Hey guys I am sure there is something obvious here that im just not seeing. I need some help with trying to figure out why I am getting a null pointer exception when I set the game.max value in the GuessingGame3 constructor. It seems like no matter what I do the value will not get set. Even when I explicitly set the value it still throws an error. I've tried changing the max variable to static as well and that didnt work either. A lot of people are saying you need to initialize the value which I did and that didnt work. Please help.     package guessinggame3;    import java.util.Random;    //provides methods that return a random integer in                              //the range 0 to 4294967296.    import java.util.Scanner;   //enable the user to input values from the keyboard     public class GuessingGame3     {        public int max;        public int answer;        public int maxGuessesAllowed;        public int numGuessTaken;        public static int currentGuess;        public static int previousGuess;        public boolean gameOver;        public int differential;        public GuessingGame3 game;  public static void main(String[] args) {      GuessingGame3 game = new GuessingGame3();     game.GuessingGame3(); }  public void GuessingGame3() {     Scanner sc = new Scanner(System.in);     System.out.println("Welcome to the Guessing Game.");     System.out.println("Enter the maximum number:");      game.max = sc.nextInt();              // input maximun number of guesses     Random generator;      // New random number generator     generator = new Random();     game.answer = generator.nextInt(game.max); // the randomly chosen answer     System.out.println("Enter the maximum number of guesses allowed:");      maxGuessesAllowed = sc.nextInt();      game.newGame(maxGuessesAllowed); }  public void newGame(int GuessesAllowed) // Given the max,generate answer {  game.maxGuessesAllowed = GuessesAllowed;  Random generator = new Random();     // New random number generator  int answer = generator.nextInt(max); // the randomly chosen answer  System.out.println("The answer is:" + answer);  game.gameOver = false;  game.differential = game.max;  game.numGuessTaken = 0;  game.guess(); }    public void guess()  {   /* Takes in int answer & returns string response */             Scanner sc = new Scanner(System.in);  while(!gameOver)  {   System.out.println("Enter your guess:");    currentGuess = sc.nextInt();   if(answer == currentGuess)     // correct guess branch    {     gameOver = true;     System.out.println("Congratulations! Would you like to play again?");     System.out.println("Enter Y for yes or N for no.");     String again = sc.next();          again = again.toUpperCase();       if(again.equals("Y"))       {        GuessingGame3 game;        game = new GuessingGame3();        game.GuessingGame3(); //Start a new game       }       if(again.equals("N"))       {        System.out.println("Goodbye.");        break;       }    }         if(currentGuess > answer)      //currentGuess is too high      {       System.out.println("Too high");      }      if(currentGuess <answer)       //currentGuess is too low      {       System.out.println("Too low");      }      if(currentGuess > max)         //currentGuess is beyond the max      {       System.out.print("Your guess is beyond the max you set.");       continue;      }      int differential = Math.abs(answer - currentGuess);      if (game.differential != 0 && differential < game.differential)         {                                       // If this is the first guess                System.out.println("Getting Warmer");  // there is differential. So no      }                                       // "warmer" or "colder."      if (game.differential != 0 && differential > game.differential)      {       System.out.println("Getting Colder");         }      game.differential = differential;  } }   }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


When does LASSO fail in terms of:   out of sample forecasting? selecting relevant variables?   (If there is a distinction between 1 and 2 to begin with.)  Also,   Under what conditions would one be better off using ridge regression or other techniques instead of LASSO?   I am looking for the most salient examples and conditions which should ring a bell for an applied modeller.

Assume that you need to build a linear model to make predictions for new observations, and that there is uncertainty about which subset of variables should be included in the model. You are only interested in making predictions, there is no theory available to guide variable selection, and you aren't interested in drawing causal inferences.   In this scenario, when wouldn't you use LASSO? Everything I read makes it sound like the perfect tool in this situation. However, when I have a nice new hammer in my hand, all problems look like nails, so I would like some examples of reasonable scenarios where variable selection and avoiding overfit are important, but when LASSO is either entirely inappropriate, or unlikely to be the best option. There are other threads on why you should use LASSO; I want to know why I shouldn't.


My opponent casts Starfield of Nyx with Herald of the Pantheon in play. Herald reduces the cost of Starfield by 1 to 4.  I cast Spell Queller.  Can I quell the Starfield as it's CMC has been reduced to 4 or is it still 5?

If I have  in play, can 's triggered ability pull a card like  from my library, which would originally have a converted cost of 4, but which is lowered by the Grand Arbiter's ability?


I recently asked a handful of questions. Since my native language isn't English some of my text isn't on par with what some users are used to reading. While I always try to learn from other users' edits I never found an option/way to thank them. Even though this might seem irrelevant I somehow feel the need to do so. Is there any option to do so?

Possible Duplicate:    Sometimes I get an edit that greatly improves a question or answer I have submitted.  I'd like to acknowledge an edit like this, so that readers can know that the revision was approved of by the OP (me!). I was thinking of comments on edit, or a checkbox noting that OP vouches for the edit.  Sometimes I would like to add a comment to the question or answer, but those don't make a lot of sense in that context. Any suggestions about the best way to do this?  Consider this a feature request, as it seems useful to know that a particular edit was endorsed/vetted by the OP.


Currently I am running the bash script like this:  $ myscript.sh param1 param2 param3 >log.txt   and it is outputting the normal information.  My question is:  how can I output all normal and error information (in, out, err) to a log file from within the script itself?  my try is the following but it is not working:  #!/bin/bash exec 2>&1 {     mycommand1      mycommand2     mycommand3 } 2>&1 | tee -a /tempfolder

I have a bash file that I need to redirect all output to one file, debug log as well as to the terminal. I need to redirect both stdout and stderr to the debug and log it for all commands in the script.  I do not want to add 2>&1 | tee -a $DEBUG for every single command in the file. I could live with | tee -a $DEBUG.  I remember there was a way to do it with something like exec 2>&1.  Currently I'm using something like the following:  #!/bin/bash DEBUGLOG=/tmp/debug exec 2>&1 somecommand | tee -a $DEBUGLOG somecommand2 | tee -a $DEBUGLOG somecommand3 | tee -a $DEBUGLOG   but it does not work. Does anyone have a solution/can explain the cause?


I'm kinda confused and can anyone say whats the right form and elaborate as to why

On the one side, the USA is just one country. Logic says it should be, then, singular, just like the United Kingdom is. Example:     The USA owns this domain.   On the other side, if I however expand "the USA" to "the United States of America", I'd tend towards using plural — the noun the verb agrees with, "States," is definitely plural. Example:     The United States of America own this domain. → The USA own this domain.   What form should I prefer?


I'm writing some formulas inside a tabular. My formulas have summation but the subscript is showing next to the summation not under it! How can I make it under it?  Example (j is next to summation!):

I have a fraction with sums above and under the line. How can I convince LaTeX to write the indices of the sums under the sigma instead of next to it?  \begin{displaymath}   \frac{\sum_{s \in S} s^2}{\sum_{p \in P} p^2} \end{displaymath}


This question bothered me for a while and hopefully someone can shed some light on the issue.  A matrix $A$ is said to be diagonalizable if there is an invertible matrix $P$ and a diagonal matrix $D$ such that $A=P^{-1}DP$. That is the definition of a matrix being diagonalizable.  Now, a linear transformation is said to be diagonalizable if there exists a basis $C$ of eigenvectors.  Why is that the same thing? Let's say that $A$ is diagonalizable, I define a linear mapping: \begin{gather*} T\colon V \to V \\ T(v)=Av \end{gather*}  Why does this say that $T$ is diagonalizable? Why does this mean that there is a basis of eigenvectors?  And also the other way around: let's say that the transformation $T$ is diagonalizable. Why does this mean that $A$ is diagonalizable?

I am following a book where the "diagonalizability" has been introduced as follows:      Consider a basis formed by a linearly independent set of eigen vectors   $\{v_1,v_2,\dots,v_n\}$. Then it is claimed that with respect to this   basis, the matrix $A$ is diagonal.   I am confused at the word "basis" here. In some other books it is said that a  matrix $A$ is called diagonalizable if there exists matrix $P$ such that $P^{-1}AP$ is a diagonal matrix.   I don't think that diagonalizability has anything to do with basis. It just happened that the set of eigen vectors form a basis of $\Bbb R^n$. Also I don't think having a set of $n$ linearly independent eigen vectors is a necessary condition for a matrix to be diagonalizable.


I do not know how to get past this screen. I tried to find a solution on the Internet but I only found how to install a desktop but that doesn't work because I need to install the GUI first.  Please help, Kind regards  Cas Muijsers

Trying to run a Ubuntu server for the first time... But everything is in a terminal. Is there a way to switch to a GUI?


I just ordered a new root server 18.04 Ubuntu with Plesk. I log in as root and want to create a folder for example: mkdir /usr/local/myfolder/hello  I get the error: mkdir: cannot create directory ‘/usr/local/myfolder/hello’: No such file or directory  It only works, when I use mkdir -p. I can only create 1 folder ahead, when I am in the directory, not a path. For me this is not normal, how can I fix this? Also my scripts dont run because of this. Thanks

on a linux machine running CENTOS v 7.8.2003 I am in a directory Neutrinos I now do  mkdir /pionloop/ this works. I then go to into this new directory pionloop and do mkdir /E_0.3 and this works as well. I thus have as a result a directory Neutrinos/pionloop/E_0.3.  Now, starting in Neutrinos I want to do this in one command and therefore do mkdir /pionloop/E_0.3 and get: `mkdir: cannot create directory ‘/pionloop/E_3.0’: No such file or directory  What is going wrong here??


For my cryptology class, we're asked to prove this statement:  Let $p$ be prime and $a, b$ be integers such that $p \nmid a$. Prove that if $p^2 \mid ab$, then $p^2 \mid b$.  I'm not sure where to even begin with this proof. I think it must rely on some property of $p$ as a prime number since the next question was to give a counterexample to show it's not necessarily true for composite $p$, but since $p^2$ is no longer a prime number (since it would be divisible by at least 1, itself, and $p$), I'm not sure where this comes in. I thought to try the definition of divisibility and say there exists a $k \in \mathbb{Z}$ such that $p^2 k = ab$, but I don't see where to go from there. Since $p^2$ isn't prime, I can't use that $p \mid ab \implies p \mid m \,\text{or}\, p \mid n$. Edited to add: we have covered the fundamental theorem of arithmetic, but I don't see how to apply that either. Perhaps to say that $k$ is either a prime or a product of primes? I'm not sure whether that produces any progress. Any hints as to first steps I could take or a sketch of the proof would be very much appreciated.

Suppose $p$ is a prime where  $p^2 \mid ab$ and $\gcd(a,b) = 1$. Show that $p^2\mid a$ or $p^2 \mid b$.   I'm not quite sure how to go about this. I know it has something to do with the fact that $\gcd(a,b) = 1$ since if we didn't have that requirement, this statement would not hold since $3^2 \mid 6*12$ but $3^2$ does not divide $6$ or $12$.   I started by saying that since $p^2  \mid ab$, $ab = p^2k$ for some integer $k$. Also since $\gcd(a,b) = 1$, $1 = ax + by$.   I do not know if this is the right way to think about this or not. Any help would be great.


When I start my PC, the following commands appear in cmd space:  /dev/sda1 contains a file system with errors, check forced. Inodes that were part of a corrupted orphan linked list found. /dev/sda1: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY. (i.e., without -a or -p options) fsck exited with status code 4 The root filesystem on `/dev/sda1` requires a manual `fsck`  BusyBox v1.22.1 (Ubuntu 1:1.22.0-15ubuntu1) built-in shell (ash) Enter 'help' for a list of built-in-commands.  (initramfs)_   Can anybody help in sorting out the issue? Thanks!

I dual boot Ubuntu and Windows 7. I was browsing on FireFox in Ubuntu and all of a sudden I get some error message, so I rebooted.  Now when I try to boot into Ubuntu I get this message:  fsck from util-linux 2.26.2 /dev/sda6 contains a file system with errors, check forced. /dev/sda6: Inodes that were part of a corrupted orphan linked list found.  /dev/sda6: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.         (i.e., without -a or -p options) fsck exited with status code 4 The root filesystem on /dev/sda6 requires a manual fsck  Busybox v1.22.1 (Ubuntu 1:1.22.0-15ubuntu1) built in shell (ash) Enter 'help' for a list of built-in commands.  (initramfs) _   How can I fix this?


I have created a User Java class to store the users' information that was provided by the user when the registered. (The information is then stored in Firebase Realtime Database.) The variables username, email, dob, weight, height and gender are all set when the user registers however I want to create the value for the CalorieIntake using the other variables in the class in a calculation.  To calculate the Calorie Intake I need to use the weight and height and this calculation will be based on if the user is a male or female.  The code I have used doesn't seem to calculate the calorieIntake or show up on the profile page, so I am now very confused as to how to calculate it and get it to show up on my profile page. Any help would be appreciated.  Below is my code in the User.java class:  public class User {     public String username;     public String email;     public String dob;     public String weight;     public String height;     public String gender;     public String calorieIntake;       //default constructor     public User() {     }      public User(String username, String email, String dob, String weight, String height, String gender, String calorieIntake ) {         this.username = username;         this.email = email;         this.dob = dob;         this.weight = weight;         this.height = height;         this.gender = gender;         this.calorieIntake = calorieIntake;     }      public String getUsername() {         return username;     }      public void setUsername(String username) {         this.username = username;     }      public String getEmail() {         return email;     }      public void setEmail(String email) {         this.email = email;     }      public String getdob() {         return dob;     }      public void setdob(String dob) {         this.dob = dob;     }      public String getWeight() {         return weight;     }      public void setWeight(String weight) {         this.weight = weight;     }      public String getHeight() {         return height;     }      public void setHeight(String height) {         this.height = height;     }      public String getGender() {         return gender;     }      public void setGender(String gender) {         this.gender = gender;     }      public String getCalorieIntake() {         return calorieIntake;     }      public void setCalorieIntake(String calorieIntake) {          if(this.getGender() == "Male"){             calorieIntake = String.valueOf(((((Integer.parseInt(this.getWeight()) * 10) + (6.25 * Integer.parseInt(this.getHeight()))) - (5 * 21)) + 5));        } else if (this.getGender() == "Female"){             calorieIntake = String.valueOf(((((Integer.parseInt(this.getWeight()) * 10) + (6.25 * Integer.parseInt(this.getHeight()))) - (5 * 21)) - 161));        }         this.calorieIntake = calorieIntake;     }  }

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


(My question is different than  and , so hold back on casting a close vote, please). So, I was reading on , and ran into this statement in the Dirac-von Neumann axioms: The space $\mathbb{H}$ is a fixed complex Hilbert space of countable infinite dimension. This is rather confusing to me; I use position and momentum as bases for this Hilbert space all the time, and those bases have cardinality $2^{\aleph_0}$. How is it that the space is countably infinite when we use uncountable basis sets to perform basic calculations?

The dimension of the Hilbert space is determined by the number of independent basis vectors. There is a infinite discrete energy eigenbasis $\{|n\rangle\}$ in the problem of particle in a box which can be used to expand a general state $|\psi\rangle$ as: $$|\psi\rangle=\sum\limits_{n=0}^{\infty} C_n |n\rangle$$ Here, the basis implies that the Hilbert space has countably infinite number of basis vectors. But one could well expand $|\psi\rangle$ in any other basis as well, say the continuous position basis. Then that superposition, $$|\psi\rangle=\int dx \psi(x)|x\rangle$$ is also possible. But this basis $\{|x\rangle\}$ is continuous and uncountably infinite. Such sets cannot be equal because they have different cardinality. Then my questions is how many independent basis vectors are really there in this Hilbert space?


I am working on proving that the equation:  \begin{align} a^2-b^3 = 1 \end{align}  where $a$ and $b$ are positive integers has only one solution $(a,b) = (3,2)$.  The equation can be rewritten:  \begin{align} (a-1)(a+1) = b^3. \end{align} When $b$ is odd, for any prime factor $p$ of $b$, we have that $p$ divides $(a-1)(a+1)$. But $a-1$ and $a+1$ are coprime when $b$ is odd, hence $p$ divides either $a-1$ or $a+1$ but not both. It follows that both $a-1$ and $a+1$ must be perfect cubes. Since there are no pair of perfect cubes with difference 2, it follows that $b$ must be even.   In this case let $b = 2n$ and for ease of reading, let $a = m+1$. The equation can be rewritten: \begin{align} m(m+2) = 8n^3. \end{align} This implies that $m$ is even, i.e. $m=2k$. The equation becomes: \begin{align} k(k+1) = 2n^3. \end{align} Depending on wether $k$ or $k+1$ is even, we have: \begin{align} q(2q+1) = n^3 \end{align} when $k=2q$, and  \begin{align} (q+1)(2q+1) = n^3 \end{align} when $k=2q+1$.   When $k = 2q$, since $\text{gcd}(q,2q+1) = 1$, we have that $q$ and $2q+1$ must be perfect cubes using the same reasoning as above. I would like to conclude by proving that there is no positive integer $c$ such that $2c^3+1$ is a perfect cube, hence the question in the title.

I am trying to solve the diophantine equation $x^3-2y^3=1$ using  $\mathbb{Q}(\sqrt[3]{2}).$  I've read this link:   The following is what i have tried:  Finding all integer solutions of $x^3-2y^3=1$ is equivalent to finding all the elements of the form $x + y\sqrt[3]{2}$ in $\mathbb{Q}(\sqrt[3]{2})$ of norm $1$ over $\mathbb{Q}$ where $x,y\in \mathbb{Z}.$ By Dirichlet's unit theorem $\mathcal{O}_{\mathbb{Q}(\sqrt[3]{2})}^{\times} \cong \mathbb{Z}/2 \oplus \mathbb{Z}.$ Thus $x + y\sqrt[3]{2}=±(-1-\sqrt[3]{2})^n$ for some $n\in \mathbb{Z}.$   But then I have to idea how to proceed. In fact, I'm not even sure if what I have tried is correct. Can anyone help me please?


I spend a decent amount of time on Stack Overflow reading questions and answers, so I also end up flagging a lot. Yesterday, I flagged  as not an answer because:   it only contains a link to the documentation. probably not important, but that link doesn't even answer the question, as the user which asked the question didn't have problems with the basic usage of the class, he had problems with customizing the behavior of the class. the rest of the answer is a comment.   But the flag got declined with the usual:     declined - a moderator reviewed your flag, but found no evidence to   support it   So, in the end, is that a real answer? Does linking to the documentation(instead of a tutorial somewhere) makes it an answer? On the same question there is a deleted answer(by a moderator) like:     You can try this tutorial: link-to-yet-another-blog-with-tutorials   If this deleted answer was in the form of my flagged answer above(let's say with the link to the documentation replaced by the tutorial link), it would have escaped the deletion? In my opinion, the answer that qualifies as a real answer(to a certain degree) is the other non deleted answer, which funny enough points to a question which has the correct answer a link to a tutorial on some blog.  Also, regarding flag decisions(although I feel that there could be a duplicate question for this), I also flagged  as not an answer(even it's author later said it was a comment). The flag was helpful but the answer remained. Shouldn't have been deleted?

Related:  (not a dupe, that's a feature request and was closed as a dupe of another one)        (old) post does indeed say that Link-only answers can be flagged as NAA, but there are a lot of posts like  which define Not An Answer is a way that it doesn't apply to link-only answers.  Can we get some up-to-date consensus on this? That link only answers are not allowed is .


In Excel 2013, how can I remove rows that are exact duplicates of each other (while keeping only one)?  That is, if there are two or more rows where every column has exactly the same value, only one row should remain after the operation.  I would expect Excel to be able to do this task off the bat, but I don't mind using some script if necessary.

I am trying to remove the duplicates items from a big Excel sheet. I would like to remove all rows that have a duplicate code values (sample below)  Before:      Name     Code item_01  xxxx01 item_02  xxxx02 item_03  xxxx01 item_01  xxxx03 item_04  xxxx04   After:  Name     Code item_01  xxxx01 item_02  xxxx02 item_01  xxxx03 item_04  xxxx04   I have played with the "Remove Duplicates" features, but I can't get the result that I want.   Any help? Thanks


Could you explain what rules are used to compute this integral? $ \int_{-\infty}^{\infty} e^{ \frac{-u^2}{2}} du = \sqrt{2\pi}$

How to prove  $$\int_{0}^{\infty} \mathrm{e}^{-x^2}\, dx = \frac{\sqrt \pi}{2}$$


What parentheses are doing after declaration of a function (last line)?  var a = 0;   function foo(a) {       alert(a);   } (a);

I'm new to both JavaScript and . In YUI library examples, you can find many uses of this construct:  (function() {     var Dom = YAHOO.util.Dom,     Event = YAHOO.util.Event,     layout = null,         ... })();   I think the last couple of parentheses are to execute the function just after the declaration.  ... But what about the previous set of parentheses surrounding the function declaration?  I think it is a matter of scope; that's to hide inside variables to outside functions and possibly global objects. Is it? More generally, what are the mechanics of those parentheses?


General theory of relativity proved that gravity does attract light ( photons ), what if I project a beam of light radially towards a black holes will it increases it's speed or not?

How do I solve the speed of light in gravitational field?  Should I just add gravitational acceleration in speed of light?  $$c'=c_0+g(r)t~?$$


When you enter a command for an application in ubuntu in the terminal and the application in not installed on the system then you get a message saying The program 'application name' is currently not installed.  You can install it by typing: sudo apt-get install <application name>  How do you get it to automatically type the above command for you or get it to ask you do you want to install <application name>  For example: say you type firefox in the terminal window and firefox is not installed in the system than it will say, The program 'firefox' is currently not installed. You can install it by typing: sudo apt-get install firefox.  How do you get it automatically type the command sudo apt-get install firefox and press enter for you.

If you try to execute a program that is not installed you will get a message  The program 'x' is currently not installed. You can install it by typing:  sudo apt-get install x   and instead of offering you to install the program for you, you have to type the actual command. How can this behavior be changed?


I am having difficulties trying to capitalize the first letter of every word. Since each field has more than 1 word, I am thinking I may need to create a loop or something similar to repeat the format in all words.  Here is my SELECT:  SELECT  UPPER(SUBSTRING(firstname,1,1))     +   LOWER(SUBSTRING(firstname,2,LEN(firstname)))    + ' ' +         UPPER(SUBSTRING(lastname,1,1))     +   LOWER(SUBSTRING(lastname,2,LEN(lastname)))  +         RTRIM(UPPER(SUBSTRING(position,1,1))     +   LOWER(SUBSTRING(position,2,LEN(position))))         AS  information   Note that firstname comes from one column, lastname from another and position from another. The issue here is not firstname and lastname, which should be only a word for each column, but in the position column we should except such things as Software Developer or Business Analyst for example and I am not sure how to convert Software developer into Software Developer.

What’s the best way to capitalise the first letter of each word in a string in SQL Server.


Let $H$ be separable Hilbert space.I’m trying to prove that      The only  proper closed ideal of $B(H)$ is $K(H)$, the compact operators on $H$   I can see that every closed ideal of $B(H)$ must contain $K(H)$ but I cannot see the other part.   I’m sure that that there must be many books which contains proof of this result but I could not find any. Any references which has proper  proof of the same fact?

I wanted to find a quick proof of the following well-known fact. Since I couldn't easily find a reference, I provide a proof below.     Let $H$ be a separable Hilbert space, and $J\subset B(H)$ be a (not necessarily closed) two-sided ideal. If $T\in J$ is non-compact, then $J=B(H)$.    I'm also interested to know if there is a shorter/simpler argument.


After training the kmeans model, how can i obtain the number of classes of the model? i've tried with get(), getInfo() and doesnt work.      Value that must to be extracted   // STEP 1: Import image we wish to classify var l8 = ee.ImageCollection('LANDSAT/LC08/C01/T1')  // Remove the clouds var cloud_free = ee.Algorithms.Landsat.simpleComposite({   collection: l8.filterDate('2018-01-01', '2018-12-31'),   asFloat: true })  // STEP 2: Draw your box which you will sample from!   // Make the training dataset. var training = cloud_free.sample({   region: geometry,   scale: 30,   numPixels: 5000 });  // Step 3: Create the clusterer and train it, play around with // number of classes var clusterer = ee.Clusterer.wekaKMeans(3).train(training);  print('clusterer',clusterer instanceof ee.ComputedObject);  var to_print = clusterer.getInfo();  print('clusterer_info',clusterer.toString());  print(typeof clusterer);  var clusterer_list = ee.List(clusterer);  print('clusterer_list',clusterer_list);  print(typeof clusterer_list);   //var to_print_2 = clusterer.get('nClusters');  //print(to_print_2);  //var to_print_3 = clusterer.Filter.filterMetadata('nClusters','equals',3);  //print(to_print_3);  // Step 4: Classify our image var classified = cloud_free.cluster(clusterer); print(classified); var cluster_1 = classified.eq(0); print('min',cluster_1);   // Display Map.setCenter(-122.31040963183364, 37.782065864682096, 11) Map.addLayer(classified.randomVisualizer(), {}, 'clusters');

After training the kmeans model, how can i obtain the number of classes of the model? i've tried with get(), getInfo() and doesnt work.      Value that must to be extracted in "//var to_print_2 = clusterer.get('nClusters')"  // STEP 1: Import image we wish to classify var l8 = ee.ImageCollection('LANDSAT/LC08/C01/T1')  // Remove the clouds var cloud_free = ee.Algorithms.Landsat.simpleComposite({   collection: l8.filterDate('2018-01-01', '2018-12-31'),   asFloat: true })  // STEP 2: Draw your box which you will sample from!   // Make the training dataset. var training = cloud_free.sample({   region: geometry,   scale: 30,   numPixels: 5000 });  // Step 3: Create the clusterer and train it, play around with // number of classes var clusterer = ee.Clusterer.wekaKMeans(3).train(training);  print('clusterer',clusterer instanceof ee.ComputedObject);  var to_print = clusterer.getInfo();  print('clusterer_info',clusterer.toString());  print(typeof clusterer);  var clusterer_list = ee.List(clusterer);  print('clusterer_list',clusterer_list);  print(typeof clusterer_list);   //var to_print_2 = clusterer.get('nClusters');  //print(to_print_2);  //var to_print_3 = clusterer.Filter.filterMetadata('nClusters','equals',3);  //print(to_print_3);  // Step 4: Classify our image var classified = cloud_free.cluster(clusterer); print(classified); var cluster_1 = classified.eq(0); print('min',cluster_1);   // Display Map.setCenter(-122.31040963183364, 37.782065864682096, 11) Map.addLayer(classified.randomVisualizer(), {}, 'clusters');


pankaj@pankajbhatt:~$ sudo add-apt-repository ppa:umang/indicator-stickynotes >>> /etc/sudoers: syntax error near line 1 <<< sudo: parse error in /etc/sudoers near line 1 sudo: no valid sudoers sources found, quitting sudo: unable to initialize policy plugin pankaj@pankajbhatt:~$

I am getting this error:  sudo: parse error in /etc/sudoers near line 23 sudo: no valid sudoers sources found, quitting sudo: unable to initialize policy plugin   I was trying to disable password authentication so I don't have to type password every time I want to install something, but I probably changed it in a not very good way. I am a newbie to Ubuntu, I got sick of Windows :)  So far I've found some people suggesting booting in single user mode, but I'm afraid of messing things up more.  How can I fix this error?


All the exe files are showing as Shortcut files on my PC. I tried installing the programs but it shows up an error of System Volume Information related.   On clicking the OK button, the installing popup comes. I think that it might be due to the virus attack. On the properties Tab, it is showing the Location of the exe files like C:\Windows....   I am attaching the screenshot of the error too. I tried scanning with K7 Antivirus too but it's not showing any Threat. Can I know how to overcome the issue.  Showing Shortcuts    Properties Tab of Safari as an example

What should I do if my Windows computer seems to be infected with a virus or malware?  What are the symptoms of an infection? What should I do after noticing an infection? What can I do to get rid of it? how to prevent from infection by malware?   This question comes up frequently, and the suggested solutions are usually the same. This community wiki is an attempt to serve as the definitive, most comprehensive answer possible. Feel free to add your contributions via edits.


Alright, so the standard way to evaluate $\sum\limits_{k=0}^n\cos(kx)$ and $\sum\limits_{k=0}^n\sin(kx)$, is to respectively take the real and imaginary part of  $$\sum_{k=0}^n{\rm e}^{ikx}={\frac {{{\rm e}^{i \left( n+1 \right) x}}-1}{{{\rm e}^{ix}}-1}}$$ $$=\frac12\left({\frac {\cos \left(   \left( n+1 \right) x \right) -\cos \left( nx  \right) }{\cos \left( x \right) -1}}+1 \right) +\frac12i\left( {\frac {\sin \left(  \left( n+1 \right) x \right) -\sin \left( nx  \right) -\sin \left( x \right) }{\cos \left( x \right) -1}} \right)$$  While this is relatively simple concept and easy to remember how to derive, is there a way to come up with these results that do not rely on complex numbers? Also, do not give an inductive proof, as that is not particularly constructive, and the form of the sum values is not easy to determine by inspecting.

How can we sum up $\sin$ and $\cos$ series when the angles are in arithmetic progression? For example here is the sum of $\cos$ series:  $$\sum_{k=0}^{n-1}\cos (a+k \cdot d) =\frac{\sin(n \times \frac{d}{2})}{\sin ( \frac{d}{2} )} \times \cos \biggl( \frac{ 2 a + (n-1)\cdot d}{2}\biggr)$$  There is a slight difference in case of $\sin$, which is: $$\sum_{k=0}^{n-1}\sin (a+k \cdot d) =\frac{\sin(n \times \frac{d}{2})}{\sin ( \frac{d}{2} )} \times \sin\biggl( \frac{2  a + (n-1)\cdot d}{2}\biggr)$$   How do we prove the above two identities?


Question: Let $A$, $B$, $C$ be groups. Assume that $A \cong B$ and $B\cong C$. Prove that  $A \cong C$.   Proof:   Let $\phi: A \to B$ and $\sigma: B \to C$  Suppose $\sigma \circ \phi: A \to C$  $i). One-to-one:$  Then $\sigma \circ \phi$ is one-to-one. Let $a, b \in A$  Suppose $(\sigma \circ \phi)(a) = (\sigma \circ \phi)(b)$  $\Rightarrow$ $\sigma (\phi(a)) = \sigma (\phi(b))$  (Since $\sigma$ is one-to-one.)  $\Rightarrow$ $(\phi(a)) = (\phi(b))$  (Since $\phi$ is one-to-one.)   $\Rightarrow$ $a = b$  $ii). Onto:$  Then $\sigma \circ \phi$ is onto.   Let $c \in C$. Because $\sigma$ is onto there exists $b \in B$ such that $\sigma(b) = c$. Also since $\phi$ is onto there exists a $a \in A$ such that $\phi(a) = b$.  Then $\sigma(\phi(a)) = \sigma(b) = c$  Then $\sigma \circ \phi$ is onto.  $iii).Opreation  - Perserving:$  Let $x_1, x_2 \in A$.  Then $(\sigma \circ \phi) = \sigma(\phi(x_1, x_2)) = \sigma(\phi(x_1)\phi(x_2))$  Because $\phi(x_1) \in B$ and $\phi(x_2) \in B$,   $\sigma(\phi(x_1)\sigma(\phi(x_2)) = (\sigma \circ \phi)(x_1)(\sigma \circ \phi)(x_2)$  Then $\sigma \circ \phi$ is operation-preserving.   $\therefore A \cong C$  I know it isn't the most elegant proof, but I was wondering if this is totally correct or if I missed something or did something incorrectly. Any help appreciated!

Let $G_1, G_2$ and $G_3$ be groups.  Let $\phi: G_1 \to G_2$ and $\sigma: G_2 \to G_3$ be isomorphisms of groups.  Show that $$\sigma\circ\phi: G_1 \to G_3$$ is an isomorphism.  I understand to prove the composition is a homomorphism (operation preserving) and a bijection.  I need help with notation and how to show the operation preserving, onto and one-to-one.  Operation preserving:  $\sigma\circ\phi(ab)=\sigma(\phi(ab))=\sigma(\phi(a)\phi(b))=(\sigma\circ\phi(a))(\sigma\circ\phi(b))$  Am I on the right track?


In the international Stack Overflow sites for logged-out users, when navigating to a specific user's profile in the top bar the partial text is truncated.  For an example in Russian Stack Overflow Community user profile, the text "на русском" is partially hide in the top bar. For the remaining page the logo is displaying properly.   Seems in other pages the HTML tag as Stack Overflow на русском, where as in the profile page the _glyph class is missing, which has the height attribute.  The issue can be reproduced in other site's community user profile too.                                  System configuration:  OS: Windows 10 Mozilla Firefox: 66.0 (64-bit) Google Chrome: Version 72.0.3626.119 (Official Build) (64-bit) Microsoft Edge: 41.16299.15.0 Zoom: 100%

I can't see the complete 'en español' underneath the Spanish Stack Overflow logo on user profile pages. Nothing changes when I scroll, but when I go to the , the logo gets shifted up a bit and it looks fine. The same thing happens on the  site.  You can tell that the logo is the correct image but shifted downwards because the top of the 'in [language]' text is visible:    I'm on Vivaldi 2.0 for Windows 10 and on Chrome 69.0.3497.100 for Windows 10. It happens only when you don't have an account for that site, both when you're anonymous and when you have connected accounts on other sites.


Assuming we have a fair die, we toss a die multiple times. Also assuming that a triple is defined as when we have three rolls in a roll that result in the same number, and that the rolls are independent, what would be the expected time until a first triple is observed? The answer I have in a book is rather heuristic. It briefly states that if you take 1/36 as the probability of observing a triple at time t>2, then the formula for the time until the first triple should be: $36 = \frac{1}{6}+\frac{5}{6}X$, where $X =$ first time a triple is observed.  I was wondering if there was a more formalistic way of coming up with the answer. Thank you!

Over the holidays I played a dice game where each player had 3 to 7 d6 to roll each turn.  The game gave certain advantages to doubles and triples.  I wanted to know the odds of rolling doubles or triples given N dice to understand the importance of "upgrading" to more dice.  My question is really about how to reason about such problems:  It's easy to see that the odds of rolling doubles with 2 d6 are 1/6 (first die can be anything, and 1/6 of the time the second will match).  It's also easy to see that with 7 dice the odds are 1.0 (6 dice could be 1..6, but the 7th must match one of them).  The middle cases are fuzzier to me.  I ended up writing a program to enumerate all of the possibilities (even 6^7 is only 279,936 cases to evaluate) because that was the only way I felt I could verify any closed formula I came up with.  This also enabled me to distinguish cases of multiple doubles (or triples).  I would like to know how to derive closed forms and how to validate such solutions without brute-force simulation.


Twitter has a nice feature to save searches so you can quickly access them quickly in the sidebar.  It would be nice to have something like that for SO/MSO/SU/SF.   Instead of having to type in my search, like  [discussion feature-request only-awesome-features]  in the search box every time, I could save them as a search preset and access them in my prefs in a tab called "Favorite searches" or something like that.  Even better, the saved searches would be available in the site's sidebar, e.g. under related tags.  EDIT: I know, the search is not the best, but searching for certain tags or groups of tags (in the syntax: [tag1 tag2 tag3]) actually works ok, IMO. That's what I want to use it for, searching for certain groups of tags.

Is there a plan for a more convenient way to save advanced search criteria in Stack Overflow?  It would be really convenient to add and remove the saved criteria in a nearly identical way to the favorite tags.  For example, I could type the following in a favorite searches TextBox and add as a favorite:  [wpf] closed:no wiki:no   And when I click on that favorite (Button), I can add additional criteria to it in the search bar.  Edit: I would like to hear a good reason (if there is one), why saved searches isn't a good idea, whereas favorite tags are.  For example, if the above is stored as a favorite, the home page could highlight wpf items that aren't closed or wiki.


In few docs I see suggestion to query the user's last login data to check if user is actively using the license or not, is there any way we can get to know if the feature license is being used properly through API or the suggested approach we can use to determine for feature license usage as well?

I need to query programmatically the Feature license and usage-based license which is available in UI. Could someone please highlight if we can query the same or is it available in UI only, Thanks.


I'm trying to show that:  $U^a_{\space\space;b}U^bU_a = 0$ (Where U is four-velocity)  and I'm stuck on how to go about it. I tried expanding it out into the Christoffel symbols, but that didn't seem to get me anywhere.  Would really appreciate advice on what I should do to proceed.  Thanks.

Ok, this question is more a result of my lack of knowledge of how to manipulate equations involving index notation rather than about physics...  I have the geodesic equation with $U^\lambda\equiv\dot{x}^\lambda$:-  $$ \dot{U^\lambda} + \Gamma^\lambda_{\mu\nu} U^\mu U^\nu $$  And I want to transform to the co-vector $U_\mu=g_{\mu\lambda}U^\lambda$.  Can I simply multiply each vector by $g_{\mu\nu}$? Like so:-  $$ g_{\mu\lambda}\dot{U^\lambda} + \Gamma^\lambda_{\mu\nu}g_{\mu\alpha}U^\alpha g_{\nu\beta}U^\beta $$  Or do I need to use $g^{\sigma\nu}g_{\nu\mu} = \delta^\sigma_\mu$ to rewrite $U_\mu=g_{\mu\lambda}U^\lambda$ and then sub it in?  Edit: Here's my attempt at the sub in method  So using $g^{\lambda\mu}g_{\mu\lambda} = \delta^\lambda_\lambda$ to rewrite $U_\mu=g_{\mu\lambda}U^\lambda$ as $U^\lambda=g^{\lambda\mu}U_\mu$. (Is this even correct?). Then differentiate:- $$ \dot{U}^\lambda=\dot{g}^{\lambda\mu}U_\mu +  g^{\lambda\mu}\dot{U}_\mu $$ Can I assume that the differential of the metric wrt time is going to be zero? Obivously this is not going to be true in general since massive bodies move! But generally in simple problems would this be taken as true?


I am stuck with this problem.  $f : [a,b] \to \mathbb R$ is double differentiable on $[a,b]$ and suppose $|f''(x)|\leq M ~ \forall x \in [a,b]$. Let $c \in (a,b)$. Then $|f(c)-f(a)-(c-a)\frac{f(b)-f(a)}{b-a}|\leq \frac{1}{8} M(b-a)^2$  I can prove this when the upper bound is $M(b-a)^2$.  $|f(c)-f(a)-(c-a)\frac{f(b)-f(a)}{b-a}|=|c-a| |\frac{f(c)-f(a)}{c-a}-\frac{f(b)-f(a)}{b-a}|$. This equals $|c-a||\frac{f'(\xi_1)-f'(\xi_2)}{\xi_1-\xi_2}||\xi_1-\xi_2|$ for some $\xi_1\in (a,c)$ and $\xi_2 \in (a,b)$. This equals $|c-a||f''(\psi)||\xi_1-\xi_2|\leq (b-a)^2M$  Although I know this is weak and I haven't exploited the $\xi '$s fully. I cannot find the solution afterer lots of tries, so any help is appreciated.

Let $f(x)$ be twice-differentiable and $f(a)=f(b)=0$ with $a<b$  How to prove that  $$\max|f(x)| \le \frac 18(b-a)^2 \max|f''(x)|$$  (With $\max|f(x)|$ beeing maximum (or minimum) between a and b.)  How would I use Taylor-Expansion and Mean Value Theorem here?


Why is there an inconsistency for (-1)^0.6 (or (-1)^(6/10)). I know in school I was taught to simplify the exponent to 3/5, which results in -1. However, when I leave the exponent as 6/10, I get a either the 10th root of (-1)^6 = 1 or ((-1)^(1/10))^6. Is there a way this can be explained without just simply saying to simplify the rational exponent first?

I know there is something wrong with this but I don't know where. It's some kind of a math fallacy and it is driving me crazy. Here it is: $$-1= (-1)^3 = (-1)^{6/2} = \sqrt{(-1)^6}= 1?$$


Would it be possible to display Latex in comments.  Yesterday I posted a math question, which someone helpfully edited. They changed all occurrences of a^b to ab. Like two squared can be written 2 * 2 = 2^2 or 22.  This resulted in answers being posted containing LaTeX which the app doesn't format leaving what look like a combination of spurious characters scattered through your math formula.  If you can format LaTeX in questions, answers and comments on the full Web site. You can format LaTeX in app questions. Why not app comments.   On an aside what's the Web address for the SE mobile site. My search engine only finds links for app download and links to the main site.

MathJax isn't currently working on the Android app, which makes it totally useless for the 'technical' sites like  or .  For example, in the Android app:    Same post in a (mobile) browser:     Please add this functionality!


I'm trying to load into Select2 the selected value extracted from the DB. Id values are saved in a JSON field that contains the id values or the field '*' that I manage as 'All'. I want to search first_name and last_name in the users' table. AJAX <script>     $(document).ready(function() {         $('#plaintiffId').select2({             ajax: {                 url: '{{ route('admin::reports.plaintiffId') }}',                 dataType: 'json',                 delay: 250,                 processResults: function (data) {                     return {                         results:  $.map(data, function (item) {                             return {                                 first_name: item.user.first_name,                                 last_name: item.user.last_name,                             }                         })                     };                 },                 cache: true             }         }); </script>  web.php Route::get('reports/plaintiffId', 'Admin\ReportController@plaintiffId')->name('reports.plaintiffId');  ReportController.php public function plaintiffId(Request $request, $term) {     $data = [];     if($request->has('q')){         $search = $request->q;         $data = $search->when($term, function ($query) use ($term){             return $query->whereHas('plaintiff', function ($query) use ($term) {                 $query->where('first_name', 'like', "%{$term}%");                 $query->orWhere('last_name', 'like', "%{$term}%");             });         });     }     return response()->json($data); }  Report.php public function scopeSearch($query, $term) {     return $query->when($term, function ($query) use ($term){         return $query->whereHas('plaintiff', function ($query) use ($term) {             $query->where('first_name', 'like', "%{$term}%");             $query->orWhere('last_name', 'like', "%{$term}%");         });     }); }  public function plaintiff() {     return $this->belongsTo(User::class, 'plaintiffId'); }  I get this error in the network  When I double-clicked on 500 in the network tab. It open a new tab, I see this error Call to a member function when() on string

So I'm refactoring my code to implement more OOP.  I set up a class to hold page attributes.  class PageAtrributes  {   private $db_connection;   private $page_title;      public function __construct($db_connection)      {         $this->db_connection = $db_connection;         $this->page_title = '';     }      public function get_page_title()     {         return $this->page_title;     }      public function set_page_title($page_title)     {         $this->page_title = $page_title;     } }   Later on I call the set_page_title() function like so  function page_properties($objPortal) {         $objPage->set_page_title($myrow['title']); }   When I do I receive the error message:     Call to a member function set_page_title() on a non-object   So what am I missing?


My Western Digital My Passport Drive () is broken, when I went to plug it in today, It made beeping sounds when connected. It makes 7 beeps, then 3, then another 3, and then it pauses for a few seconds and repeats the sequence. Something like   Now I don't know what's wrong with it or how I can solve it. Do I open it up and connect it to my computer using an external HDD station? Do I connect it via SATA? What are my option here? It's under warranty, will WD recover my data?

I have a 2TB Western Digital drive (WD20EADS). For no apparent reason, when I powered it up today it started making an odd beeping noise, and would not mount.  I'm fairly certain the drive is broken, but the sound it is making is strange, basically a longer beep, then a shorter, higher pitched one. Does this sound mean anything other than "it's dead"?  Recording of the drive:


I've got a friend who is using Windows 7 and I "sold" him the benefits of open source, and he actually wants to try Ubuntu 16.04 LTS (that's the good news)! The bad news are: he is visually impaired and he has some problems with his hands/fingers.  Are there some packages that can help visually impaired people?   Like a zoom shortcuts with his mouse … I don't know … And also packages that can write with voices? He uses accessibility stuff in his phone doing that, so it might be good on his PC as well.

Are there specific configurations and packages that could help blind people to use Ubuntu?  Blind people do use computers, and Ubuntu should be accessible to everyone.  It would be interesting to have the testimony of a totally or partially blind person who uses Ubuntu sharing their experience.   (Using Ubuntu 16.04, but I'm open to other Linux distributions)


Is there a way to hyperlink within Notes, from one Note entry & back?

In Apple Notes on the Mac, is it possible to reference a note from within another note (by way of hyperlink)? So, for example, if I had two notes:  Thoughts about pastries Pastries are great. Truly wonderful treats. But you know what my favorite types of pastries are? Donuts. I've even made a list of the types of [donuts I've eaten].  and  Donuts I've Eaten Chocolate, Glazed, Frosted, Encrusted…  How could I link the text [donuts I've eaten] from the first note to the second note?


Update:   Here I have shwon some examples of such a comments but they were already deleted after I have flagged it  How can we avoid such a comments? How can we delete it?  Is it correct?   Update:  Moderators have deleted such a comment after I flagged it with      using comments to chat with other SO users. Off-topic comment    and not  declined it

During a recent Review Suggested Edits session, I came across a reviewer who is clearly rubber stamping edits (Approved 550 edit suggestions and rejected 7), and who had missed an  by an anonymous miscreant.  How about considering mechanisms, which:   Give feedback to reviewers that their reject rate lies outside a normal range of the larger community (e.g. outside of 2 sigma)  Introduce some kind of penalty for repeat rubberstamping (e.g. revoking review rights and / or revocation of review badges?)


How can i make a windows  installation USB? I already have the iso file, and i need to install windows 7 dual boot as i have to install my company software.  I am using netbook.  I used unetbootin, but failed.  Any quick and easy solution?

I'd like to create a Windows bootable USB stick, but I don't have a Windows machine with me at the moment to do so. How could I achieve the same using Ubuntu?


I am entering the realm of cryptography and encountering Number Theory related stuff a lot (As expected). I have a good knowledge and background on mathematics but I have been away for a while. So if anyone can give me a refresher (basic, not deep) about the below it would be perfect. (links to proper explanations are also a good idea)   B : {0, 1} d   --> {0, 1}d    A Є {0, 1}d    uniform distribution

It has been a while I was away from maths, and I am doing a comeback.  I would highly appreciated if someone (in detail, and plain 6th grade English) can explain these to me.   B : {0, 1}d --> {0, 1}d A Є {0, 1}d uniform distribution vectors (I know they have more than a single characteristics, like direction and weight) but what doe they mean inside cryptography, for example, vectors of sub keys). differential (what does it mean in general? does it mean differences between numbers or so. An example would be appreciated. For example, what does Differential XOR mean)   Thanks :)


How can I show that $\arctan (x) + \arctan(1/x) =\frac{\pi}{2}$?   I tried to let $x = \tan(u)$. Then   $$ \arctan(\tan(u)) + \arctan(\tan(\frac{\pi}{2} - x)) = \frac{\pi}{2}$$  but it does not seem useful.      I'd appreciate most a proof that gives intuition and / or uses geometric   insight.

Verify the identity: $\tan^{-1} x + \tan^{-1} (1/x) = \frac\pi 2, x > 0$  $$\alpha= \tan^{-1} x$$  $$\beta = \tan^{-1} (1/x)$$  $$\tan \alpha = x$$  $$\tan \beta = 1/x$$  $$\tan^{-1}[\tan(\alpha + \beta)]$$  $$\tan^{-1}\left [{\tan\alpha + \tan\beta\over 1 - \tan\alpha \tan\beta} \right]$$  $$\tan^{-1}\left[ {x + 1/x\over 1- x/x }\right]$$  $$\tan^{-1}\left[{x + (1/x)\over 0} \right]$$  I can't find out what I'm doing wrong..


I'm working with matrices in R, and noticed something strange:  set.seed(1234) m <- replicate(10, rnorm(20)) all(m / 7 == m * (1/7)) #FALSE   Why is that ? Shouldn't the multiplication by the reciprocal be equivalent to normal division ?

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


As the title suggests. Is there a prediction of quantum mechanics that could be construed as representing an "energy-time uncertainty relation?" Does there exist any reference to such a prediction, or is it obviously false on some level?

In non-relativistic QM, the $\Delta E$ in the time-energy uncertainty principle is the limiting standard deviation of the set of energy measurements of $n$ identically prepared systems as $n$ goes to infinity. What does the $\Delta t$ mean, since $t$ is not even an observable?


KOMA scrbook class. I'd like to change the font on the half-title page, which is created by the \extratitle command.   Here is a MWE:   %!TEX TS-program = xelatex  %!TEX encoding = UTF-8 Unicode     \documentclass{scrbook}   \usepackage{xltxtra,xunicode} \defaultfontfeatures{Mapping=tex-text} \setromanfont[Mapping=tex-text]{Hoefler Text} \setsansfont[Scale=MatchLowercase,Mapping=tex-text]{Gill Sans} \setmonofont[Scale=MatchLowercase]{Andale Mono}  \begin{document}  \newfontfamily\myfunt[Ligatures=TeX]{Papyrus}  \begingroup   %begin font change \myfunt %%% Here is where \extratitle begins    \extratitle{\vspace*{18\baselineskip}   \begin{center}\textbf{\Huge Great Title}\end{center}}       \endgroup  %%end font change         \title{Great Title}     \author{The Author}     \date{}     \maketitle    \end{document}   When I compile this no errors are thrown, but the half title page doesn't use the Papyrus font. I've also tried changing the name to "Papyrus Regular" which throws a "File Not Found Error" and even "Papyrus.ttc" which is the fully name of the font in the Library/Fonts folder. This also throws a "File Not Found Error." Not sure if the issue is with .ttc fonts, Hoefler Text is a .ttc font as well and displays properly.   The related question (marked as identical) deals with font size, this question deals with the font face. The two are not identical and take different arguments.

Related question:   KOMA scrbook class. I'd like to change the size of the font on the half-title page, which is created by the \extratitle command.  I only want the font size change to apply to the half-title page and not in the rest of the document. I thought I could do this by creating a new environment but this does not seem to work.   Here is a MWE:  %!TEX TS-program = xelatex %!TEX encoding = UTF-8 Unicode   \documentclass{scrbook}   \usepackage{xltxtra,xunicode} \defaultfontfeatures{Mapping=tex-text} \setromanfont[Mapping=tex-text]{Hoefler Text} \setsansfont[Scale=MatchLowercase,Mapping=tex-text]{Gill Sans} \setmonofont[Scale=MatchLowercase]{Andale Mono}  %\usepackage{moresize}  Can't get anything larger than HUGE %\usepackage{relsize} scaling at 5x had no effect    \begin{document}   \newenvironment{zebratitle}{\changefontsizes{36pt}{\Huge}}   \newfontfamily\myfunt[Ligatures=TeX]{Papyrus}    \begin{zebratitle}   \extratitle{\vspace*{5\baselineskip}    \begin{center}\textbf{\Huge \myfunt Great Title}\end{center}}     \end{zebratitle}    \title{Great Title}   \author{The Author}   \date{}   \maketitle    \end{document}


As the title states i've tried searching but i cant get a border w/ text inside of it to center inside of a background image. As of right now it just centers but sticks to the top (if that makes sense).    .banner {   background-image: url("http://www.hdwallpapers.in/walls/early_snowfall-wide.jpg");   background-size: cover;   background-position: bottom center;   height: 400px;   width: 100%; }  #banner-content {   border: 1px solid #FFF;   margin: auto;   text-align: center;   width: 40%; }

Random misc text for the purpose of practicing

     Thanks for the help in advance!

Best way to center a <div> element on a page both vertically and horizontally?  I know that margin-left: auto; margin-right: auto; will center on the horizontal, but what is the best way to do it vertically, too?


It's weird; I have asked a few questions on this website, but when I login, they're all gone. What's wrong? What should I do to post successfully? Any guidance?

What circumstances can cause a question or answer to be deleted, and what does that actually mean?    How can a post be deleted? When can't I delete my own post? Can I still see my post even after it's deleted? Can I see a list of my deleted posts? How can I undelete one of my posts? What does deletion mean for a post? How do votes to delete work? What are the criteria for deletion? What else should I know about deleted posts? If I flag my question with a request to delete it, what will happen?       For more information, see the articles about  and  in the .


The new version of ubuntu is compatible with the Huawei Matebook D14 (Ryzen 5 3500u)? I have been looking for information about this on the internet and have not found an answer

I have a device on which I would like to install Ubuntu. How do I find out if Ubuntu will work on it?


This is my folder:    This is how it looks like when I press the menu key on my keyboard just after opening the folder:    As you can see above, it is the same menu that we get when we right click the mouse on any empty (white) place in the folder.  This is how it looks like when I press my cursor keys after opening the folder:    This is how it looks like when I press the menu key on my keyboard in this state:    Now my question is, is there any way to go to the state at the 1st picture from the state at the 3rd picture by only using the keyboard? Alternatively, going from picture 3 to this is also acceptable:

If I've got a file (or files) selected in Windows Explorer, the only way I've found to "unselect" them is click with the mouse on some empty space.  I thought Esc would do this, but it doesn't. Also changing focus with Tab or Shift + Tab doesn't work; the file(s) are still selected even if focus goes to the address bar for instance.  Does anyone know of a keyboard shortcut to do this?


I have a SRTM originally set to EPSG 4326. I need to convert it to UTM (EPSG 31983), in order to generate viewsheds.   The original version (EPSG 4326) has square pixels (0.000833333 x 0.000833333) but, when I convert to UTM, the pixel size becomes 91.9372 x -91.8611.  This means that, upon conversion, pixels are becoming rectangular. This makes it impossible to use viewshed in the processing toolbox.   Has anyone encountered this issue? What may be causing it? Any suggestions on how to solve it?

I have a GeoTiff that has been supplied to me with non square pixels (I suspect due to reprojection to lat lon at some point). However the next step in my processing chain requires a Arc ASCII grid as input and so I need square pixels.   To save me trying to guess the original projection can any one tell me how to use GDAL to resample my image so the pixels become square?


Am I correct in thinking that for a given harmonic oscillator, with constant magnitude driving force, the resultant amplitude of the steady-state motion will be generally lower above resonance than below.  If this is the case then is there a reason for this.

This is quoted from A.P.French's Vibrations & Waves:  If the driving force is of low frequency  relative to the natural frequency, we would expect the particle to move essentially with the driving force. This is equivalent in saying that $m\dfrac{d^2x}{dt^2}$ in $$m\dfrac{d^2x}{dt^2} + kx = F_0\cos\omega t$$ plays small role compared to the term $kx$. The amplitude is controlled by spring constant. On the other hand, at frequencies very large compared to the natural frequency, the opposite situation holds. The $kx$ becomes small compared to $m\dfrac{d^2x}{dt^2}$. In this case, we expect a relatively smaller amplitude of oscillation than the above case.  $\bullet$ Why does $kx$ become prominent in the first case & not in the second case? $\bullet$ What is the physical reason behind that the first case has greater amplitude & the second one smaller?


If you compute the 95% CI for a population mean from a given sample, apparently it is taboo to say something like "there is a probability of 0.95 that the true mean lies in this specific CI".  Yet when you look at what "confidence" means, it is a statement about all the possible CI (computed using the same sample size), which says that 95% of these CI will contain the true mean.  When we know that if 1% of the tickets in a lottery have the predetermined winning number, we have no problem saying (after we draw a ticket) the probability we drew a winning ticket is 1%.   Why do we have such a problem making a similar probability statement for a given CI?

It seems that through various related questions here, there is consensus that the "95%" part of what we call a "95% confidence interval" refers to the fact that if we were to exactly replicate our sampling and CI-computation procedures  many times, 95% of thusly computed CIs would contain the population mean. It also seems to be the consensus that this definition does not permit one to conclude from a single 95%CI that there is a 95% chance that the mean falls somewhere within the CI. However, I don't understand how the former doesn't imply the latter insofar as, having imagined many CIs 95% of which contain the population mean, shouldn't our uncertainty (with regards to whether our actually-computed CI contains the population mean or not) force us to use the base-rate of the imagined cases (95%) as our estimate of the probability that our actual case contains the CI?   I've seen posts argue along the lines of "the actually-computed CI either contains the population mean or it doesn't, so its probability is either 1 or 0", but this seems to imply a strange definition of probability that is dependent on unknown states (i.e. a friend flips fair coin, hides the result, and I am disallowed from saying there is a 50% chance that it's heads).  Surely I'm wrong, but I don't see where my logic has gone awry...


The  method on Object, which creates an exact copy of an object, is declared as:  protected native Object clone() throws CloneNotSupportedException;   Why is it native?

If we look at the Java Object class then we can find some of the methods like:  public native int hashCode() protected native Object clone()   What are these natives and how do these methods work?


In my website I try to convert a string to JSON which contains a newline.  JSON.parse('{"hallo":"line1\r\nline2","a":[5.5,5.6,5.7]}');   This produces an "Unexpected token" error. Do I need to escape that somehow?

I've generated some JSON and I'm trying to pull it into an object in JavaScript. I keep getting errors. Here's what I have:  var data = '{"count" : 1, "stack" : "sometext\n\n"}'; var dataObj = eval('('+data+')');   This gives me an error:   unterminated string literal   With JSON.parse(data), I see similar error messages: "Unexpected token ↵" in Chrome, and "unterminated string literal" in Firefox and IE.  When I take out the \n after sometext the error goes away in both cases. I can't seem to figure out why the \n makes eval and JSON.parse fail.


Do graphic designers format and proof read documents?  We are editors of large reports, mostly from government. The drafts we get are often a mess of formats, with heading structures not clear and the text in multiple styles, in boxes and embedded in images. We pity the poor graphic artist who would have to work out the structure of the document and fix all the text up, if the author doesn't use an editor first. So, a few questions ...   Do graphic designers do much text clean-up like this? Is not understanding the structure of a document because of poor use of heading styles a problem? Would graphic designers much prefer to get the text cleaned up and and well-styled, or isn't it really a problem?

I am a graphic designer and my project was to design and print a cocktail catalog. Everything worked fine till the client realized, when I delivered the printed catalogs, that a cocktail΄s description which was given to me was wrong.  The thing is, I sent many presented files of the work and was asking to check that everything was correct before printing the catalog and that because he made a lot of changes till the end of the desired layout.  I understand that it is also my fault, but isn't the client also responsible for this mistake?


I suspect my iPhone's battery is now much worse than it used to be. How can I assess this? Is there some kind of test I can make, to compare it with Industry average?  How long can I reproduce a movie, a specific app, or something like that?

I am looking for a way to check the current health of a battery for iOS devices, similar to how  works for OS X.   How can I check the battery health for an iOS device?


Is there any difference in buying two 1x8GB RAM and a 2x8GB RAM kit? Other than the price.

I bought 4 2x16GB Corsair Vengeance 3200 LPX kits thinking this would be the same as buying 1 128GB kit. I seemed to have lucked out in that my motherboard (ASRock x399 Fatal1ty) can use all 128GB at close to the rated clock speeds (all this despite the memory not being listed on the manufacturer's compatibility list).  When I was running benchmarks with Passmark, I discovered my RAM read/write speeds and latency got nontrivially worse as I added more RAM. With dual channel 32GB, I was on the high end of AMD machines for that RAM model (2400 passmark score; 20k MB/s uncached read); for quad channel 64GB and 128GB, the low end (sub 2100; 14k MB/s uncached read). I was a little surprised by this.  I'm trying to decide if I should return it and get a 128GB kit (e.g. Vengeance LPX 3000).    Should I expect benchmarks to fall simply because I added more RAM (i.e. would 32GB from a 128GB kit be expected to benchmark better than all 128GB)?  Could it be related to the fact that I'm running 4x32GB kits as a 128GB one? (i.e. are larger kits fundamentally engineered differently? I had assumed the differences were primarily packaging and guarantees they were from the same manufacturing batch) Are kits and motherboard manufacturer compatibility charts primarily just guarantees the RAM works at all, or are there likely nontrivial performance gains to be had with a "correct"/supported RAM setup?


I was questioning myself this month how to prove/disprove the general, specific, special Relativity law concerning the relation between gravity and time distortion.  Then I saw on the web this question above coming up a couple years ago on this site but could not answer it anymore (discussion was closed with no clear answer). I think that using the new ultracentrifuges (2 millions Gs), it can be done.  Putting a solution of Iodine 135 isotope in the centrifuge (half life 6,59 hours) and a reference Iodine 135 sample for the same origin outside the centrifuge and spinning it for one week, there should be a very significant difference. As you can see I am not a Physicist and not following all your discussions, I am a genome scientist working a lot in early years with ultracentrifugation for DNA isolation and now retired and interested in the relation between time and gravity.  The question here is a simple experiment where the decay of Iodine 135 that has been spun for one week at 2 millions Gs is compared to the decay of a reference sample that has been left on the table.  My intuition is that there will be a difference between the two samples.  It is a simple experiment (may not be at 2 millions Gs) with a simple measurement.  Any one interested in doing it?    The possibility of slowing time artificially will have many applications.

With today's ultracentrifuge technology, they can spin so fast that the sample can be subjected to  accelerations of up to 2 millions Gs. That is equivalent to two solar masses. Has someone tried to measure the time dilation in a radioactive sample? How calculate that time dilation respect to the time outside the ultracentrifuge, for example one week. I think that that time dilation will be significant enough to be measured.


A pyramid, such as a tetrahedron/3-simplex, or any other isohedron, falls from some height and lands on a vertex. It will eventually end up with a face to the ground.  Why can't it stay balanced on a vertex?  EDIT: this is not the same question as  because there symmetry is assumed. For this question I am not making any assumptions about symmetry. Also, in my situation the object is falling from a height. The issue there is assuming it starts on the ground.

I was asked by an undergrad student about this question. I think if we were to take away air molecules around the pencil and cool it to absolute zero, that pencil would theoretically balance.  Am I correct?  .


I am trying to use a separate domain name to send emails from. But when I using like mail@marketingwebsite.com , the email goes to spam folder. About the actual domain (mail@website.com) it working good , I need to be able to communicate to clients without emails going to spam with the new domain. Any Advice's would be appreciated.

This is a tricky one and I've always relied on techniques, such as permission-based emails (i.e. only sending to people you have permission to send to) and not using blatantly spamish terminology.  Of late, some of the emails I send out programmatically have started being shuffled into people's spam folder automatically and I'm wondering what I can do about it.  This is despite the fact that these particular emails are not ones that humans would mark as spam, specifically, they are emails that contain license keys that people have paid good money for, so I don't think they're going to consider them spam  I figure this is a big topic in which I am essentially an ignorant simpleton.


I tried a number of things but my Application keeps Crashing.  I tried debugging it is returned this error when I run the application.  java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference  package com.zybooks.pigdice;   import androidx.appcompat.app.AppCompatActivity;  import android.app.Dialog; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView;  public class MainActivity extends AppCompatActivity {      final Context context = this;     //private EditText playerName;     private String name;     private int target_score_display;     //public TextView player_name;     private  EditText targetScore;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         //player_name = findViewById(R.id.player_name);         targetScore = dialog.findViewById(R.id.enter_target_score);         //playerName = findViewById(R.id.enter_player_name);            Button start_game = findViewById(R.id.start_game);         start_game.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View view) {                 // custom dialog                 final Dialog dialog = new Dialog(context);                 dialog.setContentView(R.layout.dialogbox);                 dialog.setTitle("Title...");                 Button dialogButton = dialog.findViewById(R.id.start_game_dialog);                 // if button is clicked, close the custom dialog                 dialogButton.setOnClickListener(new View.OnClickListener() {                     @Override                     public void onClick(View v) {                          try{                             String value = targetScore.getText().toString();                             target_score_display = Integer.parseInt(targetScore.getText().toString());                             Intent intent = new Intent(getApplicationContext(),Gameplay.class);                             intent.putExtra("TARGET_SCORE",target_score_display);                             Bundle bundle = new Bundle();                             bundle.putString("TARGET_SCORE",value);                             intent.putExtras(bundle);                             startActivity(intent);                         } catch(NumberFormatException nfe) {                             System.out.println("Could not parse " + nfe);                         }                     }                 });                 dialog.show();             }         });     } }   Trying to pass input taken in the dialog box to the next Activity. Have been struggling with this for over 3 hours.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I am an Indian oil and petrol bunk dealer. I am travelling to UK and Europe in a tour package with my wife. I have started my business in Jan 2018. So I’m unable to refelect my proof of income in my ITR. Kindly suggest what else I can show to prove my income( i have stated my income has 1,60,000 INR per month).  Documents provided:   6 months statement of credit, over draft and saving account bank statement.    1lakh FD statement of my wife. Invoice of purchase of fuel for 6 months indian oil dealership agreement. land documents   Travel itinerary  Flight tickets Hotel booking voucher  Kindly answer my question its not answerd before. Its not duplicate My question: If I giving CA documents along with my previous documents and fill application correctly next time. Will they find any new mistakes and reject the visa again? Pls answer me.

The UK Visas and Immigration Directorate publishes  that provides helpful tips that can result in successful visa applications. Section 2 of this guidance opens is entitled "other documents you may want to provide" (emphasis mine).  Section 2: other documents you may want to provide – all visitors This section provides guidance on the types of documents that you may want to provide to help us consider your application against the Immigration Rules. Previous travel documents/passports, which show previous travel. Financial documents showing that you have sufficient funds available.  These must clearly show that you have access to the funds, such as:  bank statements building society book proof of earnings such as a letter from employer confirming employment details (start date of employment, salary, role, company contact details) where a third party (who is either in the UK or will be legally in the UK at the time of your visit) is providing financial support to you e.g. a business, a friend or a relative, documents to show that they have sufficient resources to support you in addition to themselves and any dependant family should be provided   The first item is "bank statements" and this ties in with the , which says...  evidence that you can support yourself during your trip, eg bank statements or payslips from the last 6 months  (Note 'eg' is a Latin abbreviation meaning "for example"; this appears to be optional rather than a fixed requirement.) Question: How should someone interpret this such that the chances of success are maximized? How many statements should I submit? What are they looking for and what do my bank statements tell about me?


I have python array with filepath in it, I need to sort the files path based on created date. Is there any inbuilt functionality exist for it.   files = ["/path1/filename.text", "/path2/filename.text", "/path2/filename.text"]

I have a script that needs to do some stuff based on file creation & modification dates but has to run on Linux & Windows.  What's the best cross-platform way to get file creation & modification date/times in Python?


I have slave setup and looks like it is running fine.  But does not replicate.  My Master is an IP of my Hosting and my slave in my Remote Server.  My BD master:  Variable    Valor File    mysqld-bin.000019 Position    120 Binlog_Do_DB    asistencias,caja,colegios,intranet,intranet2,papeletas,planillas,postulacion,resoluciones,visitas Binlog_Ignore_DB    mysql,test,app_convoca,intranetugel,moodle_ugel04,postfix,root_cwp,roundcube   My slave:   Variable    Valor Slave_IO_State  Waiting for master to send event Master_Host xxx.xx.xx.xxx Master_User esclavo_hosting Master_Port 3306 Connect_Retry   60 Master_Log_File mysqld-bin.000019 Read_Master_Log_Pos 120 Relay_Log_File  DB-01-relay-bin.000003 Relay_Log_Pos   284 Relay_Master_Log_File   mysqld-bin.000019 Slave_IO_Running    Yes Slave_SQL_Running   Yes Replicate_Do_DB  Replicate_Ignore_DB  Replicate_Do_Table   Replicate_Ignore_Table   Replicate_Wild_Do_Table  Replicate_Wild_Ignore_Table  Last_Errno  0 Last_Error   Skip_Counter    0 Exec_Master_Log_Pos 120 Relay_Log_Space 621 Until_Condition None Until_Log_File   Until_Log_Pos   0 Master_SSL_Allowed  No Master_SSL_CA_File   Master_SSL_CA_Path   Master_SSL_Cert  Master_SSL_Cipher    Master_SSL_Key   Seconds_Behind_Master   0   Show connected slaves  Mostrar esclavos conectados  ID del servidor Servidor 1      But it does not replicate

I am getting no errors yet replication is not working. I wonder where I am going wrong?  My master status is                File: mysql-bin.000002         Position: 2006432     Binlog_Do_DB: site3,site2 Binlog_Ignore_DB:    My Slave Status is   *************************** 1. row ***************************                Slave_IO_State: Waiting for master to send event                   Master_Host: 104.131.119.241                   Master_User: drupal                   Master_Port: 3306                 Connect_Retry: 60               Master_Log_File: mysql-bin.000002           Read_Master_Log_Pos: 2006432                Relay_Log_File: mysqld-relay-bin.000003                 Relay_Log_Pos: 2006577         Relay_Master_Log_File: mysql-bin.000002              Slave_IO_Running: Yes             Slave_SQL_Running: Yes               Replicate_Do_DB: site3,site2           Replicate_Ignore_DB:             Replicate_Do_Table:         Replicate_Ignore_Table:        Replicate_Wild_Do_Table:    Replicate_Wild_Ignore_Table:                     Last_Errno: 0                    Last_Error:                   Skip_Counter: 0           Exec_Master_Log_Pos: 2006432               Relay_Log_Space: 2006879               Until_Condition: None                Until_Log_File:                  Until_Log_Pos: 0            Master_SSL_Allowed: No            Master_SSL_CA_File:             Master_SSL_CA_Path:                Master_SSL_Cert:              Master_SSL_Cipher:                 Master_SSL_Key:          Seconds_Behind_Master: 0 Master_SSL_Verify_Server_Cert: No                 Last_IO_Errno: 0                 Last_IO_Error:                 Last_SQL_Errno: 0                Last_SQL_Error:  1 row in set (0.00 sec)


This question is similar to , but I did not do anything (that I know of) to trigger the change.  My Cruzer 4GB USB flash drive worked for a few years, then a couple days ago my desktop running Windows 7 would not recognize it.  The flash drive does not work on any USB 2.0 or USB 3.0 ports.  The flash drive works fine on two other laptops, and my 8GB Cruzer flash drive (and another different drive) works fine on the desktop.  I also installed a fresh Windows 7 OS on a new formatted drive (in the same desktop machine) and had the same problem with the 4GB flash drive.  I took out the CMOS battery on the motherboard (reset the BIOS), with no change.  I ran USBOblivion and cleared out some old USB information, but the drive still is not recognized.  Bottom line: something seems to be causing a problem with a specific USB flash drive and this machine, but the USB drive and machines seem to work fine otherwise.  Any ideas for what could be causing this or how to fix it?  Edit: I checked a few more machines.  It failed on a similar desktop.  It worked on a laptop running Windows XP.  It failed on a laptop running Windows 7.  It seemed to kind of work, but very slowly on another laptop running Windows 7.  It failed on a laptop running Windows 8.1.  It seems to work better on older machines, so maybe the flash drive is failing, but older machines are falling back to USB 1 while newer ones just give up.

I have a SanDisk Cruzer 32gb flash drive that cannot be read only on a specific computer due to some unknown reason. Do note that all my other flash drives are working fine on this computer. Here's my situation... Background Info I recently bought a HP laptop. Before wiping the laptop's hard disk, I used HP recovery media creator to store the HP recovery image in my flash drive. After I was done with wiping my laptop's hard disk and making sure my clean installation of the operating system works, I wiped my flash drive with the standard Windows formatting utility. I don't like the OEM's recovery stuffs because of all the bloatware, but I backed it up to my flash drive just in case my clean installation fails. The Problem Now, this flash drive cannot be read on my main desktop (running Windows 8) anymore. However, the same flash drive can be read on my other two computers (also running Windows 8) perfectly fine. Observations:  The flash drive cannot be accessed in Windows Explorer or any Explorer alternatives. Received "Windows can't access this disk" error messages when trying to check the disk's filesystem. The flash drive's size cannot be viewed in My Computer.  Ironically, according to the Device Manager, the USB flash drive is detected and working fine. Things I've Tried  Uninstalling the USB mass storage driver and rebooting. Uninstalling all USB drivers and rebooting. Wiping and reformatting my flash drive on the computers that it can work on using MiniTool Partition Wizard. Using BootIce to rewrite the MBR of the flash drive. Copying the MBR of my other flash drives to the problem flash drive using BootIce. I've also tried formatting in FAT16, FAT32 and NTFS.  All of the above methods have failed. Does anyone know what's the problem, or have encountered such errors before? Please enlighten me. Your help is much appreciated. Thank you. =)


I have a issue since I'm not familiar with awk. I have csv file generated from sar -d output converted to csv style:  12:33:41        unix,restarts 12:35:00,lofi4096,0,0.0,0,0,0.0,0.0 ,iscsi0,0,0.0,0,0,0.0,0.0 ,scsi_vhc,0,0.0,0,0,0.0,0.0 ,nfs1,0,0.0,0,0,0.0,0.0  12:45:00,lofi4096,0,0.0,0,0,0.0,0.0 ,iscsi0,0,0.0,0,0,0.0,0.0 ,scsi_vhc,0,0.0,0,0,0.0,0.0 ,nfs1,0,0.0,0,0,0.0,0.0   and I want to convert to this  12:33:41        unix,restarts 12:35:00,lofi4096,0,0.0,0,0,0.0,0.0 12:35:00,iscsi0,0,0.0,0,0,0.0,0.0 12:35:00,scsi_vhc,0,0.0,0,0,0.0,0.0 12:35:00,nfs1,0,0.0,0,0,0.0,0.0  12:45:00,lofi4096,0,0.0,0,0,0.0,0.0 12:45:00,iscsi0,0,0.0,0,0,0.0,0.0 12:45:00,scsi_vhc,0,0.0,0,0,0.0,0.0 12:45:00,nfs1,0,0.0,0,0,0.0,0.0   My attempt but since awk reads line by line I don't know out to keep the previous line value. I would expect that what I have should work. Any idea how I can obtain my desired result. I tried with awk, but I guess this should be possible with sed or the hard way with a custom shell script ( I'm trying to avoid doing this part ).  #!/usr/bin/awk -f BEGIN {         FS=","; } {         print $1         if ($1 != "") {                 mydate=$1;                 print $0;         }         else {                 print $mydate","$0;         } }   Running the system with Solaris 11.1.


Can someone please advise how you would be able to view the creation of a file i.e birth of a file. The stat command in the terminal doesn't work for me. thanks

I need  to find the creation time of a file, when I read some articles about this issue, all mentioned that there is no solution (like , ).  When I tried the stat command, it states  Birth: -.  So how can I find the creation time of a file?


I am making a slope raster in QGIS from DEM. My DEM was made using WGS84 coordinates system. Do I need to be using a z scale conversion factor ? If so what would that be?

I have a DEM layer from ASTER satellite and I want to get the slope information from it.  I use terrain analysis > slope, but the output is so wrong. Why is that?  Here is the DEM:     And here is the "Slope" that is totally wrong. It should stretch the values from 0 - 89.9097 but it does not.


Prove that if $A$ is a set with infinite cardinality, then there exists a bijection between $A$ and $A^2$.   I know that there exists a bijection between $\Bbb{R}$ and $\Bbb{R^2}$, but I don't think that technique can be generalized.  I think the proof of this may be highly non-trivial. Any help would be great.

The axiom of choice is equivalent to the following statement: if $X$ is an infinite set then the cardinal of $X^2$ is the same as that of $X$. Is there an elementary proof of this statement?


I have two camera lenses; one is a Yashica 35-70 mm lens which I am using on a Yashica FX-7 Super manual 35mm film camera. The other is a Canon 28-80 mm lens which came with the Canon EOS 66 35mm film camera.  Can I use either of these lenses on any of the popular DSLR cameras makes, like Canon, Nikon, Sony, or Panasonic?

I've got some lenses of brand X, but I've just got a new camera of brand Y. How can I tell if it's possible to use my lenses on my camera? I accept that I may lose a lot of automatic functionality like autofocus, aperture control and metering when using an adapter to connect the two.


In , a user edited my post to, among other things, have ` characters. The side-by-side Markdown diff shows that [the zsh manual][1] was changed to have ` characters around "zsh", but the visual side-by-side diff shows that "manual" was changed in addition to "zsh".

For example, when watching revision 2 in  in the side-by-side mode, word "answer" marked as deleted on the left hand side and as added again on the right hand side:        If we switch to the side-by-side markdown mode no "answer" word is highlighted at all (correctly):


Normally user-specific config files would be dotfiles in the home-directory. If the user wanted a little more, they could put it in a dotfiles folder and symlink the files or use gnu stow to handle that.  Is there anything like that for config files that are not in the home folder? For example, if I wanted to track /etc/sudoers in a git repo. Is there another way to do that outside of copying that file to my dotfiles directory, tracking it, and copying it when I make changes?

I am thinking on a system, where /etc were tracked on a remote git repository. I am thinking on a git workflow, where every host machine where a different branch.  Every previous versions on every machine could be easily tracked, compared, merged.  If a /etc modification had to be committed on many machines, it could be easily done by some merging script.  In case of an "unwanted" /etc change, this could be good visible (even alarm scripts could be tuned to watch that).  Anybody used already a such configuration? Are there any security problems with it?


This is my second time creating a Pokemon Go account through Google. My first account stopped working after about 2 days. I tried to figure out why that happened and a friend asked if I had verified my e-mail account. But I never received an e-mail from Pokemon Go requesting verification. And, on the second time around, I have again not received that e-mail. Will that be an issue?

I cant verify my email on Pokemon Go. If I click on 'Verify your email' they send me to  and apparently my account isn't activated.   Somebody know what to do?


When walking yesterday I stumbled upon one of these humorous1 signs "my dog runs from the gate to the door in 4 seconds, if you are slower stay where you are". This made me think about the general problem  The unfortunate guest starts running at the orange position with speed $v_\textrm{h}$, as does the dog. The dog always runs directly towards the guest with a speed $v_\textrm{d}$. The blue color shows the situation after some time. $v_\textrm{h}$ and $v_\textrm{d}$ are constant. I am curious about the shape of the dog's path. Being nowadays better with computer than with math, I will simulate this experiment2 but would like to understand whether there is hope for a formal mathematical solution - and how to get there (even pointing to the general direction would be wonderful). It would be a great test before diving into the second footnote. Now that I think about it, it should be similar to the path of a swimmer in a river who swims directly towards the bank  1 The level of humour depends on the size of the dog. 2 I will also simulate the problem where $v$ is a function of time. I started to think about some realistic functions such as $v_\textrm{h}(t) = \alpha te^{-\beta t}$ (you start fast, then get tired) or a velocity that is a function of the distance between the protagonists. I believe that this is too complicated for a formal solution.

Consider this equation :   $$\sqrt{\left( \frac{dy\cdot u\,dt}{L}\right)^2+(dy)^2}=v\,dt,$$  where $t$ varies from $0$ to $T$ , and $y$ varies from $0$ to $L$.  Now how to proceed ?   This equation arises out of following problem :   A cat sitting in a field suddenly sees a standing dog. To save its life, the cat runs away in a straight line with speed $u$. Without any delay, the dog starts with running with constant speed $v>u$ to catch the cat. Initially, $v$ is perpendicular to $u$ and $L$ is the initial separation between the two. If the dog always changes its direction so that it is always heading directly at the cat, find the time the dog takes to catch the cat in terms of $v, u$ and $L$.  See my solution below :   Let initially dog be at $D$ and cat at $C$ and after time $dt$ they are at $D'$ and $C'$ respectively. Dog velocity is always pointing towards cat.  Let $DA = dy, \;AD' = dx$  Let $CC'=udt,\;DD' = vdt$ as interval is very small so $DD'$ can be taken straight line.  Also we have $\frac{DA}{DC}= \frac{AD'}{ CC'}$ using triangle property.  $\frac{dy}{L}= \frac{dx}{udt}\\ dx = \frac{dy.udt}{L}$  $\sqrt{(dx)^2 + (dy)^2} = DD' = vdt \\ \sqrt{(\frac{dy.udt}{L})^2 + (dy)^2} = vdt $  Here $t$ varies from $0-T$, and $y$ varies from $0-L$. Now how to proceed?


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

All countable ordinals are embeddable in $\mathbb{Q}$.  For "small" countable ordinals, it is simple to do this explicitly.  $\omega$ is trivial, $\omega+1$ can be e.g. done as $\{\frac{n}{n+1}:n\in \mathbb{N}\} \cup \{1\}$.   $\omega*2$ can be done as $\{\frac{n}{n+1}:n\in \mathbb{N}\} \cup \{1+\frac{n}{n+1}:n\in \mathbb{N}\}$, and $\omega*n$ as $\bigcup_{i\le n} \{i+\frac{n}{n+1}:n\in \mathbb{N}\}$  That immediately also gives $\omega^2$ as  $\bigcup_{i \in \mathbb{N}} \{i+\frac{n}{n+1}:n\in \mathbb{N}\}$  And going further is still relatively easy: We can biject the above embedding of $\omega^2$ onto a single interval $(0,1)$, e.g. through $f(x)=1-\frac{1}{x+1}$ since this is an order preserving bijection from $\mathbb{Q}^+$ to $(0,1)$, allowing us to get $\omega^2+n$, $\omega^2*n$ etc. And by iterating that process, we can get any ordinal below $\omega^\omega$.   But this sort of embedding fails at $\omega^\omega$ as the iteration of $f$ doesn't seem compatible with taking the infinite union - figuratively speaking, we'd squish things to $0$. So what would an explicit embedding of $\omega^\omega$ look like? And the question, then, is if it is possible to give an explicit embedding of $\epsilon_0$? Is the fact that Peano arithmetic cannot prove well-foundedness of $\epsilon_0$ an indication that it cannot be embedded by such elementary functions and their iterations?  And what about even bigger countable ordinals such as the Veblen ordinals, Feferman-Schütte, Bachmann-Howard? From its definition, even if the above all are possible, I assume that the definitive bound of where one can define an effective procedure for the embedding must be Church–Kleene - is that a correct conclusion?  Lastly, does the situation change when we use $\mathbb{R}$ instead of $\mathbb{Q}$, which would allow us to use, perhaps, more easily understood yet inherently complex functions?  Edited because $\omega^2 \neq \omega^\omega$


I have this text in /etc/bash.bashrc:  alias dwa='bash /opt/dwa.sh'   I tried to delete it with the following (and similar commands):  sed -i 'alias dwa=\'bash /opt/dwa.sh\'/d' /etc/bash.bashrc   Why did my sed operation fail?

I'm having trouble with escaping characters in bash. I'd like to escape single and double quotes while running a command under a different user. For the purposes of this question let's say I want to echo the following on the screen:  'single quote phrase' "double quote phrase"   How can I escape all the special chars, if I also need to switch to a different user:  sudo su USER -c "echo \"'single quote phrase' \"double quote phrase\"\""   Of course, this doesn't produce the right result.


Hope someone out there can help answer my question or at least direct me to a path. I want to animate a plane wrapping onto a sphere as the sphere goes through the plane.   Another way of putting it: As the sphere approaches the plane, the plane that touches the sphere begins to wrap around it taking it's shape while the rest remains flat.   basically, something like this    Thank you so much for anyone that took the time to look and help!

Is there any way to achieve this effect: Where a ball intersects and "morphs" into another ball like  (Terminator T1000 style)...?  E.g: I have this blob that needs to morph into this wall, but the wall won't really change in thickness.    Thanks in advance.


I have an old file attachment (file.zip) in my Gmail account. I want to download it but now Gmail says that the file that I want to download is blocked because it is a virus. I think one trick is to forward it to another mail provider but I can't forward it for the same reason. Anyone know a trick to download that file?

Gmail seems to have deleted the attachment of an email I had sent to myself a while after I sent it. The reason Gmail hints at is that the file is detected as a virus (it's not): is there any way to get access to that file?    The "Learn more" link redirects me to , which says:     What happens if a virus is found?      If Gmail detects a virus on an attachment, we reject the message and   notify the sender. If a message that’s already in your account has an   infected attachment, you won’t be able to download it.      If an attachment you're trying to send is infected with a virus, Gmail   will display an error message to tell you, but it won't clean the   file. To send the message without that attachment, click the link in   the error message that says Remove attachment and send.      If Gmail detects that you're trying to send an infected attachment,   try running your anti-virus software in case your hard drive is   infected. If you don't have anti-virus software, you might consider   purchasing or installing one of the popular applications so you can   protect your computer and information from viruses.   If I try to forward the email, I cannot forward the attachment:    Is there anyway I can retrieve access to my file?


When two defenders (opponents) are playing the ball between each other and it then deflects off one of them to an attacker in an offside position. If the attacker then take possession of the ball, is that an offside offence?

I was refereeing a 10 year old's junior game today and this situation happened. The home team's defender attempted to  pass from their own half to their forward who was in an offside position beyond the halfway line.  I was going to blow the whistle but the ball deflected off an away defender and then went to the originally offside attacker who put the ball wide.  I viewed this as onside at the time because the ball struck the away team player, however now I think it was offside because at the time of pass, the home player was offside.  Is this offside or not?


I have calculated p-values of two independent groups (each group contains 17 samples and each sample is 100 points). I used scipy's . Further, I combined the p-values using  as suggested by one of my colleagues. However, the p-values are just too small to make any sense to me. Here is a sample output:  import scipy.stats as stats p_value_list = [3.3629559156133476e-56, 1.966307600030748e-254, 6.3484089727582271e-103,                  3.1221165197874102e-92, 5.8797795864262639e-128, 4.0807369798923832e-130,                  1.205918004734663e-187, 8.9953478731039129e-19, 2.1492251770664035e-127,                  0.11623743456915718, 6.182421882338173e-13, 3.7920992534448722e-112, 3.5888837913096105e-97,                  7.5565994692959197e-134, 0.0026669650138866794, 4.0844220972198632e-16, 4.583685848455044e-95] results= stats.combine_pvalues(p_value_list) print (results)   Which gives the following output (p is zero!)  (7172.864625387464, 0.0)   Now, my questions are:   What is the meaning of small p-values (something like 1.2e-187)? How to interpret a p-value that is zero? Since I am writing a paper based on this calculation, how can one report this in a peer-reviewed journal?

For some tests in R, there is a lower limit on the  calculations of $2.22 \cdot 10^{-16}$. I'm not sure why it's this number, if there is a good reason for it or if it's just arbitrary. A lot of other stats packages just go to 0.0001, so this is a much higher level of precision. But I haven't seen too many papers reporting $p < 2.22\cdot 10^{-16}$ or $p = 2.22\cdot 10^{-16}$.   Is it a common/best practice to report this computed value or is it more typical to report something else (like p < 0.000000000000001)?