  0 0 0 0 0  0 0 0 0 0   the code:  public static void main(String[] args) {      int[][] mdArray = new int[5][5];      for(int i = 0; i<mdArray.length; i++){         for(int j = 0; j<mdArray[i].length; j++) {             mdArray[i][j] = (int)Math.random()*10;             System.out.print(mdArray[i][j] + " ");         }         System.out.println("");     } }


How to watch on tablet a movie stored on PC?

I have a movie stored on PC harddrive. I have an andriod tablet. How to watch that movie, but on a tablet? How to stream it? Its a windows 10 PC, and its configured for sharing but I dont know how the tablet can find the shared folders and click and play the movie. Kodi works, but Im looking for something simple, as Im not building an entertainment library, just a way to instantiously switch from PC to tablet.   edit: sounds straighforward, but for some reason cant find the answer to this. None of the apps I tried work to achieve this.


How Do I load data from a CSV file to a table using java?

I have a File called Customer_Info.csv which has sample data like :  CUST_ID FIRST_NAME  LAST_NAME   USER_TYPE   REPORTS_TO_ID   EMAIL   FIRST_TIME_LOGGED_IN    FIRST_TIME_LOGIN_DATE   ADDRESS_LINE1   ADDRESS_LINE2   CITY    STATE   ZIP  10001   MICHELLE    VILLEGAS3   Savings SRINATH MICHELLE.VILLEGAS3@NOBODY.COM   Y   07-10-18    1050 WEST FIFTH STREET      AZUSA   IND 917023308  This is the table in which i need to store the data. I am storing everything in string format because it is just a staging table.  Create Table Customer_Info_ST  (  Cust_ID varchar(5),  First_Name varchar(15),  Last_Name varchar(15),  User_Type varchar(10),  Report_To_Id varchar(10),  Email varchar(30),  First_Time_Logged_In varchar(1),  First_Time_Login_Date varchar(11),  Address_Line1 varchar(30),  Address_Line2 varchar(30),  City varchar(15),  State varchar(3),  Zip varchar(12)  );   I have written the following code to store it in the table.  public class CustInfoDataLoader {  static String sql, tableName; private static PreparedStatement pstmt; private static Statement stmt; private static final String filePath = "Customer_Info.csv";  public static void main(String[] args) throws SQLException, FileNotFoundException, IOException, ParseException {      readCsv("Customer_info_ST"); //Line 24 in my code      //readCsvUsingLoad(); }  private static void readCsv(String tableName) throws FileNotFoundException, IOException, SQLException, ParseException {     CSVReader csvreader = null;      try{         Reader reader = Files.newBufferedReader(Paths.get(filePath));         csvreader = new CSVReaderBuilder(reader).withSkipLines(1).build();         sql = "insert into ? values (?,?,?,?,?,?,?,?,?,?,?,?,?)";         ManageDBResource.createConnectionToDB();         pstmt = ManageDBResource.conn.prepareStatement(sql);           String[] rowData = null;          while((rowData = csvreader.readNext()) != null) {              pstmt.setString(1, tableName);             int i = 2;             String state = rowData[11];             for (String data : rowData) {                  if(i == 9 && data != null && state != "IND") {                     java.text.SimpleDateFormat source = new java.text.SimpleDateFormat("MM-dd-yyyy");                     java.util.Date date = source.parse(data);                     java.text.SimpleDateFormat target = new java.text.SimpleDateFormat("yyyy-MM-dd");                     data = target.format(date).toString();                 }                 pstmt.setString(i++,data);                 //System.out.print(data + " ");             }             int result = pstmt.executeUpdate();             //System.out.println();             if(result == 1) {                 System.out.println("Data loaded Successfully.");              }         }     }     catch (Exception e) {         System.out.println(e.getMessage());     }     finally {         pstmt.close();   //Line 69 in my code file         csvreader.close();     }  }   and I get the following error:  Exception in thread "main" java.lang.NullPointerException at CustInfoDataLoader.readCsv(CustInfoDataLoader.java:69) at CustInfoDataLoader.main(CustInfoDataLoader.java:24)


$ \exists a, b \in \mathbb{Z} $ such that $ a^2 + b^2 = 5^k $

I saw this problem recently and found an elegant solution to it, and was curious to see if anybody would think of something else. Nice solutions to nice problems are fun to see!  Problem: Prove that, for all non-negative integers $k$, there exist integers $a$, $b$ such that $a^2+b^2=5^k$. Bonus: Prove that there exist such $a$ and $b$ that furthermore satisfy $(a,b)=1$.


Ubuntu is awesome fun amazing innovative and many other things.  but I hate that it does not support itunes or shareit. How can I run iTunes or shareit? What would happen if I downloaded the software from their web sites?


What is the volatile keyword useful for?

At work today, I came across the volatile keyword in Java. Not being very familiar with it, I found . Given the detail in which that article explains the keyword in question, do you ever use it or could you ever see a case in which you could use this keyword in the correct manner?


It is given that a certain matrix A has eigenvalue 1 repeated thrice, eigenvalue 2 repeated twice, and eigenvalue 3 with no repeats. What are the possible geometric multiplicity for these eigenvalues. Write down the possible Jordan forms of A.  My try : The characteristic equation is (l-1)^3*(l-2)^2*(l-3) . We have to find out the ordinary eigen vectors & corrosponding generalised eigen vectors to check theor geometric multiplicity . Further we will be able to write the possible jordan forms by placing 1's in the super diagonal .   But how to find the A matrix ?


IF statement never executes inside a method

I have a class named Player. There are a few player objects stored inside this class and every object has a "name", "score" and "color". I made a method that is supposed to set a TextView color according to which object I am dealing with. Here's the code:  public void setTextViewColor(TextView tw, String playerColor){      Log.i("TAG", playerColor);      if (playerColor == "BLACK")     {         tw.setTextColor(Color.BLACK);         Log.i("TAG", "tw color now black");     }     else if (playerColor == "BLUE")     {         tw.setTextColor(Color.BLUE);         Log.i("TAG", "tw color now blue");     }     else if (playerColor == "CYAN")     {         tw.setTextColor(Color.CYAN);     }     else if (playerColor == "DKGRAY")     {         tw.setTextColor(Color.DKGRAY);     }     else if (playerColor == "GRAY")     {         tw.setTextColor(Color.GRAY);     }     else if (playerColor == "GREEN")     {         tw.setTextColor(Color.GREEN);     }     else if (playerColor == "LTGRAY")     {         tw.setTextColor(Color.LTGRAY);     }     else if (playerColor == "MAGENTA")     {         tw.setTextColor(Color.MAGENTA);     }     else if (playerColor == "RED")     {         tw.setTextColor(Color.RED);     }     else if (playerColor == "YELLOW")     {         tw.setTextColor(Color.YELLOW);     } }   Now the problem is that the IF or ELSE statement never gets to execute. This is how I called the method:  setTextViewColor(newTextView, newPlayer.color);   The method is supposed to work because everytime I execute it, I can see the logcat message stating the color (the color is always correct). But I never see the "tw color now black" or "tw color now blue" message so I'm pretty sure there is something wrong with IF statement.  If the tag says the playerColor is "BLACK", then the first if statement is supposed to execute, right? But it doesn't.


Why does this Largest Prime Factor of a given number in python algorithm work?

I am unable to understand the following block of code which I came across this site itself. It creates a function to find out the largest prime factor of a given number. It is given below:  def prime_factors(n): """Returns all the prime factors of a positive integer""" factors = [] d = 2 while n > 1:     while n % d == 0:         factors.append(d)         n /= d     d = d + 1  return factors pfs = prime_factors(1000) largest_prime_factor = max(pfs) # The largest element in the prime    My doubt is that the function prime_factors(n) would return the factors of n and not the prime factors, since the while loop is only checking if d is a factor of n and not if it is also a prime as it should be.  Please point out if I'm wrong and also the reasoning behind your logic. Furthermore, if I'm correct, then kindly provide a suitable block of code and the logic behind it in simple terms. Try to keep the code as simple as possible.


Question banning should work differently on Meta

just wanted to report a problem with Data Explorer and realized I was banned from asking questions on meta. Probably because I .  Reading through the :   to prevent help vampires users who can't be bothered to form sentences users who don't do the most basic kinds of research themselves users who barely even explain what it is they are trying to do etc., etc. …   Nothing of this applies to my case. Here on meta, , so I think this should be reflected in the policy for question banning.


Can spray paint or a marker block UV for solder mask/resist?

I am planning to make a PCB and putting solder mask on it but I don't have my own laser printer to print the transparency for the mask. I do, however, live near a printing shop with a laser printer who can print glossy/photo paper but not transparencies. So I am thinking if I can use spray paint or a marker to "draw" on empty transparencies by using a soldering paste stencil as a guide. I have seen  question being answered but its not what I'm looking for. So will spray paint or a marker block UV for solder mask/resist so that the pads won't dry?


How many bits of hash are realistically needed for key verification?

Say I'm connecting to a web server secured with TLS but with a self-signed certificate. Accordingly, I call the owners of the server and ask them what SHA1 fingerprint they have.  They start reading out the hex digits to me and I follow along, but before reaching the end, I just say "That's fine thanks, no need to read the rest." as I click the OK button.  How far along is the point where its reasonable to stop checking and still remain practically secure?


Different definitions of trigonometric functions

In school, we learn that sin is "opposite over hypotenuse" and cos is "adjacent over hypotenuse".  Later on, we learn the power series definitions of sin and cos.  How can one prove that these two definitions are equivalent?


In the iOS Mail app, there are 4 emails in the "All Inboxes" section. Those 4 emails are NOT in the actual inbox on Gmail.  I thought, oh well I don't mind deleting them entirely since they're just newsletters. I deleted them directly on gmail, but they still appeared in iOS. So I tried deleting them via iOS and ... they keep coming back!  Even stranger, the 4 emails ONLY appear in "All Inboxes", they don't appear in any of the sub-account inboxes.  So, I disabled "Mail" in my gmail account. They're still here! I no longer have a "gmail" sub-account, but those 4 emails are still in All Inboxes. I tried to quit the app a few times, restart the phone. Still here...  When I tap on one of those messages, I get a black screen (dark mode), no errors.


I have two component. 1 notification and another is chat. Whenever there is new notification, I need to update icon as well.   I read that only title class will let you change title, which is outside application.  I wanted to know if someone knows how to change favicon in angular2 without using jQuery or other third party libraries.     [Note] The reason I don't want to use third party library is, that we are upgrading our application from angular1 to angular2 and we already have libraries which is 2mb after compiling and optimizing, before optimization it is 8mb (ya, very bad!), anyway we can't afford to add another third party library.


Difference between pointer to data type and data member

I am learning C and I have difficulty in understanding difference between two statements which are pointers  double **X;   and   double** X;   Are both same?  Also one more question.  When do we actually get a situtation to use pointer to a pointer like above **X


There are some situations where tag synonyms make perfect sense the way they currently are. In SF&F, the "lotr" tag is a synonym for "lord-of-the-rings". As we all know, LOTR is just an abbreviation for Lord of the Rings.  There are certain scenarios where tags are related, but not necessarily the same. The Hobbit (the-hobbit) and Lord of the Rings (lotr) are similar subjects since they have the same author, and contain some of the same elements such as plot, setting, and characters. Yet, these are two distinct subjects with their own tag.   If the question is specific to The Hobbit, then it should not have a "lotr" tag. because of this, it creates two "islands of data" when dealing with tags. These two subjects are tied together by author J.R.R. Tolkien, but they don't always carry the "tolkien" tag.  My request would be to create a tagging "class" system where adding a tag would implicitly reference another tag if the tag is a subset of the same subject. For example a question with the tag "the-hobbit" should implicitly also have the "tokien" tag. Subscribing to "tolkien" would then automatically include posts for The Hobbit, Lord of the Rings, The Silmarillion, and his other works. Of course, if you only want to subscribe to "lotr", you would still have that option.


Horizontal shaded frametitle in the CambridgeUS theme

I would like to modify (as simply as possible) the frametitle color of my frames but without changing anything else : I currently use the theme CambridgeUS and basically I would like to modify my frametitle color as it is in the Warsaw theme. I join you my current code and images to show you what I exactly want.  Wrong color but good theme :      \documentclass{beamer}      \usepackage[latin1]{inputenc}     \usepackage[T1]{fontenc}     \usepackage[francais]{babel}      \definecolor{rougefonce}{RGB}{180,1,1}     \definecolor{bleufonce}{RGB}{30,1,135}     \definecolor{vertfonce}{RGB}{0,90,0}     \definecolor{bleuleger}{RGB}{220,220,235}     \definecolor{rougeleger}{RGB}{235,220,220}     \definecolor{vertleger}{RGB}{220,235,220}     \definecolor{bleutitre}{RGB}{0,0,80}     \definecolor{bleuroi}{RGB}{0,0,180}      \usetheme{CambridgeUS}     \usecolortheme{whale}      \setbeamercolor{frametitle}{fg=white, bg = bleutitre}     \setbeamercolor{author in head/foot}{bg = black, fg = white}     \setbeamercolor{title in head/foot}{bg = bleufonce, fg = white}     \setbeamercolor{date in head/foot}{bg = bleuroi, fg = white}     \setbeamercolor{section in head/foot}{bg = black, fg = white}      \usefonttheme[onlymath]{serif}     \title{Test with wrong color}     \author{Bob}     \date{\today}     \institute{}      \begin{document}     \section{Test}     \begin{frame}{Wrong color}     \maketitle     \end{frame}        \end{document}     Right color but wrong theme :      \documentclass{beamer}      \usepackage[latin1]{inputenc}     \usepackage[T1]{fontenc}     \usepackage[francais]{babel}      \usetheme{Warsaw}     \usefonttheme[onlymath]{serif}     \title{Test with right color}     \author{Bob}     \date{}     \institute{}      \begin{document}     \section{Test}     \begin{frame}{Right color}     \maketitle     \end{frame}      \end{document}


Can we tell the difference types of recession?

Because of the the Hubble red shift pattern, Cosmologist generally assume that space is expanding. They assume this is a fact because of the observed redshifts and GR says it can be so. But how can we tell the difference between two objects receding from:   sitting "stationary" in expanding space, or moving apart through space?


Confused about the definition of holonomic constraints

I'm reading Goldstein's Classical Mechanics and he defines a constraint on particles having radii $\mathbf{r}_i$ to be holonomic if it can be written as $f(\mathbf{r}_1, \mathbf{r}_2, \dots , t) = 0$. He then says that an example of a non-holonomic constraint would be particles constrained to the exterior of a sphere: $r^2 - a^2 \ge 0$.  However, this could be rewritten as $\mathbf{1}_{\left\{\mathbf{r}\mid \:|r|^2 < a^2\right\}}(\mathbf{r}) = 0$, where $\mathbf{1}$ denotes an indicator function. As such it seems to me that the given example is a holonomic constraint. What am I missing?


"Since", "until", "from", "to" on invoices or date ranges of a form

Which is the correct form on an invoice, or a general date range in a form, and why?  Monkey dolls                        12 GBP From 2012-01-03 to 2013-01-02  Monkey dolls                        12 GBP Since 2012-01-03 until 2013-01-02   Form format (dates can be modified with a datepicker):  Since: 2012-01-03 until: 2013-01-02   Since+until makes sense and sounds ok to me, yet I know I can be very wrong, at least when it comes to the common usage in the UK and/or US, since English is not my first language.  I am interested in both British and American English.  Until now I've been using since+until, yet some articles explicitly say they may not ever be used together, while some people and some other articles get deep into grammar rules which I can't really apply on the context of invoices and forms.  Here's a recent article saying since and until can never be used together (last paragraph):   Edit: The date range can start in the past or in the future, and can end in the past or in the future. However, at the time of issuing an invoice or rendering a form, you cannot know when the document will be read or how the form will be filled.


The hydrogen is one proton and the helium is two protons and two neutrons. Neutron is a little heavier than the proton. But there is something strange. Where is the mass defection? As a result, the helium should be heavier than the sum of four protons, but it is not. So I guess the reason for binding energy. But I can't understand. In the picture, the helium's binding energy is bigger than hydrogen's. And particle's mass ( 4 protons < 2 protons and 2 neutrons) and binding energy (hydrogen < helium) Through the E=mc^2, isn't right the helium's mass bigger than the sum of 4 hydrogens?


I am trying to mount some of my hard drive and USB but getting this error  Error mounting: mount exited with exit code 1: helper failed with: mount: only root can mount /dev/sdd1 on /media/sdd1   how can I fix this?  There is no drive by the name of /dev/sdd1 and no /media/sdd1 cause when I try to unmount/detach it I get:  root@sysadmin-MS-7592:/home/sysadmin# udisks --unmount /dev/sdd1 Unmount failed: Device is not mounted  root@sysadmin-MS-7592:/home/sysadmin# udisks --detach /dev/sdd1 Detach failed: Device is not a drive


How many syllables are in the word 'hour'?

Does the word 'hour' have 1 or 2 syllables?


Who changes the foreground process group of a terminal?

Let's say I have opened a terminal window that uses bash. The process group that bash belongs to is the foreground process group of the terminal.  Now let's say I opened cat in the terminal, what will happen is that a new process group will be created and cat will belong to this process group, and this process group will now become the foreground process group of the terminal.  When cat terminates and execution returns to bash, the process group that bash belongs to will again becomes the foreground process group of the terminal.  My question is: how did the foreground process group of the terminal changed in these two times, who changed it?


how to find the sum $\sum_{k=1}^n \frac{k}{(k+1)!}$

I need to find sum of $$\sum_{k=1}^n \frac{k}{(k+1)!}$$ using sums of differences I tried to add something to find it , tried to find some differences that would help. But I hadn't result. I know that it would be very easy. But I'm new studying sums.


How to convert the time now into a custom data format?

I am using an API, and the API needs this data format:  Wed Jan 07 2015 18:58:40   How I can convert the time now to this data format, using the datetime and time modules?


What's the difference between a Long Term Support Release and a Normal Release?

What are the differences between an Ubuntu Long Term Support release (LTS) and a normal release?


How can I download Mac OS X El Capitan without app store?

I was going to install a new copy of El Capitan via my USB drive, but it turns out it's dead, it's been corrupted. I erased everything before that, so I'm stuck with the installation screen.  How can I download a new copy of El Capitan? As you know, Safari comes preinstalled. I also have a Windows computer, so I'm open to suggestions.  Here's my Macbook Air Model: MacBook Air "Core i5" 1.4 13" (Early 2014)


Particular solution of $y''-4y'+5y = 4e^{2x} (\sin x)$

How do I find the particular solution of this second order inhomogenous differential equation? (Using undetermined coefficients).  $y''-4y'+5y = 4e^{2x} (\sin x)$  I can find the generel homogenous solutions but I need help for the particular.


I am making a game in Unity 5 in C# and I need to make the terrain infinite. I have tried to make it infinite but it just keeps spawning the terrain too much times and then the game crashes. Does someone know how I can make the terrain infinite? Here is my  code.  using System.Collections; using System.Collections.Generic; using UnityEngine;  public class TerrainScript : MonoBehaviour {     public Transform PlayerTransform;     private float SpawnZ = 4139f;     public GameObject[] prefabs;     private float RoadLength = 2.2f;     private int amountRoads = 6;     private List<GameObject> roadList;      public void Start()     {         roadList = new List<GameObject>();     }     public void Update()     {         if(PlayerTransform.position.z > (SpawnZ - amountRoads * RoadLength))         {             spawnTile(0);         }     }      public void spawnTile(int index)     {         GameObject go;         go = Instantiate(prefabs[index]) as GameObject;         go.transform.SetParent(transform);         go.transform.position = Vector3.forward * SpawnZ;         SpawnZ += RoadLength;     } }


Does anyone know where Firefox is keeping the details about the bookmarks? For example, when I'm browsing the net and I see an interesting page but I don't have time to read it in that moment, I drag&drop it in bookmarks toolbar.  How does Firefox know which those pages are? I'm not talking about right_click->properties. I wish to know where on my HDD those links are kept.   TY


I'm here because I'm trying to create a GTA V map with Leafletjs API. In deed, I've got my tiles that are ready. But the aim is to put markers on the map by using GTA V in-game coordinates. To achieve it, I need to convert the coordinates to LatLong but after many researches, I can't find a solution.  At Stackoverflow, they advise me to ask my question here.  For now, I have a simple function that help me to try to "calibrate" my coordinates :  function GTAVConverter(x,y) {     var ex = 0.01255;     var ey = -0.01260;      var x = ex * x;     var y = ey * y;      var x = x - 486.97;     var y = y + 408.9;      return map.containerPointToLatLng(new L.Point(x+1440.45,y+127.45)); }   But I think there is a better way to achieve my aim. This function isn't really accurate, and if the browser window is resized, all the coordinates are moved.  Example that I want to convert :    I know that Leaflet API has a coordinates system but I don't know how it works.


How can I remap my mouse buttons in Ubuntu 16.04?

My touchpad recently went out and I need to remap my mouse to function how I want it to. In windows, I use X-Mouse Button Control which works perfectly. Is there a similar program for Ubuntu that does this as well? It doesn't matter if it's GUI based or terminal based, just so long as these settings will be activated on startup.   Thanks in advance,


While entering MySQL server I am getting an error like this:  ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111)   What's the problem and how can I fix it?


Prove that composition of analytic functions is analytic

Can I get feedback on my proof from Ahlfors ?     If $g(w)$ and $f(z)$ are analytic functions, show that $g(f(z))$ is also analytic   First step is to show that if $g'(w)$ and $f'(z)$ exist, then the derivative of $g(f(z))$ is $g'(f(z))\cdot f'(z)$.   Claim     $f'(z)$ exists iff there is some $A \in \mathbb{C}$ such that $f(z+h) - f(z) = Ah + o(h)$ where $\lim_{h \to 0} \frac{o(h)}{h} = 0$   Allow $f'(z) = \lim_{h \to 0} \frac{f(z+h) - f(z)}{h}$. Then we see that $0 = \lim_{h\to 0} \frac{f(z+h) - f(z) - hf'(z)}{h}$. Thus, set $o(h)$ is the numerator and we are done.   Assume the existence of such an $A$. Then we have $o(h) = f(z+h) - f(z) - hA$, and $\lim_{h\to 0} \frac{f(z+h) -f(z)}{h} = A = f'(z)$.  Now to prove the chain rule.   Allow $k = f(z+h) - f(z)$ and $w = f(z)$  So $g(f(z+h)) - g(f(z)) = g(w + k) - g(w) = kg'(w) + o(k)$  Thus $g(f(z+h)) - g(f(z)) = (f(z+h) - f(z))g'(f(z)) + o(k)$  Since $\lim_{h \to 0} k = \lim_{h \to 0} f(z+h) -f(z) = 0$, then $\lim_{h \to 0} \frac{o(k)}{h} = 0$   $$\lim_{h\to 0} \frac{g(f(z+h)) - g(f(z))}{h} - g'(f(z))\frac{f(z+h)-f(z)}{h} = 0$$  Therefore we have proved when $h(z) = g(f(z))$ that $h'(z) = g'(f(z))\cdot f'(z)$.   Now, to show that $h(z) = g(f(z))$ is analytic, we must show it satisfies the Cauchy-Riemann equations.   Allow $g(w) = g(x,y) = u(x,y) + iv(x,y)$ and $f(z) = f(x,y) = r(x,y) + is(x,y)$. Then $h(z) = g(f(x,y)) = u(r(x,y), s(x,y)) + iv(r(x,y), s(x,y))$  From there we see that $$\frac{\partial h}{\partial x} = \frac{\partial u}{\partial x} + i \frac{\partial v}{\partial x}$$ and $$\frac{\partial h}{\partial y} = -i\frac{\partial u}{\partial y} + \frac{\partial v}{\partial y}$$   Where $$\frac{\partial u}{\partial x} = \frac{\partial u}{\partial r}\frac{\partial r}{\partial x} + \frac{\partial u}{\partial s}\frac{\partial s}{\partial x} \\  \frac{\partial u}{\partial y} = \frac{\partial u}{\partial r}\frac{\partial r}{\partial y} + \frac{\partial u}{\partial s}\frac{\partial s}{\partial y} \\ \frac{\partial v}{\partial x} = \frac{\partial v}{\partial r}\frac{\partial r}{\partial x} + \frac{\partial v}{\partial s}\frac{\partial s}{\partial x} \\ \frac{\partial v}{\partial y} = \frac{\partial v}{\partial r}\frac{\partial r}{\partial y} + \frac{\partial v}{\partial s}\frac{\partial s}{\partial y}$$  Using the fact that both $g(w)$ and $f(z)$ satisfy Cauchy-Riemann, we can immediately do substitution to see that $\frac{\partial u}{\partial x} = \frac{\partial v}{\partial y}$ and $\frac{\partial u}{\partial y} = -\frac{\partial v}{\partial x}$  Thus $h(z)$ is analytic.  I know this is long, but I'd love any feedback on correctness or if I'm missing any steps. Thanks


What actually causes blackbody radiation?

I've spent a fair bit of time reading up on answers detailing exactly how blackbody radiation is created but I have seen two different explanations for how it is created.   The Kinetic Energy (KE) of the atoms causes them to move and collide with each other. This process causes acceleration and deacceleration of charges thus producing electromagnetic radiation. The atoms bumping around somehow smash electrons of other atoms into higher energy states and when they fall down they produce quantised photons.   Could someone please clarify for me which of the two is correct?


Limit of the reciprocal of the mean harmonic

Suppose $(x_n)$ is a convergent sequence such that $x_n>0 \forall n \in \mathbb{N}$. Set $$y_n=\frac{n}{\frac{1}{x_1}+\frac{1}{x_2}+...+\frac{1}{x_n}}, n\in\mathbb{N}$$ Prove $\lim_{n\to\infty}{x_n}=\lim_{n\to\infty}{y_n}$ <- How should I approach this? Also prove that if $x_n$ diverges to $+\infty$, $(y_n)$ diverges to $+\infty$ <- I suppose I should be able to do this if I prove the above statement?


mass copy files of specific extensions to folder

I recently recovered a drive that was corrupted. it has a ton of extra files I do not need but I do need to copy files by extension over to the new location, eg: .jpg .png .mov .mp4 .wav .pdf .doc ext, ther are held in multiple sub directories along with a lot of crap files. like .java and .txts


So recently I bought a used lens - Canon ef 28-80mm f/3.5-5.6 usm with the metal mount but it came with no lens cap and I want to buy one now but I can't see the diameter of the lens on it anywhere which I need to buy a lens cap, do any of you guys have this lens or happen to know the diameter of it?   Thanks!


QGIS 3.2 - How can I scale polygon about his center?

How can I scale a polygon about his center? I find only transform function, but the scale function here can only move the polygon with the scale factor and don't enlarge it.


(Python) Why not import modules in function instead of at the beginning and best way to import them?

I am writing a program in python. I am using about a dozen modules. Currently I have placed them in the functions themselves. My reasoning is that since a user is not going to use all the functions in a session, many modules don't have to be imported uselessly until a function requires them. But all the code I have seen till now have their imports at the beginning. What are their reasons and advantages?  Also what is the best way to import ? I have seen several types like:   from tkinter import * and then Label(), Tk() import tkinter        and then tkinter.Label(), tkinter.Tk() import tkinter as tk  and then tk.Label()?   What's the best way? I see first one is shortest. Is it also the best?


There are a bunch of theories about the true origin of the orcs. Tolkien tried out a few different origins for his Orcs throughout his life but died before he could fully revise The Silmarillion with his final view on their origins and nature.   There is a list of origins proposed by Tolkien():   Made of stone and slime through the sorcery of Morgoth; East Elves, where The Silmarillion contains a suggestion that Orcs are descended from East Elves captured by Melkor, their minds and bodies distorted and corrupted. Sentient beasts, another of Tolkien's theories proposes that Orcs may have begun as soulless animals of vaguely humanoid shapes, empowered by the will of the Dark Lord (Morgoth) and learning language only as parrots do. Fallen Maiar, there are hints in the History of Middle-earth series of books, (especially in Morgoth's Ring in the section "Myths Transformed"), that some Orc leaders, such as the First Age's Boldog, or the Great Goblin encountered by Bilbo and the Dwarves, may in fact have been fallen Maiar which had taken Orc form. Corrupted Men, while Tolkien at some point saw all Orcs as descended from the original corrupted and tortured Elves, later comments of his indicate, according to Christopher Tolkien in Morgoth's Ring "Myths Transformed" text X, that he began to feel uncomfortable with this theory. At about the same time he removed the references to the Thrall-Ñoldorin, he also began searching for a new origin for the Orcs. It seems Tolkien wanted to change the origin of the Orcs to make them corrupted and twisted Humans.  A mix of corrupted Elves and Men, A late idea of Tolkien seems to be that Orcs (or Orks, showing the late spelling change) had a mixed origin of Elves and Men. Some cross-bred with Men, Tolkien also suggested that Men were cross-bred with Orcs under Morgoth's lieutenant, Sauron (and possibly under Morgoth himself). The process was later repeated during the War of the Ring by Saruman. This possibly refers to the way the Uruk-hai and the Half-Orcs were created, in The Lord of the Rings.   Of all these theories, which is the most accepted, and which did Tolkien agree with the most? I always thought that orcs were made of East Elves, as explained in The Lord of The Rings, but the story goes beyond this, there are the stories in many other books that explain different things.  What can you tell me about this?


I held back for a while before deciding to pose this question. I've done this before but couldn't quite 're-reasoned'.     Question: If G is a group, prove that Aut(G) is a group.   Let $\alpha, \beta \in Aut\left ( G \right )$. By definition:  the group operation is preserved.  $\alpha \left ( x_{1}x_{2} \right )=\alpha \left ( x_{1} \right )\alpha \left ( x_{2} \right )$  $\beta \left ( x_{1}x_{2} \right )=\beta \left ( x_{1} \right )\beta \left ( x_{2} \right )$  $\alpha, \beta$ is a bijection from G to G.  By the two-step subgroup test, it suffices to show that  $\alpha \beta \in Aut\left ( G \right )$ whenever, $\alpha, \beta \in Aut\left ( G \right )$  and  $\alpha^{-1} \in Aut\left ( G \right )$ whenever $\alpha$ is.   A bit of help to get me going?


What is considered a creature when using Magic Missile?

Last night when I was DMing I had an NPC wizard who had Magic Missile.  The description states “each dart hits a creature of your choice”.  In this instance what would be considered a creature?  The player characters?  When I look up creature in the manual it looks like “a creature” means an animal and not a humanoid, so Magic Missile would not be effective.  I guess this would be true the other way as well: if I am playing a wizard I could not target most humanoid monsters/villains.  Am I reading this right?


The UNIX Programming Environment by Kernighan and Pike

I have recently started reading "The UNIX Programming Environment" by Kernighan and Pike. My objective is to learn about the UNIX philosophy. My question is, Do I need to install UNIX on my desktop to make the most out of the book, or will any *NIX system work? I currently use Linux (ubuntu).


is my php code is okay to avoid sql injection

I have very old php application and I am avoiding sql injection like this: Is this will avoid sql injection? <?php $con = mysqli_connect($var['dbhost'],$var['dbuser'],$var['dbpass'],$var['dbname']);  $text = $con -> real_escape_string(strip_tags(htmlspecialchars(trim(stripslashes($_POST['title']))))); $class = $con -> real_escape_string(strip_tags(htmlspecialchars($_POST['class']))); $join_back = $con -> real_escape_string(strip_tags(htmlspecialchars($_POST['join_back']))); $heading = $con -> real_escape_string(strip_tags(htmlspecialchars($_POST['heading']))); $serial =  $con -> real_escape_string(htmlentities(trim(addslashes($_REQUEST['serial']))));    $sql = "INSERT INTO site_data(admin_id,site_id,page_id,css_name,serial,data_title,data_code,data_type,time_added,visible_for,join_back,is_deleted)  VALUES('".$uid."','".$sid."','".$pid."','".$class."','".$serial."','".$text."','".$html_data1."','text','".time()."','all','','no')";   if(mysqli_query($con,$sql)) {      header("location: show_data.php"); $db->close(); exit; } else { echo "
Problem Occurred. Try again Later.
"; } ?>


c++: Garbabge value when trying to reduce coin inventory to zero

When I try to remove all coins the value returned is -2.23517e-10 What am I doing wrong? I am just a beginner so please ignore the inefficient code. The code can be found at:  So the commands you need to run to add coins is: add coin 1 2 adds 2*cents and to remove them: remove coin 1 2 removes 2*cents Type status to view inventory Here is the code where the error occurs: if (isequal(f_command, "coin"))             {//agr time hai to enter check if val is_number             // tokenize the string             auto words = choice(command);             if(stof(words[2]) == 1)                 {f_command=commands[0];                 if (isequal(f_command, "add"))                     {inv_nickels = inv_nickels + (stof(words[3])*0.01);}                 else if (isequal(f_command, "remove"))                     {inv_nickels = inv_nickels - (stof(words[3])*0.01);}


I am on Linux (Ubuntu) and I am would like to exclude certain directories (like .hg) when I am doing a  find | less     I tried the following to exclude the .hg directory from listing, but does not seem to work.  find -type d \( ! -iname \.hg \) find -type d \( ! -name \.hg \) find -type d \( ! -iname .hg \)   How do I exclude .directory in a find command


GPU computation difference between rendering and cloth baking

After reading some articles on blender speed, I see that using CUDA enabled GPU computing will be of help in rendering.   I am trying to stitch a shirt on human .obj file. For that I bake 60 frames for it to fall on the human correctly. It takes about 20 seconds for the bake. I'd want to host it real time.  youtube link of the same :   Can I use GPU computing to reduce the bake time just like rendering time ?


Accessible materials with same refractive index as polycarbonate

There is a common home-remedy for scratched flat-screen monitors that says to rub a bit of petroleum jelly into the scratch. The rationale being that because the jelly has a similar refractive index as the plastic of the screen, light does not refract when moving from the jelly to the plastic and back as it does when moving from air to the plastic and back.  This makes sense, and some people have reported successful results, but naturally it depends on the specific jelly and specific monitor. Others have reported less success which also makes sense because there is a wide variety of jellies and monitors.  In this vein, I am wondering about optical discs. Scratches are a common blight on CDs and DVDs that most people have had to deal with at some point. It stands to reason that a similar technique could be used with optical discs (at least once, to recover the data). Even better, there is not as much variety with discs; they all use standard polycarbonate with little variation in their chemical composition, so the same material should work for pretty much all discs.  Does anyone know of a material which has a refractive index as close as possible to that of polycarbonate (1.584-1.586)?  There’s two things to note:   The disc spins very fast in the drive, so it can’t be something too soft because then the particles could get spun out and splattered inside the drive. CD/DVD repair-kits often include some sort of chemical solution, but a home-remedy should be a substance that most people can easily and cheaply get a hold of.


How to get the latest version of gcc on ubuntu 16.04 lts

Hey guys i am new to this just started studying computer science and programming and this is the first time im using linux. So how to get the latest version of gcc on ubuntu or does it make a difference (im using 5.4 right now).


Why can this equation be written as determinant?


Why do some adjectives follow the nouns they modify?

Right now I can only think of one instance in which this regularly occurs.  The adjective proper is sometimes placed after the noun it modifies, e.g:      A class of cold-blooded oviparous or ovoviviparous vertebrated animals whose skin is covered with scales or scutes; the reptiles proper.   What is this word order called, and why is it ever used?  Edit: I really want to know about proper, and while the word hyperbaton relates to post-positivity when it is meant to be rhetorically impacting, it doesn't seem to fit with ubiquitous post-positivity, such as that of proper.  I've accepted hyperbaton as the correct term/reason for almost all post-positive constructions, but I'd like a complete answer to include proper.


Determine how good an AUC is (Area under the Curve of ROC)

I'm currently working on a project involving using different sets of data as a predictor to predict the outcome of out-sample data. I use AUC (Area under the Curve of ROC) to compare the performances of each set of data. I am familiar with the theory behind AUC and ROC, but I'm wondering is there a precise standard for assessing AUC, for example, if an AUC outcome is over 0.75, it will be classified as a 'GOOD AUC', or below 0.55, it will be classified as a 'BAD AUC'. Is there such a standard, or AUC is always for comparing only?


The general term of the sequence : 1, 1, -1, -1, 1, 1, ...?

Suppose we have the following sequence:  {$a_n$} such as: $a_0 = 1, \\ a_1 = 1, \\ a_2 = -1, \\ a_3 = -1, \\ a_4 = 1, \\ a_5 = 1, \\ ... $  How can we find the general term of this sequence? I tried using a trigonometric function e.g. $\alpha \sin(x+\phi)$, then we impose some constraints on $\alpha$ and $\phi$ to get that sequence, but I get lost, is there any clever way to find the general term?  EDIT: The question is identified as duplicate, but that answer does not solve the question, because I am looking for a solution that does not involve floor function.


is there some constant $C\in{\mathbb{R}}$ for every Borel subset of $[0,1]$

Let $\mu$ and $\nu$ be finite measures s.t $\nu<<\mu$. Is it true or false that there exists a constant $C$ for every $A\in\mathcal{B}([0,1])$ s.t. $\nu(A)\leq{C\mu(A)}$.  my intuition tells me no, but I can't think of counter example.


How do I get the battery status on an iPhone?


I have a PC with 4 CPUs that is running four jobs. I would like to run another job on it, but only when one of the CPUs becomes available. Is there simple command to do this (I know this is what cluster management systems do, but there should be a simpler solution?)?


I need help running python in ubuntu  I can run python without a problem in my terminal but when I create a .py file I can't get it to run.


Subspace of metrizable and separable space is separable

I need to show (using the fact that for metrizable space: space is separable $\iff$ it has got a countable base) that if $X$ is metrizable and separable, then every subspace $Y \subset X $ is separable.  My idea:  If $X$ is separable (and is metrizable), then $X$ has got a countable base. Let's call it $\mathcal{B}$. Let $U=\bigcup_{i \in I} Bi$ such that $B_i \in \mathcal{B}$. So $U$ is open in $X$. Then $U\cap Y$ is open in $Y$. So $U \cap Y=\bigcup_{i \in I} Bi \cap Y$ such that $B_i \in \mathcal{B}$. So I want to say that $\mathcal{C}=\{B \cap Y: B\in\mathcal{B}\}$ is the base of $Y$. And becasue $\mathcal{B}$ is countable, then $\mathcal{C}$ is also countable. Then $Y$ is also separable.  Is it a correct proof (if not how can I improve it)? How should I show that $\mathcal{C}$ is really a base?


Can a particle have a speed exceeding that of a photon in vacuum?

Actually I have studied that the smaller the mass of a particle, the fastest it can travel in space. (But i don't know the mass of a single proton) and my question is: can any particle travel faster than a single photon?


\footnotetext numbering for many \footnotemark - automatic solution

\documentclass{report} \begin{document} Text\footnote{text1} Text\footnote{text2}  \vbox{% \begin{itemize} \item X\footnotemark{} \item Y\footnotemark{} \item Z\footnotemark{} \end{itemize} } \footnotetext{a} \footnotetext{b} \footnotetext{c} \end{document}   generates:  Text^1 Text^2  * X^3 * Y^4 * Z^5  ------------- 1 text1 2 text2 5 a 5 b 5 c   How to recover \footnotetext numbering without manual numbering?  I assume, I know that I used \footnotemark n times, so I would like solution like (It is "pseudocode" of draft of an idea) :  \newcounter{tempcounter := footnotecounter - n} \footnotetext[ ++tempcounter ]{a} \footnotetext[ ++tempcounter ]{b} \footnotetext[ ++tempcounter ]{c}   Or other authomatic numbering solution. I don't want to manually correct this list each time I change footnotes in chapter.  P.S. I know putting list into vbox might look strange, please assume it's just a toy-example of environment that needs usage of \footnotemark+\footnotetext.


Google Chrome shortcut for opening link on new tab?

Is there a google chrome shortcut for opening a link on a new tab so we don't have to right-clivk? I'm looking at something like ctrl+click link and then page will open on a new tab similar to the way we can shift+click link to open page in a new window.


Given That A and B are two PSD () real matrices and the following holds $$ A \leq B  $$ (meaning that $$ B-A $$ is also PSD)   can I bound the eigenvalues of A using the eigenvalues of B?  Thanks


I recently purchased Minecraft, and when I try to join servers they say Invalid Session and tell me to restart the game. I have made a Minecraft account and logged in but nothing seems to be working.


As you can see in the pic the lines from the top balls do not start as expected from the south, but from the east. Below the arrows from the XOR perfectly fit to my expectation. What do I have to change?  Thanks in advance    \documentclass[border=5pt]{standalone} \usepackage{tikz} \usepackage{amsmath} \usetikzlibrary{shapes} \usetikzlibrary{decorations.pathreplacing} \usetikzlibrary{shadows}  \begin{document}   \begin{tikzpicture}[%     bit/.style={circle,shading=ball,minimum width=1cm,ball color=white,path fading=fade inside},     bit2/.style={circle,shading=ball,minimum width=1cm,ball color=blue,path fading=fade inside},     ]      \tikzfading[name=fade inside,inner color=transparent!80,outer color=transparent!30]           \foreach \n in {0,...,4,20,21,22,23,24}{%             % x                 \pgfmathparse{mod(\n,5)}                 \edef\myx{\pgfmathresult}             % y                 \pgfmathparse{int(\n/5)}                 \pgfmathparse{int(5-\pgfmathresult)}                 \edef\myy{\pgfmathresult}              \node [bit] (\n) at (\myx,\myy) {};         }          \foreach \n in {20,21,22,23,24}{%             \pgfmathparse{\n-20}             \edef\myk{\pgfmathresult}              \node [above of=\n, inner sep=0] (plus\n) {$\bigoplus$};             \draw [-stealth] (plus\n) -- (\n);             \draw [-stealth] (\myk) -- (plus\n);         }    \end{tikzpicture} \end{document}


Can I run an ATmega on 3.3V with an external 16 MHz crystal?

I have been told that is overclocking or it just will not work, but I want to be sure. And are there any real differences that would effect from this? Any tips and tricks will help, thanks!


When mesh objects are added together in edit mode to create one single 'object', how can the intersections between the mesh be removed?

Is it possible to remove the internal intersections of mesh that have been added together in edit mode to create one 'object' - ideally creating a smooth interior, e.g. for 3D printing?   I have tried booleans but they are so destructive I'm really hoping for another fix..   This is what I have right now:    And this is what I would like it to remain looking like this on the outside:    What I would like it to look like on the inside is a replica of the outside, with all the redundant mesh removed - like the inside of a toy or a clay model that has been hollowed out.   Booleans are just not working, they absolutely destroy the mesh whenever I try to use them.   Literally dying trying to figure this out, so any help would be immensely appreciated.   The key issue is that it's for optimising a model for 3D printing, AS WELL AS keeping it smooth on the outside (and non-manifold)   Thanks!!


Problem in the 11th iteration of this for loop : "for (float x = -1; x < 1.1f; x += 0.1f)"

I was trying to generate some points at 0.1 intervals along a unit[-1, +1] horizontal line. Here is the code. for (float x = -1; x < 1.1f; x += 0.1f) {     line.points.push_back(Point(x, 0.5f, x * 1.0f)); }  When I tried to draw the points later, for (size_t i = 1; i < tLine.points.size(); i++)  {     std::cout << "drawing" << '\n';     DrawLine(         (int32_t)tLine.points[i].x,         (int32_t)tLine.points[i].y,         (int32_t)tLine.points[i - 1].x,         (int32_t)tLine.points[i - 1].y,         olc::BLACK); }  I noticed that "drawing" printed on the console stops after 11 iterations the program freezes. After some debugging, I found out that the problem is the first for loop to generate the points. When I printed out the x value of that for loop, it gave me -1 -0.9 -0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.0999999 7.45058e-08 // ??? 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1  As you can see the value that is supposed to be 0 is some nonsense value. The one before that is off by a little as well. In that for loop, 0.1 is being added to -0.0999999 to give 7.45058e-08. I also manually tried to add the same two numbers but it gives 1.04308e-07 (I was hoping for it to give 0). What is going on and how can I solve this problem? Thanks.


How to prove that the number $1!+2!+3!+...+n!$ is never square?

How to prove that the number $1!+2!+3!+...+n! \ \forall n \geq 4$ is never square?  I was told to count permutations but I cannot figure out what we are permuting.... Thanks!


Different dependencies for different build profiles

Is it possible to have a different set of dependencies in a maven pom.xml file for different profiles?  e.g.  mvn -P debug mvn -P release   I'd like to pick up a different dependency jar file in one profile that has the same class names and different implementations of the same interfaces.


Multiclass Spellcaster: Do the involved classes share the same pool of spell slots?

Introduction  The eldritch knight fighter (EK) in my game is contemplating whether to dip into wizard (Wiz) for more magical versatility in combat.  Spell Slots  The  (PHB p.164/165) say:     You determine your available spell slots by adding together all your levels in the bard, cleric, druid, sorcerer, and wizard classes, half your levels (rounded down) in the paladin and ranger classes, and a third of your fighter or rogue levels (rounded down) if you have the Eldritch Knight or the Arcane Trickster archetypes. Use this total to determine your spell slots by consulting the Multiclass Spellcaster table.   So a EK6/Wiz5 would add up to a 7th level spellcaster (6/3 + 5). A snippet of the mentioned table shows:  \begin{array}{l} \text{level} & \text{1st} & \text{2nd} & \text{3rd} & \text{4th} & \text{5th} & \text{6th} & \text{7th} & \text{8th} & \text{9th} \\ \hline 1 & 2 & - & - & - & - & - & - & - & - \\ 2 & 3 & - & - & - & - & - & - & - & - \\ 3 & 4 & 2 & - & - & - & - & - & - & - \\ 4 & 4 & 3 & - & - & - & - & - & - & - \\ 5 & 4 & 3 & 2 & - & - & - & - & - & - \\ 6 & 4 & 3 & 3 & - & - & - & - & - & - \\ 7 & 4 & 3 & 3 & 1 & - & - & - & - & -  \end{array}  The table implies that the EK spell slots and the Wiz spell slots are simply one and the same pool of spell slots, but I didn't find an explicit mention of this. Or is this table only for the added class through multiclassing?  We’re both unsure of how to interpret this when it comes to expanding spell slots.  Question  Multiclass Spellcaster: do the classes have a shared pool of spell slots? If so, does it matter which class’ spells are cast when expending spell slots?  Our confusion comes from our inexperience with 5e and multiclassing - let alone spellcasters. Are we missing something, or are we just overthinking it?    Related (but without clear answer to this question):


How do I pull up the Edit Dialog after it closes?  I have enabled Math Functions and it works fine; however, after I initially enter my settings in the dialog ("Add Z Function Surface"), the dialog disappears.  How can I pull up the dialog to change my settings? I am using Blender 2.90.1, Windows 10. Thank you in advance!


Can I determine where a method was called from without custom variables?

I am writing a plugin in C#, and one method does the same thing in two different ways. What I have currently is just the same (fairly complex) method written twice, with a slight difference in the output. But I'm wondering if there is a way to determine the origin of the call, within the called method?  I.e.:  Method A() {     Method C(); }  Method B() {     Method C(); }  Method C() {     if (called from Method B)     { foo; }     else if (called from Method A)     { bar; } }   Because it's a plugin, I can't alter Method A or B to add in a variable to identify which is which.


Solving for $\sum_{n = 1}^{\infty} \frac{n^3}{8^n}$?

I was trying to solve $ \displaystyle \sum_{n = 1}^{\infty} \frac{n^3}{8^n}$ and I found a way to solve it and I want if there are generalizations for, say, $\displaystyle \sum_{n=1}^{\infty} \frac{n^k}{a^n}$ in terms of $k$ and $a$. I would also like to know if there is  a better way to solve it. Here's how I did it:  First I decomposed the series into the following sums:  $S_1  = \frac{1}{8} + \frac{1}{64} + \dots = \frac{\frac{1}{8}}{\frac{7}{8}}$  $S_2 = \frac{7}{64} + \frac{7}{512} + \dots = \frac{\frac{7}{64}}{\frac{7}{8}}$  $S_3 = \frac{19}{512} + \frac{19}{4096} + \dots = \frac{\frac{19}{512}}{\frac{7}{8}}$  And deduced that the sum can be written as $\frac{8}{7} \displaystyle \sum_{n = 1}^{\infty} \frac{3n^2 - 3n + 1}{8^n}$  $\displaystyle \sum_{n = 1}^{\infty} \frac{1}{8^n}$ is easy to evaluate -- it's $\frac{1}{7} $by geometric series  $\displaystyle \sum_{n = 1}^{\infty} \frac{n}{8^n}$ can be evaluated in a whole host of ways to get an answer of $\frac{8}{49}$.  It remains to evaluate $\displaystyle \sum_{n = 1}^{\infty} \frac{n^2}{8^n}$, for which I took a similar approach as the cubics by decomposing it into many sums:  $T_1 = \frac{1}{8} + \frac{1}{64} + \dots = \frac{\frac{1}{8}}{\frac{7}{8}}$  $T_2 = \frac{3}{64} + \frac{3}{512} + \dots = \frac{\frac{3}{64}}{\frac{7}{8}}$  And so forth, coming to the conclusion that it is equal to $\frac{8}{7} \displaystyle \sum_{n = 1}^{\infty} \frac{2n-1}{8^n}$  Now, I used this information and the above values for $\displaystyle \sum_{n = 1}^{\infty} \frac{1}{8^n}$ and $\displaystyle \sum_{n = 1}^{\infty} \frac{n}{8^n}$ to get the sum as $\frac{776}{2401}$, which is confirmed by WA.  So, I would like to reiterate here: Is there a simpler way to compute this sum, and are there any known generalizations for this problem given an arbitrary $a$ in the denominator and arbitrary $k$ as the exponent in the numerator?


Getting nullpointer exception for t1.x why?

`class test {         int x = 10, y = 5;         public static test t1 = new test();          {             System.out.println("NSB");             System.out.println(t1.x);             System.out.println(t1.y);         }          public static void main(String[] args) {             System.out.println("C main");          }      }`


I wanna develop an application which has a database which is filled with data. How should I fill the database with data? which of the following should I do? 1- Write a little android app and fill the database and somehow get access to the database file and put that in the app. (I think this is bad) 2- Use some kind of sqlite software to fill the database file and then access the database file and put that in the app.(Again I think this is bad) 3-Any other method.


Alignment for Proof Justification in flalign* space?

In problem 5 of my math homework I'm trying to typeset I'm having a gap in my knowledge about how to go about aligning the "Rule" justifications when I move from each step in my equation proof.  Is there a command I can use to just align everything right justify even if I'm trying to work with a centered/anchored equation in the flalgin* space?  \documentclass[12pt]{article}  \usepackage[margin=1in]{geometry}  \usepackage{amsmath,amsthm,amssymb,mathtools,amsfonts, enumitem, fancyhdr, color, comment, graphicx, environ, caption, subcaption} \pagestyle{fancy} \setlength{\headheight}{65pt} \newenvironment{problem}[2][Problem]{\begin{trivlist} \item[\hskip \labelsep {\bfseries #1}\hskip \labelsep {\bfseries #2}]}{\end{trivlist}} \newenvironment{sol}     {\emph{Solution:}     }     {     \qed     } \specialcomment{com}{ \color{blue} \textbf{Comment:} }{\color{black}}  %for instructor comments while grading \NewEnviron{probscore}{\marginpar{ \color{blue} \tiny Problem Score: \BODY \color{black} }} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \lhead{A Curious LaTeX Student}  \rhead{MAT 4170 \\ 9.8.19 \\ HW 2}  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{document} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     \begin{problem}{5} Let $S$ be the set of symmetries of an equilateral triangle.  We developed the following short list of rules that can be used to calculate any combination of elements of $S$.     \begin{itemize}         \item Rule 1: $F^2=R^3=I$         \item Rule 2: $FR=R^2F$         \item Rule 3: $AI=IA$ where $A$ is any symmetry in $S$         \item Rule 4: $A(BC)=(AB)C$ for any 3 symmetries $A,B,C$ in $S$.         \item Rule 5: For each $A$ in $S$ there is a symmetry $A^{-1}$ in $S$ so that $AA^{-1}=A^{-1}A=I$     \end{itemize} Simplify the following expressions using the rules above.  Be sure to justify your steps using the rules.  \begin{enumerate}[label=(\alph*)]     \item $F(FF)(FR)RR=$     \item $F^2(RF)^3F^{-1}(R^2)^{-1}F^3=$ \end{enumerate} \end{problem}  \begin{sol} \begin{enumerate}[label=(\alph*)]     \item \begin{flalign*}             F(FF)(FR)RR &= F\textcolor{red}{(F^2)}(FR)RR\\                         &= F\textcolor{red}{(I)}(FR)RR \hspace{2cm}\textrm{(Rule 1)}\\                         &= F(FR)RR \hspace{2.55cm} \textrm{(Rule 3)}\\                         &= \textcolor{red}{(FF)}\textcolor{red}{(RRR)} \hspace{2.3cm} \textrm{(Rule 4)}\\                         &= (F^2)(R^3)\\                         &= \textcolor{red}{(I)(I)} \hspace{3.55cm} \textrm{(Rule 1)}\\                         &= \textcolor{red}{I}.      \hspace{4.3cm} \textrm{(Rule 3)}\\              \end{flalign*}     \item \begin{flalign*}             (F^2)(RF)^3F^{-1}(R^2)^{-1}F^3 &=            \end{flalign*} \end{enumerate} \end{sol}  \begin{problem}{6} Prove the following statements using Rules 1 through 5 above.  Be sure to include all steps and justify each step.     \begin{enumerate}[label=(\alph*)]     \item $(RF)(RF)=I$     \item $F=RFR$ \end{enumerate} \end{problem}  \begin{sol}  \end{sol} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %Do not alter anything below this line. \end{document}


Error occur when trying to save data to SQLite

I have pass the data from Project1.java to Claims.java and named them to name and result. They can show on c.setText. But when I want to save them in SQLite database, app crashed.  Claims.java    String result;     String name;     fk = bundle.getLong("ab");           @Override             public void onActivityResult(int requestCode, int resultCode, Intent data) {                 int button = data.getIntExtra("k1", 0);                  if (button == 1) {                     switch (requestCode) {                         case 0:                             result = data.getStringExtra("text");                             name = data.getStringExtra("a");                              as=Long.parseLong(result);                             c.setText("            " + name + "------" + "RM " + result);                             break;                          case 1:                              result = data.getStringExtra("text");                             name = data.getStringExtra("a");                              as=Long.parseLong(result);                             c.setText("            " + name + "------" + "RM " + result);                             break;       button.setOnClickListener(new View.OnClickListener() {                 public void onClick(View arg0) {                      if ((name != null && name.trim().length() > 0) && (result != null && result.trim().length() > 0)) {                         SB.insertStaffBenefit(name, result, fk);                      } else {                         Toast.makeText(getActivity(), "A", Toast.LENGTH_LONG).show();                     }                  }              });      11-04 17:09:40.876  20272-20272/com.example.project.project   E/AndroidRuntime﹕ FATAL EXCEPTION: main       Process: com.example.project.project, PID: 20272       java.lang.NullPointerException               at com.example.project.project.Claims$7.onClick(Claims.java:153)               at android.view.View.performClick(View.java:4654)   After did like what @Mohit suggested, now I get another error     11-05 01:45:01.612    2505-2505/com.example.project.project   E/AndroidRuntime﹕ FATAL EXCEPTION: main       Process: com.example.project.project, PID: 2505       java.lang.NullPointerException: Attempt to invoke virtual method 'long   com.example.project.project.API.StaffAPI.insertStaffBenefit(java.lang.String,   java.lang.String, long)' on a null object reference               at com.example.project.project.Claims$7.onClick(Claims.java:153)


I'm using format to test a function in Python.  I would like the output of a function   def test(f,k):     print "{0}({1})={2}".format(f,k,f(k))   given   test(Sqrt,4)   to be  Sqrt(4)=2   But format is giving back the type 'function' and a memory address inside angle braces.  Is there a neat way to shorten the output to get what I'm after?


How to properly recursively chown files (including hidden dirs)

This conundrum is caused by running git pull from root.   There are various reasons for me to do so... I want my device to update code when booting up, and rc.local is run by root.  It all works mostly fine (npm install tends to fail when run by root, but that's a whole 'nother topic), the problem arises when I try to use the git repository with a non-root user afterward... some of the git files have been written by root, so now I can't use it anymore (permission denied).   So I'd like to recursively chown it back but there doesn't seem to be anything that really works on all of the little git files. I tried the -R flag and ./**/* path.  My guess is that neither of those techniques descend into dot-directories.


How to connect an LED indicator with a switch to this device?

I would like to know how can i add a safety switch with an LED indicator to the input of this device , so that if the safety switch is on then the LED lights , and when i want to use the device , all what i have to do is to press the normally-open switch.  I have attached this schematic and im not sure if it will work correctly ,as i am a very beginner in electronics, so is the design correct?  The device itself is an arc generator with a DC input and th following parameters (Input voltage: DC3.7-7.4V , Input Current: 2A-5A).  I know how to size the LED resistor but not too sure about the switch how can i size it please ?  Thanks


What are the rules for owning and training animals?

I'm fairly new to DMing and so is my group, so we are all on a learning curve together. We're playing D&D 5e.  Last week a fighter in our group tamed a wolf with Animal Handling and then requested that he keep the wolf. I allowed this, but now I'm not sure about how to play the wolf.  Specifically, how can he train the wolf to perform certain actions such as attacking?  What other things might I need to be aware of with a PC owning a "pet"?


Can you explain to me:   What is a Predicate Delegate? Where should we use predicates? Any best practices when using predicates?   Descriptive source code will be appreciated.


Date and Time imprints on photos taken using iPhone 6

Is it possible to imprint date and time on the photos taken using iPhone ?


How do I embed my own fonts in a WinForms app?

I want to embed fonts in my WinForms application so that I don't have to worry about them being installed on the machine. I've searched a bit on the MSDN site and found a few hints about using native Windows API calls, for instance Michael Caplan's (sp?) tutorial linked to by Scott Hanselman. Now, do I really have to go through all that trouble? Can't I just use the resource part of my app? If not I'll probably go the installing route. In that case, can I do that programmatically? By just copying the font file to the Windows\Fonts folder? I am aware of licensing issues.


Open Excel links in other than default browser

I have many hyperlinks to web pages in an Excel file and I want to open those links either in IE or Chrome depending on the link. Most of my links I use I have no issues with opening the default Chrome browser and that is fine but some I wish to open with IE. Is this possible to do with a hyperlink in the Excel file?


Restored iPad , old Apple ID, find my iPhone still on

So we have a iPad with an old Apple ID that is now disabled, can't get the restore to work because find my iPhone is still on and it keeps asking for the Apple ID and password of this account to turn off the find my iPhone  I am over it! Just painful, anyone know what to do? Dee


I would like to ask for some inputs on how I can achieve similar low-key results for a fish:    Current setup:    Small aquarium 30 x 15 x 15 cms (LBH) The sides and the back of the aquarium are covered by a black muslin cloth. The LED no longer has cardboard roll on it. I was using this to cut reflections, but it really reduced my working space. The LED helps me focus and provides continuous light.   Question: How do I implement the inverse square law here given the small space? I  don't understand how to bring the flash closer to the fish than to the background.  Thank you for reading the complete post.  Goal:   Perfectly and FULLY illuminated subject with no part lost to shadows.  Pitch-black background.


I am a student and trying to design an aperture from which a light will pass will project on a sensor. I tried to find some software simulation tool for this purpose where i can draw the aperture (entrance side) and put diffuser or lens and then see the response of the light for some specific wavelength. I found one tool "Synopsys Code V" but it is very paid solution. So can anyone tell me some substitute for this. I am looking for Free simulation tools.


How does one solve trig functions by hand?

First of all, I am not very intelligent, so the question I am about to ask would sound inane--but I am just curious, that's all.  We were always used to being attached to our calculators when it comes to utilizing the following three trig functions: Sin ($\theta$), cos ($\theta$), and tan ($\theta$).  Providing an example, we were always taught that using our calculators is the solution when it comes to solving Dot Products.  Students in the Asian countries are taught without the calculator even till this day -- unless, SAT is being involved, but that is a completely different story.  I am sure there is a way to solve them by hand -- though, it may not be as precise nor easy -- and if there is a chart that can be cited, or any specific methods that can be used, please feel free to answer them below.  Thanks for your help.


How do I cite ebooks without page numbers?

I am directly quoting a sentence from an ebook. Thus, I want to add the page numbering to its citation. However, different to the print version, which I do not have, this ebook (Amazon Kindle version) does not have page numberings but rather "positions".  Do I just pretend it's a page numbering and note in the bibliography that it is a Kindle version? Or is there another way?  In case this is of interest, I am using Latex with Bibtex.


What's the difference between a[i] , i[a] in C and C++

I write three similar demos and compile them with   gcc -S 1.c -o 1.s   these demos diff in one line :   //  1.c , get 1.s 1 #include <stdio.h> 2 int main() 3 { 4    int a[2]={111,222}; 5    int j=0; 6    printf("%d ",0[a]);  // another two are a[j] and j[a] 7    return 0; 8 }   I use vimdiff to view assemble demo  in .s files, a[j] and j[a] is the same.  there are three different line in 0[a]  ; main in 0[a] , file 1.s .loc 1 5 0 movl    $111, -16(%rbp) movl    $222, -12(%rbp) .loc 1 6 0 movl    $0, -20(%rbp) .loc 1 7 0                             movl    -20(%rbp), %eax              | no these two line   cltq                                 | in a[j] and j[a] movl    -16(%rbp,%rax,4), %eax        movl    %eax, %esi movl    $.LC0, %edi movl    $0, %eax call    printf    I learn 8086 and intel assemble last year, several days ago find AT&T and feel a little strange. In 1.s ,ctlq extend rax to 64bit , and $0 doesn't need that. Is that right?  The problem is , after compiled to .s file, a[j] and j[a] is the same,does gcc compiler recognize the base address(pointer a) and the offset (j) ? a and j are both in memory,how can gcc get eax and ebp? Check their type?


Acceleration of free particle in Minkowski space!

In Minkowski space, the equation of motion is  $$a^c=\frac{d^2}{d\tau^2}x^c(\tau)=0.$$ How is this derived?


How can I install software wihout the Ubuntu Software Center?

How can I install Gnome Dictionary or other software if my Ubuntu Software Center is not working?  Please give me explanation why my software center is not working and how to fix it.


Sorry, we are no longer accepting questions from this account

I hope this is the right place to ask this question. I have been trying to ask a question in OS but am unable to do so...    This is not a temporary thing since it has been that way for more than 90 days...   Also I have checked my answers/questions and actually went trough all my stats and found nothing special. I got one down vote on some answer but that I think is only natural. Also I am not working on a network computer and only login from my current account which is an active account on wordpress.stackexchange.com    I have no idea what might be the reason I got banned... Must I create a fake new account to be a member?    Is there anything I can do? Why did this happen?  Again, I hope this is the right place to ask this question. I went through all available data but found no definitive answer as to what I can do.


Aura component error: setcallback is not a function

Apex class  public class Controller_Apex{     @AuraEnabled     Public static string callApexmtd(){         return 'Amit kumar';     }  }   component  <aura:component controller="Controller_Apex">     <aura:attribute name="Result" type="string" />     <lightning:button label="submit" onclick="{!c.show}" />  </aura:component>   controller  ({     show : function(component, event, helper) {         var abc=component.get("c.callApexmtd");         abc.setcallback(this,function(response)         {         var state=response.getstate();         console.log('state :' + state);         if(state === 'success'){             var result=response.getreturnvalue();             console.log('result' + result);             component.set("v.result",result);         }         });     $A.enqueueAction(abc); } })   Application  <aura:application extends="force.slds" >     <c:component_apex />  </aura:application>   Error     This page has an error. You might just need to refresh it. Action   failed: Capita_one:component_apex$controller$show [abc.setcallback is   not a function] Failing descriptor:   {Capita_one:component_apex$controller$show}


How do I enable compiz in Gnome Classic?

I am running Ubuntu Oneiric 11.10.  My understanding is that Gnome Classic is with Compiz effects, and Gnome Classic (No Effects) has no Compiz.  However, when i run Gnome Classic, compiz does not seem to be running. If I open compiz-settings-manager, I have all my settings, but none of them are taking effect.  Is there something I need to be doing to enable Compiz in Gnome Classic?    As requested in the comments of the answers, here is the output of ~/.xsession-errors:  gnome-session[20450]: DEBUG(+): GsmDBusClient: obj_path=/org/gnome/SessionManager interface=org.gnome.SessionManager method=Is Inhibited gnome-session[20450]: DEBUG(+): GsmDBusClient: obj_path=/org/gnome/SessionManager interface=org.gnome.SessionManager method=Is Inhibited gnome-session[20450]: DEBUG(+): GsmDBusClient: obj_path=/org/gnome/SessionManager interface=org.gnome.SessionManager method=Is Inhibited gnome-session[20450]: DEBUG(+): Starting app: /org/gnome/SessionManager/App37 gnome-session[20450]: DEBUG(+): GsmAutostartApp: starting jockey-gtk.desktop: command=sh -c 'test -e /var/cache/jockey/check | | exec jockey-gtk --check' startup-id=102cff201a509beb8813189506573089800000204500036 gnome-session[20450]: DEBUG(+): GsmAutostartApp: started pid:20888 gnome-session[20450]: DEBUG(+): Starting app: /org/gnome/SessionManager/App29 gnome-session[20450]: DEBUG(+): GsmAutostartApp: starting update-notifier.desktop: command=update-notifier startup-id=102cff20 1a509beb88131895065698387500000204500028 gnome-session[20450]: DEBUG(+): GsmAutostartApp: started pid:20889 gnome-session[20450]: DEBUG(+): GsmAutostartApp: (pid:20888) done (status:0) Gtk-Message: Failed to load module "rgba" gnome-session[20450]: DEBUG(+): GsmDBusClient: obj_path=/org/freedesktop/DBus interface=org.freedesktop.DBus method=NameOwnerC hanged gnome-session[20450]: DEBUG(+): GsmDBusClient: obj_path=/org/freedesktop/DBus interface=org.freedesktop.DBus method=NameOwnerC hanged gnome-session[20450]: DEBUG(+): GsmDBusClient: obj_path=/org/freedesktop/DBus interface=org.freedesktop.DBus method=NameOwnerC hanged gnome-session[20450]: DEBUG(+): GsmDBusClient: obj_path=/org/freedesktop/DBus interface=org.freedesktop.DBus method=NameOwnerC hanged gnome-session[20450]: DEBUG(+): GsmDBusClient: obj_path=/org/freedesktop/DBus interface=org.freedesktop.DBus method=NameOwnerC hanged gnome-session[20450]: DEBUG(+): GsmDBusClient: obj_path=/org/freedesktop/DBus interface=org.freedesktop.DBus method=NameOwnerC hanged `menu_proxy_module_load': update-notifier: undefined symbol: menu_proxy_module_load  (update-notifier:20889): Gtk-WARNING **: Failed to load type module: (null)  `menu_proxy_module_load': update-notifier: undefined symbol: menu_proxy_module_load  (update-notifier:20889): Gtk-WARNING **: Failed to load type module: (null)  `menu_proxy_module_load': update-notifier: undefined symbol: menu_proxy_module_load  (update-notifier:20889): Gtk-WARNING **: Failed to load type module: (null)  `menu_proxy_module_load': update-notifier: undefined symbol: menu_proxy_module_load  (update-notifier:20889): Gtk-WARNING **: Failed to load type module: (null)


Let $G\cong H$. If $\exists g\in G$ s.t. $|g|=n$, then $\exists h\in H$ with $|h|=n$, and if each element of $G$ is finite, then each in $H$ is too.

If $G, H$ are groups and $G$ is isomorphic to $H$, prove the following:  If $G$ has an element of order $n$, then $H$ has an element of order $n$, and  If each element of $G$ has finite order, then each element of $H$ has finite order.    For both, isn't there a theorem that states the exact thing? If this is straight definition, what am I suppose to prove?


I need to make a small correction in a video I uploaded to YouTube. Googling shows that this is not possible. However, I remember seeing it done before. I posted a comment on a video saying that a certain part of the video was missing. I got a reply back that it was fixed, and when I went to see the video again, it was changed. How was this done?


Using Google Chrome on my iPad, it seems like every now and then it randomly "forgets" all of my cookies. Authentication cookies in particular; I get re-prompted for two factor authentication and notified "you may be clearing cookies if you see this message often". I am not clearing my cookies manually, nor does there seem to be any rhyme or reason to the cookies disappearing. It is not a particular amount of time -- sometimes it is multiple times a week, and I never use Incognito Mode.  This has happened ever since I remember installing Chrome on my ipad a year or so ago. It does not happen with desktop or android versions of Chrome. Just the iOS version.  Is this a known issue? Is there something I can do about it?


how to prove $2\sqrt{5} + \sqrt{11}$ is irrational?

I tried to let $$2\sqrt{5} + \sqrt{11} = \frac{a}{b}$$ and find contradictions   (I set $b \ne 0$, $a$ and $b$ are in their simplest form) but I cannot find any


I want to know how to prove this inequality by mathematical induction: $a_k's$ are nonnegative numbers. Prove that$$a_1a_2\cdots a_n\leq \left(\frac{a_1+a_2+\cdots+a_n}{n}\right)^n.$$ In the inductive step, I tried using the inequality $ab\leq \frac{k}{k+1}a^\frac{k+1}{k}+\frac{1}{k+1}b^{k+1}$ but I got over estimate of what I was looking for.  Is there a better way of proving this by induction?


I've been reading 70-200 f4 is vs 2.8 non is for days and still I don't know what to do. Ok..at the moment I do not do weddings. I do portraits (babies on up), I do photo shoots of a kid or kids running, playing, jumping in some field. I am commissioned to shoot landscape, buildings, horses, dogs (a lot of dogs) sometimes stationary, as a dog can be, or moving. I might shoot outdoor sports, not often. I have been known to shoot theater plays with just stage light available. I pretty much use a canon 24 - 105 to do all of this. I want a 70 - 200 and I really want a 2.8. I do not use a tripod as I started out a street photographer and love hand held shooting (better control) SO??????? can I get a 2.8 NON IS someone help me....Please!!!


Fifteen close votes on one question in low-quality queue

For this particular review:   The question got fifteen close votes over the course of an hour.  Seems like that's a lot.  This could indicate a bug.


Statistically, when is wielding a Large weapon worth it for a Medium-sized character?

In D&D 5e, according to , if a Medium-sized character uses a Large weapon, its damage dice are doubled, but it causes them to suffer disadvantage on their attack roll:  Big monsters typically wield oversized weapons that deal extra dice of damage on a hit. Double the weapon dice if the creature is Large, triple the weapon dice if it's Huge, and quadruple the weapon dice if it's Gargantuan. For example, a Huge giant wielding an appropriately sized greataxe deals 3d12 slashing damage (plus its Strength bonus), instead of the normal 1d12. A creature has disadvantage on attack rolls with a weapon that is sized for a larger attacker. You can rule that a weapon sized for an attacker two or more sizes larger is too big for the creature to use at all.  The answers to the question  support this interpretation. However, my question is not asking whether wielding oversized weapons is allowed or not. Assuming that characters are allowed to wield Large-sized weapons, when (if ever) is it statistically advantageous to do so?  Let's take the example of a Variant Human Barbarian with a starting Strength score of 16, and Great Weapon Master as their racial feat.  Are they better off using a Medium or Large Greataxe? What about when Reckless Attack, Rage and/or Great Weapon Master enter the mix? I expect that this would probably depend on the AC of the target, but how would they compare? Does this change as the Barbarian levels up and gains additional damage from their Strength modifier or Rage bonus increasing?


"Norway to ban full-face veil in nurseries, schools and universities" - is this correct?

Some minutes ago, I've seen news () where the title is:      "Norway to ban full-face veil in nurseries, schools and universities"   I understand that the meaning is "> "Norway is going to ban etc. or "Norway on the way to ban etc. as written in the article by itself:  "Norway is proposing a ban on the Muslim full face veil and other face-covering clothing because it says it hinders communication between pupils and teachers."  Now, my question if this omitting is intentionally and this structure of sentence is considered correct in English or maybe it's just a mistake and it's not correct?      Another topics of differences in tenses don't answer my question which deals with structure.


How could I place objects (buildings) on a flat surface in the BGE?

I'm working on an  in BGE, and I am not sure how I could make it so you can place buildings on flat surfaces (or unless there is an easier way). I would love to know how to place buildings when you click a certain button to place it.  I don't really need anything fancy like price and stuff like that yet. I really have no idea if  is required to do this.


Possible Duplicates:                When identifying people in a photo—for instance,      John, Valencia, and (I or me).   should I use ”I” or “me”? Which one is grammatically correct?


Euler characteristic for non-convex polyhedra.

I read a little introductory book to topology.  It basically said that for any two-dimensional manifold (well maybe just the closed ones, as I think about it) its topology can be unambiguously defined by the Euler's characteristic and orientability.  Consequently it is very nice that any convex polyhedron has its Euler characteristic $\chi=2$ which means that the global topology is the same as for the sphere.  What about the examples below? In fact $\chi>2$ which occurs in these cases do not correspond to any global topologies I know.


Getting a picture into my Tex file (on Mac)

I want to include a picture in my project that I have going in latex right now. This is the location of the file:    And this is how it's included in my project in latex (I've included the packages graphicx and float as well):    But this is the error code that I get and the picture will not show up in my .pdf when I run the code:     I have no clue as to why latex can't find the picture or how to solve this. Anyone got any ideas?


Currently this is my method to get nice hard and soft shaded edges in Blender. I "shade smooth the whole object. I then go ti it's object data, activate Auto Smooth and set a desired angle." This works for most cases but sometimes I want specific control over how some of my edges shade. Can I select a few edges and mark them to be hard? Will that information be transfered seamlessly through OBJ and FBX exports?


Select nth row using where condition in oracle database

I have a table having business days stored into it. I want to get 5th business day based on the input date i give.  For an example please consider below table      BUSINESS DAY 8/06/2004 12:00:00 AM 8/07/2004 12:00:00 AM 8/08/2004 12:00:00 AM 8/09/2004 12:00:00 AM 8/10/2004 12:00:00 AM 8/13/2004 12:00:00 AM 8/14/2004 12:00:00 AM 8/15/2004 12:00:00 AM 8/16/2004 12:00:00 AM   Here my input date is 8/08/2004 12:00:00 AM my output should be 8/15/2004 12:00:00 AM. Please help to construct query for this.  Please note that based on the requirement i may need past dates as well.   Note: I want to fetch the record neither from top nor bottom. I have to fetch the 5th record only from the row where my input condition is satisfied


problem when creating bootable usb in ubuntu

i am using ubuntu LTS and i want to create a bootable usb. so I opened the Startup disc creator in ubuntu, the problem is despite I selectIchoose the desired .iso file, it is never listed and hence i cant create the bootable usb.  anz suggestions_


Please Answer quickly i am really confused Most websites say that people thought a circle is 360 degrees because there are 360 dayes in a year but there are not they also say that the base number is 60 or 10 but i dont know what base number means and please tell me how this came to be and when ancient people found this out


Detail in bijection between Inn(G) and G/Z(G)?

I've seen other posts () about the topic of $\operatorname{Inn}(G) \simeq G/Z(G)$, but what I want to ask is a detail. When we ensure that $\operatorname{Inn}(G) \simeq G/Z(G)$, we want to say that there exists some isomorphism $F$ such that:  $$F: G/Z(G) \rightarrow \operatorname{Inn}(G), \quad F(gz) = \tau_g$$  where $g \in G, z \in Z(G)$ and $\tau_g(h) = ghg^{-1}$ for all $h \in G$  But is this $F$ really an isomorphism? I'm not pretty sure due to there is not ONE $\tau_g$ for ONE $gz$, what we have is a total of $|Z(G)| = \text{order  of }Z(G)$ elements of the form $gz$ for just ONE $\tau_g$ due to $\tau_g = \tau_{gz}$ if $z \in Z(G)$


Need a non-GUI SFTP tool better than "sftp"

'sftp' is seriously lacking relative to, say, ncftp: it has no command memory, no Tab-completion of file names, and so on. Is there a non-GUI tool for SFTP that people recommend?


Separate file for hibernation? Why use swap?

Why have one file, the swap file, with 2 purposes:   a swap file that serves the purpose for both providing some extra memory for apps (swap) and also for storing the state of the entire system (suspend-to-disk/hibernation)?   In Windows, there appears separate file for each purpose:    Swap: For swapfile.sys for Windows 10 (pagefile.sys does the same job for older versions) and hiberfil.sys is for the image of the system state in RAM for when the system is hibernated.    Wouldn't that be easier for decision making as to what size of swap to use (and what size needed for hibernation)?  Also, why would a file the size of all the RAM be needed for hibernation, if only one app is running consuming, for example, 1Gb out of 32Gb?  Question based on the discussion around the swap size decision making process here:


How can I draw a tangent ending smoothly in a circle?

I'm trying to draw a tanget on a circle, but I'm not happy with the result I get from the tangent option.    particularly, I'd like to have the lines ending smoothly in the circle. The problem is shown enlarged here:      Here is the code for this mininmal example  \documentclass{standalone} \usepackage{tikz} \usetikzlibrary{calc}  \begin{document}   \begin{tikzpicture}[thick]     \node[draw,circle,xshift=2.2cm] (big) [minimum size=25mm] {};     \node[draw,circle] (small) [minimum size=2mm] {};     \draw (small.south) -- (tangent cs:node=big,point={(small.south)});     \draw (small.north) -- (tangent cs:node=big,point={(small.north)},solution=2);    \end{tikzpicture} \end{document}   I'd greatly appreciate any advice allowing me to do this!


I have been reviewing number theory questions and there is one problem I am stuck on.  Find $x$ such that $x^{677} ≡ 3 \mod 2020$.  My approach was to start by applying Euler’s Theorem. I know that $\phi(2020) = 800$, but I don’t know if this is very useful... How should I proceed?


I've created a custom theme for beamer that I plan to use for multiple presentations. So, while I currently have the .sty file (just one at this point, as I load an inner theme and color theme, then define the outer theme) in the same directory as the presentation I'm working on now, I want it available in the future without have to maintain multiple copies.  From , I understand I can install packages in my home texmf folder (e.g. ~/texmf on Linux, which is where I do most of my work), however should I then structure my texmf folder like the beamer subdirectory in the main texmf folder (i.e. /usr/share/texmf/tex/latex/beamer/themes/[color,font,inner,outer,theme] on my Ubuntu machine), or just put put down any/all .sty files in the single directory.  Note, while I mentioned I do most of my work on Linux, answers for OS X and Windows would be useful, as I do work on both of these platforms as well - and frequently sync files between machines via Git repositories.


Is $7$ the only prime followed by a cube?

I discovered  which claims that "$7$ is the only prime followed by a cube".  I find this statement rather surprising.  Is this true?  Where might I find a proof that shows this?  In my searching, I found , which is similar but the answers seem focused on squares next to cubes.  Any ideas?


I frequently see the abbreviation "No" to mean "Number" (or "Nos" to mean "Numbers") instead of the much more common meaning of the word (a negative statement or denial).  Sources cited  say it's the correct abbreviation, but don't really explain why it got that way or why it remains true today.   This seems odd because of (a) the strong negative association with that choice of abbreviation, especially when letters are used instead of a , (b) the availability of other abbreviations like "Num." or "Nr." or "#", and (c) the fact that the English word "Number" doesn't have an o in it (the abbreviation makes more sense in Spanish, for example, as short for "Numero," but even there it's  not used without superscripts due to confusion with "no" as a negative word).   Why does English use "No." as an abbreviation for "Number?"


Is it possible to have an "Always on top" feature in (L)ubuntu?

I'm using Lubuntu 14.04 64 Bit and I need to have the "Always on top" feature so I can have any window always visible if I need to.  I've searched a lot up and down, but to my surprise I could not find anything.  Is it possible at all to have this feature ?


Question migrated, but user doesn't exist on the new site

I stumbled upon a question which was migrated from Security to Stack Overflow. The problem is that the user doesn't have an account on Stack Overflow and the question needs clarifications from the OP before it can be answered.  What happens in this case? Is the user notified to create a profile on the new site? Does he see the new question link? Does he receives notifications when a comment is posted on his question on the new site?  This situation is bad from several points: first it's a waste of time if the user cannot answer the comments. Second it doesn't add any value to the site for the same reason. And even if there is an answer to the question the user cannot accept it and the post cannot be closed as solved.  We could just close the question, but then we don't give a chance to the user to answer clarifications.  Should we do something about this or is it that this is so rare that we shouldn't bother with this?