When one wants to express wishes about the present, future or generally how it should be done. For example how should I say that it would be better to study history of fashion instead of biology: Which one is correct way to saying that?     I wish I was studying story of fashion instead of biology!      I wish I had studied story of fashion instead of biology!


Did the Triwizard Tournament continue after 1994?

Before 1994 the last Triwizard Tournament had been held in 1792, where the three headmaster judges were injured by a rampaging cockatrice.  The tournament is held every 5 years, which would put the next one in , the year . Did they carry on with the tradition, or was it deemed too risky again?


I flagged a post as a duplicate over a moth ago, and it is still active:        Why is that?  Before you say this is a duplicate of , let me explain how the answers there are not satisfactory to answer this question.  One answer there says:     it generally takes 24 hours to get a review.   It has not been 24 hours, or even 24 days. It has been over 40 days.  My only guess, based on both answers of that question, is that the "duplicate" section of the Flag Queue is full, like the Close Votes review.


Is there someone who tried to gather horcruxes like how Tom Riddle did?

(This post literally pertains to someone who ever tried to "think" of making a horcrux. Not just long ago before Tom started gathering horcrux, I am ESPECIALLY PERTAINING to those who have thought of it, when Voldemort vanished.  Gathering horcruxes is one of the most unforgivable and violent offense in nature. As Voldemort tried to obtain immortality, he also wants the idea of 'no one can ever defeat me'.  Dumbledore convinced Harry to try each and every possible way to collect Slughorn's memory about that night when Tom came asking about horcrux, that Voldemort is the only one who had successfully turned seven significant things, (diary, diadem, cup, snake, ring, locket, and unintentionally... Harry himself).     "By an act of evil — the supreme act of evil. By commiting murder.    Killing rips the soul apart. The wizard intent upon creating a Horcrux would    use the damage to his advantage: He would encase the torn portion —"   ...     "You think he succeeded then, sir?" asked Harry. "He made a Horcrux?    And that's why he didn't die when he attacked me? He had a Horcrux hidden    somewhere? A bit of his soul was safe?"    "A bit... or more," said Dumbledore. "You heard Voldemort, what he    particularly wanted from Horace was an opinion on what would happen to    the wizard who created more than one Horcrux, what would happen to the    wizard so determined to evade death that he would be prepared to murder    many times, rip his soul repeatedly, so as to store it in many, separately    concealed Horcruxc. No book would have given him that information. As far    as I know — as far, I am sure, as Voldemort knew — no wizard had ever    done more than tear his soul in two."    Excerpt from Hp HBP book 6.   It was a really dangerous thing to do... horcruxes. But Tom Riddle managed to turn and made 7 horcruxes, splitting his soul into seven hidden pieces.  Having said this, is there any chance that another bad wizard tried to gather horcruxes? For some reason, if that wizard tries to gain immortality, he also wants to be undefeatable, higher than Voldemort's rose to power.  Did someone tried to make a horcrux, specifically, did someone had that kind of idea pop into his/her head, just to gain immortality? Just like what young Tom Riddle desires?


I'm flying in economy plus with United airlines. What's the best possible seat to get with the most room? For legs, body, etc


How many packages of Ice Cream can you make out of 6 flavors

The I Scream Shop specializes in triple scoop sundaes. How many different triple scoop sundaes could be made using these flavors: vanilla, chocolate, strawberry, cherry, lime, and lemon?  I attempted to solve this problem by breaking it down into three cases: The first case involves the same flavor 3 times in a row. The second is 2 of a kind and then another flavor. The third is for ice cream containing three different flavors.  EDIT: The order of the scoops does not matter for each ice cream served.  The main problem I have is that I feel my work is not only incorrect, but also for the cases that I did manage to find an answer, I wish to find a more concrete answer instead of counting.  Case $1$: For three different ice creams, we have $\binom63= 20$  Case $2$: This case we can choose two different flavors. There are $\binom62$ ways of doing this. Now we must consider which one of these flavors doubles. At this point, I had a gut feeling that it is twice as much, but I'm not to sure how to do this for $n$ scoops.  Anyways, the total here is $\binom62\times{2}= 30$  Case $3$: We choose one flavor, so there is $\binom61= 6$ ways.  Therefore, there is a total of $20+30+6=56$ possible ice cream scoops. Again, my main concern is if there is a more concrete and general way to do the second case, or in the general, the cases between the two extremes- choosing one and choosing all different.


After git reset --hard without git add, can I still restore the unstaged files back?

I have not found any solution for this besides people saying no way. I am just hoping that someone knows a new trick that could do this.  So here is what I did.  git commit -m "test configure finished"  git status On branch master Changes not staged for commit:   (use "git add/rm <file>..." to update what will be committed)   (use "git checkout -- <file>..." to discard changes in working directory)   git push origin master   git revert HEAD error: Your local changes to the following files would be overwritten by merge:   git reset --hard fb305ae7d5e01e595986 a3753cbdd22ead4cb945 HEAD is now at fb305ae    I did not perform a git add before these commands.  Can I get those unstaged files back???


Create 26 JButton(fill with alphabet) whichever one clicked a label will disblay the letter(Can't find the error)

Need to create 26 JButtons(A-Zbuttons) when i click one of the button the only 1 JLabel will display the letter) for example if i click QButton the Label will display "Q".  Need to use GridLayout and 5 JPanel(first 4 panels hold 6 letters and the 5th panel hold 2 button and 1 JLabel).  package JFileCaninet; import javax.swing.*; import java.awt.event.*; import java.awt.*; public class AlphabetFiles extends JFrame implements ActionListener     {      private JPanel panel1;     private JPanel panel2;     private JPanel panel3;     private JPanel panel4;     private JPanel panel5;     private JLabel displayLabel;     private JButton[] alphabetButton = new JButton[26];     //char[] abc = new char[26];         public AlphabetFiles()     {          super("file sort");          setSize(400,300);          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);          buildedPanel();          add(panel1);         add(panel2);         add(panel3);         add(panel4);         add(panel5);          panel1.setLayout(new GridLayout(1,6));         panel2.setLayout(new GridLayout(1,6));         panel3.setLayout(new GridLayout(1,6));         panel4.setLayout(new GridLayout(1,6));         panel5.setLayout(new GridLayout(1,6));          setVisible(true);         }         private void buildedPanel()        {         int num=0;         for(char i='a'; i<='z'; i++)         {              alphabetButton[num++] = new JButton(""+i);              alphabetButton[num++].addActionListener(this);          }          for(int i=0 ; i<6 ;i++)//a to f         {             panel1.add(alphabetButton[i]);         }         for(int i=6 ; i<12 ;i++)//g to l         {             panel2.add(alphabetButton[i]);         }         for(int i=12 ; i<18 ;i++)//m to r         {             panel3.add(alphabetButton[i]);         }         for(int i=18 ; i<24 ;i++)//r to x         {             panel4.add(alphabetButton[i]);         }         for(int i=24 ; i<27 ;i++)//r to x         {             panel5.add(alphabetButton[i]);         }           panel5.add(displayLabel);         }         public void actionPerformed(ActionEvent e)        {         JButton holder8 =(JButton) e.getSource();         displayLabel.setText(holder8.getActionCommand());        }         }      package JFileCaninet;  public class Main {      public static void main(String[] args) {         //AlphabetFiles al =         new AlphabetFiles();         /*try         {             new AlphabetFiles();         }         catch(NullPointerException nullPointer)         {             System.out.println("NullPointer occur");         }*/      }  }


The business was registered officially.  or  The business was officially registered.  Where to place the word 'officially'?


Two normal subgroups and isomorphism theorem

Question  Let $N_1$ and $N_2$ be normal subgroups of $G$. Prove that $N_1N_2/(N_1\cap N_2) \cong (N_1N_2/N_1)\oplus (N_1N_2/N_2)$.  I think the homomorphism must be $\phi : N_1N_2 \to (N_1N_2/N_1)\oplus (N_1N_2/N_2)$ such that $\phi(n_1n_2)=(n_1n_2N_1,n_1n_2N_2)$ Then by 1st isomorphism theorem, $N_1N_2/ker\phi \cong Im\phi$ and $ker\phi = N_1 \cap N_2$ But it is hard to show that $\phi$ is surjective. What should I do?


Possible explanation of dark matter/dark energy?

Could dark matter or dark energy be explained by a massive amount of 'mass' creating far reaching gravity far beyond our galaxy? Pulling things away from us at an accelerated rate?  Or maybe a 'sucking' effect of nothingness pulling space/mass?


How does Wild Shape work with special ways to calculate your AC?

Among the effects of Wild Shapes, these two:     Your game Statistics are replaced by the Statistics of the beast, but   you retain your alignment, personality, and Intelligence, Wisdom, and   Charisma scores. You also retain all of your skill and saving throw   proficiencies, in addition to gaining those of the creature. If the   creature has the same proficiency as you and the bonus in its stat   block is higher than yours, use the creature's bonus instead of yours.   If the creature has any legendary or lair actions, you can't use them.      You retain the benefit of any features from your class, race, or other   source and can use them if the new form is physically capable of doing   so. However, you can't use any of your Special senses, such as   Darkvision, unless your new form also has that sense (PHB p.67, "Wild Shape")   Seem to come into conflict with each other when things like Draconic Resilience:     When you aren't wearing armor, your AC equals 13 + your Dexterity   modifier. (PHB p.102, "Draconic Bloodline")   and Barbarians:     While you are not wearing any armor, your Armor Class equals 10 + your Dexterity modifier + your Constitution modifier. You can use a Shield and still gain this benefit.   and Monks:     Beginning at 1st level, while you are wearing no armor and not wielding a Shield, your AC equals 10 + your Dexterity modifier + your Wisdom modifier.   and Stone Sorcerers:     As an action, you can gain a base AC of 13 + your Constitution   modifier if you aren’t wearing armor, and your skin assumes a stony   appearance. This effect lasts until you end it as a bonus action, you   are incapacitated, or you don armor other than a shield.   How would these resolve?


if statement is not getting executed in my java Spell Checker Program

I need to check whether the spelling which is given as input is correct or not, but it is not entering into my if statement.  I am able to verify the word variable is getting "RAINBOW" properly, but why it i snot entering into verification which is in if statement   import java.util.Scanner; class Character {     public static void main(String[] args)     {         String first;         String second;         String third;         String fourth;         String fifth;         String sixth;         String seventh;        String word;          Scanner sc=new Scanner(System.in);         System.out.println("Enter the first letter");         first=sc.next();         System.out.println("Enter the second letter");         second=sc.next();          System.out.println("Enter the third letter");         third=sc.next();          System.out.println("Enter the fourth letter");         fourth=sc.next();          System.out.println("Enter the fifth letter");         fifth=sc.next();          System.out.println("Enter the sixth letter");         sixth=sc.next();          System.out.println("Enter the seventh letter");         seventh=sc.next();         word =first+second+third+fourth+fifth+sixth+seventh;          if(word=="RAINBOW")             System.out.println(word);                 else          System.out.println("Wrong");       } }


I'm trying to write a program that gets a really long number So at first I keep it as a string and am supposed to perform simple operators But I do not know how I'm supposed to store such a long number to do these things  Here's what I did, Header:      class BigInteger { private:     string number;  public:     BigInteger();     BigInteger(int);     BigInteger(const char*);     BigInteger(const BigInteger&);     BigInteger(const BigInteger&&);     //~BigInteger();      void setValue(int);     void setValue(const char*);     //void setValue(const BigInteger&);      string getnum();      static BigInteger fromString(const char*);      const BigInteger operator+(const BigInteger&) const;     const BigInteger operator-(const BigInteger&) const;     const BigInteger operator*(const BigInteger&) const;     const BigInteger operator/(const BigInteger&) const; }   main:      #include "BigInteger.h"  using namespace std;  int main() {     BigInteger a("2837456897658923563425345");      BigInteger b("23784623874623874682736478236");      BigInteger c = a + b;       c /= "4237467864237846";       BigInteger d = a * b - c;   }   thats the main and how i would like it to run, In the implementation of the functions, I managed to get all the constractors to work, but i dont know how to build the operators to work because there is no type that can contain that long numbers... what can i do?


Need to remove GNU GRUB version 2.00-19ubuntu2.1

I originally posted a question about removing Ubuntu and GRUB from a dual boot system. This is what my partition map looked like at the start:    My question was marked as a duplicate by moderators, and I was directed to this post: )  I followed the directions there, and performed the following: I booted into the Windows recovery console, and ran FIXMBR on my HD.  After that, to my surprise, the computer would still boot into GRUB.  (how is this possible??) However, if I selected to boot Windows, it would say on a purple background "error: no such device: 8234ceb934ceb009. Press any key to continue...". When I press a key I get in B&W: "Invalid partition table".  I was able to boot the computer using my PMAGIC recovery disc, and run Partition Editor.  This is what I saw:    Mysteriously, a few reboots later, GRUB vanished. Now I just get the message "Invalid Partition Table". If I boot from my Windows XP installation CD, it no longer sees the installed OS, nor an NTFS partition  It sort of looks like TestDisk sees that there is an NTFS partition there:    Doing a quick search with TestDisk, however, does not seems to find it.


Two definitions for "Run as administrator"?

In my Total Commander icon properties, I see Run as administrator in two places: the Compatibility tab settings, and the Shortcut tab (Advanced button).      Question  Are they both the same?  If not, what's the difference?


Is it possible to enable NTFS compression without formatting?

NTFS offers the option to compress files on the fly, but as far as I know you need to enable this functionality when you format the volume.   Is there a way to enable it on an already formatted NTFS volume, apart for the obvious "move files away, re-format, re-import files". Possibly using a Linux boot?  If not, some insights on the technical why?  NOTE: In my case, the checkbox in the properties window for folders (see Techie007 answer) is greyed out, I just guess that it's because it has not been enabled at format time. There is no such checkbox on the drive's properties window  Context: I use win7, I'm using a 3GB external drive, formatted as NTFS with default options


If $u$ is harmonic and bounded in $0<\lvert z \rvert< \rho$, show that $u$ becomes harmonic in $\lvert z \rvert< \rho$ when $u(0)$ is properly defined.   What I was thinking so far is that so long as $u$ is harmonic in an annulus, the arithmetic mean on concentric circles is a linear function of $\log \lvert z \rvert$: $$\frac{1}{2\pi}\int_{C_{r}(z_{0})} u(z)\,dz = \alpha\log r + \beta.$$ But since $u$ is bounded, the left side stays bounded as $r \to 0$, and it must be that $\alpha = 0$.  Then $\beta = \lim_{z \rightarrow 0} u(z)$ and $\beta$ is the desired $u(0)$.  However, I'm not entirely sure how to show that $\beta$ exists, $u$ is continuous at $0$ with $u(0) = \beta$, or that the resulting $u$ is harmonic.  I was also considering using an argument similar to one used in the characterization of removable singularities, in which Cauchy's integral formula remains valid except at each of finitely many points where the function is not analytic.  But the mean value property isn't quite as powerful as Cauchy's integral formula.  (Studying for qualifiers, problem is from Ahlfors)


I am using the following code to convert the string into a float.,  number = "2.05" float_val = float(number) print(float_val)   When I run this code with Python 3.5.2, the output is as shown below   I am running the same code on a different machine with Python 3.5.1, the output is as follows   My expected output is as in Python 3.5.2. What should be done?  Thanks in advance


"TouchID requires your Password after 48 hours"     Update July 2016   Since posting this question, the message has changed to   Your passcode is required to enable Touch ID   & now   has a documented answer at       I just spotted the above message for the first time today. I've had the phone 3 weeks [new 6s] & never spotted it before.  It's not something I need to 'fix' but I wonder if anyone knows what may trigger it; & why it took 3 weeks to ask me for the first time.  .. or, incidentally & totally opinion-based - why it thinks a 6-digit code is more secure than my fingerprint.  Late thought: Does it do it 2 days after a reboot or OS update? It's done it just one more time, which was perhaps 48h+ after the 9.1 update.  Current guess is it's "new to iOS 9" which is why people have been seeing it on older devices too. I'm still convinced I get it once after every update - but it's something I just dismiss without thinking until later, when I've lost the train of thought that would allow me to 'accurately guesstimate' when it was last rebooted.


Verify that $\sqrt{2}\left\| z \right\| \ge \left|\Re(z)\right| + \left|\Im(z)\right|$

Verify that  $\sqrt{2}\left\| z \right\| \ge \left|\Re(z)\right| + \left|\Im(z)\right|.$  I started off noting that $z=x+iy$ and that $Re(z)=x$ and $Im(z)=y$  Then I know that I have to square both sides, giving me   $$2(x^2 +y^2) \ge x^2+2|xy|+y^2$$  I'm not sure what to do after this.


About few days ago, I've added an answer in Movies and TV SE. For this .  In badge description, it says Highest scoring answer that outscored an accepted answer with score of more than 10 by more than 2x. This badge can be awarded multiple times. for badge . I'm not badge digger or something but curious. As for this moment, I've +84 votes(+85 and -1) while accepted answer has -23 votes (+5 and -28). and also my answer is the highest score (even regardless + or - status) while accepted has -23, mine has +84 and another answer has +12.   Is there something that I am missing? Why don't I have the badge yet?


I changed my user password, but now i can't login. What can i do?

a few minutes ago I changed my Ubuntu user password. Then I turned off the computer and turned it on. After I entered the new password, the system would tell me that the password was wrong. I tried to enter the old password, but without success. Now, I can't log into my computer and I can't even reset my password. What can I do?


How to fix an array method throwing a NullPointerException in Java?

I am trying to make an array of video games. I wanted to implement an array method that will add a new game to the array if there is an available index that is null. however when I try to implement such a method. It throws a NullPointerException. Here is the code in the main method: public static void main(String[] args) {         Game[] arr = new Game[3];         Game t1 = new Game("The Walking Dead", 2012, "Telltale games");         Game t2 = new Game("The Wolf Among Us", 2014, "Telltale games");         Game t3 = new Game("Half-Life 2", 2007, "Valve");                  try {             arr[2].addGame(t3);         } catch(NullPointerException e) {             System.out.println("Caught NullPointer");             arr[0] = t1;         }         System.out.println(arr[0]);     }  And here is the method I have implemented in the "Game" class:   public Game addGame(Game game) {         //TODO         for(int i = 0; i < arr.length; i++) {             try {                 if(arr[i] == null) {                     arr[i] = game;                 }             } catch(NullPointerException e) {                 System.out.println("Caught exception");                 arr[i] = game;                 return arr[i];             }         }         return game;     }    I am very lost and I don't understand how it is throwing the nullpointerexception when I am explicitly trying to check for null to try and insert a new "Game" into the empty index. Any help is much appreciated! Thanks!


I study plain TEX and i need a way to draw a frame around each hbox and vbox in order to undestand how TEX works .. is it possible to do this? thanks !


Create button "Add" to add a new row in sheets

I'd like to know how to add a new row copying all formulas from previous row ..  What I'm looking for is as follows   SR. NO     ITEM CODE       DESCRIPTION       UNIT COST      1       5463345       (A V-LOOKUP)     (A V-LOOKUP)       [ADD BUTTON]       2    By pressing the Add button will create a new row with Sr. No 2 (automatic) and copy all the formulas from previous row with a new add button .  I know how to create a button(drawing) and attach script only thing is don't know what the script is to be :( There is also another submit button in this page which will take all these data into a newly created sheet (so far success) Entering the item code will thus add all the required values.


Could anyone please tell what the lsof mean is?

Hi, there. please check this image.  I had a suspicious IP address and I ran the last command. Anyone please tell what that lsof is? Did somebody run the lsof command on my server? but I've never run that command


I'm trying to calculate complexity of some algorithms but I don't no how to mesure the complexity of the operations with vectors. For example, what is the complexity of push_back()?  In c++ reference I found  "Constant (amortized time, reallocation may happen). If a reallocation happens, the reallocation is itself up to linear in the entire size."  What does it's means? Is the operation of complexity O(n)? (n is the vector length).  Thank you.


Suppose that we replace the axiom of Infinity in ZFC with the statement that every injective function from set to itself is surjective. Is this system equivalent to the system with axiom of Infinity replaced with its negation in ZFC? What is known about properties of this system (completness, consistency)? Thanks in advance.


Prove that 10101...10101 is NOT a prime.

So basically we have a number $10101...10101$ that contains $2016$ zeros and can be written as$ \sum _{ k=0 }^{ 2016 }{ 100^{ k } }$ . I want to prove that this number is not a prime without using anything besides a piece of paper and a pen. I'm stuck on this for quite a few days now.


I'm using the package fancyhdr to format my footers and headers, with my name in the header and a n of m pages format for the footer. Like so:  \pagestyle{fancy} \fancyhf{} % clear all header and footer fields \fancyhead[C]{Name} \fancyfoot[C]{\footnotesize Page \thepage\ of \pageref{LastPage}}   By default, the fancy page style only affects the pages after the first page. I know I can set the first page to the fancy page style using \thispagestyle, but I only want the first page to use the footer, not the header. Is there a way to create a custom style that just the first page will use?


I'm having a hard time getting regex matches to work in a bash case statement.   Example code:  #!/bin/bash                            str='    word1 word2'  echo "With grep:" echo "$str" |grep '^\s*\<word1\>'  echo "With case:" case "$str" in     '^\s*\<word1\>') echo "$str" ;; esac   The example works with grep, but not with case... I'm confused, because some simpler regexes work with case. Does case use a different syntax for regex? Am I just not escaping things properly?


Black border AMD Catalyst Control Center scaling option setting resets after reboot/sleep /log of ...windows

I have connected my 22 inch full hd moniter to my pc by HDMI cable . my graphic card is : ATI radeon hd 4550 . there is black border around of my screen like this :     So I run AMD Catalyst Control Center and like below picture I seted scaling options  to 0 and problem solved !     BUT when I reboot or sleep or shut dwon windows , the scaling options returns to it's previous value and the black border coms back and I should set it again !  how can i solve it ?


Can a lambda function call itself recursively in Python?

A regular function can contain a call to itself in its definition, no problem.  I can't figure out how to do it with a lambda function though for the simple reason that the lambda function has no name to refer back to.  Is there a way to do it?  How?


Is $\langle1-i\rangle$ a maximal ideal in $\mathbb{Z}[i]$?

I'm trying to show that $\langle1-i\rangle$ is a maximal ideal of $\mathbb{Z}[i]$.  I started by assuming there is some ideal $A$ that properly contains $\langle1-i\rangle$, and then I want to show that $1 \in A$, and then I will have that $A= \mathbb{Z}[i] $, so $\langle1-i\rangle$ is maximal.  Is this the right approach?  Thanks  Second Attempt: Because $\forall a+bi \in \mathbb{Z}[i]$, we have $a+bi = (a+b) -b(1-i)$, then we have $a+bi - (a+b) = -b(1-i) \in \langle1-i\rangle$, which implies $a+bi +\langle1-i\rangle = a+b +\langle1-i\rangle$.  So every coset is of the form $c +\langle1-i\rangle$, where $c\in \mathbb{R}$.  Furthermore, $-i(1-i)^2=2 \in \langle1-i\rangle$. Write $c = 2q + r$, where $q,r\in \mathbb{R}$ and $r=0,1$.  Then because $2 \in \langle1-i\rangle$, we have $2q\in \langle1-i\rangle$ and therefore $2q= 2q+r-r = c-r\in \langle1-i\rangle$, so $c+\langle1-i\rangle = r+\langle1-i\rangle$, and every coset is of the form $0 + \langle1-i\rangle$ or $1 +\langle1-i\rangle$. Thus, $1 +\langle1-i\rangle$ is the only nonzero element, and is invertible with itself as its inverse.  Thus, $\mathbb{Z}[i]/\langle1-i\rangle$ is a field with two elements, and by a theorem, $\langle1-i\rangle$ must be maximal.  Is this correct?


Show flow direction for pipes as arrows in QGIS

I have a vector layer (line features) which consists of different pipes. In the attribute data I have fields that indicate the upstream elevation and downstream elevation values.   I am trying to visually depict the flow direction in these pipes using arrows based on the upstream and downstream elevation values. I cannot seem to work out a method in QGIS. Is anyone here able to assist?


A generic noun for something being compared?

I'm looking for a noun to use in place of "comparable object," which would make sense in the following context:     Four "comparable objects" were ranked based on their performance in a recent comparison.   I keep thinking of the word "competitor," but I'm not satisfied with it, which made me think of the following analogy:  competitor : competition :: ??? : comparison


"Write a function that takes a string (character pointer) as input and returns the string reversed. The function should reverse the string in place and return it as the return value of the function."  char *strrev(char *str) {     char* end = str;     char tmp = 0;      if(str) {         while(*end) {             end++;         }          --end;          while(end > str) {             tmp = *end;             *end-- = *str;             *str++ = tmp;         }     } }   I am new to C++. I am facing difficulty with this. Can you please correct my code.


We have a SAAS based product with big vision & currently we are rebranding our product model. Is it the best SEO practice if i am going to use my Brand Name in my URL's of the main pages? Eg:        "example=My Brand Name"  Which one will be the best URL structure towards my TG?


Justification of first order ODE with separable variable method

For a first order ODE in the form of   $$ \frac{dy}{dx}= f(x)g(y) $$  it can be solved by  $$ \int \frac{dy}{g(y)} = \int f(x)dx $$  I feel quite uncomfortable with this method. It seems to me that $\frac{dy}{dx}$ is a function which happens to have a (sensible) notation $\frac{dy}{dx}$. It feels unjustified to be able to multiply part of a notation as if it is a first class mathematical object. But it seems that a lot of methods to solve differential equations rely upon these sort of free form $dx$, $dy$ manipulation.  I searched a bit on this question. It seems that $dx$ and $dy$ can have meaning in the theory of manifolds? I would like to know more about it. In particular, I want some illumination on the connection between manifold theory and ordinary calculus. So I guess I'm looking for something like, $\frac{dy}{dx}$ can actually be reinterpreted in the framework of differential geometry, so that all of the manipulations are justified. But I'm not really sure.


Seven-sided dice from five-sided dice with finite rolls

I have a 5-sided dice, and I want to use it to simulate a 7-sided dice. Is there a way to do this with a finite number of rolls?


How to format an Ubuntu SSD back to windows 10 file system

i have two SSDs 1 running on windows 10 and other Ubuntu 18.04 LTS. I would like to remove Ubuntu completely and use back as window storage.  How do i go about this?


C - Is there a way to print a character on screen immediately after it has been typed by a user, without waiting for the enter key?

I'm trying to understand how to store a character in a char variable and print it immediately on the screen right after it has been typed by a user. The user shouldn't press the enter key.  Edit: I'm using Linux.


Why $p(y_n|y_{0:n-1})$ is a constant in Kalman filter derivation?

In a derivation of Kalman filter, It says that in Equation:  $p(x_n|y_{0:n})=\frac{p(y_n|x_n)p(x_b|y_{0:n-1})}{p(y_n|y_{0:n-1})}$  the denominator $p(y_n|y_{0:n-1})$ is a constant. (See the ,Page 11 equation (28), and it said the denominator is constant in Page 12).  Can anybody explain it to me ?


I would like to solve the complex equation $(z-1)^3=9(\overline{z}-1)$.  Here's what I did:   Attempt 1: $w=z-1$, $w^3=9[cos(-\alpha)+isin(-\alpha)]-9$ Attempt 2: $(x+iy-1)^3=9(x-iy-1)$ Attempt 3: $z^3-3z^2+3z-1=9(\overline{z}-1)$   But it seems like neither of those attempts takes me to the solutions.


Annihilator of Simple Module of Finitely Generated Algebra

Let $C$ be a finitely generated $R$-algebra where $R$ is unital commutative ring. Let $S$ be a simple $C$-module. Show that the annihilator of $S$ in $R$ is a maximal ideal. What I have tried is: When $C=R$ then it is a direct consequence of the simplicity of $S$ as an $R$-module. Further, since $S$ is simple then $S$ is cyclic (i.e. $S=Cy$ for nonzero $y\in S$). Consider the map $$f: C \to S$$ $$c \mapsto cy$$ Then $\ker(f)$ is the annihilator of $S$ in $C$ and $\ker(f) \cap R$ is the annihilator of $S$ in $R$. I got an idea : If we restrict the map $f: C \to S$ on $R$. Then we have an isomorphism: $f(R)=Ry \cong R/(\ker(f) \cap R)$. So to show $R/(\ker(f) \cap R)$ is maximal, it is enough to show that $Ry$ is simple as an $R$-module. Let $ry \in Ry$ be a nonzero element. Then clearly $Ry$ contains $\langle ry \rangle$ as $R$-modules. Conversely, since $ry \in Ry \subset S$ is nonzero, $\langle ry \rangle = S \supset Ry$. So $Ry = \langle ry \rangle$ for any nonzero $ry\in Ry$. Hence $Ry$ is simple and  $R/(\ker(f) \cap R)$ is maximal. Please let me know if there is ambiguity in my answer.


sum of the decimal values upto 5 decimal points in shell preferably awk


How do I convert a string var a = "123456"; in to an array z = [1,2,3,4,5,6];? I tried everything and nothing seems to work. Thanks!


Groups of units of cyclic groups of order $2^n$

In Dummit & Foote's Abstract Algebra (2nd ed.), Corollary 20(2) states the following:     $(\mathbb{Z}/2^n\mathbb{Z})^\times$ is the direct product of a cyclic group of order 2 and a cyclic group of order $2^{n-2}$, for all $n\geq2$.   For the proof, it says "it directly follows from Exercises 22 and 23 of Section 2.3." From these exercises, I learned that $5$ is an element of order $2^{n-2}$ in $(\mathbb{Z}/2^n\mathbb{Z})^\times$ for $n\geq2$, and that $(\mathbb{Z}/2^n\mathbb{Z})^\times$ is not cyclic for $n\geq3$. But I don't see how these imply that $(\mathbb{Z}/2^n\mathbb{Z})^\times$ is a product of two cyclic groups of order 2 and $2^{n-2}$.


Equi-consistency of inaccessible cardinals

I have trouble understanding this wiki , concerning inaccessible cardinals.  First "These statements are strong enough to imply the consistency of ZFC". I guess what they mean by that is if $\kappa$ is a strongly inaccessible cardinal, then $V_\kappa$ is a model of ZFC, where $V$ is the Von Neumann hierarchy.  Then they argue that a proof in ZFC, assuming ZFC is consistent, of the consistency of ZFC+$\kappa$ is impossible. Because it would prove the consistency of ZFC, violating Gödel's incompleteness theorem.  I don't understand this, I imagine a relative consistency proof would rather be a model transformation : given a model of ZFC as input, produce a model of ZFC+$\kappa$ as output. Then we could continue producing $V_\kappa$ to get another model of ZFC. Where is the contradiction in that ? To me it seems we first assumed a model of ZFC, then produced another one. ZFC didn't produce a model of itself from scratch.


How can I keep from getting addicted to Stack Overflow?

The downside... It seems like the type of question that would be a duplicate - but I don't see any, so I'll ask anyway. I'm finding it difficult to not visit Stack Overflow for any significant amount of time. I wake up in the morning, and check Stack Overflow at 5:30 am. I check it before I close my laptop to head off to work. I check it when I connect at the office. I check it throughout the day. How do I break the combination? The upside... I have explored more methods of accomplishing tasks than ever before after having registered here and viewing some questions. I've been introduced to many new tools, practices, and theories about development that I can honestly say make me more confident as a developer.


I'm trying to print a histogram, but am having trouble piecing it all together in main. I'm new to arrays, so if anyone can help with this, it'd be much appreciated. Here are my methods:  public static void main(String[] args) {   randomIntArray(5); }  public static int randomInt(int low, int high){   int x= (int)(Math.random ()*high)+low;   return x;        }  public static int[] randomIntArray(int n){   int[] a = new int [n];   for (int i = 0;i<a.length;i++){     a[i]=randomInt (0,100);   }    System.out.println(printHist(a));   return a; }  public static int[] printHist(int[]a){   int[] k = new int[11];   int i=0;   while (i<=10) {      int counter = 0;     int h=0;     while(h<a.length) {       if (a[h] == i) {         counter++;         h++;       }       h++;     }      k[i] = counter;     i++;   }    return k; }   And here's what I get as output.  [I@fb53f6   Do I need to rethink the way I'm doing this, or is there a simple fix?


Is it ever grammatically correct to say "I'm sure they're."

I currently can't think of a good reason grammatically; but there are plenty in terms of clear communication.


Can a Devil Fruit user drown in a bathtub?

If a Devil Fruit user goes to a bathtub full of water or gets into a spa, will he drown?


Word or phrase for the moment/reason/motive you reveal to someone why you had acted a certain way prior to parting ways

A massive cliché in action movies (especially James Bond), but is there actually a word for that moment when the evil villain reveals their deadly plot to the action hero before (usually attempting and failing at) killing them? If there is no word for this, is there a phrase for the "reason that this was done" i.e. if you asked the villain why they did it (apart from probably for personal satisfaction). In a similar (but un-deadly scenario), is there a word/phrase/motive for the reason someone might feel like they wanted to tell someone (they wouldn't see again) why they had acted in a certain way prior to the final parting (i.e. telling them about past events during their final encounter)? e.g. "I acted like that because I really liked you and what you did made me feel bad at the time, and I felt like I needed to tell you because..." (is this even a good idea haha)


How can I highlight a keyword that contains a dash or a slash?

I have a Clojure listing and I want to colour certain keywords whereas I can only do for strings not including any dash ('-') or slash ('/). But I also need to consider keywords consisting of with dash and etc as well.   I have the following listing:  \documentclass[english,a4paper,12pt]{report} \usepackage[T1]{fontenc} \usepackage[latin9]{inputenc} \usepackage{listings} \usepackage{xcolor}  \input{listingsClojure}  \begin{document} \begin{lstlisting}[         basicstyle={\fontsize{9}{10}\ttfamily},         mathescape=true,showstringspaces=false,         flexiblecolumns=true,         tabsize=2,         numbersep=1pt,         numbers=left,         xleftmargin=0.2cm,         framerule=0pt,language=Clojure         ] (defn NOAsp [?n1 ?n2]   "the numbers"   (l/all       (w/asp ?n1)       (equals ?n2 (.getSourceLocation ?n1)))) \end{lstlisting}   \end{document}   And my lstdefinelanguage Clojure file:  \usepackage{soul} \usepackage{xcolor}  \lstdefinelanguage{Clojure} {     morekeywords={defn, equals,l,all,getSourceLocation,'w/asp'},     morestring=[b]",     morestring=[b]',  }   \lstdefinelanguage{none} {   keywords={},   alsoletter={+},   morekeywords={} }  \newcommand{\fsize}{\fontsize{8pt}{0pt}\selectfont} \newcommand{\fsizesmall}{\fontsize{7.5pt}{0pt}\selectfont\ttfamily}     \lstset{   basicstyle = \fsize,   identifierstyle = \fsize,   keywordstyle = \fsize\color[HTML]{71295b},   keywordstyle = [2]\fsize\bfseries \color[HTML]{859900},   commentstyle = \fsize\color[HTML]{839496},   stringstyle = \fsize\color[HTML]{2429c9},   lineskip={-2pt} }   I would like to see 'l/all' and 'w/asp' and '.getSourceLocation' together in color. Now I only see the following keywords are coloured: 'l', 'all', 'defn' and 'getSourceLocation'. More clearly, the red blocks must be coloured together:


I'm using siunitx, but I don't see how to put an asymmetric error, like this one, in text nor in a tabular environment:  $\left( 1.09^{+0.28}_{-0.23} \right) \times 10^{-3}$   Is there a way with siunitx?


Minimum dimension to embed a graph with no crossings

When adding nodes to a graph with a restriction that all nodes in the graph have a direct connection to all other nodes, how can one detect when a higher dimension is needed so the edges do not cross each other? By crossing I mean one can stretch an edge, circle around all other nodes and not touching any other edge.  For example, three nodes form a triangle and can reside in a 2D plane. Adding one node you can still put four nodes in a 2D plane without crossing edges. But adding the fifth node you have to go to 3D to avoid edge crossing.  It seems like any time a prime number of nodes is added the dimension needs to bump up.


blender api - get current location and rotation of camera tracking an object

I have a camera with an object constraint to track an empty plain axes. I want to get the camera's current rotation, since when the axes move, or when the camera changes location, the camera rotates in order to track the axes.  however, when I read the value using  C.scene.camera.rotation_euler, the values never change, even though the camera clearly has rotated in order to follow the axes.  >>> C.scene.camera.rotation_euler Euler((-0.2408553957939148, -0.0, 0.0), 'XYZ')   How do I get the correct values of the camera rotation?


How does changing to a new host / changing IP address affect SEO?

I am looking to change hosts (transfer fron a dedicated cloud to a dedicated cloud), but I'm worried my high traffic site will lose a lot of SEO authority due to changing the IP address of the the server? Is there any way to keep same IP address but change hosts? What recommendations to minimize the impact on SEO when changing hosts?


This is a question to experienced people that might help us shed some light on the issue.   We noticed a very strange behavior on our site, in Google Analytics. Some dude from Finland, namely, from Kouvola city is hitting one of our pages - only one page on our site, 'bout a hundred times per day, all with an average bounce rate of 90%+...  This is causing our overall bounce rate to go up by 1 to 3% per day... which is very disturbing.. since we're trying to do our best in order to keep it as low as possible. And obviously having it jumped from ~24% to 27%, just because of that crazy dude is not making us happy at all... We tried implementing a geo-targeted script in order to catch this particular visitor and deliver him a juicy message, and it seemed like it helped in the beginning, it has stopped for a day or two, but now he's back...   The geo-targeted script was also logging all IP addresses for page requests originating from Finland in order to find out more details and (in order to block them on the server level, later).. but thing is, it was all mainly cable or DSL connections with various, but not constantly repeating IPs... we are all wondering what is he up to really ?   I think that this page should be kept updated with ideas on how to combat this and perhaps someone could also shed light on what it might be ? What is the reason for doing this "bounce-rate attack", as I call it?  There was a similar question asked on stackoverflow earlier, with no meaningful answer - here -


My parents claimed me as a dependent, but I put on my tax form that no one can claim me as a dependent. Am I getting a stimulus check?

the question pretty much says it all. My dad says he filed me a dependent because the only criteria was to have gone to college for one semester. Which I had done in 2019. I graduated May and moved to one of the most expensive cities in the country. I pay my own rent and I put on my tax form when I started my job that no one could claim me as a dependent. Am I getting a check? Any work around for this?


Dynamically Scheduling Apex to Run at Various Points in Time for different set of records

My use case is that our Salesforce org will do callout to external system at different times of the day. All these data are stored in a custom object, which basically stores the external system URL and the time at which salesforce needs to do callout. Currently, I have around 15 such records, which may increase or decrease in the future. One option I have is to create a separate batch job for all the records to do callout. That means I need to write a 15 batch job. I'm looking for is a way where I can do all callout from one single batch by scheduling it dynamically at different intervals of time.


Sorry, if this question is naive.  If someone asks me,      "You didn't go to school today, right?"   If I did not, should I answer,  Yes or No?  Similarly,      "You do not like eating fish, do you?"   If I do not like eating fish, should I say Yes or No?


Cross Validation Vs Train Validation Test

I have a doubt regarding the cross validation approach and train-validation-test approach.  I was told that I can split a dataset into 3 parts:    Train: we train the model. Validation: we validate and adjust model parameters. Test: never seen before data. We get an unbiased final estimate.   So far, we have split into three subsets.  Until here everything is okay. Attached is a picture:    Then I came across the K-fold cross validation approach and what I don’t understand is how I can relate the Test subset from the above approach. Meaning, in 5-fold cross validation we split the data into 5 and in each iteration the non-validation subset is used as the train subset and the validation is used as test set. But, in terms of the above mentioned example, where is the validation part in k-fold cross validation? We either have validation or test subset.   When I refer myself to train/validation/test, that “test” is the scoring:   Model development is generally a two-stage process. The first stage is training and validation, during which you apply algorithms to data for which you know the outcomes to uncover patterns between its features and the target variable. The second stage is scoring, in which you apply the trained model to a new dataset. Then, it returns outcomes in the form of probability scores for classification problems and estimated averages for regression problems. Finally, you deploy the trained model into a production application or use the insights it uncovers to improve business processes.  Thank you!  I would like to cite this information from https://towardsdatascience.com/train-validation-and-test-sets-72cb40cba9e7  Training Dataset Training Dataset: The sample of data used to fit the model. The actual dataset that we use to train the model (weights and biases in the case of Neural Network). The model sees and learns from this data. Validation Dataset Validation Dataset: The sample of data used to provide an unbiased evaluation of a model fit on the training dataset while tuning model hyperparameters. The evaluation becomes more biased as skill on the validation dataset is incorporated into the model configuration. The validation set is used to evaluate a given model, but this is for frequent evaluation. We as machine learning engineers use this data to fine-tune the model hyperparameters. Hence the model occasionally sees this data, but never does it “Learn” from this. We(mostly humans, at-least as of 2017 😛 ) use the validation set results and update higher level hyperparameters. So the validation set in a way affects a model, but indirectly.  Test Dataset Test Dataset: The sample of data used to provide an unbiased evaluation of a final model fit on the training dataset.  The Test dataset provides the gold standard used to evaluate the model. It is only used once a model is completely trained(using the train and validation sets). The test set is generally what is used to evaluate competing models (For example on many Kaggle competitions, the validation set is released initially along with the training set and the actual test set is only released when the competition is about to close, and it is the result of the the model on the Test set that decides the winner). Many a times the validation set is used as the test set, but it is not good practice. The test set is generally well curated. It contains carefully sampled data that spans the various classes that the model would face, when used in the real world.  I Would like to say this: **Taking this into account, we still need the TEST split in order to have a good assement of our model. Otherwise we’re only training and adjusting parameters but never take the model to the battle field **


Inserting html img tag into table (mysqli insert)

Maybe someone can help me figuring out on how to insert a  into my database table. I've done tons of research but nothing is working.  For example: My sql query below the "content" column in my table I want to be able to place a <img src=''> html tag for the value.  $sql = "INSERT INTO custom_slideshow (username, slideshow_name, name, content, cssanimate) VALUES ('admin', 'sample', 'a', 'HTML_CODE_HERE', 'fade')";   I'm obviously getting a SQL syntax error though. Is something like this possible?


Suppose $gH = Hg, \forall g \in G$. does this imply that $g^{-1}Hg \subseteq H, \forall g \in G$?

Let $G$ be a group and $H \leq G$. Suppose $gH = Hg,  \forall g \in G$. We know that this is equivalent to $gHg^{-1} \subseteq H,  \forall g \in G$ and $gHg^{-1} = H,  \forall g \in G$. However I haven't seen any textbook write what was stated in the title. Is it false?


"Tried to" versus "try to": The -ed suffix as an intervocalic tap

This question isn't answered here:    That question asks about what happens when the following word begins with a consonant in general. This one is asking about the various possibilities for an intervocalic tap if a following word is an unstressed function word beginning with /t/. It's also asking whether there's any possibility for regressive assimilation here.  I read this in American accent book. I quote the text exactly how it is written in the book:  The suffix -ed is not pronounced precisely when it is linked to another consonant. For example, mailed the sounds very much like mail the in the following sentences:  I already mailed the letter. I will mail the letter.  The suffix -ed is not heard at all when it is linked to /t/ or /d/. For example talked to sounds identical to talk to in the following sentences:  I talked to her yesterday. I talk to her every day.   Okay but then my question is, how do Americans distinguish between these two sentences:  I try to call you. I tried to call you.  In the first sentence the /t/ will be realised by a voiced tap because it occurs between two vowels. In the second will we get a regular [t] and then a voiced tap? Will we get a double tap or a double length tap? Or will we just get a single tap? Or maybe here we will just get two regular /t/s? Do native speakers differentiate between "I tried to call you" and "I try to call you" from the context?


I've got a problem with sharing internet connection from my macbook pro to iphone. I've shared Ethernet connection in System Preference and managed to connect to the network from my iPhone but has no internet connection on the iPhone I assume that the problem is because my macbook's Ethernet connection uses proxy. I tried to enabled auto in proxy setting on iPhone but it didn't help. So the question is how to set up internet connection sharing under conditions described above. Thanks in advance.


if I run this simple query:  SELECT * from myapp.latests WHERE organization_id = 1 and user_id = 1;   I get error:  NoHostAvailable:   Running nodetool status results into:  Datacenter: eu-central ====================== Status=Up/Down |/ State=Normal/Leaving/Joining/Moving --  Address    Load       Tokens       Owns (effective)  Host ID                               Rack UN  10.0.0.53  190.96 KiB  256          0.0%              80f8bf0a-c46d-41ce-bb2e-498def5b3792  1a UN  10.0.20.5  189.35 KiB  256          0.0%              f25fe4bf-29b2-4403-8e3e-4e973a5f26ab  1b UN  10.0.0.54  183.13 KiB  256          0.0%              c46ac05a-6cb2-48f1-a776-2c57c33e7719  1a   And here is the description:  DESCRIBE myapp;  CREATE KEYSPACE myapp WITH replication = {'class': 'NetworkTopologyStrategy', 'eu-central-1': '2'}  AND durable_writes = true;  CREATE TABLE myapp.locations (     organization_id int,     user_id int,     date text,     unix_time bigint,     lat double,     long double,     PRIMARY KEY ((organization_id, user_id, date), unix_time) ) WITH CLUSTERING ORDER BY (unix_time ASC)     AND bloom_filter_fp_chance = 0.01     AND caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'}     AND comment = ''     AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32', 'min_threshold': '4'}     AND compression = {'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor'}     AND crc_check_chance = 1.0     AND dclocal_read_repair_chance = 0.1     AND default_time_to_live = 0     AND gc_grace_seconds = 864000     AND max_index_interval = 2048     AND memtable_flush_period_in_ms = 0     AND min_index_interval = 128     AND read_repair_chance = 0.0     AND speculative_retry = '99PERCENTILE';  CREATE TABLE myapp.latests (     organization_id int,     user_id int,     lat double,     long double,     unix_time bigint,     PRIMARY KEY (organization_id, user_id) ) WITH CLUSTERING ORDER BY (user_id ASC)     AND bloom_filter_fp_chance = 0.01     AND caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'}     AND comment = ''     AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32', 'min_threshold': '4'}     AND compression = {'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor'}     AND crc_check_chance = 1.0     AND dclocal_read_repair_chance = 0.1     AND default_time_to_live = 0     AND gc_grace_seconds = 864000     AND max_index_interval = 2048     AND memtable_flush_period_in_ms = 0     AND min_index_interval = 128     AND read_repair_chance = 0.0     AND speculative_retry = '99PERCENTILE';   Any idea?


If there is a disc rotating about its centre, let the surface be frictionless and if a coin is placed anywhere on the disc (not at the center) why doesn't it fly off even though there is a centrifugal force acting on it with respect to the disc's frame?


Is there anything like "displaystyle" for "arrays"?

I have this equation and I would like to "get more space" into it, how to do it?  \documentclass[a4paper,12pt]{article}  \usepackage{amsmath} \usepackage{amssymb}  \begin{document}  \newcommand{\vnull}{\boldsymbol{0}} \newcommand{\vK}{\boldsymbol{K}} \newcommand{\vN}{\boldsymbol{N}} \newcommand{\vT}{\boldsymbol{T}} \newcommand{\vD}{\boldsymbol{D}} \begin{equation*}   \left(     \begin{array}{l|l|l}       \vK & \vN^\top & \vT^\top \\       \hline       - \rho \vD(\mathcal{A}_\nu) \vN & \vD(\mathcal{I}_\nu) & \vnull\\       \hline       - \rho \vD(\mathcal{A}_t) \vT & \vnull                      & \vD(\mathcal{I}_t^+ \cup \mathcal{I}_t^-)     \end{array}   \right) \end{equation*}  \end{document}


I've seen ciphers (usually in spy drama shows) that involve taking a book and writing down an index to individual characters. Essentially it's a keyed substitution cipher, where the key is the name and exact edition number of the book.  Example:  Imagine a book that has 500 pages, with approximately 60 lines per page and 80 characters per line. We might write 238:4:64 to specify that we're on the 238th page, 4th line, 64th character. A five character message might be encrypted into 114:25:22 374:41:46 182:17:62 63:53:8 50:8:18.  Without knowing what the book is, I would imagine this is provably secure as long as the person encrypting never re-used an index. Am I correct in this assumption?    For fun, you could try this out:  12:9:3 183:15:7 238:14:11 310:9:38 194:11:17 7:1:1  I'm using a page:line:character format, ignoring titles, spaces and punctuation. The book is Charles Darwin's , 6th edition.  N.B: I'm not trying to get you to crack this, just adding it because it nicely demonstrates the way this works :)


Proof that $x^y=y^x$ is only true for the ordered pairs $(2,4)$ and $(4,2)$

I wish to prove that the binary relation $R_1=\{(x,y):x\in\mathbb{Z}^+,y\in\mathbb{Z}^+,x\neq y$ and $x^y=y^x\}$ is a finite set comprising just the two elements (2,4) and (4,2).   One can easily verify that $2^4=16=4^2$, implying that indeed $(2,4)\in R_1$ and $(4,2)\in R_1$, but proving that the set contains no other elements seems to be a little trickier.  I would suppose the proof should begin: Assume $x^y=y^x$, and one would arrive at the conclusion that either $x$ must be $2$ and $y$ must be $4$ or vice versa, but I am not entirely certain how one should proceed from such an assumption.  Your input is highly appreciated.  The problem was found in the book "Rings, Fields and Groups: An Introduction to Abstract Algebra" by R.B.J.T. Allenby (Second edition pp. 58).


How can a windows service programmatically restart itself?

I need to write robust code in .NET to enable a windows service (server 2003) to restart itself. What is the best way to so this? Is there some .NET API to do it?


How to calculate appropriate wxTextCtrl widget width for IP address entry?

I am using wxTextCtrl to get IP address from user. Obviously, no IP v4 address may be longer than 15 characters, but the glyph size depends on environment (OS, user settings, etc), so I am a bit hesitant about setting some fixed size for the wxTextCtrl that I use.  What is the best way to calculate the control size in this case?


What to modify if I dd sda1 to another machine?

There are 2 servers, they were application level clusters.   One of the servers / got corrupted, see:   The idea is the next: I would dd the sda1 from the good server to the bad one.   The Q: what should I update on the bad machine, after dd'ing the sda1?   My hints so far:    grep -r HOSTNAME /* and modify it vi /etc/sysconfig/network/* re-generate /etc/ssh/ssh_host_ vi /etc/fstab vi /etc/hosts vi /etc/passwd and /etc/group generate new blkid for sda1


What tool can I use to manage the configuration of my Windows Server environments

I help manage environments for an application that uses cloud-based Windows server VMs. The application stack consists of Windows Server 2008 and Windows Server 2012, SQL Server 2008, IIS, and SharePoint 2010. I have several environments Dev/Test/Stage/Prod. I am looking for a way to do configuration management of those environments to make sure any environmental changes are applied in a consisent way and there is a way to verify that no changes have been made to one environment that have not been made to other environments.  I have been reading up on Puppet, Chef, etc and I like the idea of doing delcarative configuration management. What is a good method or tool to use to help manage the configuration of these environments. I know a little  about SCCM but it is too expensive for this particular situation although I would still be interested in knowing if it has the capabiltiy to do those things.


What site is best suited for this type of question?

I'm looking to ask for some clarification about following paper  but I'm not sure which StackExchange site best suited for such questions.  Example question:     What does -< symbol denote? A concrete operation or just a shortcut for reducer operation?   Would it best be answered by  under Haskell tag? Or perhaps by ? Or even ?  Could anyone point me to the correct site?


How can analytically be  the ?   I found some extremely synthetic equations which from the  (in particular $\mathbf{F} = m \mathbf{a}$) tried to obtain the Kepler's laws, but even if it seemed to be a nice procedure they were too much incomplete.


Can't call methods of class1 containing array of objects of class2

I thought some concepts are clear, but apparently that's not exactly true. I'm sure it's something very simple and asking you to answer rather than blame me or mark as duplicate etc, since I searched other similar questions, but they are not exactly as mine.   So I have this simple class Bank that creates an array of objects BankAccount by giving it the size. The Bank class has method isFull to check if the array is full, which, however I cannot call from a class MainApp where I just create instances to test my methods.  Bank  public class Bank {      // array of BANKACCOUNT objects     private BankAccount[] accountList;      // will hold all the accounts      private int totalAccounts;              // to hold the total number of accounts      public Bank(int sizeIn) {         totalAccounts = sizeIn;         accountList = new BankAccount[totalAccounts];     }      // check if the list is full     public boolean isFull() {         if(accountList.length == totalAccounts) {            return true;         }         return false;     }      // add an item to the array     public boolean add(BankAccount accountIn) {         boolean added = false;         if(isFull()){             System.out.println("The account list is full");             added = false;         } else {             accountList[totalAccounts] = accountIn;             totalAccounts++;             added = true;         }         return added;     }     // other methods...   BankAccount  public class BankAccount {     private String nameOfHolder;     private String accNumber;     private double balance;     private static double interestRate;       public BankAccount(String INPname, double INPbalance){         accNumber = "NL35FAKE" + Randomize.RandomNumGen(); //created a random number for every bank account in a separate class         nameOfHolder = INPname;         balance = INPbalance;     }     // other methods...   Main program  public class MainApp {     Bank[] bankList = new Bank[3];     BankAccount acc1 = new BankAccount("Stacey", 7500);     BankAccount acc2 = new BankAccount("Maria", 15000);     bankList[0].add(acc1);     bankList[1].add(acc2);     bankList.isFull();   // THIS DOES NOT WORK.    I do not see the isFull() method unless if I call it this way:  bankList[0].isFull() which makes no sense as I want to check the link of accounts.   Thanks in advance. :)


The LIGO Gravitational Wave Detection: How frequent in the observable universe?

The currently detectable interval of black hole mergers is on the order of seconds or fractions of seconds. So each black hole merger, no matter how long the end to end process, is only detectable by LIGO for this tiny interval of time. How often are such intervals thought to happen in the observable unverse?


Maybe this question has been asked already (it should be quite simple). I've Googled loads of phrases  (PIVOT, ROWS to COLUMNS, TRANSPOSE &c.) and all I get is  TSQL this, TSQL that and or Oracle this, Oracle that, proprietary function this, proprietary function that well, you get the picture.  I have a simple table structure - if it was any simpler, it'd be a list :-) - i.e. it's two columns.  stock_date       sku ----------       --- 2016-06-01         0 2016-06-02       123 2016-06-03       123 2016-06-04       123 2016-06-06       123 2016-06-07       123 2016-06-03       245 <... &c...>   There may be many thousands of sku's but the date range will be at most a month or so, but can vary, so the code needs to cater for that.   So, I want to make the stock_date field a column.   sku     1   2   3   4   5   6   7 ---     -   -   -   -   -   -   -  123     0   Y   Y   Y   0   Y   Y 245     0   0   Y.... &c.   Ideally, the code would be dynamic and would work with any server (even MySQL).   But if it has to use common table expressions and/or window functions, that's  OK but not proprietary crosstab or pivot functions.


If $\mathbb{P}$ is non-atomic, prove that if $0<a<\mathbb{P}(A),$ then there exists $B\subseteq A$ with $\mathbb{P}(B)=a.$

The following exercise is taken from      Suppose $\mathbb{P}$ is non-atomic and $A\in \mathcal{F}$ with $\mathbb{P}(A)>0.$         Show that for every $\epsilon>0,$ we have $B\subseteq A$ such that $0<\mathbb{P}(B)<\epsilon.$   Prove that if $0<a<\mathbb{P}(A),$ then there exists $B\subseteq A$ with $\mathbb{P}(B)=a.$      I solved the first problem in this .  The following is my attempt to part $2.$  Let $\epsilon_n = \frac{1}{n+1}$ for all $n\geq 0.$ By part $(1),$ the set $\{G\subseteq A: \mathbb{P}(G) <  a\}$ is nonempty. Let  $$ x_0 = \sup\{\mathbb{P}(G): G\subseteq A, \mathbb{P}(G) < a\}. $$ Then there exists $G_0\subseteq A$ such that $\mathbb{P}(G_0) < a$ and $x_0(1-\epsilon_0) \leq \mathbb{P}(G_0).$  By using part $(1)$ inductively, for any $n\geq 1,$ let  $$ x_n = \sup\{\mathbb{P}(G): G\subseteq A\setminus (G_0\cup\cdots G_{n-1}), \mathbb{P}(G_0\cup \cdots G_{n-1} \cup G) < a\}. $$ Then there exists $G_n\subseteq A\setminus (G_0\cup\cdots G_{n-1})$ such that $\mathbb{P}(G_0\cup \cdots G_{n-1} \cup G_n) < a$ and $x_n(1-\epsilon_n) \leq \mathbb{P}(G_n).$  Let $B = \bigcup_{n=0}^\infty G_n.$ Note that $B\subseteq A,$ $\mathbb{P}\left( \bigcup_{n=0}^\infty G_n\right) \leq a$ and $\{G_n\}_{n=0}^\infty$ is mutually disjoint. So, $\mathbb{P}(B)\leq a.$ By countably additivity of $\mathbb{P},$ we have $$ \mathbb{P}(B) = \mathbb{P}\left( \bigcup_{n=0}^\infty G_n \right) = \sum_{n=0}^\infty \mathbb{P}(G_n) \geq \sum_{n=0}^\infty x_n(1-\epsilon_n). $$ I do not know how to conclude that  $$\sum_{n=0}^\infty x_n(1-\epsilon_n) \geq a.$$ Any hint is appreciated.


Are there plans to provide Ubuntu on more (bq) smartphonses?

The BQ Aquaris E4.5 Ubuntu Edition is the only official Ubuntu smartphone currently. Are there plans to enlarge the product palette to include other BQ devices (I'm especially interested in the Aquaris E6) or other smartphones in general.  I know that the first attempt to collection funding for an Ubuntu smartphone failed dramatically, but now that the flashsales of the E4.5 were a success, there might be some news I missed. Following BQ on Twitter in a non-English language is kind of annoying...


Order of Permutation : If $\tau \in S_n$ has order $m$, then $\sigma \tau\sigma^{-1}$ has also order $m$.

I dont understand the following very simple statement:  If $\tau \in S_n$ has order $m$, then $\sigma \tau\sigma^{-1}$ has also order $m$.  The proof is:  Suppose $\tau$ has order $m$.   $(\sigma \tau \sigma^{-1})^{m} = \sigma \tau^{m}\sigma^{-1}= (1)$  Then (using  exercise 17) they say that the order of $\sigma\tau\sigma^{-1}$ cannot be less than $n$ (remember we are in $S_n$), since $(\sigma\tau\sigma^{-1})^k=1 $ implies $\sigma\tau^k\sigma^{-1} =(1)$, and then $\tau^k=\sigma^{-1} \sigma = (1)$  I don't understand the last part.... Who can help me?


How do I use a gray card for shooting a cityscape?

I am shooting wide shots of storefronts. I am standing across a street and using a zoom. I am confused about how to use the QP 101 gray card.  How big does the gray card have to be in the frame?  Do I maintain my camera position and try to zoom in as much as possible to the card being held in front of the store (which means it is very small in the frame)?  Or do I have the person holding the gray card come close to me, as long as the lighting on the card is the same as on the store?


Which character to escape for this to work in ~/.bashrc

I want to add this iostat command to my .bashrc and create an alias for it: iostat -xk 2 $(findmnt -T ~ | awk 'END {print $2}')  I'm adding this to my .bashrc: alias ios='iostat -xk 2 $(findmnt -T ~ | awk 'END {print $2}')'  Unfortunately, it doesn't work. If I run the above iostat command in a terminal it works, but when I run the ios alias it no longer works. And yes, I restart my shell every time.


Get some meaning from apache logs with awk and grep

I am trying to have some meaning from my apache log files: I want to parse my access log and have some statistics about 200 status code hits (how many times each of them was hit).  So I tried to learn some awk magic and here what I got right now:  grep "HTTP/1.1\" 200" access.log | awk '{print $7 } ' | sort | uniq -c | sort -n   This is doing most of the things I want: it selects all logs entries that ended up with 200 hit from access.log then selecting a part which corresponds to path that hit generated, sort them, count each unique element and sort based on the number of times this unique element was hit.  So result looks like this:    1 /public/img/upload/image_3.jpg   2 /public/img/upload/image_2.jpg   8 /public/img/upload/image_1.jpg  18 /public/js/main.js  33 / 236 /index.html   I am trying to push it a little bit further:   because I have logrotate, I have many other files like access.log.1, ..., access.log.N and I want to get this statistics for all of them together. The only solution I have found is to use grep "my 200 expression" -R /pathToDirWithLogs which will grep over all files in directory, which clearly is not nice, because it will grep not only logs. Listing the files is also not an option, because I do not know the number N. I do not really care about each individual file in /public/img/upload/, I just care how many of them was hit. Here I am totally lost, having no idea how to start. But here is an example what I want for my simple output   11 /public/img/upload/*  18 /public/js/main.js  33 / 236 /index.html   Here public/img/upload represents all hits which were generated there: 8 from image_1, + 2 from image_2 and 1 from image_3.  Are there any awk, grep magicians to show me the way?


What is the difference between 'tell' and 'say'

Possible Duplicate:          Both words seem to be used interchangeably. I generally don't differentiate between them and intuitively pick one over the other. Is there a standardized way to distinguish between the two?


Same package from 2 different PPA in sources.list.d; how to force the install from one specific PPA?

The issue:  Let say I have a PPA for a software (i.e. Blender for example;  ) that contains for some reasons, a Python3.6 version.  What I want to achieve:  Let say I want "a better" Python3.6 package, for example from a python dedicated ppa, in my case;   The question:  How does apt chose which package to install and is there a way I can tell apt to install it from one desired ppa upon the others? I guess it will chose the most up-to-date package (am I wrong?), but what if for some reasons I want to keep a specific older version?  The example with python3.6 is "only" an example here, this may be useful for any packages.  Note about the dupplicate: Even if the answer in the suggested links in the comments are the same, the entry points, i.e. "the question" is note exactly the same and lots of people may come to the answer through this search result instead of the other. So, in my humble opinion and strictly speaking, the answer is somewhat a dupplicate, not the question.


Can you recommend a good reference for learning linear algebra with an eventual goal of applying tools from matrix theory? I have Axler's Linear Algebra Done Right and Horn&Johnson's Matrix Analysis books, but I am not sure whether to learn matrix theory, I should study linear algebra first; and if that is the case, whether Axler is the best to study.  Any help is appreciated. Thank you.


Why is there usually no correction for multiple comparisons in Bayesian statistics?

How would you explain to an only moderately statistically literate scientific reviewer that adjustment for multiple comparisons is not necessary when sampling from a Bayesian posterior?


What do "Hit:" and "Get:" mean in the output of apt-get update?

I'm very new to Linux. I'm trying to gain an understanding of APT and would like some clarity on the output of this command. What am I to glean from this?  apt-get update:   Hit:1 http://us.archive.ubuntu.com/ubuntu xenial InRelease Get:2 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] Get:3 http://security.ubuntu.com/ubuntu xenial-security InRelease [102 kB] Hit:4 http://ppa.launchpad.net/webupd8team/sublime-text-2/ubuntu xenial InRelease                                                               Get:5 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB] Fetched 306 kB in 0s (377 kB/s)                              Reading package lists... Done   What is a hit and what is a get?  Thanks.


\mathscript{F} yields undefined control sequence error

I am using MiKTeX 2.9 for compiling my TeX documents. I am getting an error with contains the line $\mathscript{F}$ showing that it is undefined control sequence. How should I rectify it?


How to calculate the gravitational force of a black hole outside event horizon at a given distance $r$?

Let $g_{bh}$ $[kg·\frac{m}{s^2}]$ be the force caused by the gravity of a black hole. How do we calculate the force $g_{bh}(r)$ outside event horizon $R_{Sch} = \frac{2GM}{c^2}$  onto a satellite with mass $m$ at a given distance $r$ from that black hole? And with that formula, is it possible to also derive the speed $v_s$ of this satellite around that black hole (also outside event horizon $R_{Sch}$)? If yes, how?


Starting Tor on Ubuntu: "no such file or directory"

I am new to Ubuntu and everything, so I dont know much of anything about the terminal.  I am trying to install and start Tor. I downloaded the 64bit version from . Then I downloaded Vidalia from Ubuntu's software center.  I entered these lines of code:  cd ~/Downloads tar -xvf tor-browser-linux64-4.0.1_en-US.tar.xz cd tor-browser-linux64-4.0.1_en-US   I was told to then enter:  chmod +x start_tor_browser.sh   But this is where I run into trouble. When I enter the line above, the output says:  chmod: cannot access ‘start_tor_browser.sh’: No such file or directory   Everything up to this point was working fine.   If I try to start Tor via Vidalia, it says Vidalia was unable to start Tor. Check your settings to ensure the correct name and location of your Tor executable is specified. But I have checked and rechecked and the Tor files, and they are exactly where Vidalia has them listed in settings.  If I try to click start-tor-browser (found in the folder named tor-browser_en-US) an error from archive manager pops up saying could not open "start-tor-browser" error opening file: no such file or directory.  I have tried to reinstall Tor, but it did not help.


Today, I uploaded this  on a  I asked on superuser.com. But strangely enough, on my computer the image which is shown on the question is valid but if I look at the same question via mobile site of superuser then I see this . which is invalid. I don't know if the other users who are reporting that the image is invalid are on a mobile device.  And here's the original link to the image uploaded:   It seems to be some kind of bug which is displaying the invalid image on the same link to some users. I doubt that it could be that the image format (.png) I used is unsupported.


mousedown event not working on dynamicallyadded elements

Is there any way to user mousedown event on dynamically added elements     $(function() {   var isMouseDown = false,     isHighlighted;   //$('#our_table').on('mousedown', 'tr', function (event) {   $("#myTable tr").mousedown(function() {     isMouseDown = true;     $(this).toggleClass("highlighted");     isHighlighted = $(this).hasClass("highlighted");     return false; // prevent text selection   }).mouseover(function() {     if (isMouseDown) {       $(this).toggleClass("highlighted", isHighlighted);     }   }).bind("selectstart", function() {     return false;   })   $(document).mouseup(function() {     isMouseDown = false;   }); });  function addRow() {   var arrTables = document.getElementById('myTable');   var oRows = arrTables.rows;   var numRows = oRows.length;    var newRow = document.getElementById('myTable').insertRow(numRows);   var cell1 = newRow.insertCell(0);   var cell2 = newRow.insertCell(1);   var cell3 = newRow.insertCell(2);    cell1.innerHTML = numRows;   cell2.innerHTML = numRows;   cell3.innerHTML = numRows; } table td {   width: 100px;   height: 50px;   text-align: center;   vertical-align: middle;   background-color: #ccc;   border: 1px solid #fff; }  table tr.highlighted td {   background-color: #999; }  body {   user-select: none; }

     0	     0	     0

     1	     1	     1

     2	     2	     2

 <button onclick="addRow()">Add Row</button>


How can I solve this third-degree polynomial? I want to solve it for $y$.  $x=y^3+y-9$  I can simplify it to $x+9=y(y^2+1)$ but I don't get any further.


Summation of $1 + \frac{1\cdot3}{6} + \frac{1\cdot3\cdot5}{6\cdot8} \cdots$

My attempt is as follows  $ \prod_{r=1}^n (2r-1)\cdot\prod_{r=1}^{n} (2r)=  (2r)!$  $\prod_{r=1}^{n} (2r)= 2^n.r!$  The general term for the denominator or $2^{r-1}\frac{(r+1)!}{2}$  $T_r = \frac{\prod_{r=1}^n (2r-1)}{2^{r-2}(r+1)!} = \frac{(2r)!}{2^{2r-2}(r+1)!.r!} = \frac{\binom{2r}{r}}{(r+1)2^{2r-2}}$  How can I proceed with the summation?


I was given an argument in a conversation today and I don't know how to respond to it:  H( k || m || k ) should be a better choice of MAC than the traditional HMAC. The person's rationale was that: "You don't know where to pick up extending from, and you don't know what to finish extending into. Sure using k twice looks ugly, but HMAC also uses the key twice, except it also hashes twice. This only hashes once and therefor is faster."  I couldn't refute this on the spot and now the more I think about it the more it bothers me. Are they right? I'd imagine that the cryptographers who decided on HMAC had way more experience when they made their decision. But then why?


Taking product of cofactor with different row

Given a matrix $A=(a_{ij})_{n\times n}$, let $C_{i,j}$ be the cofactor in position $(i,j)$. By the determinant formula, we have  $$\det A=\sum_{i=1}^n a_{i,1}C_{i,1}.$$  What about if we take a different column for the cofactors, that is  $$\sum_{i=1}^n a_{i,1}C_{i,2}$$  Must this evaluate to zero?


I have Web application. I need to check for late orders every day. I search for the best way to do that ? but I still cant find it ? Is WCF is helpful ? or there are another technology to do that ?


I used once a programm called "movie splitter" or "movie splitzer".  It was fantastic for split a movie in clips. Someone has it? Do you know how to get it? I couldn't find any similar program. Is there one? Thanks a lot


How does the "Community" user reject suggested edits?

We all know StackOverflow is community driven, so edits are allowed. However users with low rep's edits must be approved in the suggested edits review area.  It is said that "Community" approves edits when a reviewer goes to edit your edit and then closes the edit dialogue without changing anything.  -   But how does "Community" reject an edit?


How to start WampServer without providing administrator privileges?

I just set up Dexpot to start WampServer automatically when I enter a new desktop. The problem is that I've hidden my taskbar, and WampServer needs administrative rights. So I have to use Alt-Tab to get to the "Give admin rights" box, and accept it. This is not as automatically as I want. Is it possible to give WampServer admin rights every time automatically?


I am trying to A regression problem where we have n distincts points, $x_{1}, x_{2},\ldots, x_{n} \in \mathbb{R}$. We can treat observations as independent random variables $y_{1}, y_{2},\ldots, y_{n}$ depending on the given formula: $$ y_i = \theta_{0} + \theta_{1}x_i^2 + \theta_{2}\exp{(x_i)} + \varepsilon_i $$ where $\varepsilon_i$ are distributed as $N(0,\sigma^2)$. Derive the maximum likelihood estimator for $\theta_{0},\theta_{1},\theta_{2}$ . Maximising $L(y_n | \theta_0, \theta_1, \theta_2)$ is equivalent to minimising  $   \sum_{i=1}^n(y_i - \theta_0 - \theta_1 x_i ^ 2 - \theta_2 e^{x_i}) ^ 2 $ I am trying to use ordinary least squares to minimise  $   \sum_{i=1}^n(y_i - \theta_0 - \theta_1 x_i ^ 2 - \theta_2 e^{x_i}) ^ 2 $ but really would want to see a step by step solution to reaching. Kindest regards


Is there a command line based way to send pings to each computer in a subnet? Like  for(int i = 1; i < 254; i++)     ping(192.168.1.i);   to enforce arp resolution?


Verifying that $2^{44}-1$ is divisible by $89$

As the title, I was asked to show that $2^{44}-1$ is divisible by $89$.  My first attempt is to change the expression into $(2^{22}-1)(2^{22}+1)$.  Then further simplified it into $(2^{11}-1)(2^{11}+1)(2^{22}+1)$, I used my calculator and was able to show that $2^{11}-1$ is divisible by $89$ but then I don't know how to show it with modular arithmetic. I do think that it is quite similar to the form where we can use the Fermat's little theorem. $(\sqrt{2})^{88}-1$. (Though I do understand Flt can only be applied to integer.)  Can someone tell me whether I can take square root in modular arithmetic as well? I am still pretty new to the modular arithmetic. Thank you very much.


I would like to replace <Path_To_BOOST_LIB_DIR> in a file with the content of ${PREFIX}/lib but this command   sed -i .bak 's|<Path_To_BOOST_LIB_DIR>|echo ${PREFIX}/lib|' src/CMakeLists.txt  produced  set(BOOST_LIB_DIR echo ${PREFIX}/lib)  What did I do wrong?


How to find a probability density function.

Suppose $X$ and $Y$ are random variables that are independent also $X$ and $Y$ are uniformly distributed on the interval $(0, 1)$. If $Z=\max \{ X, Y \}$. Then find the probability that $Z \leq z$ and then determine the probability density function of $Z$.  So far I have said that both $X$ and $Y$ are $1$ in the interval $(0,1)$ and $0$ elsewhere.  I then said that $P(Z \leq z)=P(x \leq z~\cap~y \leq z)$ so we can split these up and then work through to get this to be equal to.  $$ \int_{-\infty}^zdx \times \int_{-\infty}^zdy=z^2$$ but then I got really confused at to what $z$ even wasand how to proceed with the question. Also the $z^2$ can't be right as this gives values greater than $1$.  Any help?


Can we allow 7.5K users  to suggest tag synonyms without a score of 5 in the tag?

Feature Request: Could 7.5K users have the privilege of proposing synonyms without the 5 upvotes per tag requirement?  (in other words unrestricted synonym suggestion)  Background: I would like to be able to suggest tag synonym suggestions.  I do not however, have the required , but someday I will.  Yet many 2.5K users do not have the requisite 5 upvotes in each tag in order to propose synonyms.  I realize that this  for low-rep users.  But could it be made available to users with 7,500 rep?  At this level, they've clearly demonstrated an understanding of the Stack Exchange site.  Note: I'm not requesting the ability to create synonyms -- merely synonym suggestions.  I believe this privilege is currently only available to moderators? (and  )  Lastly, please note that  clearly demonstrates the breadth of simple synonym suggestions which could be made (almost every Stack Exchange site has some), but many haven't even been suggested yet.


I have an Apex web service that takes a query string. I need to update this class to take an encrypted string, find the appropriate record in Salesforce, and then return an encrypted JSON response. I am struggling with writing the unit test for this. I have read through the Crypto Class documentation and am working on the trailhead but I expect I am missing something here.  In my unit test, I have encrypted the lastName param and added to the request.addParmater by calling String.valueOf of the encrypted Blob value. But when I try to decrypt in my API I get an error of Unrecognized base 64 character. This makes think I am misunderstanding how to pass the data to the web service and was hoping I could ask for some help here.  The error happens when I call the EncodingUtil on the string from the request params.   I apologize if the code is a little awkward, just trying to add the encryption in.   Here is part of the GET endpoint   @HttpGet     global static void getPatient() {         Blob cryptoKey = Blob.valueOf(Label.Okta_User_API_Cypto_Key);         System.debug('crypto key value');          RestResponse response = RestContext.response;         String email = RestContext.request.params.get('email');         String phone = RestContext.request.params.get('primaryPhone');         String lastName = RestContext.request.params.get('lastName');         String productSerNum = RestContext.request.params.get('serialNum');             ////test decrypted code here         String lastNametoDecrypt = lastName;         Blob lastNameData = null;         if(lastNametoDecrypt != null){             /////////Error line number here!!!!             lastNameData = EncodingUtil.base64Decode(lastNametoDecrypt);         }         Blob decryptedLastNameData = Crypto.decryptWithManagedIV('AES256', cryptoKey , lastNameData);         String decryptedLastName = decryptedLastNameData.toString();         System.debug('value of decrypted last name ' + decryptedLastName);          /// End test decrypt code }   Below is the unit test  @IsTest static void getPatient() {         Patient__c testPatient = [SELECT First_Name__c, Last_Name__c, Email__c, Birthdate__c, Home_Phone__c         FROM Patient__c LIMIT 1];         // Set up a test request         RestRequest request = new RestRequest();         RestResponse response = new RestResponse();          Blob cryptoKey = Blob.valueOf(Label.Okta_User_API_Cypto_Key);          Blob lastname = Blob.valueOf('kirk');                Blob encrypted = Crypto.encryptWithManagedIV('AES256', cryptoKey, lastname);          request.addParameter('email', testPatient.Email__c );                request.addParameter('lastName', String.valueOf(encrypted));         request.addParameter('primaryPhone', testPatient.Home_Phone__c);         request.addParameter('dob', '1950-01-01');         request.addParameter('serialNum', '12345-54321');         request.httpMethod = 'GET';         RestContext.request = request;         RestContext.response = response;         Test.startTest();        AccountClaimAPI.getPatient();        Test.stopTest();         System.assertNotEquals(null, response.responseBody);        System.assertEquals(200, response.statusCode);     }


Regarding the  badge. I noticed that I have voted above 600 and 50% of which are on questions. But no such badge is awarded in Stack Overflow.


How to prove that $A_5$ has no subgroup of order 30?

I need to show that $A_5$ has no subgroup of order 30. Any ideas?


Issue with Sorting Layers with an NPC and Tilemap

I have a weird thing happening, that I can't quite explain.  I have two scenes, my starting town, and an Arcanist's shop.  When I go into the Arcanist's Shop, the Arcanist NPC stays on the same sorting layer (background layer 0) as my checkered tiles, and the table is background layer 1.  When I start the game, the NPC will switch between being "behind" the table, or on top of it whenever I reenter the Arcanist's Shop scene.  It seems to switch between background layer 0 and 1 with no cause.  I've double checked my sorting layers, they're all where they should be.  I've checked the camera's culling mask, it's fine.  I've checked to see if there are any weird components on anything in my shop scene, and there aren't  See the image attached, this is the same instance of the game, just different times when I enter the Arcanist's Shop.    Screenshot of my tilemap setup:


using induction to prove that the formula for finding the n-th term of the Fibonacci sequence is:

May someone help me? I am trying to use induction to prove that the formula for finding the $n^{th}$ term of the Fibonacci sequence is:  $$F_n=\frac{1}{\sqrt{5}}\left(\frac{1+\sqrt{5}}{2}\right)^n-\frac{1}{\sqrt{5}}\left(\frac{1-\sqrt{5}}{2}\right)^n$$  I tried to put $n=1$ into the equation and prove that if $n=1$ works then $n=2$ works and it should work for any number but it didn't work. I need to prove that this formula gives the $n^{th}$ Fibonacci number.


What is the difference between the "jessie" and "jessie-updates" distributions in /etc/apt/sources.list?

The  gives this example file:  deb http://httpredir.debian.org/debian jessie main deb-src http://httpredir.debian.org/debian jessie main  deb http://httpredir.debian.org/debian jessie-updates main deb-src http://httpredir.debian.org/debian jessie-updates main  deb http://security.debian.org/ jessie/updates main deb-src http://security.debian.org/ jessie/updates main   What is the difference between the jessie and jessie-updates distribution entries?


The indefinite article applied to a group of things

What does applying the indefinite article to a group of things signify?   Inside the box was a pen, pencil and eraser.  Inside the box was a pen, a pencil and an eraser.    Or, perhaps #2 is ungrammatical and you can only use #1?


I need to check the U.K postcode against a list.  The U.K postcode is of a standard format but the list only contains the outward section that I need to check against.  The list contains a series of outward postcode with also some data relating to this outward postcode, so for example  AL     St Albans B      Birmingham BT     Belfast TR     Taunton TR21    Taunton X TR22    Taunton Y   My aim is that when I get a postcode, for example B20 7TP, I can search and find Birmingham.  Any ideas??  The question is different to the ones referred to as possible answers, but in my case I need to check a full postcode against just the outward postcode.


Prove that $ \ \forall x \exists y \ P(x,y) \ $ and $ \ \exists y \forall x \ P(x,y) \ $ are not equivalent

Prove that $ \ \forall x \exists y \ P(x,y) \ $ and $ \ \exists y \forall x \ P(x,y) \ $ are not logically not equivalent  in the domain $ \ \{-1,0,1 \} \ $.   Answer:  Let,   $ x=\{-1,0,1 \} \\ y=\{-1,0,1 \} $   Let $ P(x,y) \ $ be the property such that $ x +y  \ $ is even number.   Then $ \forall x \exists y \ P(x,y) \ $ is true.   Because,   If $ x=-1 \ $ , then take $ y=1 \ $ such that $ x + y=0 \ $ is even  If $ x=0 \ $ , then take $ y=0  \ $ , such that $ x + y=0 \ $ is even  If $ x=1 \ $ , then take $ y=1  \ $ such that $ x + y =2 \ $ is even  But $ \ \exists y \forall x \ P(x,y) \ $ is  $ False $  Am I right ?  I need help.


As we know, we define $$\sqrt{-1}=i$$ But I always wondered, what about $\sqrt{i}$? As far as i can see, it is not an integer power of $i$. Every odd root has a solution in an integer power of $i$, but I can't find one for my question. Is there something I am missing here?


I have a problem. I  deleted some gnome packages , and now Ubuntu won't work as it should.  Plus i  installed some programs for system tweak(new look of icons etc) and delete them and only left Ubuntu Tweak . I log in system and i cross with mouse over icons in slide-bar and name of icons stays but won't go away ... and desktop picture won't show up ... but 2d Ubuntu work ok but my desktop won't responding to left and right mouse clicks(marking,meny) ... ! And i can not see desktop icons but when i go in nautilus and go to home/desktop i see desktop  icons!?  I  clean unnecessary programs and they left of with Ubuntu Tweak and now unity work but and i can change desktop background picture but still can not use desktop shortcuts on desktop.  I always check out manually for updates but it is still the same.   How to reinstall Unity to the latest version without reinstallation of complete Ubuntu .Txk. More you can find here:


I'm new to Java, and I'm currently working on a model as below. I'm getting a null pointer exception at here

This is the class where I'm getting null pointer exception Presenter.java       Display d;      interface Display     {                public List<String> getLists();                  }      public void output()     {         List<String> out = d.getLists(); // getting null pointer here         for(int i=0;i<out.size();i++)         {             System.out.println(out.get(i));                  }     }      public static void main(String[] a)     {          Presenter p = new Presenter();         p.output();     }  }   I'm implementing the interface Display in the class below, and returning the newList as below.   View.java  public class View implements Presenter.Display {      String[] a = {"London","Paris","New York"};      List<String> newList = new ArrayList<String>(Arrays.asList(a));      @Override     public List<String> getLists() {          return newList;     } }   I've looked through several examples but I'm not getting how to get the value of getLists() method in the presenter class.   What am I missing here ? Please help


Sorting by row already pre-selected polygons by location by line?

I have two layers. One with small Polygons and one with a line. I want to select all Polygons which intersect with the line. Additionally the selected Polygons should be sorted by the order of the line, as a line has always a start and a end. The first polygon that intersects at the start of the line should be on top of the attribute table. The second one on second place and so on.


Every time I'm trying to install something, it shows me an error "unable to locate package xxx"  $ sudo apt-get install gddrescue Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package gddrescue  sudo apt-get install testdisk Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package testdisk  $ lsb_release -a Distributor ID: Ubuntu Description:    Ubuntu 16.04.4 LTS Release:        16.04 Codename:       xenial   How can I troubleshoot this issue?  Is that normal...? (Thanks for correcting)  sudo apt update Reading package lists... Done Building dependency tree Reading state information... Done All packages are up to date.


I did use to live in London. I did used to live in London.  Which one is correct? According to the usage of emphatic do with past tense (eg "I lived in London/I did live in London"), did should change ‘used to’ to ‘use to,’ but I didn't find anything about it except in English Grammar Today by Cambridge. However, Cambridge used did with ‘used to.’ Shouldn't emphatic did change ‘used to’ to ‘use to’?  used to From  Emphatic did We can use the emphatic auxiliary did with used to:  We never used to mix very much with the neighbours, but we did used to say hello to them in the street. (Don't use this form in written exams.)  —


For example,      I like chocolate, vanilla, and lemon and orange ice cream.    Indicating "lemon and orange" is a combined flavor, as an item in the list needing an initial and.


Quantum entanglement and spooky action at a distance

When quantum entanglement is explained in "layman's terms", it seems (to me) that the first premise, that we have to accept on faith, is that a particle doesn't have a certain property (the particle is not IN one state or another) until that property is measured.    For example, I have read that a particle may have "spin up" or "spin down" but -- here's where I get lost -- it's not that we don't KNOW which spin the particle has until we measure it, but actually the particle has NEITHER spin until we measure it.  Now, if we accept that premise, then we can see how spooky it is, when two particles are created with correlated spins -- if one has spin up, the other has spin down, but neither particle "has" either spin until one of them is measured.  At that instant, the other particle "assumes" the other spin.   At least that's how I interpret things I have read.  Certainly, if we accept that a particle doesn't actually HAVE the property until it is measured, but rather the particle exists in a superposition of states until the measurement is made, then we "regular citizens" can understand what is meant by "spooky action at a distance".  (As soon as one particle is measured, the other particle assumes the "other" spin, no matter how far away it is.  How did the second particle know the first particle was measured?  That, I think, is the spooky action at a distance (and the information transfer can be faster than light).)  However, from a layman's perspective, I want to cry out "but the particle does have a definite spin, we just don't KNOW what it is, until it is measured!  Duh!"  Now, I can't believe that all of the physics community hasn't thought of that objection -- but -- here's my point -- although the spooky action at a distance can be explained to us, once we accept the premise of superposition -- Why isn't the fact of superposition explainable also, in terms mortals can understand?  I have looked, but I haven't found a layman's explanation of why we should accept the fact that a particle doesn't have a particular spin, or other property, until it's measured.  It sure seems that the particles "have" the properties, even though we haven't measured them yet.    I know that much of quantum mechanics is not "intuitive".  If anyone can explain why particles don't have a definite property, even before we measure them, I would be grateful.


Installing Trim for new Vinyl Plank Flooring

So it looks like part of my house had the door trim installed after the carpet.  I'm currently in the process of ripping the carpet up and installing vinyl plank flooring, and noticed the huge gaps.  Are my only options replacing all of the trim or caulking the bottom?  Are there other options/products available?  I also noticed gaps in this corner of drywall, as well as the drywall sheets touching the slab.  I assume the only reason you don't do this is so that moisture isn't wicked up (given the gypsum does look soft).  I figure I can throw some drywall tape on it and mud it up.  Lastly, how do you account for the flooring around a curved fireplace?  Is there a way to flush-cut the bottom of the brick, or do you install quarter-round trim at slight angles?  I also assume all of the minor holes/gaps from tearing out the tack-board won't be an issue.


Correct interpretation of a "double-negative" in American Pop Culture (i.e. "I ain't afraid of no ghost!")

In the 2016 film Ghostbusters Dan Aykroyd states:      I ain't afraid of no ghost!   To which a lady who looks like Jennifer Anniston replies:     That's a double negative! That means you ARE afraid of ghosts!   Is this interpretation technically correct? I would've thought that a literal interpretation would've implied that he does not fear the absence of ghosts (or the absence of a ghost, or the ghost), rather than that he fears ghosts.   Which is correct?


If I have a photograph of a rectangular object whose image recedes with perspective, is it possible to work out the scale of measurements along that object?  For example: I have a photograph of a (metric) ruler.  The ruler is graduated in centimetres as shown, 30 cms.  Is it possible to work out the distance between each centimetre?  The screenshot shows the photograph.  The representation on the Picture Plane shows the nearest edge of the ruler to be 50mm and the farthest edge to be 15mm. By measuring the photo, I see that the distance between 0 and 1 is 7.5mm and the distance between 27 and 28 is 0.9mm.  Is there a way to get these results from a formula?  It doesn't need to be 100% accurate: it's for photometric software I'm writing, so it's only going to be used as a rough guide.


Hi, I have tried for hours without results. How to draw this in overleaf? thank you.


Hi all,   Love how this look, and was wondering what sort of gradient effects may've been used in the image...    Thanks so much for your help!