Error message:     Error -   Attempt to invoke virtual method 'java.lang.String   java.lang.Object.toString()' on a null object reference   and it's about this line  final String productId = task.getResult().get("product_ID_"+x).toString();   Please help me.  public static void loadwishlist(final Context context, final Dialog dialog, final boolean loadProductData){     wishlist.clear();     firebaseFirestore.collection("USERS").document(FirebaseAuth.getInstance().getUid()).collection("USER_DATA").document("MY_WISHLIST")             .get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {         @Override         public void onComplete(@NonNull Task<DocumentSnapshot> task) {             if(task.isSuccessful()){                 for(long x = 0; x < (long)task.getResult().get("list_size");x++){                     wishlist.add((String) task.getResult().get("product_ID_"+x));                     if(DBqueries.wishlist.contains(Productdetailsactivity.productID)){                         Productdetailsactivity.ALREADYADDEDTOWISHLIST = true;                         if(Productdetailsactivity.addtowishlistbtn != null) {                             Productdetailsactivity.addtowishlistbtn.setSupportBackgroundTintList(ColorStateList.valueOf(Color.parseColor("#9e9e9e")));                         }                     }else {                         if(Productdetailsactivity.addtowishlistbtn != null) {                             Productdetailsactivity.addtowishlistbtn.setSupportBackgroundTintList(ColorStateList.valueOf(Color.parseColor("#9e9e9e")));                         }                         Productdetailsactivity.ALREADYADDEDTOWISHLIST = false;                     }                     if(loadProductData) {                         wishlistModelList.clear();                         final String productId = task.getResult().get("product_ID_"+x).toString();                         firebaseFirestore.collection("PRODUCTS").document(productId)                                 .get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {                             @Override                             public void onComplete(@NonNull Task<DocumentSnapshot> task) {                                 if (task.isSuccessful()) {                                      wishlistModelList.add(new WishlistModel(productId,task.getResult().get("product_image_1").toString()                                             , task.getResult().get("product_title").toString()                                             , (long) task.getResult().get("free_coupens")                                             , task.getResult().get("average_rating").toString()                                             , (long) task.getResult().get("total_ratings")                                             , task.getResult().get("product_price").toString()                                             , task.getResult().get("cutted_price").toString()                                             , (boolean) task.getResult().get("COD")));                                      mycartFragment.cartAdapter.notifyDataSetChanged();                                  } else {                                     String error = task.getException().getMessage();                                     Toast.makeText(context, error, Toast.LENGTH_SHORT).show();                                 }                             }                         });                     }                 }              }else {                 String error = task.getException().getMessage();                 Toast.makeText(context, error, Toast.LENGTH_SHORT).show();             }             dialog.dismiss();         }     }); }

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


I have an array of String, and the items are like : 02:11, 11:12.. I want to delete the 0 in first position.  if (orari[i].substring(0,0) == "0") {    orari[i] = orari[i].substring(1,4); }   It doesn't work, why?

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


I have tried to find how to remove the email addresses to which you have sent emails in Mail.  They are not in Contacts -application.  Not in Settings.   I type masi.mathiasen... and I all the time get the contact which I removed from Contacts, just because I sent there one message before.  Then, when he has got new email address it is annoying because I am writing his name there first and get the old one as autocomplete.  How can you remove an old email-address which Mail -application uses in OSX, which is not found in Contacts?

I am trying to delete a friend's old email address so it doesn't automatically pop up when I enter his name while addressing an email. I have removed it manually from the address book, but it still shows up in Mail.  How do I stop this happening?


The "new" kind of ransomware invade your computer and crypt all your files using the RSA-2048.  Personally, I have been victim of cryptodefense: 40000 files encrypted... I'm not going to pay anything to this &? but this is a big loss. I have a lot of files in both form: crypted and uncrypted (backup from 2011...)  Is there any chance to apply a known plain text attack on RSA-2048. I read another topic and it seems that if you have two files you miss a variable (e) but is there any way to find it with more than a thousand of files?  Does that means that this is a question of calculation capacity (in that case I'm gonna wait a couple of years to have my pictures back ;-)

Assume Alice and Bob are using RSA to create a common session key and Cindy is listening, attempting to obtain the session key.  Alice and Bob each have their public- and private-key pairs ($\left[pub_{A}, pri_{A}\right]$ for Alice and $\left[pub_{B}, pri_{B}\right]$ for Bob) and Alice, Bob, and Cindy all know everyone else's public key.   Alice generates a random $n_{A}$ and sends out $En_{pub_{B}}\left(n_{A}\right)$ ($n_{A}$ encrypted with Bob's public key). Bob generates a random $n_{B}$ and sends out $En_{pub_{A}}\left(n_{B},n_{A}\right)$ and sets the session key to $n_{A}\oplus n_{B}$. Alice sends out $En_{pri_{A}}\left(n_{B}\right)$ and sets the session key to $n_{A}\oplus n_{B}$.   My thinking is, Cindy decrypts message 3 with Alice's public key to obtain $n_{B}$.  Now Cindy has a plaintext, ciphertext pair and the key that decrypts the ciphertext.  My question is, is it possible with this information for Cindy to find $pri_{A}$ in order to decrypt message 2 and find $n_{A}$?


I'm trying to make it so a villager will teleport home when the time is 13000. Here's what I got:  /time query daytime 13000   With a comparator got to a command block with this in it:  /tp @e[type=Villager,name=Wizard] -685 56 510   But it doesn't tp the villager when the time is 13000!

I simply want one command block to test for the time of day or night (e.g. time = 18000) and output a message in the chat to everyone if that time returns true.  I was trying a simple set-up with two command blocks and a comparator in the middle, but I'm a beginner and am obviously missing the correct syntax (especially to test for a particular time of day, and if true, then trigger the say "message" block).  ETA: Kudos to @Ben for the Daylight Sensor/Redstone idea, but I'd really prefer a Command Block solution for the above, since my plan is to output several messages during the day and night cycle at very specific times in the world. Thanks.


I am using a galaxy S5. I have an error that I could only play the game on wifi (not on data). I tried numerous things to fix it including reseting app preferences as suggested by a user on this website. Now I still can't play the game on data plus no roads show up in my town (they still appeared before I reset app preferences) can anybody help me to get the game to work on data or at least to make it so I can see roads again?   Thanks

It connects to Pokemon Go via wi-fi perfectly fine, but when I try and connect to Pokemon Go via 3G it just gets stuck at the first bar on the loading screen with the eventual pop up saying "Failed to get player information from the server." My 3G connection works perfectly fine with every other app I have, and has been easily able to stream HD videos so I can't see connectivity with 3G being an issue.   It makes even less sense as once connected via wi-fi, the game easily continues to operate via mobile data once I leave the house. However once the app crashes (which it usually does after 15-30 minutes) I try to reload it on mobile data and it gets stuck on the loading screen. If I can find a local free wi-fi spot nearby I can re-connect easily, and then move back onto mobile data.  I've tried removing and reinstalling Pokemon Go and that didn't work. I also reset all my app preferences on my phone and that didn't work.  Not sure if this helps, my phone is a Huawei P8, Android version 5.0.1.  I signed up to Pokemon Go using my Google account.


Why did Cirdan choose Gandalf to wear Narya, of all the Istari?  The reasoning for why he gave the ring at all doesn't seem to uniquely qualify Gandalf as the best recipient, unless Cirdan was being prophetic?     "Take this ring, master," he said, "for your labours will be heavy; but it will support you in the weariness that you have taken upon yourself. For this is the Ring of Fire, and with it you may rekindle hearts in a world that grows chill." - Círdan the Shipwright   But that was originally the mission and the presumed fate of ALL of the Istari, not just Gandalf's.

In the Lord of the Rings I recall some mention of when Cirdan gives Narya to Gandalf when the Istari arrive in Middle Earth. I think it is in the appendices but I cannot recall exactly, but I remember something about him suspecting Gandalf's origins and giving him the ring to aid in the fight against Sauron.  Throughout the novel, we learn that Saruman is more powerful than Gandalf and is his superior in some way. I recall somewhere in the novel Gandalf himself confirms this when he describes Saruman as the head of his order (here I assume that when he refers to "his order" he means the Istari - please correct me if this is wrong).  This being the case, I wonder if Tolkien ever discusses in interviews or other works the reasons that Cirdan chose Gandalf over Saruman as the person to pass Narya onto. It would seem to me that without the knowledge of the events to come that Saruman would be the more natural choice if Cirdan was intent on passing on Narya to someone else.


I'm working on a Java project, and I want to pass a Java object to a method in order to avoid code duplication. This is my code : private List<Dog> getListDogs(SearchResponse response) {      SearchHit[] searchHit = response.getHits().getHits();      List<Dog> dogList = new ArrayList<>();      if (searchHit.length > 0) {          Arrays.stream(searchHit).forEach(hit -> dogList.add(objectMapper.convertValue(hit.getSourceAsMap(),Dog.class))                 );     }      return dogList; }  I have other objects that need to use the same method like Cat Object and Horse object. Do you have any idea on how I can make my method generic in order to pass just the object type as a parameter? Something like this: private List<Generic> getListObject(SearchResponse response , GenericObject object){...

Consider this example (typical in OOP books):    I have an Animal class, where each Animal can have many friends. And subclasses like Dog, Duck, Mouse etc which add specific behavior like bark(), quack() etc.  Here's the Animal class:  public class Animal {     private Map<String,Animal> friends = new HashMap<>();      public void addFriend(String name, Animal animal){         friends.put(name,animal);     }      public Animal callFriend(String name){         return friends.get(name);     } }   And here's some code snippet with lots of typecasting:  Mouse jerry = new Mouse(); jerry.addFriend("spike", new Dog()); jerry.addFriend("quacker", new Duck());  ((Dog) jerry.callFriend("spike")).bark(); ((Duck) jerry.callFriend("quacker")).quack();   Is there any way I can use generics for the return type to get rid of the typecasting, so that I can say      jerry.callFriend("spike").bark(); jerry.callFriend("quacker").quack();   Here's some initial code with return type conveyed to the method as a parameter that's never used.   public<T extends Animal> T callFriend(String name, T unusedTypeObj){     return (T)friends.get(name);         }   Is there a way to figure out the return type at runtime without the extra parameter using instanceof? Or at least by passing a class of the type instead of a dummy instance. I understand generics are for compile time type-checking, but is there a workaround for this?


I want to read an entire file into a string. The file however is in the program arguments. I have been trying to use Scanner in order to:  Scanner scan = new Scanner(args[0]);           scan.useDelimiter("\\Z");           String content = scan.next();          System.out.println(content);   My result is just the name of the file that is in "args[0]" instead of the actual contents of the file.   I figured a loop would not work since I am not hardcoding the file into the program.

I've been using the idiom below for some time now. And it seems to be the most wide-spread, at least on the sites I've visited.  Is there a better/different way to read a file into a string in Java?  private String readFile(String file) throws IOException {     BufferedReader reader = new BufferedReader(new FileReader (file));     String         line = null;     StringBuilder  stringBuilder = new StringBuilder();     String         ls = System.getProperty("line.separator");      try {         while((line = reader.readLine()) != null) {             stringBuilder.append(line);             stringBuilder.append(ls);         }          return stringBuilder.toString();     } finally {         reader.close();     } }


I'm trying to create and fill a file in a directory that requires sudo permission.   EDIT: It seems that based on tested the suggested similar post.  sudo su -c "echo 'put in file' > file_name" echo "Some text" | sudo tee /etc/file   will both create a file within the directory that requires sudo permission

This is a pretty simple question, at least it seems like it should be, about sudo permissions in Linux.  There are a lot of times when I just want to append something to /etc/hosts or a similar file but end up not being able to because both > and >> are not allowed, even with root.  Is there someway to make this work without having to su or sudo su into root?


I need to prove that : $\mathrm{\sum_{n=0}^{\infty} {p^n\over n!} |p-n| = 2{p^p\over(p-1)!}}$ Knowing that $\mathrm{\sum_{n=0}^{\infty} {p^n\over n!} = exp(p)} $ I've tried many ways : $\mathrm{\sum_{n=0}^{\infty} |p-n| = \sum_{n=0}^{p-1} (p-n) + \sum_{n=p+1}^{\infty} (n-p) }$ $\mathrm{ \Longleftrightarrow ... \Longleftrightarrow \sum_{n=0}^{\infty} |p-n| = \sum_{n=0}^{p} n + \sum_{n=0}^{\infty} n }$ Also tried to use ln()... But nothing seems to be leading to a result... I have spent more than 3 hours just on this one... Can anyone show me the answer and the way I need to proceed in such exercises ?

I want to show that for each $n \in \mathbb N$ it holds that $$\sum_{k = 0}^\infty \frac{n^k}{k!} \vert k - n \vert = 2n \frac{n^n}{n!}.$$ But I have absolutely no idea how to do that. I tried to split the series like this:  $$\sum_{k = 0}^\infty \frac{n^k}{k!} \vert k - n \vert = \sum_{k = 0}^{n - 1} \frac{n^k}{k!}(n - k) + \sum_{k = n + 1}^\infty \frac{n^k}{k!} (k - n)$$ Now I want to show that $\sum_{k = 0}^{n - 1} \frac{n^k}{k!}(n - k) = \sum_{k = n + 1}^\infty \frac{n^k}{k!} (k - n) = n \frac{n^n}{n!}$ holds. But I got no idea how to achieve that. I tried to use induction but things became pretty messy and I don't think it will work like that. On the other hand I got the idea that it might have to do with $\exp$ or binomial coefficients but I don't see where I can facilitate that. I would appreciate some hints :)


I'm creating a generic method which should be able to return null.  As an example I've created this method GetSecondSmallest(List<T>) below. This function loops through all of the IComparable items and returns the second smallest item if possible. If this item does not exist it returns null.  public T? GetSecondSmallest<T>(List<T> items) where T : Nullable, IComparable {     if (items.Count == 0) return null;      T smallest = items[0];     T? secondSmallest = null;      // Find second smallest by looping through list      return secondSmallest; }   Two example usages of this method would be:  GetSecondSmallest(new List<int> {4, 2, 3, 1, 6, 8}) // Should return 2 GetSecondSmallest(new List<MyComparable> {new MyComparable('x')}) // Should return null   When you try to compile this code you'll see what the problem is here:     Error   CS0717 'Nullable': static classes cannot be used as constraints   How can I make this method return either an instance of T or null?    EDIT: I have already seen , but this does not answer my question, because in my situation the parameter is also generic, and should be Nullable. So the provided answers there aren't applicable.

I want to do something like this :  myYear = record.GetValueOrNull<int?>("myYear"),   Notice the nullable type as the generic parameter.   Since the GetValueOrNull function could return null my first attempt was this:   public static T GetValueOrNull<T>(this DbDataRecord reader, string columnName)   where T : class {     object columnValue = reader[columnName];      if (!(columnValue is DBNull))     {         return (T)columnValue;     }     return null; }   But the error I'm getting now is:     The type 'int?' must be a reference type in order to use it as parameter 'T' in the generic type or method   Right! Nullable<int> is a struct! So I tried changing the class constraint to a struct constraint (and as a side effect can't return null any more):  public static T GetValueOrNull<T>(this DbDataRecord reader, string columnName)   where T : struct   Now the assignment:  myYear = record.GetValueOrNull<int?>("myYear");   Gives the following error:     The type 'int?' must be a non-nullable value type in order to use it as parameter 'T' in the generic type or method   Is specifying a nullable type as a generic parameter at all possible?


I recently downloaded QGIS 2.8 and opened an existing project in it to check how it handled it and make any changes required. This project includes several raster heatmap layers.  My problem is that many of these raster layers seem to have shifted by a significant degree (but not all of them so additionally confusing). At first I thought it was a styling issue but then realised they were being displayed outside of the visible area.  They all have the same CRS set (EPSG: 27700, British National Grid), the project is set to this also.  I can see no differences between the settings for the affected raster layers and the single unaffected raster layer. Some of the affected layers are .ntf and some are .tif. The one unaffected layer is a tif.  Re-importing the layers doesn't seem to help. Creating a heatmap from scratch leads to the same problem, very odd!

I noticed that the heatmap calculation on the new upgrade version of qgis is given the raster map without any coordinate system.   Have you got the same problem?


Luftrausers is a quick, light, nigh-monochrome game of flying around in a configurable plane, shooting enemies, and dying quickly. During the game, there are missions you need to achieve: kill any 10 enemies, kill enemies while firing nonstop, kill specific enemies, score X points (by killing enemies), etc. Something enemy something kill something.  Then there's the current mission I'm on: kill 50 enemies while on fire. How does being on fire work? I usually manage to rack up a few of these every game, but I haven't figured out what "being on fire" means. I've tried getting to a low amount of health and then killing enemies, but that doesn't work — or at least not consistently.  So how do I set myself on fire? How long do I remain on fire, and is there something I'm doing that's putting me out?

A mission for the random armor selection is to "Kill 50 enemies while on fire". I take it to mean that I should kill 50 enemies in total "at very low health", but getting the counter to increase is very hit and miss.   What does "on fire" mean? Is the counter reset each round?


i need to make a comparison between directory containing the image of some running process. when i use GetProcessImageFileName() the function give me a path with something like "\Device\HarddiskVolume3...." (i'll call it DevPath), instead of "C:..."(i'll call it C_Path) i need to make comparison with other C_Path style path, so i should translate in the other kind of path, is that possible?  since i don't really need the drive letter, if is too troublesome to make a correct path translation could i simply read only the part of char after the N° backslash? making somethinglike  (Pseudocode)  if(  ReadAfter3Backslash(DevPath) == ReadAfter1Backslash(C_Path))...   now the second question is: the DevPath have everytime exactly 3 slash before starting with "normal" directory? if a full translation isn't viable will this work?  PS: i know that exist the function QueryFullProcessImageName() that can give the "C..." path style but i'v got a lot of problem with that function, it currently crash and is hard to make it portable to pre-vista OS. since this seemes to be a more difficult way to solve my problem i'm ignoring it until i have hope with translation solution.

How would I compare 2 strings to determine if they refer to the same path in Win32 using C/C++?  While this will handle a lot of cases it misses some things:  _tcsicmp(szPath1, szPath2) == 0   For example:    forward slashes / backslashes relative / absolute paths.   [Edit] Title changed to match an existing C# question.


I would like to know if there is a difference in the following sentence depending on the preposition. Both seem to be correct. I saw a celebrity while I was shopping in/on Oxford St. Thank you!

In the United States, we say that someone lives on a street, whereas I've noticed that British people say in. For instance:     Bubba lives on Washington Street.   Colin lives in Cavendish Avenue.   I believe we both would use at when a number is given. For instance:     Bubba lives at 16 Washington Street.   Colin lives at 7 Cavendish Avenue.   I don't think it matters if it's a road, avenue, street, circle, or lane — as far as I know, in America, we always live on a street. Does it vary in British English, or is it always in? If it varies, what are the rules?


I'm trying to find a cartoon that begins with an empire in Coup d'état. The king ordered the princess to escape while he held back the attackers. He sent her to a lab or something where she found a yellow robot who was assigned to protect her and they escape at the end of the episode.  The enemies have their own robot who looks like the yellow one. It is implied that both robots were created for the same purpose (protecting the princess) but he was too violent and volatile, so, even though he was superior in combat (he is running a simulation where he fights and obliterates the other robot), the yellow one is the one chosen for the task. In the next episode (or the third one; I don't remember very well) the princess and the yellow robot go to a mine to recover an artifact, which is some kind of hammer. The miners were ordered to hide there in case the robot was ever needed.  That is what I can recall of the series: It was shown in South America; only 3-5 episodes, really early in the morning. The robot was a bright yellow like Bumblebee from Transformers, but the design was more like a more rounded iron giant. It was pretty big: enough for the prince to ride his shoulder. I don't recall much of the princess besides she was in a classic princess-like long dress and had pretty long hair.   I'm pretty sure it is not Asian made. And for what I recall it was 3D, not drawn. I'm not too sure how old it is, since cartoons often take years before they make it to free TV, but the 3D was pretty good, so I don't think it is older than 10 years.

I am trying to find an old cartoon, I remember it was about a young girl, possible a princess who was protected by a red robot on her journey.  I also remember that her father (I think) created two robots, one was red and one black, and he give them a test to see which one could protect his daughter. The red robot was chosen, but the black one (I believe he was stronger) tries to stop the princess from getting where she is going. The black robot sends various robots after them but they are defeated by the red robot.  I can't remember any names, but I think that most of the action happens in a desert, there are not a lot of interactions in this cartoon, mostly the girl and the red robot traveling together and fighting other robots.  The girl might have been just the daughter of an important scientist (who created the two robots) and not a princes. She is young, probably a 10 years old.


Does anybody know a nicer expression for the sum $\sum_{i=0}^{k} \binom{n}{i} \binom{n-i}{k-i}$?

How can we prove that     $$\sum_{k=0}^{n}\binom{R}{k}\binom{M}{n-k}=\binom{R+M}{n}?$$   (Presumptive) Source: Theoretical Exercise 8, Ch 1, A First Course in Probability, 8th ed by Sheldon Ross.


As the story begins, in the books or in the show, it is common knowledge that Varys is an eunuch. As he doesn't seem to deny it, readers or viewers quickly assume this is true.  However, I wonder why would he let people know his condition. Initially, there were only two people (the sorcerer and himself) that knew. So at some point, he started to tell people and let the rumor spread.  I don't think that this is something to brag about, but maybe Varys thought that letting people know would help him somehow. Did he intentionally let people know he was eunuch? Why?  His appearance might have betrayed him, but as he has some skills in disguise, he could have chosen to hide that fact. However, he seems to delight in his condition.  NOTE: This is not a dupe. The target asks how can Eunuchs be told apart. This one asks if Varys is actually an eunuch and did he disclose his identity voluntarily.

In the first or second book, when Daenerys is in a city, she wants to enter a building ( I think) and she thinks:     [...] and there was a eunuch guarding the door [...].   How could she understand that the person she saw (that she haven't seen before) was a eunuch? Do eunuchs have something distinctive so people can tell them apart?   Are they like Varys? Shaven head and no beard?


So my question is about the UA subclass for Barbarian, The Path of the Beast. The question is when I choose the claws option, both of my hands become natural weapons (Cause ya know, claws). So in this case can I make an off-hand strike with the claw with a bonus action? If yes then is it d6+str+rage or just d6+rage? If it is the latter then can I take the dual wield fighting style and add the str bonus to the bonus action offhand attack?

Do natural weapons such as those granted by being a Tabaxi or an Aarakocra count for the purposes of two weapon fighting? Would they have the light property to allow it and if not what about if you take the dual wielder feat that removes the restriction on them being light?  From a logical perspective I would think claws or talons would be light enough to count and with them being "natural weapons" this means they are definitely weapons so it would make sense for them to be considered light and one handed.


How can I prevent this from happening. All I want is normal code - no comment.  /account/** = ssl, authc   Here nothing is grayed out in a comment-like fashion, but on stackoverflow /** = ssl, authc is.

I noticed that sometimes my code gets highlighted in different colors when rendered.   What is syntax highlighting? How does it work? Why isn't my code being highlighted correctly? How do I report a bug or request a new language? How do I use syntax highlighting? What languages are currently available on Stack Exchange?


In my textbooks and lectures (I'm a second year physics student) I often come across statements such as $$``dV=4\pi r^2dr\text{ can be thought of as the spherical volume element between }r\text{ and }r+dr."$$  Is this meant only symbolically, or is it a precise statement? For instance, I get \begin{align}\int_r^{r+dr}4\pi r^2dr&=\frac{4}{3}\pi\left[r^3\right]_r^{r+dr}\\&=\frac{4}{3}\pi(r^3+dr^3+3rdr^2+3r^2dr-r^3)\\&=\frac{4}{3}\pi(dr^3+3rdr^2+3r^2dr)\\&=4\pi r^2dr+\text{increasingly smaller terms.}\end{align}  Moreover, a Taylor expansion of the spherical volume function at a point $r'$  around a general point $r$ gives $$V(r')\approx\frac{4}{3}\pi r^3+4\pi r^2(r'-r)+\cdots.$$ Since the volume of a spherical shell between $r$ and $r+dr$ is generally (?) the volume of a sphere with radius $r+dr$ minus the volume of a sphere with radius $r$, we get $$\text{volume between }r\text{ and }r+dr\approx\frac{4}{3}\pi r^3+4\pi r^2dr-\frac{4}{3}r^3\approx4\pi r^2dr.$$  This leads me to think that what $4\pi r^2dr$ really is, is a good approximation (in fact, a first order Taylor expansion) of the volume between $r$ and $r+dr$, which can furthermore be assumed to be perfectly valid in the limit $dr\to 0$.  Maybe ... I'm just being pedantic?

Let's consider two spheres in the $(x,y,z)$ 3D-space, both centered in the origin: the inner with radius $r$ and the outer with radius $r + dr$.   To compute the volume of the spherical shell between their two surfaces, one should simply proceed as follows:  $$dV = \frac{4}{3} \pi (r + dr)^3 - \frac{4}{3} \pi r^3 = \frac{4}{3} \pi (r^3 + 3 r^2 dr + 3 r dr^2 + dr^3 - r^3)$$  $$dV = \frac{4}{3} \pi (3 r^2 dr + 3 r dr^2 + dr^3)$$  but usually the last two terms between the brackets are neglected. I know $dr$ is infinitesimal, but can infinitesimals (raised to $n$-th power, $n>1$) be neglected and still obtain an exact result? How can this be justified?


I'm quite new to JavaScript and I experiment a lot to get used to it. I trying to write JavaScript function that determinates if the date is from the past or future. It used datepicker form and somehow the if statement isn't working properly because whatever date I select it displays "Date from the future".   function selectDate() {     var d = new Date();     var day = d.getDate();     var month = (d.getMonth() +1);     var year = d.getFullYear();     var x=document.getElementById("dateSelection");  if (month.length < 2) month = '0' + month;     if (day.length < 2) day = '0' + day;  if (d > x) {     document.write("Date from the past" + "
");     document.write("Today is " +day+ "/" +month+ "/" +year+ ""); } else (d < x) {     document.write("Date from the future" + "
");     document.write("Today is " +day+ "/" +month+ "/" +year+ ""); }

Can someone suggest a way to compare the values of two dates greater than, less than, and not in the past using JavaScript? The values will be coming from text boxes.


i have 16.04 installed. i used ubuntu live cd to allocate a new space by dividing root partition.  i put windows 10 usb, did legacy support option and it could see windows instalation.   then i chose my unallocated part from which gparted did in ubuntu live cd  this image shows before this allocation. devsda2 was divided 500 gb and 400 gb. other one is allocated.    but windows did no accept to install that drive.  there were 4 drives. 3 of them were like in the picture.  because it says the disk is gpt. cant do.  "Windows cannot be installed to this disk. The selected disk is of the GPT partition style".    So i make listdisk list part select that partition (it wwas partition 4 there in console but while installing windows screen , there was 3).  i wrote convert mbr inside that prtition but it said cant convert to mbr, only cdroms etc can cause. It was like this. So now i couldnot convert. i cant clean disk because i have ubuntu there.  are thre any ways?

I recently have upgraded my PC, my new Motherboard (ASUS M5A99X EVO) uses UEFi instead of the regular MBR option.  I have a Ubuntu 11.10 installation that I did when I had my previous hardware (MSI MS 7267) , Ubuntu alone boots fine, and so does Windows 7, however Windows 7 is using UEFI (GPT) boot whereas Ubuntu is using MBR.  I have my OSs in separate drives, so that GRUB2 wont' get replaced by the Windows Bootloader and viceversa, as I said both OSs boot fine on their own, but to do that I have to disconnect one drive in this case the Ubuntu drive as it prevents Windows from loading.  Now my question is, How can I change/convert Ubuntu's drive so that instead of using MBR it uses GPT and allow Windows to boot?.   Preferably without reinstalling the whole system or lose any data.  And if I were to wipe the drive, How can I install Ubuntu in GPT, UEFI, whatever it is mode?.  I have used gdisk to convert from MBR to GPT, but now Ubuntu can't boot seems like grub just doesn't start.  I have re installed the OS, and the drive is GPT now by default however grup-pc is still being used instead of grub-efi.  How can i make Ubuntu boot from EFI?.


I came across this , which is kind of asking about books, and has been close voted and put onhold.  I was the last person that voted to close (at that time there was no answer).    First, I thought it was a few seconds lag, but the difference is 1+ minutes.  Not sure whether this is a bug or problem with timezone?

Question:   Answer:   The question was closed at 11:57:57 (according to the hover-over-"x-mins-ago" bar) and the answer was posted at 12:16:35. It's a fairly lengthy answer, so it's possible that it was started to be written before it was closed but I swear I've started to answer a question then I got a banner along the top saying "this question has been closed" and the answer was no longer post-able.


Another question here has already asked , as my level is too low to comment I ask the question in full.  The final step is: "by doing Bird's side missions."  What is the first step of unlocking or triggering these missions?  A note: I didn't put Bird in the question intentionally as it is a spoiler, some people may not want to know the upcoming villains by reading a question and I do not know the policy here on Spoilers.

In Arkham Origins, which I am absolutely loving, I can't find any way to do the classic, and often essential "Disarm and Destroy move".  This is the one where you press X + Y on Xbox, or Square + Triangle on PS3, and you punch a dude, take his weapon (knife, glowstick, shield, gun), and break it. Which means it can't be used again.  It's totally essential to combat, as bad guys become progressively more prepared throughout the game. I can't perform it by default, and there's no unlockable option for it in the Waynetech upgrade screen. I got the Double Special upgrade, which mentions in the description that you can use it with other Specials, but it still doesn't work.  Anyone else having this issue? I feel there's a small change you can't use the ability until the game tells you to i.e. I might play a mission where it will tell me to use the ability, and from there it's unlocked.


This question is different from a previously asked question (linked above) as this golden ratio construction only utilizes two circles and a line, and is thus far simpler than the golden ratio construct in a previously asked question, which uses two squares, a circle, and a line.  Thanks!  Illustrated below, please find a new, extremely simple golden ratio construction with just two identical adjacent circles and a line, wherein the ratio of the red line to the blue line is the golden ratio PHI (1.6180....)   Is there any prior art?  I have been searching long and hard, but cannot find a similar golden ratio construction.    The simple construction is created as follows.   draw two adjacent circles with the same diameter. draw a line from the top of one circle through the center of the second circle. the ratio of line segment h to line segment g (the red segment to the blue segment) will then be exactly PHI or 1.6180....   I've been searching numerous books/online websites/resources for any previous similar constructions.  If you know of any, please do share!  Thanks!  P.S. User @Peter Woolfitt provides a seemingly very nice proof here of a slightly different construction, and any more proofs, either trigonometric or geometric would be weclome!

The below Golden Ratio Construction results in a ratio of PHI (1.6180...) between the blue line and red line, as found in Geogebra.  This seems like a simple construction of the golden ratio, yet so far I have not found anything similar.  If you know of a similar golden ratio construction, please do share!  Thanks!  This Golden Ratio construction is made in the following manner:   Draw two adjacent squares Square1 and Square2. Draw a circle with radii equal to the side of the Square, placed at the  corner of Square2 as drawn below. A line passing through the two opposing corners of the two adjacent squares will then define the golden cut in conjunction with the circle, as shown below.  The ratio of segment t to segment s, (or the blue segment to the red segment), is the golden ratio PHI.     Has anyone come across anything the same or similar?  And of course trigonometric and geometric proofs of the golden ratio construction are always welcome!


As the title suggests, if I have one bed set up in my base, then go adventuring and bring a bed with me, will my spawn change back to the original bed location each time I pick up the bed I just slept in?

In particular this is useful to know when one is exploring. I tend to put a bed down, sleep for the night, and pick it up again before I continue exploring.  In this case, where would I respawn if I died?  Perhaps where the bed was, or the bed I previously slept in, or my original spawn location?


Hi I am travelling from india to canada I have a vaild canada visa  The flight which i booked layover in newyork for 5hrs  Should I take a transit visa ?

In Europe usually you don't need to go through immigration to change planes (unless you are entering/exiting Schengen). Is it the case in the US as well? May I catch a connecting flight on one of the US airports if I don't have US visa?


I am planning a database which has a mini chart of accounts.  My account codes are names like:   CURRENT_DEBTORS CURRENT_CREDITORS CASH_AT_BANK   I am thinking of using the account codes as a primary key in the account database, which would mean it would be a foreign key in a transactions table.  The field would be something like CHAR(20) in MySql.  The transactions table would get about 10,000 entries per month.  How will this long-ish character index affect performance?  I can use a surrogate key if I have too, but would prefer not too.  (I'm not too worried about disk space, of course).

Is there a measurable performance difference between using INT vs. VARCHAR as a primary key in MySQL? I'd like to use VARCHAR as the primary key for reference lists (think US States, Country Codes) and a coworker won't budge on the INT AUTO_INCREMENT as a primary key for all tables.   My argument, as detailed , is that the performance difference between INT and VARCHAR is negligible, since every INT foreign key reference will require a JOIN to make sense of the reference, a VARCHAR key will directly present the information.  So, does anyone have experience with this particular use-case and the performance concerns associated with it?


Can a set that is closed under a binary operation have inverses for all of its elements.. without the existence  of an identity element?  My mind is telling me that in order to even have inverses, there needs to exist an identity element.  I am attempting to prove that the group Axioms 1)associativity 2)identity element 3) exisistance of inverse elements  are independent of each other, meaning you can't have 2 and imply the third one.

Lets view groups as consisting of a binary operation, a distinguished element $e$, and unary operation $x \mapsto x^{-1}$. Then the group axioms can be stated as follows.   $(xy)z=x(yz).$ $xe=ex=x.$ $xx^{-1}=x^{-1}x=e.$   Supposing we dropped axiom 2 and forgot about $e$, we would need to rephrase 3. One possibility would be  3'. $xx^{-1}y=x^{-1}xy=yxx^{-1}=yx^{-1}x=y.$  So my first question is, can 3' be shortened and simplified?  Now suppose we dropped associativity, as well. Then 3' needs to be further rephrased. One possibility would be  3''. $(xx^{-1})y=(x^{-1}x)y=y(xx^{-1})=y(x^{-1}x)=y,$ and $x(x^{-1}y)=x^{-1}(xy)=(yx)x^{-1}=(yx^{-1})x=y.$  Again, my question is, can 3'' be shortened and simplified?


"If you don’t see the Get Windows 10 app on your PC, it might be because:  Your device isn’t up-to-date with at least Windows 7 SP1 or Windows 8.1 Update.  Windows Update is turned off or is not set to received updates automatically.  You’ve blocked or uninstalled the necessary Windows Update functionality.  Your device is not running genuine Windows."  My computer meets all of these criteria, I still do not have the Windoes 10 Icon displayed.

I want to get Windows 10, but I do not see this icon in the notification area (tray):    How do I get the icon to get Windows 10?


I have wondered to my self if I can search on YouTube through Siri (iPhone 6s), when I have tried the "help" with Siri it(she?) showed me how can I use it with Facebook and twitter. My questions are this:        How can I use "help" for a specific app (like "help with YouTube ") and get all the commands I need for the specific app.   Are there any commands in the YouTube app? (like if the YouTube is closed and I want it to be open and search for a specific song)

Could YouTube, Todoist, myEmail (fill in name app your looking for) be controlled/used with Siri?  Could a third party iOS app be controlled by Siri?


Running a sample code with \usepackage{asymptote}, I get asymptote.sty not found. I have installed ProTeXt which installed MikTeX 2.9. Now, to resolve this issue, I installed asypictureb package the definiton given as User-Friendly Integration of Asymptote into LaTeX by MikTeX Package Manager (I couldn't find a package named asymptote). Even after installation and rebuilding the system, I get the same error. What should I do?  The Code:  \documentclass{standalone} \usepackage{asymptote}  \begin{document}  \begin{asy}[width=10cm,height=10cm] import three;  currentprojection=perspective(300,-650,500,center=true);   // define two types of ions surface iona = scale3(20)*unitsphere; surface ionb = scale3(25)*unitsphere;  // surface properties and color of the ions material White = material(diffusepen=gray(0.4),emissivepen=gray(0.6)); material Red = material(diffusepen=red,emissivepen=lightred);  // style of lines connecting ions pen thick=linewidth(2);  for(int x=-1; x<2; ++x) {   for(int y=-1; y<2; ++y) {     for(int z=-1; z<2; ++z) {       draw(shift(100*(x,y,z))*iona,White);     }   } }  for(int x=-1; x<2; ++x) {   for(int y=-1; y<2; ++y) {     for(int z=-1; z<2; ++z) {       if(x<1) draw(100*(x,y,z)--100*(x+1,y,z),thick);       if(y<1) draw(100*(x,y,z)--100*(x,y+1,z),thick);       if(z<1) draw(100*(x,y,z)--100*(x,y,z+1),thick);     }   } }  for(int x=-1; x<2; x+=2) {   for(int y=-1; y<2; y+=2) {     for(int z=-1; z<2; z+=2) {       draw(shift(50*(x,y,z))*ionb,Red);     }   } } \end{asy}  \end{document}

is shipped out with TeX Live, but not with MiKTeX, not even with a full installation.  Do you nonetheless know a way for manual installation? MiKTeX needs to know the path of the sty files, and the Asymptote binary file needs to know the path of the asy scripts. Thought of adding the Asymptote folder to the list of registered root directories in MiKTeX, but MiKTeX complains, that this would be “Not a TDS-compliant root directory”.  There is already a similar question: .


I installed Ubuntu 14.04 LTS in my HP Compaq 6910P notebook. Now I want to use Mac based software, since I can use Windows based software through Wine.  But I do not know how to install and run Mac based application in my Ubuntu 14.04.

Just wondering, are there any projects like WINE, but for Mac software? That is, can we use a program that acts like a compatibility layer to run Mac apps?


I am programming in C and have initialized 2 arrays as shown below:  char names[3][10] = {"foo","ba", "foofoo"}; int values[3] = {1,2,3};   I would like to initialize these in the form:  int foo = 1; int ba = 2; int foofoo = 3;   This would not be a problem if the arrays were small, but I am wondering if there is a particular way in which I could initialize these variable names within a for-loop?

I have a large array in C (not C++ if that makes a difference). I want to initialize all members of the same value.  I could swear I once knew a simple way to do this. I could use memset() in my case, but isn't there a way to do this that is built right into the C syntax?


I tried to add a new Desktop Entry but it failed... I think the reason is the run file type.    Is it possible to make a .desktop entry for a run file?  [Desktop Entry] Version=1.1 Type=Application Name=XAMPP Comment=XAMPP Control Panel Icon=/opt/lampp/htdocs/dashboard/images/xampp-logo.svg Exec=/opt/lampp/manager-linux-x64.run Path=/opt/lampp Actions= Categories=Development;

I am using Ubuntu 18.04. I have installed XAMPP and created a .desktop file to run it.  [Desktop Entry] Type=Application Name=XAMPP Control Panel Version=7.3.0.0 Exec=sudo -i python /opt/lampp/share/xampp-control-panel/xampp-control-panel.py Encoding=UTF-8 Terminal=false Comment=Start and Stop XAMPP Icon=/home/lee/.local/favicon.ico   But, for some reason it won't run. The "Exec" line runs fine on the CL. I have it set to execute. Any ideas?


How to load a background image in my lightning component. Here is my code. **Header.css**     .THIS body{         background-image : url({!URLFOR($Resource.folder,'Images/BG.png')});         background-repeat: no-repeat;         background-position: center center;         background-attachment: fixed;         background-size: cover;      }   It shows an error as follows.

I want to add background image, to part of my header i wrote code like this.  but its not working.   <div style="{!'background:' + v.backgroundColor + ' url(' + v.backgroundImageURL +') no-repeat;background-position: center;background-size: cover;'}">  </div>     doInit : function(component, event, helper) {          var url = $A.get('$Resource.RollingHillsGrey1');         component.set('v.backgroundImageURL', url);     }


To care less would mean the caring is more, having room to care less.

What's the deal with the phrase "could care less"?  Whilst growing up, I've always known people (parents etc) to use the phrase "couldn't care less", but I've also come across people who use the phrase "could care less" to mean the same thing (that is, "I do not care at all about that").  To me "couldn't care less" seems a lot more logical. If I couldn't care less about something, that implies I do not care about it at all. In contrast to this, to my mind the phrase "could care less" seems to indicate "I do care about this to some degree at least", but that's definitely not the meaning intended.  What's going on here? Is my (logical) analysis correct or in error?


Click on the tag "ruby-on-rails" from a job or just go to  and you'll see a lot of jobs (969 for me right now), a lot of them not containing the tag. I think that the results are actually just the search result for the "Ruby on Rails" string, using OR.

This URL specifies a tag search for Go jobs ("tag/go"):    However most of the results aren't tagged "go." (Tags are indicated by blue rectangles.)  Instead, results include jobs that merely refer to the keyword in the body of the post. A tag search should only display careers that are tagged with the search term.  Note that this is true of any term, not just "go," which is admittedly more generic. Searches for "ruby" or "python," for example, reveal the same issue--results that aren't tagged with "ruby" or "python."  A tag search should only search tags, exactly as implied by the URL.


I continously have a sound for something going on, and then going off again half a second later in Windows 10. Looking at the notification icons, I see an icon popping in and out every 5-10 seconds. However, it's so quick I can never tell what it is.  This notification sound goes of continously, all the time my pc is on. I have tried looking through the logs, but not sure where to look. I would assume that something somewhere would show me the log about what the cause of the sound is.  Where can I get a better view of what is going on in my system. What notification icon is coming and going so quickly I cannot determine what it is.

New with Windows 10 seems to be the Notification Area. Now, I've seen a few notifications (in the Action Center). The problem is that I haven't understood any of them (actively using computers for 30 years now), and once I click them they are gone. Is there any way to view these past user notifications so I can try and make some sense out of them?


I have set a Debug Log in my sandbox Org but it did not capturing any logs.  Please advice what it my be the reason for it.

Normally, you can put debug monitoring on a user by name to see the details on the error they're getting (especially for the non-descript Error Loading a Visualforce Page).  But when you are trying to debug a site page, how do you get a debug log for the guest user?  Update  As of Spring '18 Salesforce has dropped the requirement to include the debug_logs cookie to get debug logs for the force.com site requests.     In Winter ’17, we introduced a change that required guest users to set   browser cookies to activate debug logging. We had the best of   intentions: All your public site visitors share one guest user   license. Thus, when you enable logging for the guest user, the   visitors’ collective activities can fill your debug logs quickly,   hitting the log-size limit and causing log truncation. Sadly, people   didn’t like the Winter ’17 change. Setting cookies is complicated, and   the change made collecting debug logs for public users’ asynchronous   activity impossible. We’ve seen the error of our ways. Your public   users no longer need a debug_logs browser cookie to trigger logging.   This change applies to both Lightning Experience and Salesforce   Classic.


I don't know how to show $$ \int_{0}^{\infty} \frac{1}{1 + x^t} \mathop{\mathrm{d}x}=\frac{\pi/t}{\sin(\pi/t)} $$ for $t > 1$. I guess I'm supposed to use properties of gamma function and Euler's reflection formula. (I'm sorry if it turns out to be trivial -- I'm not a math student.)

I have found a proof using complex analysis techniques (contour integral, residue theorem, etc.) that shows $$\int_0^{\infty}\! \frac{\mathbb{d}x}{1+x^n}=\frac{\pi}{n \sin\frac{\pi}{n}}$$ for $n\in \mathbb{N}^+\setminus\{1\}$   I wonder if it is possible by using only real analysis to demonstrate this "innocent" result?  Edit A more general result showing that  $$\int\limits_{0}^{\infty} \frac{x^{a-1}}{1+x^{b}} \ \text{dx} = \frac{\pi}{b \sin(\pi{a}/b)}, \qquad 0 < a <b$$ can be found in


Soo I was thinking about this all night and I think I know how it works but im not sure, for example when i want to have a good pidgeot I should try to catch like a 10Cp Pidgey, so he would basicly be lvl 1 I guess? And when I have this pidgey I should evolve him into a pidgeotto and after that pidgeot, WITHOUT powering him up sooo he would be like 60 CP I guess? since he would get some CP thanks to the evolution.  And when I finally have this "lvl1" pidgeot I should max upgrade him? This way he gets the most powerfull moveset right??

When activating the evolution for a caught Pokemon, it seems to amplify the Combat Power (CP). Thus it seems most beneficial to evolve your Pokemon with the highest CP, if you have multiple of the same kind.   But what I am not sure about is whether it makes an efficiency difference if you spend candies and dust to boost CP before evolving, to gain more from the amplification? Or is it more efficient to just evolve without spending, and then using the leftover candies afterwards, since they now give a bigger CP boost per candy?   I only tested with a Rattata so far, which gained +8 CP per candy before evolving, and +15 CP afterwards. I collected no numbers on the amplification efficiency though, and now ran out of materials for further testing.  Or maybe it is a balanced calculation and makes no difference at all? I would love to have some insight on that.    Some data I collected thus far: (GPC = CP gain per candy)  79 CP Weedle (GPC 6) evolved to: 84 CP Kakuna (GPC 6), evolved at 90 CP to: 297 CP Beedrill    Note: The max-CP "half circle" in the profile stayed filled roughly at the same relative position throughout the evolutions.


How much time would it take for a traveler (in traveler's perspective) to reach a star at distance $d$, if it accelerates at 9.8 m/s² (for a comfortable travel)?  I understand that $V = V_0 + a\times t$ and such related high-school physics, and I know there is something called Lorentz transformations that I can grab the formulae from the Internet, but I can't really put the numbers together to get what I want, so I would also like to know how to derive the answer to the question from the basic equations.  Also, it is not quite clear to me the role of the $E = mc^2$ in this travel, specifically: in travellers perspective, can it accelerates at 9.8 m/s² indefinitely, using always a constant energy output? In other words, would the ship's engine "feel" the ship heavier, or the mass increase effect would only be observable from another frame of reference?

Suppose I wanted to travel to one of the recently discovered potentially Earth-like planets such as Kepler 186f that is 490 light years away. Assuming I had a powerful rocket and enough fuel, how long would it take me?


I want to convert my thesis(pdf) to word, as university requires a softcopy to check plagiarism through Turnitin. I need an app or software which I can trust with my thesis.  Note: I have already tried opening pdf directly in word. It is a mess.

I often have to write up reports based on the analysis of some data. I use R to analyse the data and export tables, figures, and text. This is then included into a LaTeX document either using input or Sweave ().  However, when I collaborate with others, I sometimes need to provide a document in Open Office / MS Word format.  Question:  Thus, assume the simplest scenario   I have a LaTeX document with text, tables, and figures I need to export this reliably into Open Office or MS Word format: this includes mathematical formulas, table formatting, and quality figures) I don't need to go back from MS Word to LaTeX   What is a reliable, efficient, and preferably free process?  Initial Thoughts:   Export to HTML,  LaTeX - LyX - ODF Use odfWeave  that deals with some specific issues associated with LaTeX to Open Office conversion    I was hoping that there is an expert out there who has worked out a good system already.


I need to get image original width for which I'm going to change src attribute, this way:  <input hidden type="file" id="loader" accept="image/*">  $('#m1new').click(function(){     $('#loader').click(); });  $('#loader').change(function(){ var a = this.files[0]; var reader = new FileReader(); reader.onload = function(e) {     var src = e.target.result;     $('#imgt').attr("src", src);     } reader.readAsDataURL(a); var a = $('#imgt').width(); console.log(a); });   Console says - undefined.

I am creating a jQuery plugin.  How do I get the real image width and height with Javascript in Safari?  The following works with Firefox 3, IE7 and Opera 9:  var pic = $("img")  // need to remove these in of case img-element has set width and height pic.removeAttr("width");  pic.removeAttr("height");  var pic_real_width = pic.width(); var pic_real_height = pic.height();   But in Webkit browsers like Safari and Google Chrome values are 0.


Can you set a file association in Internet Explorer to open .doc files in Google docs?   I use a SaaS application with integrated email that only runs on IE and I would like to open file attachments with one click in Google Docs.  I've searched Google extensively and can't find an answer to this question, but I have to believe there is a way to do it.

Is there any way that I could simply double click on a document file and have it open Chrome straight into google docs?


I'm using Popcorn.js and it creates the following HTML code:

Hello

   But now I'm trying to add/remove .myClass to .test using jQuery when the div inside of #row1 is display: inline.  I've tried .height(), .lenght() and .width() (but this one doesn't work, because the width of the div is always 1246px)  Any help would be greatly appreciated!  ** EDIT **  The whole HTML code:

Is it possible to toggle the visibility of an element, using the functions .hide(), .show() or .toggle()?  How would you test if an element is visible or hidden?


I went to Australia last year.  I have gone to Australia in the past year.    I know it is perfectly alright to use past simple for the first sentence.   But why do you use present perfect "have gone" for the second one ?

Both are in the present perfect, but one uses the verb 'to go' and the other 'to be'. Is there a rule for this?  Is there any chance that the differences between "I have been" vs. "I have gone", are differences in English dialect (I don't know if this is the right word).  Edit Could I say that North American English speakers use "I have gone", and maybe U.K speakers say "I've been"? Or vice versa.


I have recieved a Group of shape files with unknown coordinate System. The coordinates are like: 536605 , 5658923 and I can not find the corresponding projection/coordinate System. It looks like that the data has been from dxf to shp converted. I have tried to Change their coordinate to the one I need  (ETRS_1989_UTM_Zone_N32) in Arc Catalog. When I add them to the mxd for the data with coordinate System, still they would have shift and do not place correctly. I tried to change it now in a new mxd to UTM32N and it comes a bit closed but still is in another ocation. what other Options I have to correct this data?  I use ArcGIS 10.5 but the toolboxes of projection and Transformation are not available.

I have a Shapefile but its coordinate system is Unknown, and there is no *.prj file.   How can I identify it now?


I'm trying to convert  tags into  tags in a Shopify store in content that's dynamically loaded through a 3rd party app, meaning the HTML is added after the page finishes loading.  Before I do the conversion, the  tags already have 'click' event listeners added to them through the 3rd party script.  My current code looks like this:  var widgetHTML = $(".cbb-frequently-bought-selector-list").html(); widgetHTML = widgetHTML.replace(/<a /g, '<span ').replace(/<\/a>/g, '</span>'); $('.cbb-frequently-bought-selector-list').html(widgetHTML);   After this code executes, the original 'click' event listeners are gone.  Is there a way to temporarily save a reference to all existing 'click' event listeners on all  tags, then execute the above code, then add the 'click' event listeners back onto the new  tags that replaced the  tags?

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I'm importing a json file in python, but the file is full with accent characters in the city name (from portuguese language) and I need to somehow remove then from this file to further use. For example, the words 'São Paulo', 'Santo André' and 'Foz do Iguaçu' should become in the json: Sao Paulo, Santo Andre and Foz do Iguacu.     { "type": "FeatureCollection", "features": [          { "type": "Feature", "properties": {"id": "1100015", "name": "São Paulo", "description": "Alta Floresta D'Oeste"}, "geometry": { "type": "Polygon", "coordinates": [-62.1820888570, -11.8668597878] }},         { "type": "Feature", "properties": {"id": "1100023", "name": "Santo André", "description": "Ariquemes"}, "geometry": { "type": "Polygon", "coordinates": [-62.5359497334, -9.7318235272] }},         { "type": "Feature", "properties": {"id": "1100031", "name": "Foz do Iguaçu", "description": "Cabixi"}, "geometry": { "type": "Polygon", "coordinates": [-60.3993982597, -13.4558418276] }} }

I have a Unicode string in Python, and I would like to remove all the accents (diacritics). I found on the web an elegant way to do this (in Java):  convert the Unicode string to its long normalized form (with a separate character for letters and diacritics) remove all the characters whose Unicode type is "diacritic".  Do I need to install a library such as pyICU or is this possible with just the Python standard library?  And what about python 3? Important note: I would like to avoid code with an explicit mapping from accented characters to their non-accented counterpart.


I have been trying to track down story I read in a middle school or high school class about a decade ago. It involves a soldier that was sent to "the end of time" in a gigantic battle for the universe. All of the soldiers in the battle get cybernetic enhancements to aid in their fighting ability. That was just the main character's back story. The main part had to do with the soldier coming home or to a comfortable time and trying to live in peace, but he spots a group of soldiers also from the war that start causing trouble in his town and so he fights them to protect the locals.  I appreciate any help. I don't know why but occasionally i think of that story and have tried to track it down a few times, obviously to no avail.

I read this story in an anthology in the eighties or early nineties.  It was about an old man who lived outside a western-like town, though that might have just been how I imagined it.  He goes to town and some ex-military thugs are there causing problems.  Flaunting some odd interdimensional military tech of some sort.  He doesn't want to intervene as doing so would be bad but in the end he must.     By intervening, his military identity is revealed and that causes him (some paradox or causality law) to have to go back and fight the war again.   The war is at the end of time or the universe.  The man is maybe a colonel of the sky something... Not much to go on; I have been searching my collection and wracking my brain for years trying to recall the story.


Can a glyph of warding be set to activate if a creature of a specific humanoid race touches it? For example, could a glyph of warding be set to activate if a changeling touches it, as a way to detect a disguised changeling?

So, say you are a wizard 15/warlock 2. You have the Lance of Lethargy invocation, which pushes an enemy you target with eldritch blast and hit back 10 feet. Say you put a demiplane entrance ~5 feet behind the enemy you target with it. When you hit, you throw the enemy in. Before all this, you had put a Glyph of Warding in there on one of the surfaces. What would be the limit to the trigger for this? Would it be forced to be touch or proximity, or could you base it off something like hostility towards the caster?      ... When you cast this spell, you inscribe a glyph that later unleashes a magical effect ... You decide what triggers the glyph when you cast the spell. For glyphs inscribed on a surface, the most typical triggers include touching or standing on the glyph, ... (PHB 245)   The key word here is "typical". Based on Google's definition, the informal definition of "typical" is     showing the characteristics expected of or popularly associated with a particular person, situation, or thing.   This means, if my assumption is true, that the triggers in the PHB are only the most common ones. Other than the one about being forcibly at maximum 10 feet in diameter in the PHB, I cannot see a limit. Though I probably should assume this would all be DM discretion, (and I know that I sound like a broken record here) but could the trigger be hostility toward the caster, or something else, like being a specific race, gender, from a specific place, etc., or would it be forced to being something from the PHB?


In Stack Overflow, how do I exit the site? If I click "delete" from the user home page my account is deleted. I can't find "sign out". Please tell me.  (I am not leave,just clear cookie,but I can't find "sign out",so I think "Delete" is "sign out",so I have a try but my account is deleted.)

In the previous version the logout button is under your username, which it can be found by clicking the down arrow. However, in the new version, after a couple minutes of searching, it is under the "site-switcher" button:        This is really illogical since the logout button is usually under your username, including Google and Yahoo! services.  I suggest bringing back the  which will definitely benefit new users and even old users.


Recently I built new PC with Ubuntu OS 14.04 (64bit). I noticed the D-Link Wireless N Nano USB Adapter doesn't get detected and installed automatically. The device is properly detected (listed in lsusb) but does not work out of the box  Following are the adapter specifications: •Model No: DWA-131 •Hardware Version : B1  How to install this wireless adapter? Thanks

Can someone help me with this problem ? I am new to Linux, so I do not know commands and I never did something like installing or compiling with command-line.  I bought WiFi adapter from Edimax, model EW-7811UN for my PC (not laptop, so I do not have wifi card, only ethernet). When I go through guide on CD, I came across a version of kernel. It said I need version 2.6, but I have 3.5.0-22-generic.   I got errors like I do not have file or folder etc. Can someone tell me where I can download compiled driver and where I need to put it? Or some other advice. I don't want downgrade kernel when it is not necessary.


I had downloaded feist and installed it just to test the gaming capability of ubuntu, since am new to it.  Now as I can see it works perfectly fine, I am trying to uninstall it. But every time when I try to uninstall this game, I get an error message and it fails. Please help.

I am using Ubuntu 11.10. By using wine software i installed some software like nimbuzz and ibibo messenger. Both the programs are not working and showing the bug as We're sorry, but an unknown error has caused ibibo Messenger to close.  So I wanna uninstall those.   How to uninstall those type of programs which I installed through Wine?


I have lenovo thinkpad T520. Just updated to 13.04. I can see desktop icons, but no menu. I can start terminal, but I cannot close windows, move them or resize them. Also, Alt+Tab does not work. I have tried a few things, such as   but no luck. Please help, I've waisted a whole day on this.  Thanks!

When I login, nothing happens.   I am presented with my desktop wallpaper.    No Dash, no Launcher, nothing.


Armageddon and Deep Impact Dante's Peak and Volcano Wyatt Earp and Tombstone   I'm certain there are more examples, those are just the ones that came right to mind.  But how is that that separate studios will release similar movies in a close time frame to one another?  this is a question that has often caused me some deep thought.

Everybody perhaps knows of Jon Favreau's movie  which is going to be released in 2016. But quite recently I learned (and to my utter surprise) that another Jungle book movie is coming in 2017 and it's called .   Now, this movie has big names too with Christian Bale as Baghera, Benedict Cumberbatch as Sher Khan, Cate Blanchett as Kaa and a young Indian boy in the live action role as Mowgli.   How often does this happen, with two big productions with big cast making a movie on the same subject? I want to ask why this is happening and if there are any really significant differences between the two (apart from the cast, of course).


Since normal contact force between two surfaces depends on molecular interaction between them, then why does its value change with the acceleration of the elevator?

Note: For the purposes of my question, when I refer to free fall assume it takes place in a vacuum.   From my (admittedly weak) understanding of the equivalence principle, falling in a gravitational field is physically indistinguishable from floating in interstellar space. This would make sense to me if gravity simply caused an object to move at a constant velocity. Moving at a constant speed, or floating in space, are just two different ways of describing an inertial frame, and are fundamentally no different. But free falling in a gravitational field means accelerating continuously, and doesn't an accelerating body experience a force? Then isn't free falling fundamentally different from floating in space?


I have created some filters in the  section of StackExchange. Normally, it displays the number of new questions next to the list in a way: my list (23)  However, it does not happen now since few days, even though there are new questions matching the filter. I see this happened some time ago  but not pinging the answerer since he did not connect for two days now and he is "formerly a dev at Stack Exchange :)".

When I was entering Filtered Questions page on the StackExchange, in the Select Filter area I could see the number of new questions related to given filter.  It was very useful to see, if there are any new messages for the given filter.  What has happened to that feature? Is it gone for good or only temporarily?


I'm trying to set the font of PowerShell to be Lucida Console 14, but something strange is happening.  When I launch PowerShell, the font is what I want it to be, but a second later (before the prompt appears) it changes to Raster Fonts 12x16.  I've tried the various font setting suggestions in other answers, but haven't found anything that fixes this.  At the moment, I have a shortcut on my desktop (copied from the start menu).  The Font tab is set up like this:    When I launch PowerShell from that shortcut, it starts up with the correct font, but soon changes.  Once it's changed, if I go into the Properties of the running PowerShell window, the Font tab shows:    On the running window, Defaults still shows the correct font, as set up on the shortcut.  Something appears to be changing the PowerShell font after it opens -- any ideas what it could be?  Added information:  I don't think I have a profile set up:  PS C:\> Test-Path $Profile False   Also, I've noticed that if I manually fix the font, then run chocolatey and install something, the font sometimes changes back to Raster Fonts 12x16.

I have a strange problem on my laptop - when I run Powershell within an existing console window, the font choice for the window changes.  For example, this is cmd.exe immediately after opening the window:   The fonts, window size and colours used are correct - the font is Lucida Console at 16pt.  Then, I run PowerShell and this is the result:    The font has changed to "Raster Font" at 12x16 pixels! Other window properties - colours, row count, column count - are unchanged.  Any idea why it switches?  Note: while researching this - because the Raster Font is horrendously ugly and it bugs me - I have found others reporting problems setting the font for the powershell console window (such as the question ""). Though my problem is different (since I'm starting Powershell from an existing console window, not from the start screen), I suspect a solution for one might help the other.


Does Platform 9 3/4 have some sort of Magical Blood Detection Charm?   For example, let's say that a Muggle saw a Hogwarts student pass through Platform 9 3/4 as though the wall was intangible, what would happen if the Muggle attempted to do the same? Would a charm exist to block them off since they don't have magical genes?  Does the same apply to Squibs? Or since they have wizard genes, but just repressed and not active, they can pass through the Platform?

Suppose someone from "Harry's world" married a Muggle, and they want to escort their child. Can the Muggle parent get through to the Hogwarts platform?


I'm building a currency converter and I've pretty much finished the program. However, I am trying to eliminate redundancy by implementing a function or a define block. I've tried a number of things but it does not seem to be working. My current code is like this: EUR = 0.83  EGY = 16.22  def currency_converter():   money = total_value   new_value = 0   if currency == 1:     new_value = money*EUR_CON     print("Your total is " + "$" + str(money) + " US Dollars  which is " + "e£ " + str(new_value) + " European Euros.")   elif currency == 2:     new_value = money*EGY_CON     print("Your total is " + "$" + str(money) + " US Dollars  which is " + "e£ " + str(new_value) + " Egyptian Pounds.")  I want to essentially make the clause under the if/elif block a function. I've tried doing this: def conversion(EUR_CON,GDP_CON, BRL_CON, EGY_CON, YEN_CON):   new_value = money*conversion()   print("Your total is " + "$" + str(money) + " US Dollars  which is " + str(new_value)+ str(conversion)  if currency == 1:     conversion(EURO_CON)  But it's not working. Can someone help?

I want to write a function in Python that returns different fixed values based on the value of an input index.    In other languages I would use a switch or case statement, but Python does not appear to have a switch statement.  What are the recommended Python solutions in this scenario?


I am doing a specific exercise where the quaternion group is realised as a Galois group of some field extension. It goes like this: let $K = \mathbb Q(\sqrt 2,\sqrt 3)$ and $\alpha = (2 +\sqrt 2)(3 +\sqrt 6)$. I want to show that $\alpha$ is not a square in $K$. I tried to solve equations explicitly to derive some contradiction but I didn't succeed. Any suggestions? Thanks in advance.

Let $E=\mathbb{Q}(\sqrt{2},\sqrt{3})$ and $$ L = E \left( \sqrt{ ( \sqrt{2}+2 ) ( \sqrt{3} + 3)} \right) \ . $$ I want to show that $L/\mathbb{Q}$ is a Galois extension with the Quaternion group as its Galois group.   I know $E/\mathbb{Q}$ is Galois and $L/E$ is also Galois, but it is not true in general that if $K_1/K_0$ is Galois and $K_2/K_1$ is Galois then $K_2/K_0$ is Galois (take $K_0 = \mathbb{Q}$, $K_1 = \mathbb{Q}(\sqrt{2})$ and $K_2 = \mathbb{Q}(\sqrt[4]{2})$ as a counter-example).


I have two lists of two-dimensional arrays. In one list (a), I have arrays of Tkinter entries. In the other (b), I read in the entries using .get(). For some reason, all of the two-dimensional arrays in (b) are overwritten by the last indexed array (read from a). Are separate objects needed to prevent this? Here is my code:  from Tkinter import * import ttk print "\n"  def create_grid(x, y, data=None): # x is rows, y is columns      empty = [None] * x # if coordinates not needed     for i in range(x):         empty[i] = [None] * y       if data == 1: # if coordinates needed, adds in pairs         for i in range(x):             for j in range(y):                 empty[i][j] = [None] * 2        return empty  def process(event):     global a     global b     global c      for i in range(2):         for j in range(2):             for k in range(2):                 b[i][j][k] = a[i][j][k].get()      print b  w = Tk() w.wm_title("test")   a = [create_grid(2,2)] * 2 b = [create_grid(2,2)] * 2   for i in range(2):     for j in range(2):         for k in range(2):             a[i][j][k] = Entry(w)             a[i][j][k].grid(row=(2*i)+j, column=k)  button = Button(w, text="process") button.grid(row=8, column = 0, columnspan = 2) button.bind("<Button-1>", process)   w.mainloop()

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


postCategory column having an arrays like  Array (     [0] => movie news     [1] => breaking news     [2] => political news )      //So please tell me how to select data  <?php  $select_posts = "select *                   from blogposts                   where postCategory = 'political news'                   IN(postCategory)                   order by postId DESC                   LIMIT 1,6";  $run_posts = mysqli_query($con,$select_posts);  while($row=mysqli_fetch_array($run_posts)){      $postId = $row['postId'];      $postTitle = $row['postTitle'];     $postContent = $row['postContent'];     $futureImage = $row['futureImage'];     $postCategory = $row['postCategory'];     $postTags = $row['postTags'];     $postAuthor = $row['postAuthor'];     $postDate = $row['postDate'];   ?>

             <a href="blog-single.php?id=<?php echo $postId; ?>?postTitle=<?php echo str_replace(' ', '-', $postTitle);?>"> <?php echo substr($postTitle,0,60); ?>

 <?php } ?>

I have an array full of random content item ids. I need to run a mysql query (id in the array goes in the WHERE clause), using each ID that's in the array, in the order that they appear in the said array. How would I do this?   This will be an UPDATE query, for each individual ID in the array.


let P$_n$ be the following statement: Every group of n persons that contains at least on male contains only males. What is wrong with the following proof by induction that this statement is true for all n? Certainly P$_1$ is true. Now assume that P$_n$ is true, and take any group of n+! persons containing at least one male. Let G={p$_1$,p$_2$,p$_3$,...p$_n$,p$_n$$_+$$_1$} denote this group, with p$_1$ being known male. The subgroup {p$_1$,p$_2$,p$_3$,...p$_n$} of G must contain only males, by the induction assumption. Furthermore the n-person group {p$_2$,p$_3$,...p$_n$,p$_n$$_+$$_1$}, which we now know contains some males, must also contain only males, again using the induction assumption. Thus G consists of all males; p$_n$$_+$$_1$ follows from p$_n$.  I don't know where to start or anything. Any help or hints would be helpful.

I'm having some trouble with the following problem:   "A french man is trying to prove that any non empty group of french soccer players satisfies the following:  'if the group has at least one player who is better than Messi, then all the members of the group are better than Messi'.  To prove this, the french man uses induction on the number n of members of the set of soccer players. The statement is obvious if n=1. Let's suppose now that the statement is true for sets of k french players. We will use this to prove that the statement is true for every set of k+1 french players. Let {P1, P2,..., Pk+1,} be a set of k+1 french players. Let's suppose that at least one of them is better than Messi. Without losing generality, we can assume that P1 is better than Messi. Let's now consider the sets {P1, P3,..., Pk+1} and {P1, P2,..., Pk} (each one of these sets contains at least a player who is better than Messi).By the induction hypothesis, it follows that all the players of these sets are better than Messi, i.e., P1,P2,...,Pk+1 are better than Messi.   Where is the error in this argument?"  This is my guess:  We have 2 sets of players: {P1, P3,..., Pk+1} and {P1, P2,..., Pk}. I will call the first one S1 and the second one S2. Now, S1 ∪ S2 contains players that are better than Messi. I'm guessing that, somehow, S1 ∩ S2 is empty and, thus, S1 and S2 are disjoint.  Please help me!  Thanks.


in my blender i created a character and his armature with bones assigning with automathic weights to the body, dont ask me hard questions cause im newbie, i got some problems with my character first i tryed to assign evertying to 1 object so i can move the entire object in animation, not working cause i did part of my character without scalling, so when i move all the body the other part stays there, second when i try to move a leg the other leg moves to and it becomes kinda buggy, i already tryed to create the bones again and again but nothing works, and i need to end this really fast if i can get some help i put the file in upload and send the link here    Here is the blend file that i uploaded in the website

Let's say I'm really new to Blender, and have just barely figured out what keyframes are for. Explain a Blender skeleton to me like I'm five. Do I need to use it, and how exactly does it connect to the rest of the model?


I have been trying to create an array of a class containing two values, but when I try to apply a value to the array I get a NullPointerException.  public class ResultList {     public String name;     public Object value; }     public class Test {     public static void main(String[] args){         ResultList[] boll = new ResultList[5];         boll[0].name = "iiii";     } }   Why am I getting this exception and how can I fix it?

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


I'm wondering how I could record the screen of my iPhone without jailbreaking? Are there any Apps that will do this? I know how to take a screen shot but I don't know how to record video.

OS X Yosemite brought support for recording iPhone/iPad screen natively without having to using AirPlay applications like AirServer or Reflector.   How do I record the iPhone screen on macOS ?


I'm recieving data using an OSC server and the data looks like this:  b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xbbP\x128\xe6/\xd4\x00\x00\x00\x00\x00\x00\x00\x00' b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xbbOw\x8f\xa7\xac\x10\x00\x00\x00\x00\x00\x00\x00\x00' b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xbb\x10\x1f\xf2JN\xed\x00\x00\x00\x00\x00\x00\x00\x00' b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xbah[\nY\xe9K\x00\x00\x00\x00\x00\x00\x00\x00' b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xb8\x8f\x97\xb1\x04\xc4B\x00\x00\x00\x00\x00\x00\x00\x00'   The data title is: Person0/elements/alpha_absolute and the arguments is: dddd (4 floats)  The rest seems to be encoded. I don't understand how to get the 4 floats I'm supposed to recieve  This is my whole code:  import socket  print('Program Initiated') UDP_IP = "127.0.0.1" UDP_PORT = 6000  sock = socket.socket(socket.AF_INET,  # Internet                  socket.SOCK_DGRAM)  # UDP sock.bind((UDP_IP, UDP_PORT))  while True:     data, addr = sock.recvfrom(2048)  # buffer size is 1024 bytes  if 'alpha' in str(data):     print(data)

I received some text that is encoded, but I don't know what charset was used. Is there a way to determine the encoding of a text file using Python?  deals with C#.


I have an object Timecard ( pse__Timecard_Header__c ) inside which there is a field called Period__c. I have another object Period (c2g__codaPeriod__c).  In system.assertEquals I want to compare these two things the field (Period__c) from Timecard and ID of period   pse__Timecard_Header__c th1 = new pse__Timecard_Header__c(             CurrencyIsoCode         = 'USD',             pse__Project__c         = project.ID,             pse__Resource__c        = pmResource.Id,             pse__Monday_Hours__c    = 8,             pse__Tuesday_Hours__c   = 8,             pse__Wednesday_Hours__c = 8,             pse__Thursday_Hours__c  = 8,             pse__Friday_Hours__c    = 8,             pse__Start_Date__c      = Date.today().toStartOfWeek(),             pse__End_Date__c        = Date.today().toStartOfWeek()+6         );   insert th1;            System.runAs(pmUser) {         delete th1;         system.assert([select ID from pse__Timecard_Header__c WHERE Id = :th1.Id ].IsEmpty());                               }         system.assertEquals(th1.Period__c, c2g__codaPeriod__c.Id);   This is giving me error Comparison arguments must be compatible types: Id, Schema.SObjectField. Also I would like to know whether I can use system.assert and system.assertEquals both.


If I have a program written in C, how can I run this program in a terminal with just a single word (the program's name), no matter where it is on the system?

How do I add a directory to the $PATH in Ubuntu and make the changes permanent?


Prove that for $n>1$,the non-bounded function $u=\ln\ln\left(1+\frac{1}{|x|}\right)\in W^{1,n}(\Omega)$,Here $\Omega=B(0,1)\subset \mathbb{R}^{n}$  I think we have to prove that $$ \int_{B(0,1)}\left|\ln\ln\left(1+\frac{1}{|x|}\right)\right|^{n} dx<\infty,$$  and  $$ \int_{B(0,1)}\left|D\ln\ln\left(1+\frac{1}{|x|}\right)\right|^{n} dx<\infty,$$ but it hard for me to compute these integrates.

The entire problem statement is:  Let $n>1$ and let $U=B(0,1)\subset\mathbb{R}^n$. Show that $u:U\to\mathbb{R}$ given by  $$u(x)=\ln\left(\ln\left(1+\frac{1}{|x|}\right)\right)$$ is in $W^{1,n}(U).$  My attempt at the proof is as follows:  To show that $u\in W^{1,n}(U)$ it suffices to show that $|Du|\in L^{n}(U)$. Consider $$u_{x_i}=\frac{1}{\ln\left(1+\frac{1}{|x|}\right)}\frac{1}{1+\frac{1}{|x|}}|x|^{-2}\frac{x_i}{|x|},$$ which simplifies to, $$u_{x_i}=\frac{1}{\ln\left(1+\frac{1}{|x|}\right)}\frac{1}{1+\frac{1}{|x|}}\frac{x_i}{|x|^3}.$$ Thus, $$|Du|=\frac{1}{\ln\left(1+\frac{1}{|x|}\right)}\frac{1}{1+\frac{1}{|x|}}\frac{1}{|x|^2}$$ which can be manipulated to, $$|Du|=\frac{1}{\ln\left(1+\frac{1}{|x|}\right)}\frac{1}{1+|x|}\frac{1}{|x|}.$$  Moreover, since $U=B(0,1)$ we can bound the second term from above which gives, $$|Du|\leq\frac{1}{\ln\left(1+\frac{1}{|x|}\right)}\frac{1}{|x|}$$  Thus, we can instead show that $$\int_U\left(\frac{1}{\ln\left(1+\frac{1}{|x|}\right)}\frac{1}{|x|}\right)^n<\infty.$$  Converting this into polar coordinates we have with $r=|x|$, $$\int_0^R\int_{\partial B(0,r)}\left(\frac{1}{\ln\left(1+\frac{1}{r}\right)}\frac{1}{r}\right)^n\,dSdr=\int_0^R\left(\frac{1}{\ln\left(1+\frac{1}{r}\right)}\frac{1}{r}\right)^n\int_{\partial B(0,r)}dSdr$$ Note that $\int_{\partial B(0,r)}\,dS=n\alpha(n)r^{n-1}$, which is the surface area of $B(0,r)$. Thus, we have then $$n\alpha(n)\int_0^R\left(\frac{1}{\ln\left(1+\frac{1}{r}\right)}\frac{1}{r}\right)^nr^{n-1}\,dr=n\alpha(n)\int_0^R\left(\frac{1}{\ln\left(1+\frac{1}{r}\right)}\right)^n\frac{1}{r}\,dr$$  And so this is where I get stuck in the problem, since I don't how I can evaluate that last integral to show it's finite.  Thank you for any help or feedback!


How do I login to Gamecenter without my password

A long time ago, I made a game center account to which I attached my CoC village. This account hasn't been used anymore, and I have forgotten the ID and the password.  Now I want to transfer that game to my new phone which has a new game center ID, but need a transfer code from the old account to do so. Is there a way to recover my old game center account details?


I've been trying to solve this linear algebra problem for some time and have gotten stuck.  I've been asked to either prove or disprove the following statement: For $V$ an $\mathbb{ R } $ vector space, if $A$ is a matrix with the property that $Ax \in \langle x \rangle = \{ax \mid a \in \mathbb{ R } \} $ for every vector $x \in V$, then $A$ is square and diagonal.  I suspect the statement to be true due to lack of counterexamples.  I can pretty easily show that $A$ must be square, otherwise the dimensionality doesn't work out right.  I haven't really got much of an idea where to go on the diagonal part though.  My great apologies if this is a duplicate question-I searched somewhat thoroughly and didn't find it anywhere, however.  Thanks in advance! From the linear transformation view point, for every $x \in V$ there is an $a \in \mathbb{ R } $ such that $T(x) = ax$.  We have the expression $$x = c_1 e_1 + \ldots +c_n e_n$$  where $e_i$ is the ith standard basis vector for $V$.  Therefore, $$ ax = T (c_1 e_1 + \ldots +c_n e_n)  $$ whereby $$ a\left( \sum_{i=1} ^n c_i e_i \right) = \sum_{i=1} ^n c_i T (e_i)  $$ Therefore,  $$  \begin{pmatrix}     a c_1 \\     \vdots\\     0   \end{pmatrix} + \ldots +    \begin{pmatrix}   0 \\    \vdots \\    a c_n   \end{pmatrix} = c_1 \begin{pmatrix} a_{1,1} \\ \vdots \\ a_{1,n} \end{pmatrix} + \ldots + c_n \begin{pmatrix} a_{n,1} \\ \vdots \\ a_{n,n} \end{pmatrix}   $$   where the matrix representation of $T$ is the matrix $A = \left[ a_{i,j} \right]$, $1 \le i, j \le n$.  From here I'm having some difficulty once more.  Does this in fact give that $a_{i,j} = 0$ for $i \ne j$?  I'm having difficulty seeing how.

Let $T: V \rightarrow V$ be a linear operator.  I need to demonstrate that if all nonzero vectors of $V$ are eigenvectors of $T$, then there is one specific $\lambda \in K$ such that $T(v) = \lambda v$, for all $v \in V$.  I understand that, if all nonzero vectors of $V$ are eigenvectors of $T$, then $T$ must be a scaling transformation. It just stretch or shrinks vectors, but doesn't change their  directions.  So, the statement says that if it happens, then, there is a single $\lambda$ such that $T(v) = \lambda v$. In other words, if there is such transformation, then it scales all vectors by the same scalar $\lambda$.  Applying the transformation to our standard basis vectors, we have: $$ T(e_1) = \lambda_1 e_1 \\ T(e_2) = \lambda_2 e_2 \\ \vdots \\ T(e_n) = \lambda_n e_n $$  I understand I need to prove that $\lambda_1 = \lambda_2 = \dots = \lambda_n$, but I can't see how!  EDIT  $$ v = c_1e_1 + c_2e_2 + \dots + c_ne_n \\ T(v) = \mu v = \lambda_1c_1e_1 + \lambda_2c_2e_2 + \dots + \lambda_nc_ne_n \\ $$  Since what's multiplying $v$ coordinates is $\lambda_i$, then all of them must be $\mu$. I'm not sure how to 'mathematize' this. Is this idea correct?  EDIT 2 Extending the left hand side of EDIT 1, we have: $$ \mu v = \lambda_1c_1e_1 + \dots + \lambda_nc_ne_n \\ \mu(c_1e_1 + \dots + c_ne_n) = \lambda_1c_1e_1 + \dots + \lambda_nc_ne_n \\ \mu c_1e_1 + \dots + \mu c_ne_n = \lambda_1c_1e_1 + \dots + \lambda_nc_ne_n \\ $$  And since $e_i$ are linearly independent, $\mu = \lambda_1 = \lambda_2 = \dots = \lambda_n$. Is this proof correct?


This question seems to be a close parallel of , but it's about a different design by a different author.  I read a  about a "helical engine" design by NASA engineer David Burns. The design allegedly exploits relativistic effects to seemingly violate conservation of momentum (as in the earlier question). It involves an oscillating mass which travels faster in one direction than the other, thus having higher relativistic mass on one side and imparting unbalanced momentum to its container.     But, Burns asks, what if the ring’s mass is much greater when it slides in one direction than the other? Then it would give the box a greater kick at one end than the other. Action would exceed reaction and the box would accelerate forwards (see video below).   Read more:   Now, I'm not a physicist, but I'm just smart enough to have gotten the sense that this is almost certainly nonsense. As soon as I read "may violate the laws of physics" in the headline, in fact. Is it nonsense, and if so, what is unaccounted for in this model that would balance the momentum transfer at each side of each oscillation? How does the math play out?

The  is a proposed propulsion mechanism for spacecraft in which some form of microwave device provides the propulsion. The consensus from the physics community, including many voices on this site, is that the proposed device would violate conservation of momentum.   Several experiments have been conducted, by three main groups: (i) , from Satellite Propulsion Research Ltd, (ii) a research group at the Northwestern Polytechnical University in Xi'an, China, and (iii) Eagleworks Laboratories at NASA's Lyndon B. Johnson Space Center in Houston, Texas. However, few of these experiments have been performed in vacuum (and none of the vacuum tests has been published in a peer-reviewed journal), which means the effect of air currents around the device cannot be ruled out.  This device has been the subject of many questions on this site, including          and their many closed duplicates.  Many of these questions ask what the proposed explanations are, but then veer off into territory of the form "assuming it is true, how does it work?", so they have been (rightfully) closed as counterfactual physics. I feel this sort of bundling does a lot of harm to the discussion, and there is some scope to ask what exactly is being proposed as an explanation. So:     What do the proponents of EmDrive claim is the theoretical justification of the device's function?   Please limit answers exclusively to references, and indicate whether they are peer-reviewed or not. Please limit answers to serious attempts at explanations, as opposed to vague claims about the 'quantum vacuum' - or indicate if an experimental paper does not have any such theoretical explanation or reference.  To be clear, this is not the place to discuss whether the explanations are correct or not. If you have specific questions about any of these sources, ask it separately. (However, if your question starts with "assuming that this works", be prepared for it to be closed.) If you feel there are not enough resources on this thread, you can  but please do not post another question asking people to look for more references.


I am not a native English speaker, but I am interested in learning a certain grammar rule. I did come across many sentences where the subject and the verb switched their positions.  For example, I can say that I don't like apples nor does my friend. Here, the modal verb does comes before the subject my friend.  Another example: not only is he a great person, but he is humble.  What is this rule and when is it appropriate to use it?

I have seen this construction quite often:      Online ads have been around since the dawn of the Web, but only in   recent years have they become the rapturous life dream of Silicon   Valley.   What is the rule there?. When your sentence doesn't start with pronoun + verb, invert them as verb + pronoun?. I know it sounds awkward but is it possible (grammatically correct) to use something similar to:      Online ads have been around since the dawn of the Web, but only in   recent years they have become...   And in any case, does this only work with have (or has)? Maybe it works fine with 'had' but I can't think of an example right now.


I want to close slide panel after click outside it or on X button inside, I have working code but there is one issue, if inside panel there is any element with class or ID after click on it panel also is closed. Here is my fiddle  and my code:   const open = document.getElementById("open") const slide = document.getElementById("slide") const close = document.getElementById("close")  open.onclick = function() {     slide.classList.toggle("active") }  document.onclick = function(e) {     if(e.target.id !== "slide" && e.target.id !== "open") {         slide.classList.remove("active")     } } .main {   max-width:600px;   overflow:hidden; } #slide {   position:absolute;   top:0;   right:0;   width:400px;   height:100vh;   transform: translateX(100%);   border: 1px solid; } #slide.active {   transform: translateX(0); }
   Click to open

X
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I have some HTML menus, which I show completely when a user clicks on the head of these menus. I would like to hide these elements when the user clicks outside the menus' area.  Is something like this possible with jQuery?  $("#menuscontainer").clickOutsideThisElement(function() {     // Hide the menus });


So, I'm tracking a video, then applying a vide on top using "Motion Tracking" and "Compositing" in Blender. My video's colors always came out a bit "whiter" and "higher contrast" than the original, so I fiddled around with the color values and found out that setting the source video's settings to "Raw" (In "Footage Settings" -> "Color Space") fixed it! However, now, when I try the same thing, it won't work anymore. In the "Tracking" panel, changing the settings to "Raw" fixes the colors, but if I go into "Compositing" and do the input color (in the "image" node) to "Raw", the video turns much whiter and brighter than it should be. (Changing it to sRGB turns it darker, but still too white compared to the original footage.) I currently have this node setup (see below), but the video footage is the same color even if I connect the "Image" node to "Composite" and "Viewer" directly.  And THIS is how the image looks in the "Tracking" panel, and how it originally looks:  How can I fix this? What causes the video to get whiter than it should be? Thanks for the help!

I already searched the internet but could not find a solution to this. Maybe it is the same question as  but there was no answer.  I want to render a video with tracking, but the output "loses" color information and gets kind of greyish. I first thought that it is related to the renderer, but it happens in Cycles and Eevee. Therefore i made a sample image, added it to the image sequence editor and rendered it as 1 frame. Resulting in the same problem.  I placed the original image beside blenders output so that you can see the difference. The only idea I came up with is that something with the lighting is not correct but I can't find a setting for that.  I am using Blender 2.80 with the default settings. Only set the output resolution to match the input resolution.