Should sympathy votes be used to counter unexplained downvotes?

Summary There's been a lot of activity about mass down voting today, and what seemed like a lot of mass sympathy voting, so I'm asking about how we should handle sympathy voting. Argument Against: Some people feel that if you simply answer a question that is being asked that your answer is justified regardless of whether the practice in question could be harmful.  Is the point of SO to help people answer questions they have or to help them code properly? I believe the answer is to help them code properly.  This isn't just another Q and A site, this is Stack Overflow, we are a community and we need to decide what is important in our eyes as a whole, as I see It I believe a lot of people would agree proper coding is better than blindly answering questions to help people as it will prevent security issues as well as resource issues if you follow more modern coding practices. But is that what down voting is for? Down voting bad questions/answers is the only way to prevent bad content on the site. Argument for: However some people feel the need to help no matter what, which is understandable.  I think we should try our best to help out people in our community. I also think that comments could help the issue if left with a downvote, even though I don't think this should be mandatory. I also think editing questions/answers is perfectly fine for correcting these kinds of issues as long as it doesn't warp the original point of the question mainly how do I do x with y and maybe z? But is that what up voting is for? Up voting is the only way to bring good questions/answers to light. So the question remains: Should sympathy votes be used to counter unexplained downvotes on blindly helpful answers?


Inseparable polynomial over a non-perfect field

Assume that $F$ is a field and $\operatorname{char}(F)=p$. Let $a$ be an element in $F$ without $p$th root, then the polynomial $$x^{p^n}-a$$ is irreducible and inseparable over $F$ for all $n$.    I have proved the inseparable part by considering the derivative of the polynomial, but I'm having trouble with the irreducible part. Any help?


How to pin a batch file to the Taskbar (Quicklaunch)

explains how to Pin a batch file to the Taskbar in Windows 7.  I was able to do that in Windows 7 and it worked fine.   But I'm unable to make it work in Windows 8. The explanation doesn't make the syntax clear for adding the path and filename of the batch file.  It's been several years since I did it in Windows 7 so I may not have done this part right, but I have tried every combination I can think of.    Here are a few examples I've tried:  "C:\Windows\System32\cmd.exe" "/C" C:\Users\[username]\winbats\dogbones.bat "C:\Windows\System32\cmd.exe" "/C" "C:\Users\[username]\winbats\dogbones.bat" "C:\Windows\System32\cmd.exe" /C C:\Users\[username]\winbats\dogbones.bat C:\Windows\System32\cmd.exe /C C:\Users\[username]\winbats\dogbones.bat C:\Windows\System32\cmd.exe /C "C:\Users\[username]\winbats\dogbones.bat"   They all open a command prompt, but none executed the batch file.   Does anyone know the correct syntax or another way to pin a batch file to the taskbar in Windows 8?


If electron carries negative charge, why bother looking for it's electric dipole moment?

I got confused after reading about spherical electron, would there really be some type of unknown particles popping in and out of existence within the virtual particle cloud around the electron that give electron it's property? Why is it important for the electron to have electric dipole moment?


Storing features in NoSQL database like Cassandra?

I want to make a new contrib development based on NoSQL databases like Cassandra.   Does anyone know of a University or Research Group, or anyone else, who works in "Geo-Cassandra" currently?


This is the error:                                                                java.lang.NullPointerException: Attempt to invoke virtual method 'int java.util.ArrayList.size()' on a null object reference                                                                        at trainedge.alarmmanager.AlarmAdapter.getItemCount(AlarmAdapter.java:46)  This is the Adapter class where i am getting the error  public class AlarmAdapter extends RecyclerView.Adapter<AlarmHolder> {      Context context;      public AlarmAdapter(Context context, ArrayList<Alarm> setItems) {         this.context = context;         this.setItems = setItems;     }      ArrayList<Alarm> setItems=new ArrayList();       @Override     public AlarmHolder onCreateViewHolder(ViewGroup parent, int viewType) {         View v= LayoutInflater.from(context).inflate(R.layout.simple_card_item,parent,false);         return new AlarmHolder(v);     }      @Override     public void onBindViewHolder(AlarmHolder holder, int position) {          Alarm alarm=setItems.get(position);          holder.tv_label.setText(alarm.getLabel());         holder.tv_time.setText(alarm.getTine());      }      @Override     public int getItemCount() {          return setItems.size();     } }   This is the Model  public class Alarm {     public String label;     public String tine;      public Alarm() {     }      public String getLabel() {         return label;     }      public void setLabel(String label) {         this.label = label;     }      public String getTine() {         return tine;     }      public void setTine(String tine) {         this.tine = tine;     }      public Alarm(String label, String tine) {          this.label = label;         this.tine = tine;     } }


Is this a presentation of the other flag in the NAA review queue?

I was just reviewing the  and I came across  and flag description:    The answer has been flagged as very low quality and then it also has a flag that says:     It's not an answer, or at least not to this question, however this was accepted instead of the real answer. – May 7 '12 at 5:53  × 4   Now I am in the review queue a lot and I don't recall ever seeing this before, is this an other flag that is being shown?  What is this unusual description that I am seeing?


What is a word that describes cities, towns, and villages?

According to the Merriam-Webster Dictionary, a city is "an inhabited place of greater size, population, or importance than a town or village"; a town is "a compactly settled area usually larger than a village but smaller than a city"; and a village is "a settlement usually larger than a hamlet and smaller than a town".   One can deduce from these definitions that the word "city" cannot be used to describe a town or a village, and that the word "town" cannot be used to describe a city or a village.   If, therefore, one wanted to speak of both a city and a town, as for example, "The city of Philadelphia and the town of Hershey", what word could he use to describe both of them, in saying, for example, "Both of these [] are in Pennsylvania"?   Thank you.


Restoring all data and dependencies from dpkg --set-selections '*'

So I can run on one machine:  dpkg --get-selections '*' > selection.txt   On another machine:  dpkg --set-selections < selection.txt   ... followed by either of the following:  aptitude install apt-get -u dselect-upgrade   ... to install the packages that.  However, it appears that some information gets lost in the process, such as whether a package (say xyz) got installed automatically as dependency of another package (abc). You can see that whenever you do something like apt-get --purge remove abc. On the original machine you would be notified that package xyz was installed as dependency of abc and that you may use apt-get autoremove to get rid of it.  Now I am aware of deborphan and debfoster, but they're cumbersome to use given the (simple) task at hand.  It seems saving and restoring the selections as shown above is not sufficient to restore the subtle dependencies of installed packages.  Is there a way to back up the complete set of metadata for package management and restore it then in its entirety?


strange results in adding double numbers

I began read about Java programming these days, and I find something strange in simple code  double sum= 0.012 + 0.012+ 0.012;         System.out.println("the value is" + sum);   the output is. 0.036000000000000004  but if I add 0.12 + 0.12 + 0.12 the result is 0.36 why?


I know what this command does. It sets up swap area on a device or in a file. The device being a partition, and file being a simple file.  But I want to know what it does internally on the disk.  Correct me here if I am wrong, Swap is slower than RAM, but faster than simple Disk for operations.  This is my question.   What changes does mkswap makes on disk? I mean, the swap area is still on disk (be it a partition or a file), right?, then how come it works faster than rest of the disk? It must be doing some changes on the disk? What are these changes?  EDIT - It is in reference to this video,    here it is being told that data accessed frequently is moved to the outer area of the disk. So, I guess mkswap might move the swap partition/file to some outer area of the disk.


Upgrade Ubuntu version with the terminal

My PC works with Ubuntu (16.04, 32-bit) and Windows (7, 64-bit) options.  My Ubuntu is broken. The only thing I can do in my user in Ubuntu is to open a terminal.  I want to try to upgrade to Ubuntu 17.10  64 bit using only the terminal.   I seek a step by step instructions that need no prerequisite knowledge.


Links in site profiles stripped from network profile

I have a link in my profile, advertising a Stack Exchange question of mine (which I believe is acceptable use of the profile page). The link works fine on my individual profile pages. For example,  and . However, on  the links do not show.  The link is present on the GIF and on the text (two separate links, both to the same place). Both work fine on the individual profile pages but both are absent from the network profile page. The GIF and text are present, just without being linked.  Is there a reason for disallowing links from the network profile page, or is this a bug?


What's the difference between cosmic time and conformal time?

When they say that the age of the Universe is about 13.7 billion years, they are giving the age in cosmic time, is that right?. There's this other thing called conformal time which I don't understand. What would be the age of the Universe measured in conformal time?


Everytime I make a new project, I end up in having troubles because I forgot to create the database collation by UTF-8 or there are some characters that slipped trough that I didn't see like é/à/.. but also the double .. or tripple ... seem to be very nasty. I usually use mysqli_real_escape_string to make sure he writes the characters away, and when i print them i use htlmentities. But that doesn't work for all characters, and defenitly not for double .. or tripple ... .  Is there a general rule / guideline that I should keep in mind when setting up a project, so I don't have troubles with these special characters?


I have a specific port number with me and  want to check if it is active or not. I tried:  netstat -an | grep $portnum   Is this correct?


Null-pointer exception in postProcessXLS method to export datable to spreadsheet

Good day people. I am working on a java-ee project, specifically working on exporting a datable to spreadhseet(xls). I have a method called postProcessXLS. I use this method to auto adjust the column width of the generated spreadsheet and also to add cell styles and formatting. When i run the app, the method postProcessXLS throws a null pointer exception without referencing the line.  bean   public void postProcessXLS(Object document) throws IOException,     BadElementException, DocumentException {     try {         HSSFWorkbook wb = (HSSFWorkbook)document;         HSSFSheet sheet = wb.getSheetAt(0);         HSSFRow header = sheet.getRow(0);          HSSFCellStyle cellStyle = wb.createCellStyle();         cellStyle.setFillForegroundColor(HSSFColor.GREEN.index);         cellStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);          for (int i = 0; i < header.getPhysicalNumberOfCells(); i++) {             HSSFCell cell = header.getCell(i);              cell.setCellStyle(cellStyle);         }          for (int colNum = 0; colNum < header.getLastCellNum(); colNum++) {             sheet.autoSizeColumn(colNum);         }     } catch (Exception ex) {         LOG.error("Could not process spreadsheet" + ex);     } }


Complicated module update error HTTP error 0

I'm recently getting the error below:     HTTP error 0 occurred when trying to fetch .   Downloading updates failed:      Failed to download captcha from       Blockquote   I'm running my website on a shared platform, so I can't change the parameters of PHP...  Based on this long thread drupal dot org/node/247009 I have already tried several many potential solution with no luck so far. This is what I tried and it did not work:   gave 777 recursive permissions to tmp and site/default/ tried on different browsers (Edge, Firefox, Chrome) in jquery update module I changed the jquery default version to 1.10 I set the jquery source from google, and I set the jquery to non-minified I checked and in settings.php I do not have any base url set the file which failes to be downloaded is very small in size 103KB, so I     guess it's not about uploading to large files I checked my PHP version and it did not change recently it;s 5.3.29 I also checked the PHP memory limit and it's set to 256MB which to me it's not that low for uploading a 103KB file  I I tried the update of a different module, and I get the same error   What could be the problem? Where to look next?


Assume a Divine Soul Sorcerer. The spellcasting feature of the class states (highlight mine):  Additionally, when you gain a level in this class, you can choose one of the sorcerer spells you know and replace it with another spell from the sorcerer spell list, which also must be of a level for which you have spell slots.  Can I do this when I gain level 1 in the class? Let's say I choose the affinity good, which gives me the cleric spell "Cure Wounds" because of the Divine Magic feature:  Your link to the divine allows you to learn spells from the cleric class. When your Spellcasting feature lets you learn or replace a sorcerer cantrip or a sorcerer spell of 1st level or higher, you can choose the new spell from the cleric spell list or the sorcerer spell list. You must otherwise obey all the restrictions for selecting the spell, and it becomes a sorcerer spell for you. In addition, choose an affinity for the source of your divine power: good, evil, law, chaos, or neutrality. You learn an additional spell based on that affinity, as shown below. It is a sorcerer spell for you, but it doesn't count against your number of sorcerer spells known. If you later replace this spell, you must replace it with a spell from the cleric spell list.  If my class allows me to replace a spell when I gain Level 1, then the Divine Magic would allow me to replace the "Cure Wounds" with for example "Guiding Bolt". Now intuitively I would say no, because Level 1 is the first level and you can't have less, so you don't "gain" it. However some features explicitly state "Starting at 1st level", for example the feature "Favored by the Gods" from the same Divine Soul Sorcerer. This does hint to me that there might be a "gaining" of 1st level, otherwise this extra wouldn't be necessary.  Starting at 1st level, divine power guards your destiny. If you fail a saving throw or miss with an attack roll, you can roll 2d4 and add it to the total, possibly changing the outcome. Once you use this feature, you can't use it again until you finish a short or long rest.  Bonus question: Is it any different if I multiclass into sorcerer and my first Divine Soul Sorcerer level is not my first character level?


Laptop Screen automatically rotates after some time from the time of log-in in Ubuntu 18.04 LTS

As my laptop screen automatically rotates after some time from the time of log-in  As i'm using 18.04 LTS and i also tried "xrandr -o normal" but after some times it again starts to rotate


How to generate a pem certificate? in an easy way, for testing

A third-party app I have requires a *.pem certificate to be able to open a wss connection. How can I generate a *.pem file, keeping in mind that I need that only for testing, therefore I want an easy, not necessarily a really secure way to do so.  I'm on Arch Linux.


Is it possible to solve a fraction that has 0 at denominator?


How to show every field is a Euclidean Domain.

I'm having trouble proving this. This is what I have so far:  Let $F$ be a field. Let $v(x) \rightarrow 1$ for all $x$ not equal to $0$.  So if we let $x$ be in $F$ where $x$ not zero then we can write $x$ as: $x=qy+r$ for some $y$ in $F$. If $r$ not zero then $V(r)=1$.  Not sure what to do from here. I know eventually I'm supposed to get no remainder $(r=0)$ but I'm stuck at applying the definition and valuation map.


Windows 10 keyboard shortcut for moving apps between desktops

(Related: )  I can switch between Task View desktops easily using Ctrl+Win+Right and Ctrl+Win+Left.  Is there any keyboard shortcut to take the currently-focused window and move it to the next/previous Desktop?  It seems like the default workflow is intended to be:   Win+Tab Right-Click the window Move To --> Desktop #   That's kind of annoying.  If there's no built-in keyboard shortcut, is there a program that can add one?


How small must an object be in order for it to be subject to the laws of quantum mechanics?


Attempting to create a simple function and it's backfiring; NullPointerException

so I'm creating a code. In it, I wanted to make two eyes for the helmet. To do it, I need to create a function so that I can draw two ellipses in one function. After creating the design for the eyes, I found I hadn't closed that section which resulted in all of the shapes in my Processing file to be moved around the page.  I then closed the section, but now I'm getting a NullPointerException.  How do I fix this?  float Helmet_Ratio=.4; int i=0;  void setup() {   size(1280,720);   smooth(); }  void draw(){    eye(1200,300);    eye(1275,350);    }     void eye(int y, int z){    fill(0);    ellipse(y,z,15,15);    fill(0);    ellipse(y+75,z+0,15,15); } {   background(255);  //This is where the problem begins  {   //Pattern Background   int x = 15;   if (x > 20) {    rect(0, 0, 55, 55); } if (x < 20) {   strokeWeight(3);   fill(0,200,0);   rect(0,0,25,25); }   for (i=0; i<125; i++)  {    pushMatrix();    fill(0,32,32);    rotate(.75);    rect(0,i*12,1280,i/5);    popMatrix();  }  {    //Helmet 1 Red   strokeWeight(0);   translate(50,0);   fill(255,0,0);   ellipse(width/2.25,height/2,240,250);    //Helmet 1 Lense   beginShape();    endShape();    //Helmet 2 Blue   strokeWeight(0);   translate(250,0);   fill(51,51,255);   ellipse(width/2.25,height/2,200,195);    //Helmet 3 Yellow   strokeWeight(0);   translate(250,0);   fill(255,255,0);   ellipse(width/2.25,height/2,150,160);    //Helmet 4 Black   strokeWeight(0);   translate(-750,0);   fill(32,32,32);   ellipse(width/2.25,height/2,200,195);    //Helmet 5 Pink   strokeWeight(0);   translate(-225,0);   fill(255,102,255);   ellipse(width/2.25,height/2,150,160);  }  }  }


Manhattan, time traveling mist wall, a flying white horse and a bridge of light to heaven

I remember reading this book in the late 80's or early 90's. It was a - sort of - semi SciFi contemporary fairy tale.  It was set in Manhattan in contemporary times, near future and (I think) late 1800's. There was a mist wall round New York that ships could disappear into and arrive out at different times.  There was a man with a white horse, the horse could fly but had forgotten how. The man is brought forward from the past but (like the horse) forgets who he is.  An engineer arrives from the future in a gigantic ocean liner and builds a bridge of light to heaven (possibly at the last millennium turn over).   It was a very involved book with a huge cast of characters that all had some part to play in the story.  In the 1800's story there was a girl suffering from consumption, she slept in a glass room on the roof of her house, open to the freezing winter air, it was what kept her alive. She was rich (the family had made money in whaling) but somehow she and The Man (the guy with the white horse, who was pretty much a nobody) met and fell in love (I think).  Some of the story was set around a lake in upstate NY, and one character started off in San Francisco (contemporary times) and traveled to the lake.  Anyone any idea what I'm talking about?


I am new to python and I tried this:  import numpy as np  x = np.arange(0.7,1.3,0.1) print (x) y = np.arange(0.6,1.3,0.1) print (y)   The output was [ 0.7  0.8  0.9  1.   1.1  1.2  1.3] and [ 0.6  0.7  0.8  0.9  1.   1.1  1.2]. Why in the first case 1.3 appears in the list and in the second case it doesn't?


Why there is null pointer exception but I have checked there is no null

public static boolean isIsomorphic(String s, String t) {     HashMap<Character, Character> res1 = new HashMap<Character, Character>();     HashMap<Character, Character> res2 = new HashMap<Character, Character>();     char[] sToArray = s.toCharArray();     char[] tToArray = t.toCharArray();     if (s == null && t == null)         return true;     if (s == null || t == null || s.length() != t.length())         return false;     for (int i = 0; i < sToArray.length; i++) {         ***if ((!res1.containsKey(sToArray[i])) && (!res2.containsKey(tToArray[i])))*** {             res1.put(sToArray[i], tToArray[i]);             res2.put(tToArray[i], sToArray[i]);          } else {              if ((res1.get(sToArray[i]) != tToArray[i]) || (res2.get(tToArray[i]) != sToArray[i]))                 return false;          }      }     return true;  }   Given two strings s and t, determine if they are isomorphic. When the test case is "ab" "aa"; there will be an nullpointerexception for if ((!res1.containsKey(sToArray[i])) && (!res2.containsKey(tToArray[i]))) I checked res1 does not equal to null and res2 does not equal to null. Could anybody tell the reason? Thanks very much!


Postgres: DROP TABLE and ALTER TABLE hangs because of locks

After issuing DROP TABLE or ALTER TABLE command pg_stat_activity table becomes full of Locks and the query hangs forever. Killing PIDs and reissuing query gives the same result. The problem disappears after the system gets restarted (I restart docker container for that). How to investigate this issue?


Please clarify should I write group's subsidiary or group subsidiary? what is the correct way to write this? Could you please also clarify the rule?  I see, there are a lot of similar situations, for example, management representation or management's representation, management report or management's report


Trigger updatedAt=NOW() for hunded-thousand rows will not actual

I am using SQL Trigger to update updatedAt column if there is a new data inserted/updated in PG 9.6. Here is the function that will be called by trigger CREATE FUNCTION sp_updatedatstamp() RETURNS trigger AS $updatedat_stamp$   BEGIN     NEW."updatedAt" := now();     RETURN NEW;   END; $updatedat_stamp$ LANGUAGE plpgsql;  Here is the trigger script create trigger tg_de_installment_cdcupdatedat before insert or update     on     public.table for each row execute procedure sp_updatedatstamp()  Here is the Table Definition CREATE TABLE table (     id serial NOT NULL,     "type" text NULL,     "transactionDate" timestamptz NULL,     remark text NULL,     "createdAt" timestamptz NULL,     "updatedAt" timestamptz NULL,     "deletedAt" timestamptz NULL,     CONSTRAINT table_pkey PRIMARY KEY (id) );  This code is working fine with small data, until an application execute bulk update query (100K+ rows will be updated) that takes 30 minutes. The trigger will makes all 100k+ rows uses updatedAt of first rows, which makes the other rows updatedAt not correct. At the end, our data pipeline with schedule 5 min, will lose this data. Is there a way to makes the SQL Trigger uses it actual timestamp for huge data?


Novel about a guy who is possessed by the divine essence and the world ends?

I read this novel back in the mid-80's but I'm pretty sure it was written in the 70's.  Strange things start to happen around a homeless man - like the laws of chance are changed.  The investigators discover that they can figure out what is going to happen next by interpreting the dreams/vision of the man.  One such dream is of a large body of water that is split into two pieces. Turns out that means that "C" (sea) - the speed of light has been halved.  The homeless man had become the embodiment of the creator essence. The creator was hiding, because it was tired of trying to keep the universe working and from the fight with is adversary - chaos.  At the end of the book, the creator allows the world to be destroyed and recreates it - except that planets are cubes and move in squares.  Yes - it was rather bizarre.


Display settings fail to apply on 13.04 with Gnome 3.6/3.8

When running the Display settings (gnome-control-center display) under Gnome 3.6 on Ubuntu 13.04 I'm unable to apply any settings (even if nothing changes). The error I get is:  Failed to apply configuration: %s GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SettingsDaemon was not provided by any .service files.  Background:  I've tried to use the newer 3.8 release from the PPA's but that didn't help, I've now reverted to the 3.6 release. I've also tried removing all my gnome related config files, but that didn't make a difference.  The error message:


Please, what I'm doing wrong in this test:  \documentclass{article}   \usepackage{tikz}   \begin{document} \begin{tikzpicture}  \pgfmathparse{10*2} \node at (4,-5) {$2 \cdot 10 = \pgfmathresult$};  \end{tikzpicture} \end{document}   It gives as output a line:  2 * 10 = -5.0   instead of:  2 * 10 = 20   ?


How to use an array as argument to a VARIADIC function in PostgreSQL?

I am trying to make a case-insensitive version of json_extract_path_text(), using the citext module.  I would like this to be a simple wrapper around the built-in function, the only difference being that it accepts citext as the first parameter instead of json. I want this to be a straight pass-through to the native implementation, just with a type conversion beforehand. Here's what I have so far:  create extension citext;  create or replace function json_extract_path_text ( string citext, variadic params text[]) RETURNS text IMMUTABLE AS $$     BEGIN         SELECT json_extract_path_text(string::json, params);     END; $$ LANGUAGE 'plpgsql';   This doesn't work properly, however, because of the type mis-match:   ERROR:  function json_extract_path_text(json, text[]) does not exist LINE 1: SELECT json_extract_path_text(string::json, params)                ^ HINT:  No function matches the given name and argument types. You might need to add explicit type casts. QUERY:  SELECT json_extract_path_text(string::json, params) CONTEXT:  PL/pgSQL function json_extract_path_text(citext,text[]) line 3 at SQL statement    I've tried hacking around a solution using dynamic string construction and EXECUTE, but this is a real hassle and I feel like there must be a cleaner way to pass VARIADIC params through to the inner function. I can't see any obvious way to do so, however. How can I accomplish that?


I understand that SO is the most popular SE site, but what percent of users start there? How often do people come initially to the other SE sites and then perhaps join SO?  Is this a statistic that can be pulled up by site?   The real reason I want to know this is that if I am seeing an opinion of people on Writers let's say 50 people agree and upvote, am I 99% seeing the opinion of 50 programmers who are also sometimes write, and missing out on the general population?


If $f$ is measurable and $fg$ is in $L^1$ for all $g \in L^q$, must $f \in L^p$?

Let $f$ be a measurable function on a measure space $X$ and suppose that $fg \in L^1$ for all $g\in L^q$. Must $f$ be in $L^p$, for $p$ the conjugate of $q$? If we assume that $\|fg\|_1 \leq C\|g\|_q$ for some constant $C$, this follows from the Riesz Representation theorem. But what if we aren't given that such a $C$ exists?


My price calculator is returning values like 25.00000003 yet all my menu items are to the tenth

I realize might not be the prettiest way to do this but with my limited knowledge and lab requirements...  HOWEVER... I cannot figure out why it often calculates my meal price to .00000002 or .0000003 ... I have tried to look up options and even went through the walk through to see what I had off... but it appears to be the same. I even changed a few of my codes to match. Additionally, if I remove the cents off of the prices it will work and not do that...   _courses: {     appetizers: [],     mains: [],     desserts:[],   },     get appetizers() {     return this.courses.appetizers;   },   get mains(){     return this.courses.mains;   },   get desserts() {     return this.courses.desserts;   },   set appetizers(appetizers) {     this._courses.appetizers=appetizers;   },   set mains(mains) {     this._courses.mains= mains;   },   set desserts(desserts) {     this._courses.desserts= desserts;   },   get courses() {     return {       appetizers: this.appetizers,       mains: this.mains,       desserts: this.desserts,     };   }, addDishToCourse(courseName, dishName, dishPrice)  {    const dish= {     name: dishName,     price: dishPrice,   };  return this._courses[courseName].push(dish);  }, getRandomDishFromCourse(courseName) {   const dishes = this._courses[courseName];     const randomIndex = Math.floor(Math.random()*dishes.length);     return dishes[randomIndex]; }, generateRandomMeal() {   const appetizer = this.getRandomDishFromCourse("appetizers");   const main = this.getRandomDishFromCourse('mains');   const dessert = this.getRandomDishFromCourse("desserts");    const totalPrice = appetizer.price + main.price + dessert.price;    return `Your meal is ${appetizer.name}, ${main.name}, ${dessert.name}. The price for your meal is $ ${totalPrice}.`; } }; menu.addDishToCourse("appetizers", "salad", 5.99); menu.addDishToCourse("appetizers", "calamari", 7.85); menu.addDishToCourse("appetizers", "nachos", 5.50);  menu.addDishToCourse("mains", "steak", 18.25); menu.addDishToCourse("mains", "BBQ chicken", 11.75); menu.addDishToCourse("mains", "lasagna", 14.50);  menu.addDishToCourse("desserts", "chocolate cake", 3.99); menu.addDishToCourse("desserts", "tiramisu", 4.99); menu.addDishToCourse("desserts", "ice cream", 4.50);  const meal = menu.generateRandomMeal(); console.log(meal);```  This is in CodeAcademy so built in structure already. Thanks in advance from this newbie!


Where to store credentials used in a function?

I am writing a function in functions.php under my theme. The function contains a cURL command that uses credentials like "account_id" and "password". These credentials are not from user input.  Where can I store these credentials? And how would I retrieve them to use them in my function?


Does anyone what the largest array is that I can allocate in Visual C++ 2010? The maximum number of elements, I mean. Can I do something like int tarray [unsigned long], where unsigned long is some unsigned number larger than a 32-bit integer?


Is it possible to derive the time dilation expression directly from the space-time interval?

Is there any way of deriving the time dilation expression: $$\Delta t'=\gamma\Delta t$$ from the space-time interval: $$s^2=c^2t^2-x^2-y^2-z^2$$ I know how to derive the time dilation expression by using geometry and simplifying, but I was wondering if there is a way to do it directly from the invariant as it encodes a lot of special relativity within it. Thanks!


What is the common English name for that "plastic part on the tip of a shoelace" which helps to easily insert the lace into the shoelace holes? (I'm not sure that's the correct name).  Edit: There are also metal parts of the kind.


NullpointerExpection returned when back pressed

I am sending the value from Activity A to Activity B and data is set to the view, it is working fine but when I press back button it is returning the nullpointerexpection in textView.setText() method . I have implemented as follows:   Intent i = getIntent();     serialArrayList = i.getParcelableExtra("member_list");      gridView = (GridView) findViewById(R.id.officerGrid);     adapter = new DistrictOfficerGridAdapter(this, serialArrayList);     gridView.setAdapter(adapter);      gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {         @Override         public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {              startActivity(new Intent(getApplicationContext(), MemberDetailsActivity.class));             Intent in = new Intent(DistrictOfficerActivity.this, MemberDetailsActivity.class);             in.putExtra("name", serialArrayList.getTitle());             in.putExtra("desig", serialArrayList.getPosition());             in.putExtra("contact", serialArrayList.getMobile());             in.putExtra("addr", serialArrayList.getAddress());             in.putExtra("blood", serialArrayList.getBloodGroup());             in.putExtra("image",serialArrayList.getPhotos());             in.putExtra("email", serialArrayList.getEmail());             in.putExtra("desc", serialArrayList.getDesc());             in.putExtra("website", serialArrayList.getWebsite());             in.putExtra("land", serialArrayList.getLandline());             startActivity(in);          }     });   And the data is received from MemberDetailsActivity and implemented as follows:      nam = getIntent().getStringExtra("name").toString();         design = getIntent().getStringExtra("desig");         contat = getIntent().getStringExtra("contact");         addr = getIntent().getStringExtra("addr");         blood = getIntent().getStringExtra("blood");         image = getIntent().getStringExtra("image");         website = getIntent().getStringExtra("website");         email = getIntent().getStringExtra("email");         landL = getIntent().getStringExtra("land");     name.setText(nam.toString());     desig.setText(design.toString());     phoneNumber.setText(contat.toString());     address.setText(addr.toString());     bloodG.setText(blood.toString());     Glide.with(getApplicationContext()).load(image).into(imag);     web.setText(website.toString());     emai.setText(email.toString());     landline.setText(landL.toString());


Which constant to add when applying 'Box-Cox transformation' to negative values?

Questions   How big constant should we add to negative values when applying the 'Box-Cox transformation'? The data that I am handling is 'daily return of stocks' Shouldn't we subtract some amount after the Box-Cox transformation if we add a constant to negative values to apply the Box-Cox transformations?    Background Information   Since daily return of stocks does not follow the normal distribution, I tried to apply Box-Cox transformation. However, some of daily returns are negative so I could not transform them. According to , I can add a constant to make those negative numbers non-negative. The excerpt from the article is as follows:      Box-Cox transformations are designed for non-negative responses, but can be applied to data that have occassional zero or negative values by adding a constant α to the response before applying the power transformation. Although α could be estimated, in practice one often uses a small value such as a half or one (depending, obviously, on the scale of the response).    My data is the daily return of the company Apple (ticker : AAPL) from 2000.01.01 to 2011.12.31. The minimum value was -0.518692 (Yes, it's true. The price of Apple stock dropped 52% in one of the days in Sep. 2000) The summary and histogram of my data before the Box-Cox transformation is as follows:      To make my data just not negative, I added 0.52 to all of daily returns. The number 0.5 also appeared on the article above that I hyperlinked, so I thought it would be an appropriate constant. But the problem is that the center of the histogram moved a lot from zero, which is far away from the center of the original histogram. The summary and histogram of the data after the Box-Cox transformation is as follows:      If I used the constant 1 instead of 0.5 as a constant to add my data, the center of the histogram would be around 0, not far away from the original histogram (the histogram of data before Box-Cox transformation). Then my question is how big a constant should be?  Also, shouldn't we subtract a constant after the transformation? If you add a constant to data to make them possible to get Box-Cox transformed, the original data's amount gets bigger. It's bigger than the original data. After the transformation, don't we need to do some operation to make them smaller to its original size? But the thing is after the Box-Cox transformation, the histogram of data moved to the left, which means that the data got smaller than the original data already... So I am curious to know whether changing the data by adding a constant requires any other operation (e.g. subtraction) and if it does not require anything, why not?


Fresh install of Ubuntu 18.04.4 Slow and Freezes

I am fairly new to the linux operating system.   I recently installed ubuntu 18.04.4 onto a brand new samsung evo 860 SSD through a bootable image drive. I've had no lag on that bootable drive.  My computer has been extremely laggy and it's been freezing 5 minutes into startup every reset and I'm unsure why.   I have already updated and upgraded through the terminal. The image I downloaded was straight from the ubuntu web page. This is my second installation.   My computer specs are  Threadripper 1920x CPU   4 8GB vengeance lpx RAM   Asus ROG STRIX 2080 TI GPU   1TB samsung evo 860 SSD


Dark Energy / Accelerating universe: naive question

Folks, I have a naive question regarding the subject of dark energy and an accelerating universe:  From what I understand/read, it seems that the further we look out into deep space, the faster the objects are moving away from us - in all directions.   Is this basically what is meant by "accelerating universe"?  Because it seems that this situation is exactly what we should expect to see (according to Big Bang theory). The further out we peer into space, the further back in time we are "seeing", so wouldn't we expect to see higher rates of acceleration/expansion the further back in time we peer?


How to Solve Null Pointer exception i my code?

When i run my java code:  public class LalaLuLu { public static void main(String[] args) {      try{          String path = "D:/Gem/FINAL/Datatest.csv";         File file = new File(path);         InputStream is;         System.out.println(file.exists());          FileReader fr = new FileReader(file);         BufferedReader br = new BufferedReader(fr);          PrintWriter os = new PrintWriter ( new FileOutputStream("D:/Gem/FINAL/out_datatest1.txt"));         String output = "";         int count = 0;         do{             output = br.readLine();             String[] a = output.split(";");             System.out.println("total kolom: " + a.length);             os.println(output);             System.out.println(count++ );         } while (!output.equals(""));      } catch (Exception e) {         e.printStackTrace();     } } }   When i run, the error on this line :  output = br.readLine(); String[] a = output.split(";");   And error I am getting is:  java.lang.NullPointerException   at DAO.readdata.readdataCSV(readdata.java:47)   Can you tell me how to solve this error? Thank you


After updating to 16.04, bluetooth audio A2DP mode stopped working

I have a nice bluetooth audio receiver connect to my HiFi stereo, and I used to be able to connect it in 14.04 as a A2DP sink with nice quality.  After upgrading to 16.04, the device connects only as headset, and when trying to switch it in A2DP mode, I have this error in my syslog:   May 21 11:35:50 RRyS pulseaudio[6159]: [pulseaudio] module-bluez5-device.c: Refused to switch profile to a2dp_sink: Not connected   and the quality of audio is abismal. How can I fix it?


This is what I want to express:     I want to get to know more algorithms that have been created.   I have thought about changing the sentence into     I want to gain a better insight into algorithms that have been created.   But it seems inappropriate.  Any better phrase (or single word) to replace get to know?   (Or better way to construct the sentence?)


Rounding a decimal without fractions doesn't add fractions

I have the following code:  var voucherAmountValue = "5"; var totalValue = Math.Round(Convert.ToDecimal(voucherAmountValue), 2);   When I write totalValue to the console, it prints 5. I'd expect the fractional digits to be added, printing 5.00 for totalValue, but it doesn't: it still prints 5.  How can I add the fractional digits to a decimal that doesn't have them?


Windows 8 tablet keyboard dock hard drive

I've bought an ASUS TX300CA Windows 8 transformer tablet which has a detachable keyboard dock.  The tablet is a Core i7 machine and has serious power - so I want to use it to do sporadic and ad-hoc software development on it.  The tablet has a neat feature that although the detachable tablet part has only a 128Gb SSD, when you attach the keyboard dock, you get an additonal 500Gb of magnetic hard drive.  What I want to be able to do is to install applications so that they will install either completely on the tablet drive or completely on the dock drive.  For example, I'd like to put most of Microsoft Office on the tablet, but put say Microsoft Visual Studio on the dock drive.  Can this be done?  What's best practice for this?  TIA,  Paolo


About estimating the age of the universe

So the age of the universe can be estimated by doing 1 over Hubble's constant, but why is this?


5 Likert Scale and Normal Distribution prior to parametric testing

I have data from a 5 point Likert scale item which approximately 1/4 of the responses only account for 1 through 4 of the 1 through 5 available.    Do I have to  standardize the min/max response categories that is reported in SPSS descriptives for output or will creating z-scores be sufficient?    The variables have differing degrees of distributions due to this and the transform functions (e.g., SQRT, LG10) have not solved my problem. My sample (N=162) is the first part of a test/retest for instrument reliability. I have run all the processes thinking that what looked normal and based on criterion (2 or 3 times the SD is sufficient to estimate skewness to identify 'normal distribution' regardless of visual).    I'm at the point of frustration and exhaustion...any expert advice?


In Friends S1E7, what did Joey say in a low, twisted voice?

In Friends S1E7, "The one with the blackout", Chandler was locked in an ATM vestibule with Jill Goodacre. A conversation between him and Joey is as follows:  Chandler: I am trapped in an ATM vestibule with Jill Goodacre. Joey: (something inaudible) Chandler: Like that never crossed my mind.  So I wonder what Joey said. I cannot find this line in online substitles.


Finding the dimension of a given vector space

What is the dimension of the space of all $n \times n$ matrices with real entries   which are such that the sum of the entries in the first row and the sum of   the diagonal entries are both zero?   I tried by finding number of independent entries. The number of independent entries on the diagonal is $n-1$. The number of upper triangular independent entries is $\frac{n(n-1)}{2}-1(n-1)$, and the number of lowertriangular independent entries is $\frac{n(n-1)}{2}$. Now adding them will give dimension. Am I right?


I have an Acer Chromebook c720. I would like to install Ubuntu on it but do not want to use crouton, as it is not real Ubuntu. I am aware there are other posts on the subject, but they are all different and very old. I don't know which tutorial is correct.   How should I proceed?


How to take this exterior derivative of the expression $du - \sum_i p_i dx_i$?

I am reading the  about applying the method of characteristics in the fully nonlinear case. We have the fully nonlinear equation $$ \tag{1} F(x_1, \cdots, x_n , u, p_1, \cdots, p_n) = 0,$$ here  $$\tag{2} p_i = \frac{\partial u}{\partial x_i}$$ is the partial derivative of $u$ with respect to $x_i$.   In the method of characteristics, we wish to reduce the PDE to a family of ODE. Let assume that $u$ is a solution to (1).  $$s\mapsto (x_1(s), \cdots, x_n(s), u(s), p_1(s), \cdots, p_n(s))$$ be a curve so that (1) is satisfied for all $s$. Then it is claimed that the following holds:   \begin{equation} \begin{split} \sum_i (F_{x_i} +F_up_i)\dot x_i + \sum_i F_{p_i}\dot p_i &=0\\ \dot u - \sum_i p_i\dot x_i &=0\\ \sum_i ( \dot x_i dp_i - \dot p_i dx_i) &= 0. \end{split} \end{equation}  I can see that the first two equations follow from taking total derivative with respect to $s$ of (1) and the expression $u(s) = u(x_1(s),\cdots, x_n(s))$. In the wiki page, it is claimed that      ... the third follows by taking an exterior derivative of the relation $du - \sum p_i dx_i = 0$.    Unfortunately, I fail to see how the third equation are derived using exterior derivative. Could you give me the steps so I could check my work, please?  P.S.: I’ve been struggling a lot lately on Frobenius theorem and systems of total differential equations. If you could explain that, I would deeply appreciate it.


Every highway's entrance or exit is causing traffic problem.    As you can see, there is a small road that immediately goes in the large road.  What is the best way(s) to deal with traffic in a highway's entrance/exit? Is there something I'm doing wrong with the highway on the picture?


Which airline’s carry-on size limits apply when one airline sells ticket but flight is operated by another?

I am taking a flight purchased from United for Seattle (SEA) to Casablanca (CMN). Some segments are operated by other carriers but in United’s name. The ticket says:     United 4688 Operated by trans states airlines dba united express   …and…     United 8647 Operated by Air Canada Rouge   Whose luggage rules apply for the carry-on bag and the "personal item"? Unfortunately, the dimensions vary significantly between their various sets of rules.  Carry-on bag:   United: 22" x 14" x 9" Air Canada: 21.5" x 15.5" x 9" | 55cm x 40cm x 23cm   Personal item:    United: 17: x 10" x 9" Air Canada: 17" x 13" x 6"  |  43cm x 33cm x 16cm


Rolle's theorem with a supplementary condition

I have to find the types of roots (i.e real or complex) of the equation $$ 11^x + 13^x+ 17^x -19^x = 0 \dots (1) $$  If $$ f(x) = 11^x + 13^x+ 17^x -19^x = 0 $$ , then obviously $ f'(x)= 0 $ has a 0 solution, and indeed every derivative of $f(x)$ has a  0 solution.   In this context a question arises in my mind : if all the conditions of Rolle's Theorem are satisfied for a function $g(x) $ in $[a,b]$, and in addition if $g'(c)=0$ ,then is it necessary that $c$ lies between $a$ and $b$ ?    If it's true, then we can conclude that $f(x)=0 $ has more than 2 real roots right?  Any insight ? Thank you.


Is there a way to prepend something on every line using tcolorbox and minted?

The  shows a nice example of prepending a command prompt on every line of a shell input (page 317), but it apparently only works for the listings library. Is there a similar option for the minted library? I searched through the manual for minted, but the only option I found that might offer this option was the formatcom option… but I don't think that is going to work.   For the record, I would be fine with the output in , but I    can't figure out how to format this inside the definition for a \newtcblisting (color, font weight, etc.), and  don't want to have to include my prompt info on every line throughout my file.    My current MWE is as follows:   \documentclass{article} \usepackage{tcolorbox}   \tcbuselibrary{minted}  \newtcblisting{bashinput}[1][]{   listing engine=minted,   minted language=bash,   minted options={     fontsize=\small,     breaklines,     autogobble,     numbersep=2mm},   listing only,   ,#1}  \begin{document}  \begin{bashinput} user ~$ vi /etc/sysconfig/network user ~$ grep Dipole file-name -A1 | tail -n1 | awk '\{print \$8\}' \end{bashinput}  \end{document}   Ideally, I could just add a line after listing only, containing something like every listing line={\textcolor{red}{\small\ttfamily\bfseries  ~$}}


Let $k$ be a field of characteristic zero, $x,y$ commuting variables over $k$.  Question 1: Is it possible to characterize all ideals of $k[y,y^{-1}]$ and of $k[x,y,y^{-1}]$?  I guess that the answer to $k[y,y^{-1}]$ is simpler than the answer to $k[x,y,y^{-1}]$?  Question 2: Is it possible to characterize all maximal ideals of $k[y,y^{-1}]$ and of $k[x,y,y^{-1}]$?  Example: (1) $I= \langle \frac{x}{y},x \rangle= \langle x \rangle$ is maximal in $k[x,y,y^{-1}]$? (2) $J= \langle x,y \rangle$ is not maximal in $k[x,y,y^{-1}]$, since $1=y^{-1}y \in \langle x,y \rangle$, so $J=k[x,y,y^{-1}]$. Thank you very much!


Blank questions and answers in the Stack Exchange Android app

This seems to be a result of a recent update of the Android app: certain questions and answers, such as both the question and the answer in , show a box with the username, score, etc., but no content inside the box.  Sometimes the content is visible for a moment then disappears. This has happened in one other case as well, but I don't have a link to it, because I was hoping it wouldn't happen again.


Is this true: $\left|e^{\alpha}-e^{\beta} \right|\leq |\alpha-\beta|$ ($\alpha$, $\beta$ have non-positive real part)

Let $\alpha,\beta$ be complex numbers with non-positive real parts. Then prove OR disprove $$\left|e^{\alpha}-e^{\beta} \right|\leq |\alpha-\beta|.$$  I have check the correctness of the above inequality for some trivial cases but I don't know how to, in general, prove OR disprove. Please give me some hints.


Error in amsmath package preventing my latex document from compiling?

I am currently trying to compile a latex document but get the following error message.  Command \iiint already defined. ...{\iiint}{\DOTSI\protect\MultiIntegral{3}}   Can anyone please tell me how to resolve this?


NAS share isn't working since update 20.04

I since the recent software update I am unable to access my NAS drive using NEMO. I use smb://192.168.0.11 in the NEMO address line (as I did previously) and now it gives me an error "Could not display smb://192.168.0.11. Error: Failed to mount Windows share: Connection timed out. Please select another viewer and try again. I tried editing the SMB file but it still doesn't work..


I have set of many cases that I want to test on a single function. Let's say: @pytest.mark.unittest def test_simple_test_id_odd():     numbers = [1, 2, 3, 4, 5, 6, 7, 8]      for number in numbers:         assert number % 2 == 0  When I run this it stops on the first number with the error. I want the test to go all over the numbers and check each one of them. I don't want to write a test for each number, it does not make sense, it's too long. How can I test all the numbers and raise error for every one of them that failed?


How do I fix this on a null object reference

pls help     Caused by: java.lang.NullPointerException: Attempt to invoke virtual   method 'android.view.View android.widget.TextView.findViewById(int)'   on a null object reference           at com.example.c1.firebaselogin.ClockActivity.onCreate(ClockActivity.java:61)   AlarmManager alarmManager; private PendingIntent pending_intent;  private TimePicker alarmTimePicker; private TextView alarmTextView;  private AlarmReceiver alarm;   ClockActivity inst; Context context;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);        this.context = this;      //alarm = new AlarmReceiver();     alarmTextView = (TextView) findViewById(R.id.alarmText);      final Intent myIntent = new Intent(this.context, AlarmReceiver.class);      // Get the alarm manager service     alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);      // set the alarm to the time that you picked     final Calendar calendar = Calendar.getInstance();      alarmTimePicker = (TimePicker) findViewById(R.id.alarmTimePicker);        Button startalarm;     startalarm = (Button)findViewById(R.id.start_alarm);     startalarm.setOnClickListener(new View.OnClickListener() {         @TargetApi(Build.VERSION_CODES.M)          @Override         public void onClick(View v) {              calendar.add(Calendar.SECOND, 3);             //setAlarmText("You clicked a button");              final int hour = alarmTimePicker.getCurrentHour();             final int minute = alarmTimePicker.getCurrentMinute();;              Log.e("MyActivity", "In the receiver with " + hour + " and " + minute);             setAlarmText("You clicked a " + hour + " and " + minute);               calendar.set(Calendar.HOUR_OF_DAY, alarmTimePicker.getCurrentHour());             calendar.set(Calendar.MINUTE, alarmTimePicker.getCurrentMinute());              myIntent.putExtra("extra", "yes");             pending_intent = PendingIntent.getBroadcast(ClockActivity.this, 0, myIntent, PendingIntent.FLAG_UPDATE_CURRENT);              alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pending_intent);               // now you should change the set Alarm text so it says something nice               setAlarmText("Alarm set to " + hour + ":" + minute);             //Toast.makeText(getApplicationContext(), "You set the alarm", Toast.LENGTH_SHORT).show();         }      });      Button stop_alarm= (Button) findViewById(R.id.stop_alarm);     stop_alarm.setOnClickListener(new View.OnClickListener() {         @Override         public void onClick(View v) {               int min = 1;             int max = 9;              Random r = new Random();             int random_number = r.nextInt(max - min + 1) + min;             Log.e("random number is ", String.valueOf(random_number));              myIntent.putExtra("extra", "no");             sendBroadcast(myIntent);              alarmManager.cancel(pending_intent);             setAlarmText("Alarm canceled");             //setAlarmText("You clicked a " + " canceled");         }     });  }  public void setAlarmText(String alarmText) {     alarmTextView.setText(alarmText); }    @Override public void onStart() {     super.onStart();     inst = this; }  @Override public void onDestroy() {     super.onDestroy();      Log.e("MyActivity", "on Destroy"); }   my line 61 is startalarm = (Button)findViewById(R.id.start_alarm);  and my xml is  <Button         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="Set alarm"         android:id="@+id/start_alarm"         android:onClick="startTimer"         android:layout_alignParentLeft="true"         android:layout_alignParentStart="true"         android:layout_marginTop="8dp"         app:layout_constraintTop_toBottomOf="@+id/alarmText"         android:layout_marginLeft="63dp"         app:layout_constraintLeft_toLeftOf="parent"         app:layout_constraintBottom_toBottomOf="parent"         android:layout_marginBottom="8dp"          />   thank you


I'm late town hall 7 with maxed cannons,archer towers,Wizard towers and Mortars my air defenses are level 4 which i will upgrade them very soon to max. my walls are level 6 mostly. should i max my walls and Tesla before going to Town hall 8?


Prove that $\int_0^{a}{\int_x^a{t^{-1}f(t)dt}} = \int_0^a{f(x)dx}$

I got stuck on this problem from Real Analysis by Folland. Can anybody give me any hints on how to solve this?     If $f$ is Lebesgue integrable on $(0, a)$ and   $$ g(x) = \int_x^a{t^{-1}f(t)dt} $$   then $g$ is integrable on $(0, a)$ and      $$ \int_0^a{g(x)dx} = \int_0^a{f(x)dx} $$


Suppose  $$a_1 , a_2 , ... , a_n$$ are given real numbers that are greater or equal than $1$.  Prove that $$\sum_{k=1}^n \frac{1}{1+a_k} ≥ \frac{n}{1+\sqrt[n]{\prod_{k=1}^{n} a_k}} $$ I tried using Bergstrom but the it results the opposite inequality(less or equal). And I tried writing them as $$a_1 = x_1 + 1$$ so I can work on positive real numbers but it gets really complicated.  Please help. Thanks!


A quotient space of a manifold by a covering space action is Hausdorff

Let $M$ be a topological manifold and suppose there is a covering space action of a group $G$ on $M$. This means that each $x\in M$ has a neighbrohood $U$ such that $g_1(U)\cap g_2(U)$ nonempty implies $g_1=g_2$, for any $g_1,g_2\in G$. Then is it true that the quotient space $M/G$ is Hausdorff? (I am trying to show that $M/G$ is a manifold. The hypothesis that the action of $G$ is a covering space action gives that the projection $M\to M/G$ is a covering map, so $M/G$ is locally Euclidean. But I can't see why $M/G$ should be Hausdorff.)


If a moderator deletes the question-OP's comments, the mod is mistakenly marked as OP also

I've seen the screenshots from  and noticed that when a mod deletes question-OP's comments, the mod's name gets the blue-OP-box too:        .  rolfl is certainly not the OP of that question, so their name should be wrapped in the box in such cases.


I was pondering a bit more about  question regarding being able to "omit" the base case in a proof by strong induction due to vacuous truth. The post states:  Strong induction proves a sequence of statements $P(0), P(1), …$ by proving the implication "If $P(m)$ is true for all nonnegative integers $m$ less than $n$, then $P(n)$ is true." for every nonnegative integer $n$. There is no need for a separate base case, because the $n=0$ instance of the implication is the base case, vacuously.  However, if we consider $n=0$, we would have that the statement is vacuously true, which I would take to mean that the implication is true regardless of the validity of $P(0)$. However, clearly it's necessary for $P(0)$ to hold for an induction proof to be valid. So I'm confused on how, by omitting the base case, $n=0$ isn't just a tautology, making the implication true regardless of whether $P(0)$ actually holds.


Problem downloading "not free" programs from Ubuntu Software Center

I bought "Quick 'n Easy Web Builder" in Ubuntu Software Center on 15 march, 2013 and it worked OK after unlocking it with my license key.   Now I have replaced my computer (with Ubuntu 12.04LTS) but I cannot download the program anymore: when I try to start the download in Ubuntu Software Center I invariably get the message:  "Condizioni d'uso - Unable to load page - Problem occurred while loading the URL https://apps.ubuntu.com/cat/tos/plain/ - Cannot resolve proxy hostname()".   The same problem seem to happen with all paid programs, while I can download free ones without problems.   Thank you! Paolo


Is it possible to view the scene in the viewport camera view at 1:1?

I'm manipulating some things in the scene from camera view, and I'd like to be able to tell exactly how big they will appear in the render.  Is there some way to make the camera view zoom to 1:1 in the viewport, without rendering the scene?


I found this sentence in      “He was feared by other, lesser, men.”   is this sentence correct in grammar?  I can't make sense out of it. I suppose it should be "He was feared by other lesser  men". is my opinion correct? thank you


How to stop loop using character input without pausing loop

Good day,  I am trying to create a program that obtains orientation data from Sensors then uses that in a PID control algorithm to create corresponding PWM signals. I would like to be able to stop the program by pressing enter. I tried using opencv's waitKey(); however it does not accept my keyboard inputs. I also tried cin.get(); but it pauses my loop which creates a problem. My pwm would not get refreshed once the quadcopter changes orientation. I tried researching other methods however I could not get them to work. Here is a sample of my code using the two methods mentioned above.  Using cin.get():  using namespace std;  int main(void){      while(1){         /* get orientation data */      /* output corresponding pwm */      //Press enter to stop loop         if(cin.get() == '\n'){             /* Stop Pwm */              break;         }     }     return 0; }   Using waitKey();  using namespace std; using namespace cv;  int main(void){      while(1){         /* get orientation data */          /* output corresponding pwm */          //Press ESC to stop loop         int key = waitKey(33){         if(key == 27){             /* Stop Pwm */              break;         }     }     return 0; }


How to automatically create 4:3 AND 16:9 versions of my LaTeX Beamer slides?

As someone who often gives talks abroad, I usually do not know beforehand which resolutions the projector supports. Thus, I always create both a 4:3 and a 16:9 version of my slides, using e.g.  \documentclass[aspectratio=169]{beamer}   Is there a way to create both without having to change this line? I use pdflatex.


Cauchy principle value of $\int_{-\infty}^{\infty}\sin(x)/(x-a)dx$

I need to find the cauchy principle value of $\int_{-\infty}^{\infty}\sin(x)/(x-a)dx$ ? I'm think of rewriting in terms of $e^{i\theta}$ and try to rewrite as contour integral?   Need some aid on how to calculate this integral please. Thank you for help


What should I do if I come by a seemingly inappropriate profile picture?

Is there a way to bring a seemingly in to the moderators notice?   What should I do if I come by such a profile picture?


\newcommand with \raisebox in section title

I have defined the following command to typeset 'C++':  \newcommand{\Cpp}{C\raisebox{-.23ex}{\texttt{++}}}   Using the command in a paragraph works as expected. However, I can't use it in a section title. I seems like it has something to do with \raisebox.  Here an mwe:  \documentclass[11pt]{article}  \newcommand{\Cpp}{C\raisebox{-.23ex}{\texttt{++}}}  \begin{document}     \section{\Cpp} % doesn't work! because of \raisebox ? \Cpp-Compiler \end{document}   How can I redefine the \Cpp command to work in a section title?


Proof by contradiction attempt pertaining to divisibility

I have tried proving the following question using contradiction, but I am not sure if that totally makes sense. The question is as follows:     Prove that if $a, b \in \mathbb{Z}$ and $a^2-3b^2$  is divisible by 4, then at least one of $a, b$ must be even.   So, here is my attempt: Asume for a proof by contradiction that $a, b \in \mathbb{Z}$, $4|a^2-3b^2$, and both $a$ and $b$ are odd. Now, let $a = 2k + 1$, $b = 2m + 1$, for some $k, m \in \mathbb{Z}$ and substitute it into $a^2-3b^2$. $$a^2-3b = (2k+1)^2 -3(2m+1)^2$$ $$=4k^2+4k-12m^2-12m-2$$ $$=2(2k^2+2k-6m^2-6m-1)$$ This is contradiction since $4$ does not divide $a^2-3b^2$ if both $a$ and $b$ are odd. $\square$


Prove that a triangle can be inscribed in the hyperbola $xy=c^2$ whose sides touch the parabola $y^2=4ax$. I have no idea how to start this problem. In my first attempt I assumed any three points on the given rectangular hyperbola and wrote down the equations of each of the three chords. Then I tried proving that each of the three sides are tangents to the given parabola...then I put the value of $x$  from the equation of the chord in the equation of the parabola and tried to prove that the discriminant of the quadratic is equal to zero...but I am unable to proceed after that. Need help...thanks!!


I am working on a Data warehouse. I have tables with up to 200M records. Some of these tables have around 20+ indexes (I can't provide a reason why they have been created in the first place). This is making the job of maintaining these indexes too painful and has a direct impact on the DWH import job in both performance and run time.  How can I find the least used indexes on each table? (in order to get rid of them)


What to chose ArgumentNullException or NullReferenceException

I'm writing a small lib of method extensions.   For example we have extension method   public static T GetRandom<T>(this IEnumerable<T> collection)   Which exception ArgumentNullException or NullReferenceException will be the clearest for case when collection is null? Or something else?


What are these mysterious gaps in the progression of post id?

Initially, I assume that PostId is auto-incremented. Except for very rare cases, where the data is completely wiped from the database, leaving some holes in the PostId progression, I expect that the PostId would always lead me to a question, an answer, or a tag wiki.  However, when I looked at the SEDE data as research for , with the following query, I found some big gaps in the progression:  ;WITH n(n) AS (     SELECT 1     UNION ALL     SELECT n+1 FROM n WHERE n < 26000 ) SELECT n FROM n left join postswithdeleted d on d.id = n where d.posttypeid is null ORDER BY n OPTION (MAXRECURSION 26000);   On A&M, there are roughly 6000 ids not accessible by any means, broken into 6 ranges, roughly 1000 ids each:   934 → 1929 (996 ids), post id 933 posted on 2013/01/14 10160 → 11154 (995 ids), post id 10159 posted on 2014/06/08 11751 → 12746 (996 ids), post id 11750 posted on 2014/07/10 15640 → 16636 (997 ids), post id 15639 posted on 2014/12/11 17353 → 18351 (999 ids), post id 17352 posted on 2015/01/07 24612 → 25609 (998 ids), post id 24611 posted on 2015/09/03   Since the gaps are quite uniform, I guess there must be a reason behind it. What caused these gaps in the progression of PostId?


Rationale behind voting to close "Duplicate of.." causing the question to be closed instantly?

On occasion I noticed that voting to close "duplicate of" instantly closes the question and marks it as a duplicate.  I've seen it happening for identical questions (reposts) and that makes sense. It also happened with this .  I'm just wondering how does SO (currently) determine that the question to be closed should rather be closed instantly instead of simply recording my vote?


I can't increase the size of ext4 or the partition in which Ubuntu is installed , it says that it is in maximum size:


How can I limit the number of rows in an Oracle query

I have PHP + Oracle query like this :  $query_pag_data = "SELECT P.FORM_NO, P.MODEL_NO, P.PRODUCTION_STATUS, P.REMARKS, P.DATE_ADDED, P.TIME, P.QTY_PLAN, M.MODEL_NO, M.MODEL_NAME                     FROM SEIAPPS_PRODUCTION_STATUS P, SEIAPPS_MODEL M                     WHERE P.MODEL_NO = M.MODEL_NO ORDER BY P.DATE_ADDED DESC, P.TIME LIMIT $start, $per_page";   When I tried to search the problem, everyone said the problem is in LIMIT cant used in oracle. How can I use LIMIT in ORACLE ?  Please advice.


From Wikipedia article :  Spectral lines are the result of interaction between a quantum system (usually atoms, but sometimes molecules or atomic nuclei) and a single photon. When a photon has about the right amount of energy (which is connected to its frequency) to allow a change in the energy state of the system (in the case of an atom this is usually an electron changing orbitals), the photon is absorbed. Then it will be spontaneously re-emitted, either in the same frequency as the original or in a cascade, where the sum of the energies of the photons emitted will be equal to the energy of the one absorbed (assuming the system returns to its original state).   A spectral line extends over a range of frequencies, not a single frequency (i.e., it has a nonzero linewidth).   The lifetime of excited states results in natural broadening, also known as lifetime broadening. The uncertainty principle relates the lifetime of an excited state (...) with the uncertainty of its energy.  Can you provide proof for the last statement? (Maybe without using QED, if possible)


I am trying to remove the background from the image in PS. I am new to PS and have tried the Color range option as follows with no luck   From the menu Select/Color Range Click on the background area which will select some of the gray area Adjust the Fuzziness and Range as shown below Click on the eyedropper with a plus (+) next to it Click on the gray areas that are not selected until you have a good coverage Click OK Press Ctrl-J to create a new layer with the selection   Any help would be great


Exception thrown: read access violation. cur was 0xCDCDCDCD

I am trying to display the second list. when I run the code, the second list gets printed but the compiler throws an exception that says "cur was 0xCDCDCDCD". I am trying to let the user input a list and then the compiler creates a second list with the square of elements of the first list. here's the code with the question.  /* Write a program that inputs from the user a simple linked list of integer elements. The program should create a new list that is the list of the square of the elements of the previous list. Output the list. */ #include <iostream> #include <cmath> using namespace std;  struct node {     int data;     node* next; };  node* input(int n) {     node* cur, * head, * tmp;     tmp = new node;     cout << "enter a new node" << endl;     cin >> tmp->data;     head = tmp;     cur = tmp;     for (int i = 0; i < n - 1;i++) {         tmp = new node;         cout << "enter a new node" << endl;         cin >> tmp->data;         cur->next = tmp;         cur = tmp;     }     return head;  }    node* square(node* head, int n) {     node* head1, * cur, * cur1, * tmp;     cur= head;     tmp = new node;     tmp->data = pow(cur->data, 2);     head1 = tmp;     cur1 = tmp;     cur = cur->next;     for (int i = 0;i < n - 1;i++) {         tmp = new node;         tmp->data = pow(cur->data, 2);         cur1->next = tmp;         cur1 = tmp;         cur = cur->next;     }     return head1; }  void displayList2(node* head1) {     node* cur;     cur = head1;     while (cur != NULL) {         cout << cur->data << " ";         cur = cur->next;     } }  int main() {     int n;     cout << "enter number of nodes: ";     cin >> n;     node* head, * head1;     head = input(n);     head1 = square(head, n);     displayList2(head1); }  is there a problem with the heap memory or something similar? what am I doing wrong?


Why are almost every planet or star rotating?

Is there any simple reason? Why is spinning so common?


I made a new Blender file and added Quick Smoke to the default cube. I changed the renderer from Eevee to Cycles and switched to GPU Compute. When I render, all I see is the cube; the smoke doesn't appear. I've tried switching the cache type to Final and rebaking the sim and nothing changes. When I save the file and close and re-open Blender, nothing changes, and if I rebake after that, nothing changes.  Viewport:    Render:   I should note that while I am on 2.9 alpha, this happens in 2.82 and 2.83 beta as well.  Before this gets marked as a duplicate, I've tried everything listed on other questions on this site and on Google that I could find.


Should sources helping me understand concepts but not crucial to reconstruct my work be cited?

For example, to calculate a specific exponent E, I need to read book A on summation, book B on multiplication, book C on exponent. After that I can do E.    C is surely cited, but is it required A and B to be cited too? If not, should they be cited? If both A and A' are excellent resources to understand what's summation is, is it fine to cite both of them? C' is also about exponent, but C is the one actually makes me understand what the exponent is. Should C' be cited?


Why free-fall acceleration is considered constant rather than increasing?

The force acting on a body of mass $m$ is $mg$, where $g$ is acceleration of free fall ! But why should there be a #uniform acceleration of free-fall in the first place? As per Newton's universal law of gravitation there's an inverse square law of force acting with respect to separation ; Thus as object falls towards Earth separation decreases and so the force, and hence acceleration, should likewise increase! How to reconcile this argument with a universally accepted constant acceleration $g$?


Pluscom MAC address shows up but "wireless unavailable"

I've got a pluscom pci card plugged into my desktop and although the mac address shows up in network manager, it says "Wireless unavailable".  I'm using Ubuntu 12.10 Gnome Shell Remix...  edgar@edgarQuantal:~$ iwconfig eth0      no wireless extensions.  lo        no wireless extensions.  wlan0     IEEE 802.11bg  ESSID:off/any             Mode:Managed  Access Point: Not-Associated   Tx-Power=0 dBm              Retry  long limit:7   RTS thr:off   Fragment thr:off           Power Management:off  edgar@edgarQuantal:~$ ifconfig eth0      Link encap:Ethernet  HWaddr 6c:f0:49:02:1f:b8             inet addr:192.168.0.7  Bcast:192.168.0.255  Mask:255.255.255.0           inet6 addr: fe80::6ef0:49ff:fe02:1fb8/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:1425 errors:0 dropped:0 overruns:0 frame:0           TX packets:1393 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:995753 (995.7 KB)  TX bytes:134079 (134.0 KB)  lo        Link encap:Local Loopback             inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:363 errors:0 dropped:0 overruns:0 frame:0           TX packets:363 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0            RX bytes:40828 (40.8 KB)  TX bytes:40828 (40.8 KB)   It looks the same as the problem as here, seems quite complicated:   Tried downloading the driver but I get this:  Unpacking firmware-ralink (from .../firmware-ralink_0.36_all.deb) ... dpkg: error processing /home/edgar/Downloads/firmware-ralink_0.36_all.deb (--install): trying to overwrite '/lib/firmware/rt2870.bin', which is also in package linux-firmware 1.95"


How to thank a potential supervisor's email?

I have recently interviewed by a professor in US after sending him my CV. A few days after the interview he mailed me and told me to do the formal application process and mention him as the professor I want to work with. Now, I want to thank him for considering me as a choice of his future PhD student. What should I write?


Should I use a categorical cross-entropy or binary cross-entropy loss for binary predictions?

First of all, I realized if I need to perform binary predictions, I have to create at least two classes through performing a one-hot-encoding. Is this correct? However, is binary cross-entropy only for predictions with only one class? If I were to use a categorical cross-entropy loss, which is typically found in most libraries (like TensorFlow), would there be a significant difference?  In fact, what are the exact differences between a categorical and binary cross-entropy? I have never seen an implementation of binary cross-entropy in TensorFlow, so I thought perhaps the categorical one works just as fine.


How to remove a system app from the Play Store updates list

I wonder how I can remove SwiftKey Keyboard form the updates list.    Notes   It's a system app. Its Disable button is grayed out.


Creating list of list based on index and value

I have been given a list of  positive integer numbers upto 10^6 and total number of item in the given list will be 10** 4 at most. I want to store these values in a particular order as explained below. I want to iterate through the list and want to place the index value of item in the inner list corresponding to that item. Example Given List : [3,0,1,1] output : [[1],[2,3],[],[0]] #expected output basically output list should contains lists with index corresponding to item value in given list which should contain index value I have comeup with this solution. sequence = [[]] * 4 given = [3,0,1,1] index = 0 for num in given:     sequence[num].append(index)     index+=1 print(sequence)  but the output I am getting is [[0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3]] and cannot figure out why.


Java loop efficiency ("for" vs. "foreach")

(A question for those who know well the JVM compilation and optimization tricks... :-)  Is there any of the "for" and "foreach" patterns clearly superior to the other?  Consider the following two examples:  public void forLoop(String[] text) {     if (text != null)     {         for (int i=0; i<text.length; i++)         {             // Do something with text[i]         }     } }  public void foreachLoop(String[] text) {     if (text != null)     {         for (String s : text)         {             // Do something with s, exactly as with text[i]         }     } }   Is forLoop faster or slower than foreachLoop?  Assuming that in both cases the text array did not need any do sanity checks, is there a clear winner or still too close to make a call?  EDIT: As noted in some of the answers, the performance should be identical for arrays, whereas the "foreach" pattern could be slightly better for Abstract Data Types like a List. See also  which discusses the subject.


GeoServer not running on port :8080 on Windows 7?

After Installing GeoServer on my windows machine, then I restarted tomcat but it doesn't start.   Before installing the geoserver localhost:8080 is working.   What's wrong ?


Why is there no on/off button for irons?

I've never seen any iron have an on/off button. So my guess is that most of them do not have one. Is there any specific reason for that?


The Stack Exchange policy seems to be to disallow edits of fewer than six characters. However, often in technical subjects an edit of a single character can make a critical difference.  I just experienced this , where I wanted to correct a key-stroke sequence for a computer operation. The correction amounted to a single character, changing M-x to C-x. The hack I came up with, and for which I am embarrassed to have had to resort, was to add a sequence of x's to the end of the post. My intent was to follow-up that with a second edit to delete the x's. Quite a kludge.  Please either provide me guidance on how to properly perform these types of edits, or consider changing the policy for some or all Stack Exchange sites.


I'm trying to draw two arrows between nodes as follows:  A ------> B   <--/---   The arrows should be parallel, in opposite directions but not on top of each other. (I can bend the arrows but that's not what I'm after.)  What's the cleanest way to do this in TikZ? And can I have just one of the arrows "struck out" as in the example?


"An autonomous being" vs "autonomous being"? When to place an indefinite article?

He treats her as property rather than an autonomous being.  or   He treats her as property rather than autonomous being.  Which of the above sentences is correct and why?


Do I get less scrap if I "soften up" an enemy ship before I board and finish off the crew?

Sometimes, to make boarding a ship easier, I'll send off a volley or two of burst lasers to knock out the medical bay or injure the crew before I teleport over to fight them.  When I do this, of course, it causes several points of damage to the enemy ship's hull.  Does it make any difference in the amount of scrap I receive at the end of the fight whether I weaken the enemy ship in this way, or capture it by teleport without firing a shot?  (My impression is that it doesn't, but I'm looking for something more solid than a hunch.)


How do I test whether means are equal when I have summary stats for 2 samples from one population and for 1 sample from a second?

I think this is a "meta-analysis" situation.  I've got 3 samples (from 3 studies); I've assumed that two are from population A (treatment A) and one is from population B (treatment B). I have the sample means, standard errors & sample sizes for each sample (and that's all). I want to test if the pop A mean equals the pop B mean.   I did t-tests for samples A1 vs B1 and A2 vs B1 and got p-values of like 0.6 and 0.3 respectively. What can I say about A vs B overall? How do I get an overall p-value for the null hypothesis $\mu_A = \mu_B$?  I can compute the sample mean of A1 union A2, by taking the weighted average of the two means. It would be nice if I just had the sample variance of A1 union A2, but I don't (I'd guess it's about equal to the sum of the A1 variance and A2 variance..).  [sorry I'm sure there's a bunch of answers to this on here and elsewhere, but I'm unable to identify/understand them]


Comparing character of an array to a string

What's the best way to compare character of an array to a string.      import java.io.Console;     class msd{     public static void main(String[] args){     Console console= System.console();     String letter="Hello";     String[] Arrayname=letter.split("");      if(Arrayname[0] == "H")     console.printf("success");     else     console.printf("failure");     }    }   Output      failure   Expecting to be success.


Simulating data to fit a mediation model

I am interested in finding a procedure to simulate data that are consistent with a specified mediation model.  According to the general linear structural equation model framework for testing mediation models first outlined by  and described elsewhere such as , mediation models for outcome $Y$, mediator $\newcommand{\med}{\rm med} \med$, and predictor $X$ and are governed by the following three regression equations: \begin{align} Y    &= b_{11} + b_{12}X + e_1                \tag{1}  \\ \med &= b_{21} + b_{22}X + e_2                \tag{2}  \\ Y    &= b_{31} + b_{32}X + b_{32} \med + e_3  \tag{3} \end{align} The indirect effect or mediation effect of $X$ on $Y$ through $\med$ can either be defined as $b_{22}b_{32}$ or, equivalently, as $b_{12}-b_{32}$.  Under the old framework of testing for mediation, mediation was established by testing $b_{12}$ in equation 1, $b_{22}$ in equation 2, and $b_{32}$ in equation 3.  So far, I have attempted to simulate values of $\med$ and $Y$ that are consistent with values of the various regression coefficients using rnorm in R, such as the code below:  x   <- rep(c(-.5, .5), 50) med <- 4 + .7 * x + rnorm(100, sd = 1)   # Check the relationship between x and med mod <- lm(med ~ x) summary(mod)  y <- 2.5 + 0 * x + .4 * med + rnorm(100, sd = 1)  # Check the relationships between x, med, and y mod <- lm(y ~ x + med) summary(mod)  # Check the relationship between x and y -- not present mod <- lm(y ~ x) summary(mod)   However, it seems that sequentially generating $\med$ and $Y$ using equations 2 and 3 is not enough, since I am left with no relationship between $X$ and $Y$ in regression equation 1 (which models a simple bivariate relationship between $X$ and $Y$) using this approach.  This is important because one definition of the indirect (i.e., mediation) effect is $b_{12}-b_{32}$, as I describe above.  Can anyone help me find a procedure in R to generate variables $X$, $\med$, and $Y$ that satisfy constraints that I set using equations 1, 2, and 3?


How can I get the most possible depth of field out of close-up/macro shots?

I own a Nikon D40X and just the kit lens and I'm considering buying either a macro lens or some extension tubes.  I don't necessarily want to do true 1:1 macro, just some close ups of bugs, fungi and flowers.


Because Ebola takes over the immune system and uses it to replicate more and more of the virus, how does the body survive?   Is it a case of the virus being self-limiting and eventually just getting 'too big for its britches' so to speak? Or does the body somehow eventually start producing antibodies to fight it off?


Database table: Some people say that the database table name should be "plural" and some debate for "singular". Is there any standard for renaming the database tables?  Database table columns: Some argue that database column should start with table name as a prefix and some say that it is repeating the same thing twice.   Can anyone help me with what's right and why?  Thanks in advance


Please help me to solve the problem below.         Consider the polynomial $p(x) = a_0 + a_1x + a_2x^2+\dots+ a_nx^n$, with real coefficients.   Pick out the case(s) which ensure that the polynomial $p(\cdot)$  has a root in the interval $[0, 1]$.     (a) $a_0 < 0$ and $a_0 + a_1 +\dots+ a_n > 0$. (b) $a_0 +a_1/2+ \dots +a_n/(n + 1)= 0$. (c)$\frac{a_0}{1.2}+\frac{a_1}{2.3}+ \dots+\frac{a_n}{(n + 1)(n + 2)}= 0$.


I'm an average home user, but still sometimes use terminal for simple tasks. When I type "terminal" in unity, it offers me three choices - but what`s the difference? I hate always choosing randomly and thinking about what I did.


My HTML is using  a lot of js files (10 js files) including jquery js .  There are 4 js files which are not needed instantly ,but later that is when clicked on some button .  Could you please let meknow if is it possible to load js file at required time only ??  My html looks this way   <html>    <head>       <script type="text/javascript" src="js/accordian/jquery-1.9.1.js"></script>       <script type="text/javascript" src="js/accordian/jquery-ui.js"></script>       <script src="js/bootstrap.min.js"></script>       <script type="text/javascript" src="js/customerscreen_sub.js"></script>       <script type="text/javascript" src="js/toppings.js"></script>       <script type="text/javascript" src="js/crusts.js"></script>       <script type="text/javascript" src="js/customerorders.js"></script>       <script type="text/javascript" src="js/common.js"></script>       <script type="text/javascript" src="js/url.js"></script>       <script type="text/javascript">


Why did the Enterprise go on her mission?

My question is: Is there an official reason why the Enterprise went on their 5-year Mission? Or was it just to explore new worlds?


In regards to image attachments inserted into a post, I would like to wrap the img tag inside a div tag for specific design purpose.  Is there a way to do this automatically after attaching the image file, like through hooks/filters maybe?  Thanks in advanced!!


How to get those lines which have higher length among all the lines in the file using awk command

I want that line from the file which have highest length among all the lines using awk command.


LaTeX include filepath/name with non-ascii characters

Trying to compile   \documentclass{article} \begin{document} \include{übergröße} \end{document}   with pdflatex and the file übergröße.tex in the same directory leads to the error:  This is pdfTeX, Version 3.14159265-2.6-1.40.19 (TeX Live 2018/Some Linux) (preloaded format=pdflatex) restricted \write18 enabled. entering extended mode (./test.tex LaTeX2e <2018-04-01> patch level 5 (/usr/share/texmf-dist/tex/latex/base/article.cls Document Class: article 2014/09/29 v1.4h Standard LaTeX document class (/usr/share/texmf-dist/tex/latex/base/size10.clo)) No file test.aux. (./.tex) [1{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map}] (./test.aux ! Undefined control sequence. <argument> ...spacefactor \accent@spacefactor \OT                                                1\ss e.aux l.2 ...cefactor \accent@spacefactor \OT1\ss e.aux}   How do I include or input files whose path or filename contains non-ascii (unicode) characters?


Redirect to different URL and show another URL(page in this URL Does Not Exist) in address bar in ASP.net

I have a link that redirects to  "/Certification/abc123.asp". Now what I want is page should redirect to some another page that is "details.aspx?URL=/Certification/abc123.asp" but URL in address bar should appear  "/Certification/abc123.asp". I have created Url rewriting rule in web.config.  Below is my code: in web.config   <rule name="Redirects to Certifications" stopProcessing="true">       <match url="(.*certifications*)"/>       <conditions>         <add input="{HTTPS}" pattern="^OFF$"/>       </conditions>       <action type="Redirect" url="http://{HTTP_HOST}/ERRoot/details.aspx?url={REQUEST_URI}"  appendQueryString="true"/>     </rule>   By this I match my URL, if it contains "certifications" then it redirects to "details.aspx" page with Querystring key "url" that contains original URL. But my URL displays the page i have redirected to.  I want "/Certification/abc123.asp" to display in my address bar.  Note: There is no page like /Certification/abc123.asp. It is just a URL  Please help. Thanks in advance !!!


Catastrophic Backtracking in Regular Expression for multiple email ids

I'm using the following regular expression to validate email addresses:      ([_A-Za-z0-9-+]+(.[_A-Za-z0-9-]+)*@[A-Za-z0-9-]+(.[A-Za-z0-9]+)*(.[A-Za-z]{2,})$)   but I am getting Catastrophic Backtracking in Regular Expression when the string is:     abc@damkovnai.un;efg@damkovnai.un;hij.kumar@damkovnai.un;klm.verma@damkovnai.un;   When I remove the last semicolon, the result is true, but when the semicolon exist in last position in the string then the output is Catastrophic Backtracking, even though I want the result to be false.


Does anyone know how o load wp_editor via AJAX in WordPress?  My markup and editor is getting loaded properly but editor controls are not getting loaded properly, it may be because Javascript is not running in AJAX call.  Any help would be appreciated.


How to get rid of opened duplicate window

After I open an additional view of a window, how do I get rid of it?  Example below:    Dragging to the right/left does not help.  I am using 2.72 on Windows 7.


From definition of $e^T=\sum_{k\geq 0} \frac{T^k}{k!}$, so $e^0=0^0$...  So, why $e^0=I$ for exponential operator?  Any help would be appreciated.


How am i supposed to download these drivers and utilities? I am a complete newb to linux, any help will be greatly appreciated!  Note: The drivers and utilities are windows based


replacing a chain - which coating type or make (nickel vs silver vs TI Nitride vs diamond like)?

I've been riding a 2017 Giant AnyRoad CoMax for about 2.5 months now and today I checked the chain wear with a Park Tool Chain Wear Indicator:    The wear is between 0.5 and .075.  I plan on replacing the chain when it gets to .75, which is probably about a month away, perhaps slightly less.  So, its time to look at ordering a replacement chain.  Upon going to the web page for the bike:    The specification for the chain is "KMC X11", seems simple enough, but upon searching Amazon for "KMC X11":    or the KMC page for 11 speed chains:    I find I'm overwhelmed with the options.  They include:  -"DLC" (Diamond Like Coating)  -TI Nitride  -Silver  -"ECO PROTEQ"  -Nickel  Weights seem to include L (light), SL (super light), and XL (extra light).  The most popular choice on Amazon seems to be the "KMC X11.93 Nickel":    which is also the least expensive by far at $24.  All the others listed above are at least 2x as much, some 3x - 4x as much.  I ride my bike 90+% for commuting, so saving large amounts of weight (ex. carbon vs aluminum frame) is significant, but when getting down to counting grams it doesn't much matter for my riding purposes.  Of course the manufacturer's description of the more expensive chains (i.e. all the options other than Nickel) imply that they are worth the extra cost and provide all-worldly benefits, but I'm skeptical I would notice a difference.  So here are my questions:  -What are the advantages of Silver or TI Nitride over Nickel?  -Is there such a thing as "Diamond Like Coating" or is this just manufacturer hype?  -Would I notice the slight weight difference with the L vs SL vs XL, or is this something that would only matter to a competitive cyclist trying to shave a few seconds off a run?  -Other than the coating, are the more expensive chains actually built more robustly?  Of course the KMC website claims the more expensive chains are more resistant to stretching, but is the difference enough to be significant?  -My inclination is to go with the $24 Nickel chain, is there a compelling reason that the 2x-4x more expense chains would be better for a non-competitive cyclist?  Edit: somebody linked a semi-related post that mentioned Nickel plating, thanks for the suggestion, but that post did not address by other inquiries


Is there any application (or sequence of commands) for this function: seeing the result of the actions, while using a GUI interface, being automatically translated into a Terminal (or similar CLI environment) on the same machine.  I saw this in action long years ago in VBA for Applications (for example the Macros in Excel). I wonder if there is same function in Linux.


How to get server MOTD on non-server install

Is there a way to get the fancy MOTD that shows up on an Ubuntu Server install on my Ubuntu Alternate install? Like this:  Welcome to Ubuntu 11.10 (GNU/Linux 3.0.0-12-server x86_64)   * Documentation:  https://help.ubuntu.com/11.10/serverguide/C    System information as of Sun Nov  6 00:38:01 PDT 2011    System load:  0.0                Processes:           88   Usage of /:   0.8% of 227.98GB   Users logged in:     0   Memory usage: 14%                IP address for eth0: 10.13.37.147   Swap usage:   0%    Graph this data and manage this system at https://landscape.canonical.com/


How to know all the optional arguments of Latex commands\environments?

For external packages CTAN provides the needed documentation, however, for built-in Latex commands I am not aware of any proper documentation except for  which doesn't really list all the options  I would like to know how I could check all the available environments, commands and relative optional fields of all the built-in commands of Latex more or less like I would use the man command under linux.  I'm looking for something exhaustive like the  documentation that breaks down every single piece available.


How to reinstall PulseAudio (Ubuntu 12.04)

I was trying to fix my audio problems using suggestions from . One of the comments suggested I execute this and only this:     killall pulseaudio   So I did, and I restarted my computer just in case, but all it did was remove my soundcard and I still couldn't hear anything. Now I don't know how to get my soundcard back.  Please note that I am extremely inexperienced when it comes to Ubuntu.


If() inside WHILE-BufferedReader.readLine() does not work

UPDATE:  Thank you all for your answers, especially pertaining to .equals().   The only detail is that the "msgCode = ..." and "msgValue = ..." statements are enough to return an empty stirngBuilder. I.e., I don't even have to declare the IF statement to make it stop working.   Any clues?  ORIGINAL: Please let me know why StringBuilder returns nothing (perhaps doesn't even work) when I include the rest of the code (besides stringBuilder.append(...)) inside the while().  When I include just stringBuilder.append(...), then there is a return value.  while ( (receiveString = bufferedReader.readLine()) != null ) {     stringBuilder.append(receiveString + "\n");      // analyze the first 3 characters in the message     String msgCode = receiveString.substring(0, 3);     Number msgValue =  Integer.parseInt(receiveString.substring(4, receiveString.length()-4));      // use IF-ELSE since SWITCH doesn't work with String     if (msgCode=="ATT") {         dataATT[2*dataATTcount+1] = msgValue;          dataATTcount++;     } else {         dataMED[2*dataMEDcount+1] = msgValue;          dataMEDcount++;                          } }   Thanks


Will my linux binary work on all distros?

I found a good replacement IDE for Delphi called Lazarus. But I don't have a question for programmers.  Will the statically linked Linux binary work on all Linux distributions? I.e. it does not matter on what Linux distro I built it and it will work on Debian / ArchLinux / Ubuntu / OpenSUSE / ... whatever?  As a result of my findings, does really only matter 32bit vs 64bit? I want to be sure before I publish.


non greedy regex to select everything between curly braces but not the starting and ending curly braces

I need a greedy regex to select everything between curly braces but not the starting and ending curly braces  for example:   {here {first} and {second} and {third}}   output should be  {first}, {second}  {third}


Can I install software from debian package without internet

This is a silly question but can you install software from debian packages without having an internet connection ?


I think that the original purpose of Programmers (originally called ) hasn't fulfilled its purpose, and right now it functions as a duplicate of Stack Overflow.  The question  has 4k views and is on top of the meta questions list. One main answer:     "... Stack Overflow is for when you’re front of your compiler or editor working through code issues. Programmers is for when you’re in front of a whiteboard working through higher level conceptual programming issues..."    This is only a nice theory, in practice this site (Programmers) is a redundancy, any question that I thought to ask here I could ask on Stack Overflow. The real "white board" questions are not welcome there as they are too broad and usually get downvoted and closed.


I have to share a pc with my brother, which is a big fan of Windows 10. I, on the other hand, want to write programs on Kali Linux. You see where this is going.  I first wanted to setup a dual boot system, but the hard drive is filled with games, so I was looking around and heard about Linux Live USB sticks. I quickly set one up, but all my data is removed after rebooting the system and the partition, the OS is running on, is just big enough to fit the filesystem and can't be resized.  Is there a way to install Kali Linux normally (no Linux Live stuff) on a standard USB stick?


How to install on a laptop with no CD drive and no usb boot option

I have an old 32-bit laptop with a broken DVD drive and the USB boot option doesn't work either. Its currently running Windows Vista.  How can I install Ubuntu on to it?  I know about WUBI but it seems to be dead (I can't find it anywhere).


How to tell Debian not to worry about certain dependencies?

I'm using docker to provide an mta.  But it's broken apt because it won't let me install packages that need an mta (e.g. bsd-mailx).  For individual packages I can force it; download the package and use dpkg -f -i package.deb but that still leaves apt fretting about an unresolved dependency, which prevents me installing other packages that are nothing to do with the MTA.  e.g.  $ apt install silversearcher-ag Reading package lists... Done Building dependency tree        Reading state information... Done  The following packages have unmet dependencies:  bsd-mailx : Depends: default-mta or                       mail-transport-agent E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).   Is there a way to tell it that there is a mail-transport-agent package installed? (I'm on Debian 9)


Calc question about inequality and electric circuit theory

In electric circuit theory, the combined resistance $R$ of two resistors $R_1 > 0$ and $R_2 > 0$ connected in parallel obeys  $$\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2}$$  Show that $$R < \sqrt{\frac{R_1 R_2}{2}}$$. This proves that $R$ cannot be large if the individual resistances $R_1$ and $R_2$ are small.  Can anyone show me how to solve this questions?