Attempt to invoke virtual method : SQLite

I'm struggling with CAMERA2 API and SQLite. After the video captured the clip name must save in the db Those are the steps I'm trying to figure out.  1.In the video capturing class, will call for the db activities class      VS_dbActivity dbActivity = new VS_dbActivity();     String msg = dbActivity.sendData(mNextVideoAbsolutePath);   2.In the dbActivity class trying to send mNextVideoAbsolutePath into db  public class VS_dbActivity extends AppCompatActivity{  private VS_dbConfig dbHelp;  public String sendData(String filePath) {     dbHelp = new VS_dbConfig(this);     SQLiteDatabase db = dbHelp.getWritableDatabase();     // some example }   }  In the above-mentioned class, I didn't add the constructor. Is it necessary adding constructor? What happens if didn't use the constructor.  When I'm run this app it will appear error in  SQLiteDatabase db = dbHelp.getWritableDatabase();   Error log :---->>  FATAL EXCEPTION: main                                                                                Process: com.android.ejsoft.video_upload_000web, PID: 334                                                                                java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.sqlite.SQLiteDatabase android.content.Context.openOrCreateDatabase(java.lang.String, int, android.database.sqlite.SQLiteDatabase$CursorFactory, android.database.DatabaseErrorHandler)' on a null object reference                                                                                at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:274)                                                                                at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:223)                                                                                at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:163)                                                                                at com.android.ejsoft.video_upload_000web.dbManage.VS_dbActivity.sendData(VS_dbActivity.java:28)                                                                                at com.android.ejsoft.video_upload_000web.Camera2VideoFragment.sendFilePath(Camera2VideoFragment.java:578)                                                                                at com.android.ejsoft.video_upload_000web.Camera2VideoFragment.access$1200(Camera2VideoFragment.java:60)                                                                                at com.android.ejsoft.video_upload_000web.Camera2VideoFragment$4$2.onInfo(Camera2VideoFragment.java:555)                                                                                at android.media.MediaRecorder$EventHandler.handleMessage(MediaRecorder.java:1159)                                                                                at android.os.Handler.dispatchMessage(Handler.java:102)                                                                                at android.os.Looper.loop(Looper.java:135)                                                                                at android.app.ActivityThread.main(ActivityThread.java:5753)                                                                                at java.lang.reflect.Method.invoke(Native Method)                                                                                at java.lang.reflect.Method.invoke(Method.java:372)                                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405)                                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)   Isn't there anyway without doing constructor for getting the context of the activity? Thank you for your valuable time.


loop thorough every file in file system with AppleScript

How can I loop through every file in my file system with AppleScrip? And by every file I literally mean every single file, including hidden ones. Can it be done with AppleScript and how?   I will check Date Modified of every single file to investigate what changed after playing around with a specific program.


I've got a lot of question about normal force. First, what causes normal force. Next, how do the object know how much normal force to exert. Lastly, how is this not an application of Newton 3rd law. Imagine a book on a table. The book is exerting a downward force on the table(weight), the table is exerting a normal force on the book(upwards) . People keep saying that they act on the same objecr, the book, but the book's weight is acting on the table, so why is this not Newton 3rd law


Versioning in PostGIS on PostgreSQL database

I have a cadastral database which requires multi-user editing/updating on daily basis.   I am trying to migrate from Esri enterprise geodatabase to PostGIS/PostgreSQL. I am not sure PostGIS offers versioning option similar to the Esri versioning.


Adding Layer Files (.lyr, .lyrx) to QGIS

At college we use ArcGIS Desktop 10, but that does not function on my Mac so I have QGIS there instead.  I want to do my exercises with QGIS, but in ArcGIS Desktop we use .lyr files with ArcMap and .lyrx files with ArcGIS Pro, and they are not supported by QGIS.  Does anyone know, how I can connect the *.lyr files to my *.shp files to use them on my Mac with QGIS?


Will grammar errors become correct after enough people use them for enough time?

First let me state the obvious—based on my own experience—that hordes of people are confused about certain basic grammar principles. For example, I so often see mistakes in choosing the pronoun to use with direct objects, especially when introduced by and with another person, as in "Joe talked about the book with Anna and [I/me]." Another one is the near 100% usage of "lay" instead of "lie" (and "laid" instead of "lay") nowadays, even in published sci-fi books that most certainly had professional editors proofread them.  Do you see these kinds of changes as predictors of the future? Will they become correct after enough people have used them long enough?  Both of these problems drive me bonkers, and I fight my own little battle against them when possible.  I know that dictionaries are descriptive rather than prescriptive. They're technically history books. But grammar and style books seem less so, to me. Those seem as though they ought to be prescriptive in order to reduce the erosion of structured and meaningful language.  In this tension between "what people are doing" and "what people should be doing," are we doomed to forever bear these errors just because too many people don't know the proper way? Is it worth fighting against them? Do I capitulate to the people who are quick to accept any mass public usage as a fait accompli?  Update  I don't imagine for a second that my own writing is error free. The difference with me is that when I do learn I have something wrong in my mind, I immediately change once I clearly understand it.  I also am not imagining that language is static or ignorant that today's correctness is all too often yesterday's error. The whole point of my question here, then, is: is there value in slowing the change, and if so, how is that done and how effectively?  Another way to look at what I'm trying to ask is that in a way I am hoping to define the limits of pedantry. If being pedantic is slavish adherence to outdated rules in the face of actual and foregone changed reality, then when do we conclude that a change is a foregone conclusion?  Poking fun at my own errors to highlight supposed pedantry on my part is to miss everything I am trying to say.    Update 2  It may not be an easy question, but since language change actually does or does not happen, and every person acts with more or less intention in regards to language change, there must be an answer. What I wanted to explore is the value in efforts to teach the "proper way" vs. the opposite end of the spectrum where any new usage is not just accepted but welcome or even sought out. You know, I'm reminded of something: the conservative/liberal scale:     |------+------+------+------+------+------| radical              moderate             radical liberal                                 conservative   The funny thing about those at the ends of the spectrum is that they both want things to change. The radical liberal wants language to change to something new quickly, just for the sake of newness or evolution or some other not-necessarily-realistic ideal. Similarly, the radical conservative wants things to change just as much, but back to the way it used to be, just for the sake of sameness or continuity or some other just-as-not-necessarily-realistic ideal.  I'm not particularly asking where we should be on this scale as that's purely subjective. I'm trying to ask about something purely practical and real-world: what is actually effective? Is language change inevitable, and how fast? Are efforts to reduce its rapid morphing either effective or worthwhile in any measure? All these things considered, what position with respect to language evolution is livable, practical, and sensible?  Feel free to edit my grammar. No comment necessary.  Update 3  Something that may be of interest to both my supporters and detractors: . I enjoyed it. I don't disagree with him, but I am not sure I am wholehearted in this lack of disagreement.


Context to distinguish "we" inclusive versus exclusive

In English, "we" has no  - context is needed to determine whether it means we-including-you or we-excluding-you.  What context can a speaker provide to disambiguate without sounding awkward?  I'm wondering in particular how to reword sentences like "We need to meet tomorrow."


Count the number of points of a multipoint-feature

I try to use the fieldcalculator in QGIS 2.18 to count the number of points of a multipoint-feature. Is it possible?


Shortcut to open Terminal and run some commands

Is it possible to create desktop shortcut, that would do as follows:   open Terminal change directory make a command inside that directory type password (sudo)   I tried with Terminal profiles, but I didn't find option for 2. and 4.


How many players can play splitscreen in COD: WWII?

How many players can play split-screen, and what game modes are (or aren't) available?   How many players can play local co-op? How many players can play local multiplayer? How many players can play online multiplayer from a single console?   These questions don't appear to be specifically addressed anywhere on , and I didn't see any mention in any of the reviews I've read. Even the packaging of the game itself (I haven't seen it, basing this claim off of the standard Xbox One game packaging details) only answers the first of these three questions.


How to find pantone shades of a particular color?

A client came to me with their logo for a campaign and wanted me to do the collaterals. I did a few thing for her. Now she wants me to give her the names of pantone colors matching the exact two colors in her logo. How do I find the pantone shades for them? Please help!  Thanks


I am reading the Bishop Pattern Recognition and Machine Learning and am on section 9.3 An Alternative View on EM:  I am confused as to how Bishop obtains the expression $Q(\theta, \theta^{old}) = \sum_{Z}p(Z | C, \theta^{old}) lnp(X , Z | \theta)$  Thank you for insight!  ANSWER:  In the method of maximum likelihood, we're generally interested in p(X|θ), or equivalently logp(X|θ). We seek a θ that makes this quantity most likely.  However, in our model, in addition to observations X we have latent variable(s) Z which we haven't observed but we have some idea of what it could be (we've elsewhere described a probability distribution guessing Z). So, we're now interested in p(X,Z|θ), or equivalently logp(X,Z|θ), instead of just choosing a θ to maximize p(X|θ).  Yet it's hard to find the θ that maximizes logp(X,Z|θ) if we don't even know what Z is. Instead, we seek the θ that maximizes logp(X,Z|θ) weighted over our distribution of what Z might be.


I want to open header file in /usr/local/include. How to open it by terminal?


Where is the possible location of Engineer's sacrifice scene?

Is this scene happening on Earth? I mean, perhaps this scene was made completely with CG effects. But if not, which waterfall looks like that? Please, answer with images and sources.


How do I find an available nickname in Pokémon Go?

The app keeps asking for a nickname, and I have entered dozens of names, but it keeps saying that the names aren't available. How can I find an available name?


Can we assure $\frac{d^2}{dx^2} G(\textbf{r},\textbf{r}') = \frac{1}{3} \delta (\textbf{r}-\textbf{r}')$?

Recently, I've made a question regarding the proof of $\nabla ^2 G(\textbf{r},\textbf{r}') = \delta (\textbf{r}-\textbf{r}')$ for $G(\textbf{r},\textbf{r}')=\frac{1}{4\pi|\textbf{r}-\textbf{r}'|}$. This question was answered and can be found here . However, I'm now wondering whether or not we could affirm that $$\frac{d^2}{dx^2} G(\textbf{r},\textbf{r}') = \frac{1}{3} \delta (\textbf{r}-\textbf{r}')$$ I tend to believe that this should be right as all $x,y$ and $z$ coordinates should be equivalent. But is there any formal proof for that? Thanks!


Intuitive proof of the sin and cos addition formulas?

I refer to these formulas:  $\sin(x±y)$ and $\cos(x±y)$  Is there an obvious or intuitive proof to derive their simpler identities in terms of $\sin(x), \sin(y), \cos(x), \cos(y)$?  I am tagging this with complex analysis because I'm open to such an explanation if it's simple enough to understand.


How can I search for a specific string in a object array?

I need write a method that searches an object array of Club Members for a specific member and returns true if the member is found. This is what I have now.   public boolean isMember (String name){     boolean found = false;     int arrayIndex = 0;     while(arrayIndex < members.length && !found){         if(members[arrayIndex] == name){             found = true;         }         arrayIndex++;     }     return found; }


Finding a digit in the sequence of all natural numbers.

I came across a riddle and I wanted to do know if I solved it correctly:     If we write every natural number next to each other:   Example: $012345678910111213\cdots$   What is the digit at position $10000$?   My attempt: Left side is the amount numbers and right side is the digit size of the number: $$10 \qquad 1$$ $$90 \qquad 2$$ $$900\qquad 3$$ $$1777.5\qquad 4$$  Now we have $10000=10\cdot 1 + 90\cdot 2+900 \cdot 3+1777.5 \cdot4$  So it should be the second or third digit of $999+1778=2777$  is this correct? And is it possible to write a closed formula to get a specific position?


How to setup IP alias to local network on Windows?

On Mac there is this command  sudo ifconfig lo0 alias 10.10.10.10   I need the equivalent in Windows.  What would it be? What do I need to look for exactly?


When opening my inbox on on MSE, MSO, SU or SO I see a 404 resource not found for:  https://meta.stackoverflow.com/teams/theme.css?v=10056:1520526728:10063:1520539764  Notice the /teams/ there. I'm part of the teams beta on Stack Overflow but this issues hunts me on every site.  Due to this error my Inbox notification keeps popping up, indicating I have unread messages, which is not the case because I've already read all of them.    Can this be looked at?


My question can be split into two parts:   Is there any advantage in using a shorter integer variable (e.g. short or unsigned char) to loop over array (or stl container) indexes; and What are the advantages (if any) of using iterators with stl containers.   Code example for problem 1:  const size_t a=100000000; const unsigned char b=5; float array[a][b];  for (size_t j=0; j<a; ++j)   for (unsigned char i=0; i<b; ++i)     std::cout << array[j][i] << std::endl;   Does using unsigned char in the i-loop save me anything? Does array[j][i] implicitly cast i into a size_t?  Code example for problem 2:  vector<float> a(1000,0.); vector<float> b(a);  for (size_t i=0; i<a.size(); ++i)   cout << a[i] << endl;  for (vector<float>::iterator it=b.begin(); it!=b.end(); ++it)   cout << *it << endl;   Is there an advantage in using the iterator approach? If not in this case, then when? And Why?  Bonus question: In for (size_t i=0; i<a.size(); ++i), is a.size() re-evaluated every time? Do I win anything by getting the size first?  const size_t size = a.size(); for (size_t i=0; i<size; ++i)   Does std::vector simply return the value of a member variable when I call vector::size() or does it do something more elaborate?


Extract date from a variable in a different format

Let me explain you the problem   $ date +%c -d "$d" Tue 31 Dec 2013 01:13:06 PM CET $ date +'Today is %F' -d "$d" Today is 2013-12-31   This solution corresponds to current date.  But I have one variable which stores date other than current date  $Prev_date="Wed Dec 25 06:35:02 EST 2013"    I am looking for solution to read this date as 2013-12-25 and store it in a variable.  I have tried this:  a=`date --date=$Prev_date '+%y/%m/d'` echo $a   It's giving this error:  date: illegal option -- date=Wed usage: date [-u] mmddHHMM[[cc]yy][.SS] date [-u] [+format] date -a [-]sss[.fff]


Elementary proof of tangent half angle formula

Hi all, I am interested to find elementary proof of tangent half angle formula.  My solutions are the following:  Triangle $AOB$ is such that $|AB|=1$ and $\angle AOB=\theta$. We then extend $OB$ to $P$ and $Q$ such that $|OP|=|OQ|=1$. Thus we will have two isosceles triangles: $AOP$ and $AOQ$.  From the picture, $\tan{\left(\frac{\theta}{2}\right)}=\frac{AB}{BP}=\frac{\sin{\left(\theta\right)}}{1+\cos{\left(\theta\right)}}\ \ \ =\frac{BQ}{AB}=\frac{1-\cos{\left(\theta\right)}}{\sin{\left(\theta\right)}}$  Could You guys please check my solution. I am also wondering if there are other elementary solutions, please share, thanks!


Do removed parts of a Druid's Wild Shape form persist after said Druid exits Wild Shape?

A player wanted to use Wild Shape as an unlimited supply of feathers for our ranger to make his own arrows with and it sparked a discussion on whether or not parts of a Druid that are removed from said Druid's Wild Shape persist after the Druid is no longer in Wild Shape.  I have been unable to find any rules that either allow or disallow this action. Whereas there are specific rules on what happens to gear the druid is wearing, I have found no statement on what happens to removed physical parts of the Wild Shape form.  I have thought of two reasonable solutions:   Removed pieces of Wild Shape form persist indefinitely. This would make a Druid Indistinguishable from a normal creature until knocked out of druid form and would make the party assassin happy as he now has a reliable fresh supply of Giant venomous snake venom to apply to his daggers. Removed pieces of wild shape form persist until the Druid leaves Wild Shape. This would avoid the issues of unlimited resources, but raise other questions such as whether blood spilled by the Wild Shape also disappears or whether a creature that has "become poisoned for 1 hour" would stop being poisoned when the Druid is knocked out of that shape because the poison has dissipated with his Wild Shape.   Which (if either) of these lines up with the rules? Or does this fall under DM fiat?


My question is related to the mollifier properties in the appendix of Evans' PDE.  In proving that $f^{\varepsilon}$ is smooth, he constructs the difference quotient, with the original integral over $U.$ He then goes to the effort of writing the exact same line but changing the region of integration to V where V is some open set compactly contained within U.   I am wondering why he does this.   I'm sure it has something to do with the next line when he mentions uniform convergence of the mollifier's difference quotient to the partial derivative on V. Obviously I am a little lost and don't have a clear understanding of everything that's going on here.   Also, after he concludes the partial derivative of $f^{\varepsilon}$ exists, he writes it as an integral over U again. If someone is able to clear up my misunderstandings it would be greatly appreciated!


How do I match and replace text using regular expressions in multiline mode?  I know the  option, but what is the best way to specify match all with the new line characters in C#?  Input:  <tag name="abc">this is a text</tag>   Output:  [tag name="abc"]this is a test [/tag]     Aahh, I found the actual problem. '&' and ';' in Regex are matching text in a single line, while the same need to be escaped in the Regex to work in cases where there are new lines also.


Trying to build a Ping functionality, that wil return a dialog to the user displaying the host is up or not when a button it's clicked

Below is the code I'm working on. The code will execute a Swing-based GUI, with a simple JFrame that holds a button which when pressed will run the Ping utility in the background. If the host is either reachable or not, a dialog will be displayed with a successful/unsuccess message. import javax.swing.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.IOException; import java.net.InetAddress;  public class App {  private JTextArea clickThisButtonTextArea; public JButton button1; private JPanel panelMain;  public App() {     button1.addActionListener(new ActionListener() {         @Override         public void actionPerformed(ActionEvent actionEvent) {             try {                 sendPing("8.8.8.8");                 //JOptionPane.showMessageDialog(null, sendPing("192.168.0.1"));             } catch (IOException e) {                 e.printStackTrace();             }         }     }); }  public String sendPing(String ipAddr) throws IOException {     InetAddress ip = InetAddress.getByName(ipAddr);     boolean ipReach = ip.isReachable(5000);     System.out.println("Sending Ping Request to " + ipAddr);     if (ip.isReachable(5000)) {         JOptionPane.showMessageDialog(null, "Host is reachable!");         System.out.println("Host is reachable");     } else {         JOptionPane.showMessageDialog(null, "Sorry, no host!");         System.out.println("Sorry ! We can't reach to this host");     }     return null; }  public static void main(String[] args) {     JFrame frame = new JFrame("App");     frame.setContentPane(new App().panelMain);     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     frame.pack();     frame.setVisible(true);     frame.setLocationRelativeTo(null);     frame.setSize(250,250);   }  } The image below shows a tcpdump of traffic flowing out after the button is pressed vs. a ping ran from the terminal.  Any insights will be greatly appreciated.


Can someone give an example of an ideal $I \subset R= \Bbb{Z}[x_1,...x_n]$ with $R /I \cong \Bbb{Q}$?

Question in the title. I have never seen a quotient of $R$ by a maximal ideal $I$ that is an infinite field, so I would also be interested in the case that $R/I$ is any infinite field. If no such examples exist, I would also like to hear about the case where $R$ is a polynomial ring over $\Bbb{Z}$ in infinitely many variables.


When I come to I'm in thick brush, lying there on the damp ground like   some log. I can't see a thing, it's so dark.   My head propped up   by prickly brambles, I take a deep breath and smell plants, and dirt,   and, mixed in, a faint whiff of dog crap. I can see the night sky   through the tree branches. There's no moon or stars, but the sky is   strangely bright. The clouds act as a screen, reflecting all the light   from below. An ambulance wails off in the distance, grows closer, then   fades away. By listening closely, I can barely catch the rumble of   tires from traffic. I figure I must be in some corner of the   city.   I try to pull myself together and pick up the scattered   jigsaw puzzle pieces of me lying all around. This is a first, I   think. Or is it? I had this feeling somewhere before. But when? I   search my memory, but that fragile thread snaps. I close my eyes and   let time pass by.   With a jolt of panic I remember my backpack.   Where could I have left it? No way can I lose it––everything I own's   inside. But how am I going to find it in the dark? I try to get to my   feet, but my fingers have lost all their strength. (Kafka on the   Shore, tr. by Philip Gabriel)   If the sentence were ‘this is the first’, I would not have raised my question. What does a first mean?


What is the difference between ./ and ../?

when we specify the file path some times we specify like ./filename and some time ../filename what is difference between these two?


My sister is a British citizen. She has invited me to see her family in the UK and has sent all required documents. She is able to bear all my expenses as she works as architect and her job is well paid. The problem is that I have no bank statements to present to the embassy. Should I apply without bank statements?


What are the arguments for QgsDistanceArea().setSourceCrs()

I am really struggling with migrating a custom plugin from QGIS 2.x to 3.x. Below is a code snippet that seems very straightforward, but I can't find documentation that I understand for setSourceCrs().    # First, make sure the point is not within a half meter of the start   # or end points.   da = QgsDistanceArea()    # Function call in API 2.x   # da.setSourceCrs(lyrDb.lyr.crs().srsid())    # My attempt is missing the second argument   da.setSourceCrs(lyrDb.lyr.sourceCrs())    line = parent.geometry().asPolyline()   n = len(line)   d = da.measureLine(line[0], p1)   if d < 0.5:     return 0   d = da.measureLine(line[n - 1], p1)   if d < 0.5:     return 0   As you can see, previously the only argument required for the function was an integer for SRID. The new API wants two arguments as shown below, but very little explanation. Taken from   void QgsDistanceArea::setSourceCrs (const QgsCoordinateReferenceSystem & crs, const QgsCoordinateTransformContext & context)       I think I have the first argument correct, but I have no idea about the second. What do I need to send for the context argument?   Are there any other sources for documentation for the API?  This solution worked for me. It essentially passes an empty parameter into context, but that's okay because I'm not doing a transformation. I tested and it works as expected.    # First, make sure the point is not within a half meter of the start   # or end points.   da = QgsDistanceArea()   context = QgsCoordinateTransformContext()   da.setSourceCrs(lyrDb.lyr.crs(), context)   line = parent.geometry().asPolyline()   n = len(line)   d = da.measureLine(line[0], p1)   if d < 0.5:     return -1   d = da.measureLine(line[n - 1], p1)   if d < 0.5:     return -1   For the record, though it helped, my question was not solved by , nor is it a duplicate IMO.  That question was specifically concerned with calculating an ellipsoidal area which requires a transformation. The code that I am migrating concerns only a projected layer, which does not involve a transformation.  I came here after spending hours searching for an answer, and in my opinion it is because the documentation for pyQGIS API is sparse at best. However, I fully admit that the post above helped me figure out my solution, assuming it is a solution. It appears to work, and that is all I can say. Surely, there must be a proper way to call setSourceCrs when no transformation is required.  That said, I am happy so feel free to do whatever is appropriate with this question. This is my first foray into StackExchange, and I'm not familiar with protocol.


I am very tired of all the Samsung bloatware imposed on me so I am trying to back up my data prior to rooting the phone and cleaning it up.  There are numerous claims on the internet that this is done using this adb command:  adb backup -apk -shared -all -system -f myBackupAndroid.ab   Some also suggested adding backslashes before spaces after the backup. That didn't affect my results, which is (basically) empty file:    This is pretty nasty trap set on anyone who doesn't double check the status of the backup, before doing something like factory reset.  Unless this is intended by android developpers, what did I do wrong? How to get actual backup of android data? I am using android 4.1.2 on Samsung GT-S7710 - which is Galaxy XCover 2 as I found by googling (they are too shy to mention product name in their OS release).


I was reviewing the  for PostgreSQL and I saw that Pg is likely going to get "identity columns" sometime soon.  I found some mention in  but nothing much  is_identity         yes_or_no         Applies to a feature not available in PostgreSQL identity_generation character_data    Applies to a feature not available in PostgreSQL identity_start      character_data    Applies to a feature not available in PostgreSQL identity_increment  character_data    Applies to a feature not available in PostgreSQL identity_maximum    character_data    Applies to a feature not available in PostgreSQL identity_minimum    character_data    Applies to a feature not available in PostgreSQL identity_cycle      yes_or_no         Applies to a feature not available in PostgreSQL    doesn't say much either     An identity column differs from a primary key in that its values are managed by the server and usually cannot be modified. In many cases an identity column is used as a primary key; however, this is not always the case.   But, I don't see anything else on them. How do identity columns work? Do they provide any new functionality or is this just a standard method to create sequences? Any breakdown of the new feature and how it works?


Illustrator reducing double stroke svg to a single stroke svg

I have a double stroke svg that I want to reduce to a single stroke svg. The area on the svg is defined as some white shapes that are overlayed on a black background, with anchors outlining the shapes and background.     I hope this makes sense  I almost want something like the monoline tool developed for text, so that I can simplify an icon to a single line svg for a lazer cutter.   Thanks.   Here's the closest thing I can get to a single line:


Unexpected results when trying to match string pattern

Given a string, return true if the first instance of "x" in the string is immediately followed by another "x". It will not work for the case of doubleX("axxbb"). It should return true but gives false.  boolean doubleX(String str) {   for (int i = 0; i < str.length(); i++) {     if (str.substring(i) == "x") {       if ( str.substring(i) == str.substring(i + 1)){       return true;       }      }    }   return false; }


Qgis map composer shows a huge red cross

I can show this best by a picture:    This cross also shows when I export it as raster or pdf. What is it and how can I get rid of it?  I am using Qgis 2.4 and the map was done with the help of the Grass plugin AniMove on Linux Mint.


I have Sprint shares. What does this merger with T-Mobile mean for my shares?

Over the weekend Sprint and T-Mobile announced again that they would try to merge.  Assuming the powers that be in the US don't have any issue with this deal and it moves forward as proposed, what does it mean for me as a shareholder?  I have 2,000 Sprint shares, and as part of the deal it looks like one Sprint share will be worth ~10% of a T-Mobile share as of the price on Friday.  So does that mean that, if this goes through in early 2019, my 2,000 Sprint shares would turn into 200 T-Mobile shares? What if the price of Sprint stock goes up from here? What if it craters? Is this price/ratio set in stone?  If my stock does get converted, does that happen automatically? Will Fidelity all of a sudden show that I own TMUS stock instead of S?


Prove that the set $C$ of points in $\mathbb{R}^2$ such that at least a coordinate is irrational is connected set.  Ok, I know that the set of Irrational numbers isn't connected but how that helps me?  I tought in:   Let $A \subset C$ a nonempty a clopen, then we need to show that $A=C$, ok, how I can continue?


How to free space on a full /boot partition?

Stuck running Ubuntu 16.04 LTS on a Lenova desktop with a small boot partition now with 0(zero) bytes after many upgrades. Currently at 4.4.0-71-generic but new upgrades fail. Have tried suggestions from many "solutions" but still can not upgrade.  None of the following free-up space:  sudo apt-get clean  sudo apt autoremove --purge  sudo apt-get autoremove --purge  sudo purge-old-kernels  sudo apt autoremove  sudo apt-get purge linux-image-4.4.0-67   Have also purged all the other old linux-images that do not have dependencies.  Any new suggestions?


There is a famous saying in Tamil language: "Paarthaal pasu pol, paaindhaal puli pol" which translates to "Looks like a cow, leaps like a tiger".   This is usually used to describe a person who on first look gives an impression that they are silent and submissive, but when confronted, they dominate the confronter.   The closest English proverb which I could think of is Appearances are deceptive, but it doesn't essentially capture the silent nature and the combative nature of a person.   Is there an English saying which means the same?


What is a good color combination, visibility for outside use

I am designing the layout for a touchscreen for outside use, What are some good color combination to use that will be visible under the sun light for outside use? Maybe bright neon colors?


Client requesting artwork file for print production

I have recently completed a package design for a client.  He has now asked for the artwork file (AI) so the printers can set up the dye cut etc, he has specified the need for all artwork included.  My question is should I hand it over or is there an alternative as I don't want them to have the ability to alter my design without my consent as well as if changes are needed in the future I want them to be coming to me for it.


Command line option to check which filesystem I am using?

Is there a command that will show which file system (ext3, ext4, FAT32, ...) the various partitions and disks are using?   Similar to how sudo fdisk -l lists information about disks and partitions?


Can a spell scroll be upcast using a higher-level spell slot?

For example,  says:  You create three glowing darts of magical force. Each dart hits a creature of your choice that you can see within range. A dart deals 1d4 + 1 force damage to its target. The darts all strike simultaneously, and you can direct them to hit one creature or several. At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the spell creates one more dart for each slot level above 1st.  If a PC finds a scroll of Magic Missile, can it be cast as you would with a level 2 slot (and what are the conditions to do this)? Or will it always be level 1?


What command can I use to minimize the current terminal window?

Which command can I use to minimize the current terminal window. i.e. this should do the same as a click on the minimize window control:


After the news about the release of the new entry-level SL3, I got to wondering in which cases would someone go for the twice the price 7DmkII?  As far as I can tell, the 7D can burst faster (10 x 5 fps) and has GPS, but loses or ties with the SL3 in pretty much everything else, and the DIGIC 6 versus 8 might lead to a gigantic difference too.   Am I missing anything in this comparison?  Source:   Edit: Please note that I'm aware that the 7D is theoretically "better", as in better constructed, better materials, more direct control of the configurations, etc, in line with pro bodies. It is not a generic "old pro vs new consumer" (which is not covered by the suggested QA either), but rather a concrete instantiation of that generic problem, considering those two models.


How can I convert audio from MP4 or FLV video files to mp3?

Is there an application that allows me to extract the audio from a MP4 or FLV video file and store it as an MP3 file for use in a portable media player?


I recently asked a  on security.stackexchange.com. The question was related to XSS so in my opinion it belonged to the security website.  There was a comment on the question saying that a similar question exists on SO and my question was a duplicate (I think he gave it a down vote). The guy was right but the question was asked on another website (SO). There may be a case when person asking a question might not have an account with the other website.  Is it a good practice to mark questions duplicate if you have seen a similar question on some other website?


Windows 10 fails to upgrade from Home to Pro edition

I have a legitimate Windows 10 key, which I got from Microsoft Imagine as part of being a student at my school.  I have previously used the key 1 time on another computer of mine and successfully upgraded it from Home to Pro.  Now I am trying to upgrade my other computer from Home to Pro, using the same key.  I have tried this through the Microsoft Store app, where it says install and allows me to enter a product key. It then tells me to hold on and that it is preparing for the upgrade.  Briefly afterwards it restarts my computer, but my windows edition is still Windows 10 Home.  I have also tried to enter the key through the control panel, but with the same result.  Can this key only be used to upgrade a single computer?  It seems it should tell me earlier in the process then. After all it acts like it is upgrading and even restarts to finish the upgrade.  Any ideas why this doesn't work? I would like to upgrade to the Pro edition to enable Hyper-V.  Thank you in advance for your help.  EDIT:  Regarding the duplicate claim.  Moab I would argue it isn't a duplicate as this key was not from the same source. As Joel Coehoorn specified in his answer there are different types of keys. The error message in the link you gave is also an error I never got. Meaning that the behaviour response from Windows was different.


how to save terminal files that you opened with "$ sudo vi"

I am currently following a tutorial that asked to open a file with "sudo vi /..." first and formost I have half an understanding of how to type but I managed and now I need to save the file but how do I do that? I tried to use ctrl x but that doesnt work and there is no other means in the file/ edit section of the terminal. Please help.  kind regards coolxm


When is the image of a linear operator (between Banach spaces) closed?

Let $T: X \longrightarrow Y$ be a continuous linear map between two Banach spaces.  When is $\operatorname{Ran}(T)$ a closed subspace?  What theorems are there?   Thanks :)


How to burn Live CD from ISO file - ISO file too large

Ok so I'm stuck right at the beginning. I can't figure out how to burn a Live CD for Ubuntu. My drive capacity is 704MB and the .iso file is 1.2+ GB so it won't fit.  I want to install Ubuntu 14.04 in it's own partition but I don't know how. I downloaded the .iso and unpacked it to a folder on my HD. What next?


Duplicate of:                    My sentence fragment possibilities are        ... can help rule out false alarms   ... can help to rule out false alarms      I feel like both are technically correct, and that the latter sounds somewhat more formal while the former may be a little more clear.  I often come upon the general issue of when to use "to [verb]" or just "[verb]" — is there a general rule?  Is only one of them actually correct?  (Even if someone can explain how to describe the difference between these cases would be appreciated, i.e. "infinitive vs. ____" )


Prove that if $p$ and $p^2+2$ are prime then $p^3+2$ is prime too

I'm trying to figure out how to prove that if $p$ and $p^2+2$ are prime numbers then $p^3+2$ is a prime number too. Can someone help me please?


I'm a total newbie here. How do I open .cpp file from the github directory? what command should I use? I'm in the directory where the .cpp file is stored but I do not know how to open that in the terminal.


Right click graphics problem Ubuntu 14.04

Strange graphics surrounding right click anywhere i click in the gui. This problem goes off when i log out and back in! But every alternate time this happens, only solution being i log out back and in!  This is very strange problem, help would be appreciated!


Am I correct or not? I think that a ring of  in one variable is not a , because there are holomorphic functions with an infinite number of $0$'s, and hence it will have an infinite number of irreducible factors! But I am unable to get a concrete example. Please give some example.


Traveling to GDL from Mexicali, I'm a US Citizen

I just recently bought tickets to travel from Mexicali to Guadalajara. However, I am a US Citizen and I live in the US. I am just crossing the border by foot, and catching a flight in Mexico to go to GDL (since they're why cheaper in Mexico) However, do I need some type of Mexican paperwork indicating I am traveling within Mexico? Or can I just use my American Identification to board the flight?


could the origin of the borg be tied in somehow (creatively) with the original series episode "The Lights of Zetar"? Were they 100% certain they destroyed them in the compression chamber or just drove them out into another time/space dimension?  It IS Star Trek after all with all the time warp travels and such.  (just a seed of thought)


Why is the derivative of $\Psi$ continuous at $x=0$?

I am reading an one-dimensional barrier problem. To evaluate the unknown constants $A,B,C,D$, the continuity of $\Psi(x)$ and $\frac{d\Psi}{dx}$ is used at $x=0$ where the potential has a discontinuity. I understand continuity of $\Psi$. But why is the derivative of $\Psi$ continuous at $x=0$? It has a step function which is not differentiable at $x=0$.


$A \in \mathbb{Z} ^{n \times n}$. Show that $\det(A) = \pm 1$.

Im stuck with this question because I'm probably misunderstanding it.  There is given that $$\mathbb{Z}^{n \times n} = \left\{A \in \mathbb{R}^{n \times n} \mid (A)_{ij} \in \mathbb{Z} \text{ for }i,j \in \left\{1,\cdots,n\right\}\right\}$$ I have to prove that for a matrice $A \in \mathbb{Z}^{n \times n}$ always: $$\det(A) = \pm1 \Longleftrightarrow A^{-1} \in \mathbb{Z}^{n \times n}$$ $A$ is invertible here.  I were thinking that if you take $A \in \mathbb{Z}^{n \times n}$ then $$A^{-1} = \frac{\operatorname{adj}(A)}{\det(A)}$$ Now if $\det(A)$ is different from $\{-1,1\}$ then you would get elements in $A^{-1}$ that are not in $\mathbb{Z}$. Or not because elements in $\operatorname{adj}(A)$ could be multiples of $\det(A)$.  The question is: how do I know that $$\operatorname{adj}(A)_{ij} \neq c \cdot \det(A)$$ for all elements in $\operatorname{adj}(A)$ where $c$ is an integer?


Bibliography more authors of the same year a/b/c wrong order

I have a problem in my bibliography, I have several sources of the same author in the same year. They are automatically supplemented in the bibliography with a/b/c and so on. In the PDF output they are displayed in the wrong (at least not the right for me) order.  \usepackage[   backend=bibtex8,   style=authoryear-comp,   dashed=false,   hyperref=true,   maxbibnames=9,   maxcitenames=3,   firstinits=true,   isbn=false,   url=false ]{biblatex} \usepackage[autostyle=true,german=quotes]{csquotes} \DeclareFieldFormat{postnote}{#1} % no prefix «S.» before page in citation \renewcommand{\labelnamepunct}{\addcolon\addspace} % colon instead of dot before title \DefineBibliographyStrings{ngerman}{andothers={et\ al\adddot}} %et al. instead of u.a. \DeclareFieldFormat{pages}{#1}% no prefix for the `pages` field in the bibliography   These are my entries from the bibliography file:  @Misc{2016Kommissiononline2,   Title                    = {Single European Sky},   Author                   = {{Europäische Kommission}},   HowPublished             = {\url{http://ec.europa.eu/transport/modes/air/single_european_sky/index_en.htm}. Zugriff am: 15.07.16},   Year                     = {2016},   Owner                    = {lebster},   Timestamp                = {2016.07.12},   Url                      = {http://ec.europa.eu/transport/modes/air/single_european_sky/index_en.htm} }  @Misc{2016Kommissiononline23,   Title                    = {Single European Sky 2+},   Author                   = {{Europäische Kommission}},   HowPublished             = {\url{http://ec.europa.eu/transport/modes/air/single_european_sky/ses2plus_en.htm}. Zugriff am: 27.07.16},   Year                     = {2016},   Owner                    = {lebster},   Timestamp                = {2016.07.15},   Url                      = {http://ec.europa.eu/transport/modes/air/single_european_sky/ses2plus_en.htm} }   This is the respective output:    Has anyone an idea how to get the a/b/c entries in an alphabetical order?


Not sure why this Java Null Pointer Exception is happening

I have a method that return an array of files in a given directory that is giving me a null pointer exception when executed. I can't figure out why.  private ArrayList<File> getFiles(String path) {      File f = new File(path);     ArrayList<File> files = new ArrayList<>(Arrays.asList(f.listFiles()));      return files; }   thanks for your help


I'm a little bit confused about calculating entropy changes along irreversible paths by integrating over a reversible path. When using the central equation I can understand the argument, entropy and all the quantities we use to calculate the entropy change are state functions that have well defined end points. So the process between these two states doesn't matter, we will get the same entropy change. I find it difficult to grasp how we can use dS=dQ/T to calculate entropy changes in irreversible processes. Since Q is path dependent I don't see how the original argument applies. We can take the free expansion as an example, if we try to use dS=dQ/T we will get zero entropy change as no heat flows into the system. But using the central equation where all quantities are state functions we get a entropy change which is larger that zero as expected.


Many characters die in comics, only to come back to life later, in some form or another. Which one stayed dead for the longest period of time.  To qualify, the character must:   Must have existed in comics before death. Have been implied dead. Come back to life (Any form of resurrection is accepted including was-never-dead) Return in the same continuity (the returned character must be the same as the dead one, not just appear in an alternate universe) Time is measured in the real world, i.e. the difference in time between the publishing dates of the two comics. While any comic publishing company is okay, an ideal answer would also mention the longest for both Marvel and DC   Which character in comics stayed dead the longest?


How can I change the Cardinality of a field which has previous data present?

I want to change the Cardinality of a field which has existed values in drupal 8.


How to make the opening of browser(all test in one browser) static in testng for selenium

I am using selenium and testNG framework for my project.  Now what is happening is each class is opening up a browser and then run its methods, eg, if I have five classes, then five browsers will open simultaneously and then run the tests. I want to Open Browser at the start once and run all the methods and then close it.  public class openSite { public static WebDriver driver; @test public void openMain() {   System.setProperty("webdriver.chrome.driver","E:/drive/chromedriver.exe");   WebDriver driver = new ChromeDriver();   driver.get("http://vtu.ac.in/"); } @test //Clicking on the first link on the page public void aboutVTU() { driver.findElement(By.id("menu-item-323")).click(); } @Test //clicking on the 2nd link in the page public void Institutes() { driver.findElement(By.id("menu-item-325")).click(); }   Now What I want is the testNG should open browser once and open vtu.ac.in once and then execute the methods aboutVTU and Institutes and give me the result


How to change equation numbering globally?

I would like to change equation numbering like: (1a) (1b) (1c). How should I do this? My code is like this:  \begin{equation} first equation with number(1a) \end{equation} \begin{equation} first equation with number(1b) \end{equation} \begin{equation} first equation with number(1c) \end{equation}


After nominating to re-open, link remains as if you can nominate again

First of all I know this is a super small bug, but it's still a bug (in my opinion, anyway). When you nominate to re-open a closed question, the link to re-open stays there and if you click it a second time, the same dialog appears as if it is going to let to do it again (but of course doesn't let you).  Normally, I would ignore small things like this. However, I think this kinda makes StackExchange sites appear a little funky. In a way, it (sorta) makes it look bad. I myself have to laugh at this, and I'm sure others have also laughed at it.  The point is, it shouldn't even allow you to press this link again in the first place. Or at least don't show the same dialog asking if you're sure you want to nominate to re-open. Just immediately alert the user that they already nominated.  That is all.


Does $A \times B \cong A \times C$ imply that $B \cong C$?

Suppose that A, B and C are finite groups, and $\times$ is the direct product, is the implication $A \times B \cong A \times C \Rightarrow B \cong C$ true? I have been told that the reverse implication is true, but no one seemed to know whether this one holds. And if so, how would one prove this statement?


I had to calculate $\tan(π/16)+\tan(5π/16)+\tan(9π/16)+\tan(13π/16)$  I tried writing $π/16=x$ and then writing the sum as $\tan x+\tan(9x-4x)+\tan9x+\tan(9x+4x)$ and then simplifying using $\tan(x+y)$ and $\tan(x-y)$ but it didn't simplify to anything, can anybody please give a hint on how should I approach this.


How to stop text from filling the "empty" spot?

How do I stop my figures from being pushed into an "open" spot, and having text fill the "empty" spot? The paper does not have a very clear flow because while one paragraph is talking about Figure 1, Figure 1 is actually AFTER the paragraph that is talking about Figure 2. I have tried changing the \begin{figure}[!ht] but it has not solved my problem.  I'm basically looking for a way just to put empty spaces and order the document how my Source is typed.  \begin{figure}[!ht] \centering \begin{minipage}[b]{.45\textwidth} \includegraphics[width=1\linewidth]{Flee.jpeg} \caption{Whether the victim was fleeing} \label{fig:complete} \end{minipage} \hspace{.5cm} \begin{minipage}[b]{.45\textwidth} \includegraphics[width=1\linewidth]{Threat.jpeg} \caption{Whether the victim was a threat } \label{instruct} \end{minipage}  \end{figure}   Here are my packages  \usepackage{amsmath, amssymb} \usepackage{epstopdf}% To incorporate .eps illustrations using PDFLaTeX, etc. \usepackage{subfigure}% Support for small, `sub' figures and tables \usepackage[numbers,sort&compress,merge]{natbib}% Citation support using natbib.sty \usepackage{multirow} \usepackage[singlelinecheck=false]{caption} \usepackage[labelsep=:]{caption} \usepackage{pgfplots} \usepackage{indentfirst} \usepackage{dirtytalk} \usepackage[dvipsnames]{xcolor}  \usepackage{geometry} \geometry{margin=1in}


How to run Thunderbird on startup, minimised?

How can I set Thunderbird to launch automatically in the minimised or hidden-in-Launcher state?  First component of problem is starting it. I do not know which 'Command' is needed.  Second component of problem is keeping it minimised, or hidden from Launcher (given that it's unlocked from Launcher).


Lie Group Decomposition as Semidirect Product of Connected and Discrete Groups

I've believed for a long time that every Lie group can be decomposed as the semidirect product of a connected Lie group and a discrete Lie group. However, in , it is mentioned that this is not true, and that there exist obstructions to this decomposition. Unfortunately, the level of complexity in the answers goes a bit over my head.  This type of decomposition is also addressed in .  With this loss of faith in my intuition, I have three questions:   Is it true that Lie groups do not necessarily decompose into the semidirect product of a connected group and a discrete group? If this decomposition doesn't always work, then is there a particularly nice argument as to why it doesn't? If this decomposition doesn't always work, then is there a nice example I can use to convince myself that my intuition is wrong?   Edit: As much as I love Qiaochu Yuan's answer, which is thorough and (as usual) a role model among Stack Exchange answers, this is not what I'm looking for. I'm aware of the general extension problem, and that not every short exact sequence splits, but my intuition has led me to think that each Lie group can be decomposed this way. I will certainly play around with his outline for a construction, but I would much prefer a more concrete answer. Once again, thank you!  Edit: As of yet, playing with the construction suggested by Qiaochu hasn't yielded anything interesting. This question is still open to answers!


How can I add a PPA from a previous release?

I've been trying to get , but it's only available through Quantal, and I'm running Raring. Is there a way to force-install a PPA from a previous release? I tried manually downloading all the packages and running sudo dpkg -i but I get lots of errors about dependencies, some of which don't look like they can be resolved. Am I stuck with having to compile vim myself?


Recently I've been messing around with making a few minigames, and have used a few plugins to help make it easier to create and run them. However, a newer one I'm making requires me to use the /summon command in order to spawn zombies. However, no matter what I put in, I can't spawn hostile mobs. All other entities still spawn perfectly fine. Strangely, the /spawnmob command which comes with Essentials can summon hostile mobs fine. I would rather use /summon since it's more customizable though. Here's a list of plugins I have installed.   Essentials EssentialsChat HolographicDisplays PermissionsEx setspawn [A plugin I have made, just a simple timer] Vault VoxelSniper WorldEdit WorldGuard   Please let me know if you have any ideas on what I'm doing incorrectly or isn't functioning the way it should.


Replicate a complex partition structure with LUKS and LVM volumes

I have two external hard discs on an OpenSUSE 13.1 system.   On one I have created a partition structure:   An encrypted LVM partition (LUKS) Several volumes (10) on this LVM partition, some formatted with xfs, some with ext4.    sdf                              8:80   0   5,5T  0 disk   └─sdf1                           8:81   0   5,5T  0 part     └─extern-2-crypt             253:5    0   5,5T  0 crypt      ├─extern--2-nelson--home   253:10   0     8G  0 lvm   /extern/nelson/home     ├─extern--2-lucien--boot   253:11   0   300M  0 lvm   /extern/lucien/boot     ├─extern--2-nelson--root   253:12   0  11,5G  0 lvm   /extern/nelson/root     ├─extern--2-nelson--space  253:13   0  90,1G  0 lvm   /extern/nelson/space     ├─extern--2-lucien--backup 253:14   0   400G  0 lvm   /extern/lucien/backup     ├─extern--2-lucien--home   253:15   0    20G  0 lvm   /extern/lucien/home     ├─extern--2-lucien--raid   253:16   0   3,5T  0 lvm   /extern/lucien/raid     ├─extern--2-lucien--root   253:17   0   8,5G  0 lvm   /extern/lucien/root     └─extern--2-lucien--space  253:18   0    30G  0 lvm   /extern/lucien/space    How can I replicate this structure easily including the LVM config from one disc to the other (with only one disc running at the same time)?   I know of sgdisk (8) and parted (mentioned in ), but that covers only the partition, not the LUKS information and certainly not the LVM config.


Set myself as owner of /etc with chown command now getting all kinds of errors

I needed to edit a .config file (which I know for a fact is not creating these problems, just to clear that up) and it wouldn't let me save it, so I took ownership of /etc and all contents with the command chown -hR username /etc and that let me edit the .config file but now whenever I try to install any packages or use any sudo commands, it doesn't work  (I've checked for errors in the sudo file in sudoers.d and there was nothing wrong with that).   So how do I return it to the previous owner?


Difference when passing a pointer as argument and return pointer in C++

This is how my program works: promt user to input a string, using compress_string() function to pass the string as argument. Using a temporary queue to take all non-space characters from string, then put them back to the string. The final string will have no space at all.  #include <iostream> #include "Queue.h" #include <cstring> using namespace std;  char* compress_string(char *s){     Queue q;     int cnt=0;     char tmp;     for(int i=0; i<strlen(s); i++){         if(s[i] != ' '){             q.enQueue(s[i]);             cnt++;         }     }     delete[] s;     s = new char[cnt+1];     for(int i=0; i<cnt; i++){         q.deQueue(tmp);         s[i] = tmp;     }     s[cnt] = '\0';     return s; }  int main(){     char *s = new char[20];     cin.getline(s, 20);     s = compress_string(s);     cout << s;     return 0; }   Here is problem: it works only when I return a pointer and then assign it to the input pointer as following:   s = compress_string(s);   If I make the compress_string() a void function which also means not return anything from it, and modify in the main function like this:  compress_string(s);   the output are now all non-sense characters.  I thought when I pass *s to the compress_string() function, it is already a pointer so it will have effect after getting out of the function. So where did everything go wrong? Thanks everyone.


I got the following html:

Val1

Val2

   and JS code:  $(document).ready(function(){ $('#otherdiv').on('mouseup', function(e){      var left  = e.clientX  + "px";      var top  = e.clientY  + "px";      var div = $('.overlay');      div[0].style.left = left;      div[0].style.top = top;      $(".overlay").show(200);    });  $(document).on('click', function(e) {     $('.overlay').hide(200);   }); });   I need to hide my .overlay when the user clicks somewhere outside it and show it when the user clicks #otherdiv. When I attach an event to document and click on otherdiv, my overlay shows and then immediately hides. How to fix that behaviour? Thank you.


Consider a map $T:\mathbb{R}^2\to\mathbb{R}^2$ such that $\lVert T(x)\rVert=\lVert x\rVert$.   Is this equivalent to stating that $\langle x, y\rangle=\langle T(x), T(y)\rangle$ for all $x,y\in\mathbb{R}^2$, where $\langle\cdot,\cdot\rangle$ denotes the usual inner product?


Why do I keep getting a pop up that is titled "Archive Manager" with an error message stating "An error occurred while loading the archive" when I am trying to download the H&R Block Tax Software?


Proving the "extension property" for polynomial rings

Aluffi III.2.6 suggests proving the following:     Let $\alpha : R \rightarrow S$ be a fixed ring homomorphism, and let $s \in S$ be an element commuting with $\alpha(r)$ for all $r \in R$. Then there is a unique ring homomorphism $\overline \alpha : R[x] \rightarrow S$ extending $\alpha$ and sending $x$ to $s$.   I've managed to prove this by postulating the behaviour of $\overline \alpha$ on zero-degree polynomials (which coincide with $R$, thus $\overline \alpha$ coincides with $\alpha$ on those) and on $x$, then using the ring homomorphism properties to show that the whole $\overline \alpha$ is uniquely determined to prove its uniqueness, and then showing that $\overline \alpha$ indeed satisfies the homomorphism requirements (thus it's a well-defined homomorphism).  But this whole construction looks awfully lot like proving $\mathbb{Z}[x_1, \dots, x_n]$ satisfies the corresponding universal property in the corresponding category. Could I somehow reduce the original claim to the latter construction?


Since "400 level" should be hyphenated as "400-level", should "300 or 400 level" be hyphenated as "300- or 400-level," or is there another way to write this?


I could do \subsection{} and \subsubsection{} but not \subsubsubsection{}. This command does not seem to be available in LaTeX. Is there an alternative command?


Thermoelectric couple heating on both sides

In college my physics professor showed us a thermoelectric couple powering a fan.  He also explained how if you apply a current it cools one side and heats the other side.  I have been working on a cooler that uses a TEC to cool the inside (see my posts  and ) but something is wrong.  When I give power to the TEC in the correct direction, one side gets so hot I burned myself, but the other side was getting warm.  Why is this side not getting cool?


How to see list or history of all deleted answer on StackOverflow?

I am curious to know if any way exist to see my deleted history like favorites. I did not found any related answer. One more thing, I talked about all history. I can see one at a time if I browse  the question but no one will remember all link which had been deleted.


How to tell if a recursively defined sequence diverges.

Let $x_1:=a>0$ and $x_{n+1}:=x_n+1/x_n$ for $n\in\mathbb{N}$.  Determine whether $(x_n)$ converges or diverges.  My answer:  $(x_n)$ is divergent.  Proof:  Assume that $(x_n)$ converges to $x$.  Then $\lim (x_{n+1})=\lim (x_n)$.  That is, $x=x+1/x$.  This equation has no solution.  Hence, $(x_n)$ is not convergent.  Therefore it is divergent.  My question.  Is the proof above a legitimate one?  Something just doesn't feel right to me.  Or should I just show that the sequence is unbounded.  Or am I altogether wrong?  Thank you.


A domain $R$ is a Dedekind domain iff it is integrally closed, Noetherian with Krull dimension at most one. I think they put Noetherian in the definition not only to make proofs easier but also because it's important. To see that it's really necessary to have Noetherian in the definition do you have an example for me of a domain $R$ which is integrally closed, not Noetherian with Krull dimension one? All my examples of domains which are not Noetherian fail to have Krull dimension one.


Show network-wide rep on network profile

All that empty space would be a great place to put the network-wide rep and badges, as appears in the flair.    This would fill the space, in addition to making it more in line with the regular site-specific profile.


How can I view the time of a text message in iOS 7?

In iOS 7, I've noticed that some SMS/MMS messages have a date and time stamp displayed above the message.  Although this is useful, not all text's in the list receive such a date and time stamp.  Is there a way that I can view the date and time for ever text message?


How can I get the amount of available memory portably across distributions?

The standard files/tools that report memory seem to have different formats on different Linux distributions. For example, on Arch and Ubuntu.   Arch  $ free               total        used        free      shared  buff/cache   available Mem:        8169312     3870392     2648348       97884     1650572     4110336 Swap:      16777212      389588    16387624   $ head /proc/meminfo  MemTotal:        8169312 kB MemFree:         2625668 kB MemAvailable:    4088520 kB Buffers:          239688 kB Cached:          1224520 kB SwapCached:        17452 kB Active:          4074548 kB Inactive:        1035716 kB Active(anon):    3247948 kB Inactive(anon):   497684 kB  Ubuntu  $ free              total       used       free     shared    buffers     cached Mem:      80642828   69076080   11566748    3063796     150688   58358264 -/+ buffers/cache:   10567128   70075700 Swap:     20971516    5828472   15143044   $ head /proc/meminfo  MemTotal:       80642828 kB MemFree:        11565936 kB Buffers:          150688 kB Cached:         58358264 kB SwapCached:      2173912 kB Active:         27305364 kB Inactive:       40004480 kB Active(anon):    7584320 kB Inactive(anon):  4280400 kB Active(file):   19721044 kB    So, how can I portably (across Linux distros only) and reliably get the amount of memory—excluding swap—that is available for my software to use at a particular time? Presumably that's what's shown as "available" and "MemAvailable" in the output of free and cat /proc/meminfo in Arch but how do I get the same in Ubuntu or another distribution?


Why am I punished for someone else's poor answer

Apologies if this has been asked / answered before (let me know and i'll delete this). But i've searched a bit and haven't seen anything about it other than a few comments on different posts.  Why do I get -1 rep if I downvote an answer ?  Recently I've come across an annoying habit on stackoverflow (particularly in the Ojective-c tag), where I think new users are trying to get quick rep points, or bump up their stats by just answering any question. One user in particular just keeps posting the same link to a github repo for any question tagged with UITableview. Others don't answer questions, just post their working code that doesn't achieve the asker's desired result.  In these cases the answers are of EXTREMELY poor quality, so I downvote, leave a comment explaining why I downvoted (because I hate random downvotes) and depending whether they edit / comment back later I may flag it.  As I mentioned before its generally new users that do this, so what happens is, I get -1, and they don't login for 14 months. The answer doesn't get edited or deleted and i'm stuck with my -1 for pointing out a poor answer.  How does this make sense?  Can we change this?  What if we change it to only get a -1 if you don't leave a comment explaining it, I would be more of a fan of that. It would curb random downvotes and still allow others to denote poor answers. I for one have noticed very little downvoted answers, but a lot of comments like "This doesn't answer the question" with no reply. In my view it looks like people are afraid to downvote for the sake of their rep.  Any thoughts welcome


Difference between "such things as" and "things such as"?

I read a lot of English books, and I have noticed that when authors need to list examples of something, they tend to use "such things as" rather than "things such as", although they both sound correct. The latter even seems to have a better structure, since it doesn't split the "such as" (a phrase commonly used to indicate examples).   Is there any subtle difference in meaning between the two? Why is the former preferred?  For example:     Eventually, the device becomes stable, but its final state is unpredictable since it is based on such things as construction differences and thermal noise.


I've been taking GR, and all of a sudden I am not sure that I know the necessary and sufficient requirements of the tensor coefficients. This is because the lecturer asked me to prove that that "there exist no tensor constructed from the metric and its derivatives, other than the metric". This leads me to have exactly two questions:  (1) Suppose $g_{\mu \nu}$ is the metric tensor, $c$ is a real number and $\nabla_\rho$ the covariant derivative. Why are the following not tensors?   $c g_{\mu \nu}$ $\nabla_\rho g_{\mu \nu}$   (2) Is it wrong that the sufficient and necessary condition for the tensor coefficient is that they have well defined transformation rules, such that they takes the same form in all coordinates? Is this not the same as saying that the tensor transforms as a tensor?


fstab mount always read-only even I was set the options to read-write

I want to mount /dev/sdb1 to /home/user/sdb1 but the partition always read-only. This is my /etc/fstab configuration: UUID=0B02A9EE38EE115F /home/user/sdb1 ntfs defaults 0 0  I see on  the defaults option is rw, it means read-write. But I got my mounted partition in read-only mode. $ sudo cat /proc/mounts | grep /dev/sdb1 /dev/sdb1 /home/user/sdb1 fuseblk ro,relatime,user_id=0,group_id=0,allow_other,blksize=4096 0 0  Even, I changed the "defaults" options to specific options. The file system is still read-only. UUID=0B02A9EE38EE115F /home/xdnroot/sdb1 ntfs rw,suid,dev,exec,auto,nouser,async 0 0  How could this happen? And how to fix it using fstab. Not manual unmount and mount again with rw option.


What does a forward slash followed by a number mean in IP?

If an IP Address is indicated like this: 10.39.25.151/24 , what does the /24 mean?


Can a "flat function" be a particle trajectory?

Recently I came across the concept of a , which is a smooth function $f:\mathbb{R}\to\mathbb{R}$ all of whose derivatives vanish at a given point $x_0\in\mathbb{R}$, the canonical example being  $$ f(t) = \begin{cases} e^{-1/t^2},& t\neq 0\\ 0,& t=0. \end{cases} $$  Now I wonder if such a function can in any way describe the trajectory of a physical object where $t$ is time and $f(t)$ is its position. The reason why I am not sure is as follows: If I throw a ball in the air, its velocity becomes zero at the highest point. Naively I could reason that it must stay there, because it cannot move anymore once the velocity is zero. But we all know that this reasoning is flawed, because the 2n derivative, acceleration, is not zero at this point, which is why the ball starts picking up speed again and comes down to earth.   But what if the 2nd derivative, acceleration, would vanish too, and the third, and so on infinitely. Would this mean that the ball comes to a halt at this point. And, by generalizing from the ball to any particle, that the $f(t)$ shown above cannot be the trajectory of a physical object? Rather the function would have to be constant at least on one side of the flat point?


Find $(1+i)^i$ in simpler terms, without imaginary exponents.

I was asked to find $(1+i)^i$, I don't know what to do when there is an imaginary component in the exponent.  since $1+i=\sqrt{2}e^{-\frac{1}{4}i \pi}$ then $(1+i)^i = \sqrt{2}^i e^{\frac{1}{4} \pi}$ but now we run into the same problem again, what is $\sqrt{2}^i$?


How do I make the button work when I enter "1" in the textField?

public MultiplicationTable() {     JLabel jl;     JTextField tf;     JButton btn[];     Container c;     JPanel p1, p2, p3;     int a;     String value;      super ("Multiplication Table");     c = getContentPane();     p3 = new JPanel (new FlowLayout());     btn = new JButton[1];     btn[0] = new JButton ("Show Times Table");     jl = new JLabel ("Enter a Number:");     tf = new JTextField(5);     p3 = new JPanel (new BorderLayout(5,5));     p3.add (jl, BorderLayout.NORTH);     p3.add (tf, BorderLayout.CENTER);     p3.add (btn[0], BorderLayout.SOUTH);      btn[0].addActionListener(         new ActionListener()          {             public void actionPerformed(ActionEvent e)              {                 String Value;                 Value = tf.getText();                 if (Value == "1")                 {                     System.out.print ("asd");                 }             }         }     );  }   I would like to make the action listener for the button as I enter "1" in the text field. I really need to work on these codes. I wish you could help. Thanks!


When Voldemort created Horcruxes, he divided the soul into it. Once he died only soul was present.  Then from where exactly his body came from? Peter Pettigrew used Harry's Blood but whose flesh he used to bring back Voldemort?


I have a query here:  SELECT MAX(Sales.Revenue-Sales.Costs), Company.Name FROM Sales  INNER JOIN Company ON Company.ID = Sales.ID WHERE Sales.Date <= DATE_SUB(CURRENT_DATE, INTERVAL 1 MONTH);   My question: where should I use an index and why?


I have a Windows 10 Home, which as I understood from online tutorials does not support windows built in encryption tools like Bitlocker. Moreover, it seems that may device does not support encryption anyway, as under System Information/Device encryption support I do not have "meets prerequisites", as mentioned , but rather (translated): "Possible causes of automatic device encryption failure..." Nevertheless, I would really like to encrypt the drive, in case the computer is stolen, on the other hand would be really nice if it is done in the background or close to that, so it does not disrupt the current workflow (meaning I dont need to choose some file, move it in a specific folder, encrypt and add new files by hand). Basically a full drive encryption. What are my options? I was reading about TrueCrypt, but there is a  on their website:


How do ability score improvements improve modifiers?

First time player in a group figuring out things as we all go.  I just hit level four as a Ranger, and I get to improve one ability score of my choice by 2, or I can increase two ability scores of my choice by 1.  My first thought was Strength, as I've been rocking a score of 11 with a mod of +0 so far. But I read that Rangers use (wisdom mod + 10) for their spell casting modifier. Currently my wisdom is 13, with a mod of +1. If I increase either STR or WIS, will the modifier increase as well? How and why?  A Monk in our party went from 9 CON to 11 during their ability score improvement, and by doing so their modifier went from −1 to 0.  We're all pretty new, so between eight people we're currently sharing one book, and all trying to locate our own copies for later campaigns. That's making it… inefficient for us to learn these things quickly.


First time I've got the following message on SO:     Too many of your edits were rejected,   try again in 7 days.   Although, I have made ~50 accepted edits this day.  I'm sure that should outweigh the ~5 rejected edits, right?    My suggestion:  bool allowEdit(USER u) {     if(u.rejected * 5 > u.accepted)         return(false);     else         return(true); }   Think of it this way: if I do a 1000 accepted edits, and mess up on 5 [rejected], does that mean I should get banned for 7 days?    Hmmm... There seems to be a bug; the message only appears when clicking edit from review.  But otherwise, I can't edit , even when going to it from the homepage.


Justifying the Normal Approx to the Binomial Distribution through MGFs

Would absolutely love if someone could help me with this question, in a step by step way to help those who are uninitiated to Statistics and Mathematics.   So, I am trying to "prove/justify" through MGFs how as n(the sample size) increases and goes to infinity, a standardized binomial distribution converges to the Standard Normal Distribution. So in the beginning we have $X_n $~$ Bin(n,p)$ then we standardize this $R.V.$ by subtracting the mean $E(X_n)=np$ and dividing by the $SD$ which is $np(1-p)$. After doing this, we get a new $R.V.$ with $mean=1$ and $variance=SD=1$. It is the distribution of this standardized quantity that converges to a fixed distribution, correct? Namely the Standard Normal Distribution. Let's call the standardized version of $X_n$, $Z_n$.   I think what we need to do is to find the MGF of $Z_n$ and show that this MGF becomes the Standard Normal Distribution's MGF as the sample size $(n)$ heads toward infinity. Now $Z_n$ is a function of $X_n$ which we know the MGF of which is $(1-p+pe^t)^n$.   Now I know that $Z_n$ is a linear transform and that we should be able to use this to simply the MGF but I don't understand how the course notes do it, mostly because they skip a lot of steps and it is difficult to follow. There is also a Taylor Series Expansion for the exponential that I am confused about although I do understand the concept of the series expansion.  Help would be greatly appreciated! I would love assistant in exactly how we can prove this via MGF.   Thanks so much in advance :)


Could someone please provide an explanation for the origin of ? (Ideally someone who I have been speaking with on the h-bar)  Any advanced maths beyond basic calculus will most probably leave me at a loss, though I do not mind a challenge! Please assume little prior knowledge, as over the past few days I have discovered that much of my understanding surrounding the process as virtual particle pairs is completely wrong.


How do you wait for input on the same Console.WriteLine() line?

I want to pose a question such as:  What is your name? Joe  How would I accomplish this using Console.WriteLine to also wait for the response on that same line instead of it being broken into:  What is your name? Joe


Run a command after a specific USB was plugged in

I want my usb to run a command or a script --like autorun-- when it is plugged in. I've also searching and found out that autorun was not present because of some security reason(s). How do you run a command after a specific type of USB is plugged in ?


$x ≡ a \pmod{m}, x ≡ b\pmod{n}, x ≡ c\pmod{r}$

What could be an example of three positive integers $m, n$, and $r$, and three integers $a, b$, and $c$ such that the $\mathrm{gcd}$ of $m, n$, and $r$ is $1$, but there is no simultaneous solution to  $x ≡ a \pmod{m}$  $x ≡ b\pmod{n}$  $x ≡ c\pmod{r}$


How to create record Type Selector that changes the way your form looks depends of the record type selected in LWC

As you can see in the picture ,I want to be able to select a record type then the form that appears will depend on the record type selected , I will have two record types


How to color labelnames in bibliography?

I would like to have the names of authors/editors (editors only if no authors given) in a certain color (e.g. red).    \documentclass[% ]{scrbook}%  \usepackage[english]{babel} \usepackage{filecontents} \begin{filecontents*}{\jobname.bib}     @InCollection{DelPercio2014,   author    = {Del Percio, Alfonso and Reisigl, Martin},   title     = {Angewandte Diskursforschung},   booktitle = {Diskursforschung - Ein interdisziplinäres Handbuch},   publisher = {transcript Verlag},   isbn      = {9783839427224},   date      = {2014},   location  = {Bielefeld}, }  @InCollection{Angermuller2014c,   author    = {Angermuller, Johannes and Macgilchrist, Felicitas},   title     = {Einleitung: Konzepte und Kontroversen der Diskurstheorie},   booktitle = {Diskursforschung: ein interdisziplinäres Handbuch},   editor = {Hans Wurst},   publisher = {transcript Verlag},   pages     = {17--20},   date      = {2014},   origdate  = {1999},    location  = {Bielefeld}, }  @Book{Motakef2015,   title     = {Prekarisierung},   publisher = {transcript Verlag},   author    = {Motakef, Mona},   isbn      = {978-3-8376-2566-0},   date      = {2015},   location  = {Bielefeld},   url       = {http://www.transcript-verlag.de/978-3-8376-2566-0/prekarisierung}, } \end{filecontents*} \usepackage[   backend=biber,   style=ext-authoryear,   innamebeforetitle=true,   ]{biblatex}  \addbibresource{\jobname.bib} \begin{document} \chapter{Titel} \footcite[23-44]{Motakef2015} \footcite[19\psq]{Angermuller2014c} \footcite[123]{DelPercio2014} \printbibliography \end{document}   Right now it looks like this    but it should be colored as seen here:


Is there any way to do n-level nested loops in Java?

In other words, can I do something like  for() {     for {        for {        }     } }   Except N times? In other words, when the method creating the loops is called, it is given some parameter N, and the method would then create N of these loops nested one in another?  Of course, the idea is that there should be an "easy" or "the usual" way of doing it. I already have an idea for a very complicated one.


How to avoid Duplicate Content issues when dealing with 'Language Only' and 'Language and Location' URLs

I am working on an eCommerce site, which wants to target the UK, US and Australia.  Due to their cultural variations in the English language, and the fact they all have their own currency, the website's Subdomains have been set up as follows:   www.example.com (Targeting US) en-gb.example.com (Targeting the UK) en-au.example.com (Targeting Australia)   I have placed the following hreflang attributes, within the <head> Tags of the above Sub domains:  <link rel="alternate" href="https://www.example.com" hreflang="en-us" /> <link rel="alternate" href="https://en-gb.example.com" hreflang="en-gb" /> <link rel="alternate" href="https://en-au.example.com" hreflang="en-au" />   After continued research, I can see that it is advisable to implement a 'catch-all' URL for the English language.  Therefore, a URL that does not target a specific region.  In my case, the URL would be:   en.example.com (Targets English speakers outside of the UK, US and Australia)   Given that en.example.com would either adopt GBP, USD or Aus Dollars, there is a risk that search engines may see this as duplicate content with one of the above Subdomains.  With this in mind, should additional modifications be integrated, such as the use of Canonical links etc?


Which is more idiomatic in a bash script: `|| true` or `|| :`?

I don't do terribly much shell scripting, so I was a little surprised when I was reading  and I saw the syntax they used in this documentation:     A non-zero return from the command in any submodule causes the processing to terminate. This can be overridden by adding || : to the end of the command.   I had to look up that || : was a shorthand for forcing a command to exit successfully.  Anytime I've had to make a command exit successfully, I used || true.  Is || : considered to be more idiomatic?


Replace string in one file with contents of another file when match column

I have two files like:  file 1 :  a stringori to replace, this stringori comme again  other stringori2 to replace, stringori2 commes again ...   file 2:  stringori newstring stringori2  newstring2 ...   I want to get the result:  a newstring to replace, this newstring comme again  other newstring2 to replace, newstring2 commes again


I'm trying to work on UART for AVR. After setting the baud rate registers UBRRnX, I'm trying to configure the UCSRnA register.    I'm trying to set the 2nd bit, U2XO. Which is the right way to do it? UCSR0A = (1 << U2X0)   or  UCSR0A = UCSR0A | (1 << U2X0) (Notice the OR operator in the 2nd statement)


Prove that $\dim(U_{\perp}) = \dim(V ) − \dim(U)$.

Let $V$ be a finite-dimensional inner product space over field $F$, and let U be a subspace of $V$ . Prove that the orthogonal complement $U_{\perp}$ of $U$ with respect to the inner product $\langle \cdot , \cdot\rangle$ on $V$ satisfies $\dim(U_{\perp}) = \dim(V ) − \dim(U)$.


Finding probability density of $Y=X^2$, assuming $X\sim U(-1,1)$

Suppose $X$ has a uniform distribution on $(-1,1)$, and let $Y = X^2$. How do we find $f_Y$?


Is there a reason to prefer bare wire for Grounding Electrode Conductor?

Is there a reason I should use bare copper instead of THWN for a grounding electrode conductor (e.g. bonding water pipes and ground rods; not an equipment grounding conductor)?  I cannot find anywhere that says THWN must be run inside conduit/raceway when used as a grounding electrode conductor. Section 250.62 indicates the conductor can be "solid, stranded, insulated, covered, or bare" and 4 and 6 awg THWN are generally cheaper in my area than bare copper (both solid and stranded), so I'm just wondering if there is some section of code I am missing or a practical reason to prefer a bare conductor since bare wire seems to be in wide use for this purpose where I look.


I was wondering if anyone knew how to get rid of this burning sensation on my hands from some peppers that I chopped earlier this evening. I've washed my hands multiple times and it seems that I am unable to wash off the acid. Does anyone know of a technique to rid myself of this?


by using netstat -n -o -a i see that process id 4 listening to that port.  TCP    0.0.0.0:3000           0.0.0.0:0              LISTENING       4  By using task manager i found that process id 4 is NT Kernel & System     hence  Since i need that port for other service, i am wondering, why the kernel needs to hold that port?   can i release it?   how can i find the specific feature that use that port?


I have a unix installation that's supposed to be usable both as a chroot and as a standalone system. If it's running as a chroot, I don't want to run any service (cron, inetd, and so on), because they would conflict with the host system or be redundant.  How do I write a shell script that behaves differently depending on whether it's running in a chroot? My immediate need is a modern Linux system, with /proc mounted in the chroot, and the script is running as root, but more portable answers are welcome as well. (See  for the case of Linux without /proc.)  More generally, suggestions that work for other containment methods would be interesting. The practical question is, is this system supposed to be running any services? (The answer being no in a chroot, and yes in a full-fledged virtual machines; I don't know about intermediate cases such as jails or containers.)


Can you give an example of a field of characteristic zero (other than the complex numbers, real numbers and rational numbers)?


Do I have to pay interest to increase my credit score?

I am going to ask this oft repeated question one more time because:  I have heard many of my friends say that the best way to increase your credit score is to take a loan ( at an interest) and then pay it over a period of time. Their main point being that you have to pay real interest on a loan to increase your score. If you use a credit card and pay in full every month (and therefore pay zero interest) your score will not improve appreciably. I highly doubt this, can you confirm or refute.


I've been keeping a log of expensive running queries, along with their query plans, in a table to allow us to monitor trends in performance and identify areas that need optimising.  However, it's come to the point where the query plans are taking up too much space (as we're storing the entire plan against each query).  I'm therefore attempting to normalise the existing data by extracting the QueryPlanHash and QueryPlan to another table.  CREATE TABLE QueryPlans (     QueryPlanHash VARBINARY(25),     QueryPlan XML,     CONSTRAINT PK_QueryPlans PRIMARY KEY     (       QueryPlanHash     ) );   As the definition of the query_plan_hash in sys.dm_exec_query_stats is a binary field (and I'll regularly be inserting new data), I was using VARBINARY for the data type in my new table.  However, the insert below fails...  INSERT INTO QueryPlans     ( QueryPlanHash, QueryPlan ) SELECT queryplanhash, queryplan FROM (     SELECT        p.value('(./@QueryPlanHash)[1]', 'varchar(20)') queryplanhash,       QueryPlan,       ROW_NUMBER() OVER (PARTITION BY p.value('(./@QueryPlanHash)[1]', 'varchar(20)') ORDER BY DateRecorded) rownum     FROM table     CROSS APPLY QueryPlan.nodes('/ShowPlanXML/BatchSequence/Batch/Statements/StmtSimple[@QueryPlanHash]') t(p) ) data WHERE rownum = 1   ....with the error  Implicit conversion from data type varchar to varbinary is not allowed. Use the CONVERT function to run this query.   The problem is that the query plan hashes are already in binary format, however stored as VARCHAR in the XML Query Plan e.g.  0x9473FBCCBC01AFE   and CONVERT to BINARY gives a completely different value  0x3078393437334642434342433031414645   I tried changing the value definition in the XQuery select to binary, but then it returned no values.  How would I extract the value of 0x9473FBCCBC01AFE from an XML query plan as a VARBINARY, rather than a VARCHAR?


Is conservation of energy a set of principles that is inevitable in any 'possible world'?

It is usually stated in various books or stories 'Energy can't be created or destroyed , but is conserved'. I guess this is within a closed system. Are there any axioms or principles in physics that would be contradicted if certain types of energy could be destroyed or changed into some form that is 'unusable' by any closed or open system? Are the conservation laws axioms? Saying the principles of energy conservation are valid approximations given what is presently known is only a partial answer to this question. I'm wondering if any principles are known now that would determine energy can not be destroyed in many situations not 'covered' by such approximations.  Could conservation laws be formulated 'a priori' or without empirical evidence?


3 Input XNOR gate made with XOR and not gates

hi i have implemented this equation with XOR and Not gate but i'm not getting the correct answers (A.B.C)+(A'.B'.C')    What is the Problem ?  thank you


Quickly send pre-written response on Mac mail?

I get a lot of emails from recruiters sending irrelevant jobs to me, so I have a standard response that I copy and paste into replies. At the moment I do this manually from a saved text file. Is there a quicker way of doing this?   I was imagining there would be some way to save a reply so 1 button or shortcut would send this reply.


Getting coordinates from mouse click in QGIS 3 (python plugin)

I am trying to get coordinates from a mouse click in QGIS 3 and python 3 using the plugin builder.  I have tried using the response , and i can manage to get the coordinates printed to the python console in QGIS but at the same time i get the message that "'TypeError: 'QgsMapToolEmitPoint' object is not iterable" or "'QgsMapToolEmitPoint' object does not support indexing"   I can't remember i ever seen a python program causing an error but still manage to compute and output the wanted result. The "not iterable" error traces back to the line with the for loop "for point in ... " the "does not support indexing" error is caused if i do e.g. x = pointTool[0]  Here is a version of the code:  from qgis.gui import QgsMapToolEmitPoint   def display_point(pointTool):     #print(pointTool)     cood = []     for point in pointTool:         cood.append(point)     print(cood)  # a reference to our map canvas canvas = iface.mapCanvas()  # this QGIS tool emits as QgsPoint after each click on the map canvas pointTool = QgsMapToolEmitPoint(canvas)  pointTool.canvasClicked.connect(display_point)  canvas.setMapTool(pointTool)  display_point(pointTool)


We know that $$\sum _{k=1}^{\infty } \frac{H_k}{k^3} = \frac{\pi^4}{72}.$$ Is there a closed form for the sum $$S=\sum _{k=1}^{\infty } \frac{(-1)^k H_k}{k^3}?$$ Mathematica doesn't give anything resembling a closed form and I have no idea if one exists.


What does "probability distribution" mean?

I mean statements such as: "the probability distribution of X" or "its probability distribution". I am quite confused about such expressions.  Could someone please explain the relationship between, Probability, Probability Distribution, density function? I have checked on Wikipedia for a while, still only clear about that, density function can be used to calculate the probability.


Problem starting Steam on ubuntu 15.04 64-bit

After installing and updating, whenever I start Steam, it gives me the following error:  Running Steam on ubuntu 15.04 64-bit STEAM_RUNTIME is enabled automatically [2015-05-02 16:48:39] Startup - updater built Apr 13 2015 15:17:10 SteamUpdateUI: An X Error occurred X Error of failed request:  BadValue (integer parameter out of range for operation)   I tried to find a solution to a similar error, but I was not able to find. Can anyone please help?


Summing up the elements of a finite field.

I want to show that $\sum_{x\in \mathbb F_{q}}x^i=0$ if $q-1$ does not divide $i$. Can someone give me a hint?


Is there a closed analytical expression for $I(x)$ with $x,t \in \mathbb{R_+}$ and  $$I(x) = \int_{0}^{x} t^tdt$$  ?  I suppose this integral is some classic example for a function without analytic closed form. I have searched this site the web and testet several CA systems but could not find a result.   Question 2: In case there is not, is there way to show this?


The Last Obstacle -- Measuring sidebearings in LuaLaTeX

I've just realised that this question might be interpreted as a duplicate of , and therefore eligible to be closed as such. Apologies for the lapse of memory; I'll leave the community to close one or the other.    I'm slowly (as always) coming to the conclusion that I should make the move from Xe- to Lua-(La)TeX, but, as far as I can see, there is still one last obstacle.  In XeLaTeX, I can do this:  \def\kright#1{\leavevmode #1\kern-\XeTeXglyphbounds3 \the\XeTeXcharglyph`#1 } \def\kleft#1{\leavevmode \kern-\XeTeXglyphbounds1 \the\XeTeXcharglyph`#1 #1}   Which compensates for left or right sidebearings, and allows me to align the 'edge' of text precisely (See, for example, this answer to  and also this question: .  I believe these sidebearing measurements may be available within LuaTeX, but so far have not been able even to get close to finding the document that will tell me how to do it. Can someone help?  BTW, I know that microtype can do something similar, but I understand that it's driven by an external table which takes a lot of effort to set up -- I'm looking for the general solution for an arbitrary (Open Type, probably) font.


Why does light follow the Fermat's principle of least time?

When I asked why did light follow the law of reflection, I was answered that it obeys the principle of least time. So my question is, why does it even obey the principle of least time?


I want to find all integers $a$ and $b$ that satisfy $a^b=b^a$, where $0<a<b$. By guessing I found that $a=2$ and $b=4$ is a solution. I'm not sure whether it is the only solution, though intuitively I think it is. How can I prove this? Thank you!


Pressing Tab for autocompleting the directory name in terminal, appens a space after the directory name and not a "/" sign

When I use "cd" command to move to certain directory in terminal, I press Tab button to autocomplete the directory name, and a "/" sign appends at the end. But, when I use some other command (say "mv"), clicking on Tab button to autocomplete the directory name, autocompletes the directory name, but does not append "/" after it, but a space. So, I have to manually delete the space by pressing Backspace button and type "/". But, in my friend's laptop, it does not occur. Whichever command he uses, he always gets "/" after presing Tab button to autocomplete the directory name. Please tell how to solve this problem. I have freshly installed 12.04 LTS version.  See the screenshot here:


Writing QGIS field calculator expression?

I have an attribute table with a real data type column named "Volume". Some of these cells have no value, and I want to replace the NULL with a dummy value like -999.  In the Field Calculaor I select "Update Existing Field", select the "Volume" field and I attempt the following:  1) I code CASE WHEN NULL THEN -999 END - Result: the entire column becomes NULL.   2) Then I try CASE WHEN  "Volume" IS NULL THEN -999 END - Result, the NULL valued cells now show -999 BUT all the other formerly filled cells are now NULL. After many hours of trying other expression variations I can't figure this out. My guess is I am missing a basic concept.  Oh, and how can I "undo" a bad field calculator update besides quitting QGIS and  discarding the updates.


Recently I have developed software using SQL Server 2012. Now when I try to connect, I get this error message:     Cannot connect to AAFI\SQLEXPRESSA network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 – Error Locating Server/Instance Specified)


How to unlock iPhone 5 (iOS 7.0.2) after forgetting my Apple ID?

I have an iPhone 5 (iOS 7.0.2) which is locked and I can't unlock it because I've forgotten my Apple ID.  Is there any solution?


I was looking at , and noticed that:   The accepted answer was below another answer. It's not like the other answer had more votes, it had the same amount of votes. The accepted answer is by the asker (which I though wasn't possible).   Screenshot here:    Is it something to do with the fact that the asker answered and accepted their own question and answer?


New to ConTeXt, looking for better manual than PRAGMA

I am an experienced user of LaTeX learning ConTeXt. However, I find the manuals on the PRAGMA website to be less than ideal. Does anyone have a suggestion for a manual or text?


what is the need of dummy variable and what are alternative to it

I know that in a linear regression if independent variable is categorical variable with k levels then we will be needing k-1 dummy variables, what happens if we model the relationship with k dummy variables


I want to make simple subtract operation on float so that I don't get a final decimal but I got same result with float  Better than my bad english : code !      private double test(final double reloadingTime) {     double timeRestant = reloadingTime - 0.1;     System.out.println(timeRestant);     return timeRestant; }   main :       double test = test(2f);     test = test(test);     test = test(test);     test = test(test);     test = test(test);     test = test(test);   console :  1.9 1.7999999999999998 1.6999999999999997 1.5999999999999996 1.4999999999999996 1.3999999999999995   So two questions: Why? And how can I can get the true result?


How to change screen resolution scaling in Ubuntu 18.04 LTS

I recently upgraded from Ubuntu 16.04 to Ubuntu 18.04. I want to change my screen resolution scaling from 1.00 to 0.75. It was very easy in 16.04 version. Please help me to change the scaling.


I had the understanding that the constant \textwidth is the width of text from the left margin to the right margin. I have been using the same as width specifier in my tables with paragraph. However, even if the widths all add up to \textwidth, the width of the table is quite a bit more than the text above and below it. Could you please explain the bahaviour?  Here's the MWE  \documentclass[a4paper, 11pt]{article}  \usepackage[a4paper, top=1in, bottom=1in,, left=1in, right=1.5in, showframe]{geometry} \usepackage{lipsum}  \begin{document}  \lipsum[1] \noindent\begin{tabular}[]{|p{0.05\textwidth}|p{0.6\textwidth}|p{0.35\textwidth}|}         \hline         \textbf {Sr. No.} & \textbf {Item} & \textbf {Projected Budget} \\ \hline         1. & Test 123 column 2 & 123456789 \\ \hline         2. & test456 Column 2 & 987654321 \\ \hline     \end{tabular}    \end{document}


A rod of length $L$ & mass $M$ is rotating in a circle about one end then calculate tension in the rod at a distance $x$ from the support. For its solution why should we take mass of $L-x$ portion of rod instead of taking mass upto $x$ distance from support as we have the formula, $T = m{\omega}^{2} x$ I am in confusion....


Traces of powers of a matrix $A$ over an algebra are zero implies $A$ nilpotent.

I would like to have a result similar to . Namely:      Let $R$ be a commutative $\mathbb{C}$-algebra, $A \in \mathcal{M}_n(R)$ such that $\mathrm{tr}(A)=\cdots=\mathrm{tr}(A^n)=0$. Does it follow that $A^n=0$?   I have no idea weather or not the analogy of eigenvalue exists for matrices over algebra so I can't simply generalize considerations from cited post. Any help will be appreciated.