I have an object with a method, destroy:  let object = {     destroy() {         handleDestroy.call(null, this);     } }  function handleDestroy(obj) {     obj = null; }   I know that technically the object is not destroyed even if it did work, but I am wondering why I can't reassign objects to null or other types of objects this way? When I call handleDestroy with the object as a parameter, or if I invoke the destroy method, object remains unchanged.

The primitive types (number, string, etc.) are passed by value, but objects are unknown, because they can be both passed-by-value (in case we consider that a variable holding an object is in fact a reference to the object) and passed-by-reference (when we consider that the variable to the object holds the object itself).  Although it doesn't really matter at the end, I want to know what is the correct way to present the arguments passing conventions. Is there an excerpt from JavaScript specification, which defines what should be the semantics regarding this?


We have enabled "Long Paths" GPO for all our servers and clients on the network. Yet when copying files from network to local drive or from one share to another we constantly get failed files due to "File names too long"  Is there still a 256 Character limit even when long paths are enabled? how do I get around this issue?

I updated to the Windows 10 home anniversary edition version 1607 and set LongPathsEnabled to 1 with regedit.exe but the File Explorer doesn't seem to work with long paths still. If you select a long path file and try to rename it, no option will be available. I restarted the computer after making the changes and update.   Is there any way to enable renaming in the File Explorer in the new updated version? Did I miss a step somewhere?


I am not sure how I would express these sets as a difference. My original attempt was to show that it is the set $[a,d]$ and take away the universal set. I would appreciate any help. Thank you in advance.

So if $a < b < c < d$ , how do I express the set $[a,b] \cup [c,d]$ as the difference of two intervals? Is it as simple as $[a,d] -[b,c]$?


Trying to create a BST that sorts Fractions.  The treenode class  public class TreeNode<E> { protected E element; protected TreeNode<E> left; protected TreeNode<E> right; public TreeNode(E e){     element = e; } }   The fractions class...      import java.util.ArrayList; import java.util.Stack;  public class Fractions { private String fractionS; private ArrayList<String> tokenArray; public Fractions(String s){     this.fractionS = s; }  public String toString(){      return fractionS;  }  public String extractNumber(int n, String s){     String num = new String ();     char c;     for (int i = n; i<s.length(); i++){         c = s.charAt(i);         if (c >= '0' && c <= '9'){             num+=String.valueOf(c);         }else{             break;         }     }     return num; }  public Double getNumbers(){     char c;     Stack<String> numStack = new Stack<String>();     for (int i = 0; i<this.fractionS.length(); i++){         c = this.fractionS.charAt(i);         if (c >= '0' && c<= '9'){             numStack.push(extractNumber(i, this.fractionS));             i += numStack.peek().length()-1;         }     }     Double denominator = Double.parseDouble(numStack.pop());     Double numerator = Double.parseDouble(numStack.pop());     Double solution = numerator/denominator;     return solution; }   public int compareTo(Fractions f) {     Double d1 = this.getNumbers();     Double d2 = f.getNumbers();     if (d1<=d2){         return 1;     }else{     return 0;     } }   I get a NullPointerException on the call for compareTo method. Just trying to figure out the NullPointerException. I can do the rest myself. This is for a class, and I don't want to get in trouble.  Including the instantiating of fractions...  I also made changes to fractions class.  public void createTree(){ tokenizer(); Stack<String> numbers = new Stack<String>(); int count = 0; for (int i = 0; i<tokenArray.size(); i++){     char c = tokenArray.get(i).charAt(0);     if (c == '/'){         count+= 1;     }else if (c >= '0' && c <= '9'){         numbers.push(tokenArray.get(i));     } } for (int i = 0; i <count; i++){     String denominator = numbers.pop();     String numerator = numbers.pop();     insert(new Fractions(numerator + "/" + denominator)); }

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?


Water goes up in plants by cappilary action. So that should also explain water inside coconuts.  My doubt relates to the easy experiment of transfering water from a filled glass to an empty one using some chord or even a toilet paper pressed as a chord.   Even if the paper is initially dry, water is gradually transferred until levels are equal at both glasses.  But it is not possible (at least I couldn't make happen) to transfer any drop of water to an empty glass whose bottom is above the water level of the filled glass.  So how is it possible for a coconut? Maybe its internal pressure is below atmospheric?  I know there are other similar questions, but the answers tends to follow the capillarity action (what is obvious to me, but seems incomplete), or postulates great negative pressures. (But if it is 1 atm outside, at most it should be zero inside, and a perfect vaccum inside plants is too strange).  But there is maybe some combined effect of capillarity and negative pressure that is not well discussed so far.

Which force actually drives water so high up, since pure atmospheric pressure will only get you up to about 10 meters if you're using suction and a long straw and yet tallest trees are over 100 meters ( trees do basically have long continuous 'straws' all the way up.)


I am choosing between two models of servers, the major difference between them being the the availability of Hyper-Threading.  Servers in question are SYS-E32-1 and SYS-E32-3  (an  brand) and use either Intel Xeon  or , both  ( Core-i Xeon CPU):   SYS-E32-1:       4c / 4t 3.2 GHz+ SYS-E32-3:       4c / 8t 3.4 GHz+   The big difference between them is that the first has 4 core/4 threads configuration, while the latter has 4 core/8 threads, due to Hyper-Threading being enabled.  I am going to run CentOS 6 and other OS guests on a CentOS 6 host with KVM virtualization. Currently I assign 1 virtual CPU per virtual machine, as that's enough for my current loads. Our normal load is the usual web services.  How much should the performance differ for me? Is it close to having twice more computing power or nearly the same computing power, distributed over twice more cores?

This is a  about  Related:      I have a question regarding capacity planning. Can the Server Fault community please help with the following:   What kind of server do I need to handle some number of users? How many users can a server with some specifications handle? Will some server configuration be fast enough for my use case? I'm building a social networking site: what kind of hardware do I need? How much bandwidth do I need for some project? How much bandwidth will some number of users use in some application?


I have recently started renting an Ubuntu VPS from OVH. I have configured it as an iRedMail instance, planning on using it to send and receive personal emails. This all went smoothly, and the mail is indeed sent and received properly.  My problem is that a few popular email providers like gmail and outlook mark the (personal / non-commercial) email sent from this domain as spam. Therefore, I went through the classic checklist for this kind of problems :   IP address isn't blacklisted on any spam list at all All DNS records are setup correctly, including DKIM, SPF and DMARC The content of the emails doesn't look like spam (all classic personal messages)   I ran through spam tests, here are the results from  (last was 10/10, I did another one not to use my personal email) and . Nothing out of the ordinary, everything seems perfect except "Bayes spam probability is 99 to 100%", could this cause the mails being put into spam ? I have literally no idea why this probability is so high, my mail server isn't an open relay, I don't have any proxy server open, and my VPS provider blocks SMTP port if it detects outgoing spam.  Does anyone have an idea of what might cause my problem ?  Thanks !  PS : There are obviously other posts like mine, but I've already checked them and none of them provide an answer to my case.

This is a  about avoiding outgoing mail being classified as spam.   Also related:                    I'm wondering how to prevent my emails from my site being marked as spam? I'm using sendmail.  I'm trying to send emails through my ruby-on-rails application. The mails are all written in swedish (if that does make a difference?). I don't know why they keep getting marked as spam.  Are there any things that I can do to minimize the risk?


I am Trying to configure unreal engine on Ubuntu 18.04, And When I run ./Setup.sh, I got the error of a package that have unmet dependencies: The following packages have unmet dependencies:  libmono-system-web-extensions4.0-cil : Depends: libmono-system-drawing4.0-cil (>= 3.0.6) but it is not going to be installed Depends: libmono-system-servicemodel4.0a-cil (>= 3.2.3) but it is not going to be installed Depends: libmono-system-web-services4.0-cil (>= 1.0) but it is not going to be installed Depends: libmono-system-web4.0-cil (>= 2.10.3) but it is not going to be installed E: Unable to correct problems, you have held broken packages.   How can I solve this ?  This is what I got running apt-cache policy:  libmono-system-web-extensions4.0-cil: Installed: (none)  Candidate: 5.14.0.177-0xamarin3+ubuntu1604b1  Version table: 5.14.0.177-0xamarin3+ubuntu1604b1 500 500 https://download.mono-project.com/repo/ubuntu stable-xenial/main amd64 Packages  500 https://download.mono-project.com/repo/ubuntu stable-xenial/main i386 Packages

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


[root@CentOS-72-64-minimal ~]# df -h Filesystem      Size  Used Avail Use% Mounted on /dev/md2        204G  202G     0 100% / devtmpfs         16G     0   16G   0% /dev tmpfs            16G     0   16G   0% /dev/shm tmpfs            16G  1.6G   14G  10% /run tmpfs            16G     0   16G   0% /sys/fs/cgroup /dev/md1        488M  186M  277M  41% /boot tmpfs           3.2G     0  3.2G   0% /run/user/0    [root@CentOS-72-64-minimal ~]# du -sch /* 0       /bin 183M    /boot 0       /dev 22M     /etc 836K    /home 4.0K    /installimage.conf 12K     /installimage.debug 0       /lib 0       /lib64 16K     /lost+found 4.0K    /media 4.0K    /mnt 4.0K    /opt 0       /proc 244M    /root 1.6G    /run 0       /sbin 4.0K    /srv 0       /sys 32K     /tmp 2.6G    /usr 6.1G    /var 11G     total  [root@CentOS-72-64-minimal ~]# df -i Filesystem       Inodes  IUsed    IFree IUse% Mounted on /dev/md2       13565952 803442 12762510    6% / devtmpfs        4057932    443  4057489    1% /dev tmpfs           4063363      1  4063362    1% /dev/shm tmpfs           4063363    559  4062804    1% /run tmpfs           4063363     13  4063350    1% /sys/fs/cgroup /dev/md1         131072    344   130728    1% /boot tmpfs           4063363      1  4063362    1% /run/user/0   please help me  thanks

I have a SCSI disk in a server (hardware Raid 1), 32G, ext3 filesytem. df tells me that the disk is 100% full. If I delete 1G this is correctly shown.  However, if I run a du -h -x / then du tells me that only 12G are used (I use -x because of some Samba mounts).  So my question is not about subtle differences between the du and df commands but about how I can find out what causes this huge difference?  I rebooted the machine for a fsck that went w/out errors. Should I run badblocks? lsof shows me no open deleted files, lost+found is empty and there is no obvious warn/err/fail statement in the messages file.  Feel free to ask for further details of the setup.


I've tried logging in on the accounts page and after clicking install in the app store. I've checked/changed time settings. I have this problem with both OTA 10.1 and the rc channel.

For some reason whenever I try to update or install an app via the store, Ubuntu Touch keeps asking for my Ubuntu One account, but logging in doesn't work. What can I do?


When I compile this code in eclipse ,it throws a NullPointerException,but the code in the book is written in this way.Here is this code.   InputStream in = ClassLoader             .getSystemResourceAsStream("javagames/filesandres/Test1.txt");  try {             InputStreamReader reader =new InputStreamReader(in);             BufferedReader buf = new BufferedReader(reader);             String line = null;             while ((line = buf.readLine()) != null) {                 System.out.println(line);             }         } catch (IOException e) {             e.printStackTrace();         } finally {             try {                 in.close();             } catch (Exception e) {             }         }     }


When I refer to TI's reference design for the charging chip I do not see those capacitors. Upon researching I found out that they are smoothing capacitors. Why are they used here and are they really necessary for the circuit to work and what would be the consequences if I remove them ?

What's the purpose of the two capacitors in parallel on each side of the regulator in      I've seen similar setups in other similar circuits and can guess that it's related to one being polarized an one not, but I don't really understand what's going on there.


$A=\begin{pmatrix} 2&0&0\\ 1&3&0\\ -3&5&3 \end{pmatrix}.$  I can find the characteristic polynomial $C_a(A)= -A^3 + 8A^2-21A+18$.  How to continue from here to use the Cayley-Hamilton theorem to find the inverse matrix, $A^{-1}$?

Find the inverse of the matrix $$\begin{pmatrix} -1 & 2& 0 \\ 1& 1 &0 \\ 2 & -1& 2 \end{pmatrix}$$ using the Cayley–Hamilton theorem.  Thanks!


In the new snapshot of Minecraft (13w36b) there is a button in the options menu labeled "Super Secret Settings". When I clicked this button, an Enderman-ish sound played. Does it do anything or is it just a sound?

In the new snapshot of minecraft (13w36b) there is a super secret setting in the options menu. when hitting the button an enderman-ish sounds play. Does it do anything or is it just a sound?


I've been asked to do a small animation for a multi story ice cream store. I want to have a steel background texture with a transparent image of an ice cream on just the front face of the elevator door. Most solutions I've read through mention unwrapping the face, but that gives me the following message:  "Object has non-uniform scale, unwrap will operate on a non-scaled version of the mesh". The transparent image also applies itself to all faces of the door.    This is what I have. And this is what I want. How do I go about doing this?  Thanks in advance,  Joe

I'm designing this animal-type creature, and want to add a transparent .png image to its face with the face features (object has a subsurf). On the left is the image with the features, on the right is the part of the object where I want it to be.    I tried to import the image as a plane, but matching the shape of the plane with the face didn't work, and the lines of the face left shadows on the head, and could be seen as a different object from some angles (although it's the closest I've gotten yet). It looked like this:    So , I tried selecting the faces of the head that the features should go over, and create a new material for it. Unfortunately, since the .png is transparent, the result produced was this:    (where it's impossible to tell the transparency from a black background default color, and where I wouldn't know where to start to adjust size and position).  I also tried UV mapping, but then the whole object became black with the features repeated all over.   Is it something I have to go into Nodes for? I'm kind of stuck here. Creating a new material and applying it is simple, but applying a material that is an image is a bit more complex it seems... Ideally, I would reproduce the same technique for the adhesive bandage on its arm (seen on the right of image 1).


Let's consider the real numbers as a $\mathbb{Q}$-linear space and denote it by $\mathbb{R}_{\mathbb{Q}}$. It was proved  that $\dim  \mathbb{R}_{\mathbb{Q}} > \aleph_0$. I suspect that the dimension is actually $\mathfrak c$. But how could we prove it's really $\mathfrak c$ ?

It would seem that one way of proving this would be to show the existence of non-algebraic numbers. Is there a simpler way to show this?


I don't know much about how apk and apps in android work. Title says it all. In my specific case, I installed icon packs from a playstore app to be used along with Nova Launcher. Now I want to get rid of the app that provided the icons pack (it is occupying space). I disabled it with pm disble .. command. And the icons aren't gone. So, I guess, I'd be fine if I delted the app as well. but I am not sure.   So, does uninstalling an app does more messing with the system than uninstalling it does?

One of the main advantage of rooting is removing bloatware [I guess]. Is removing unwanted brand-based or operator-based app any different from disabling it from All Application in Settings? I don't find any improvement in memory too since these apps were pre-loaded in OS and you can't use those space any way.


Let $A$ a $n\times n$ invertible at left. In fact, I just want to prove that it's invertible at right (the rest is obvious). All what I can say is that there is a $B$ s.t. $BA=I.$ To prova $AB=I$, I have problem. I have that $$AB=AB^2A=BA^2B,$$ but I can't conclude that it's $I$.

If $A$ and $B$ are square matrices such that $AB = I$, where $I$ is the identity matrix, show that $BA = I$.    I do not understand anything more than the following.   Elementary row operations. Linear dependence. Row reduced forms and their relations with the original matrix.   If the entries of the matrix are not from a mathematical structure which supports commutativity, what can we say about this problem?  P.S.: Please avoid using the transpose and/or inverse of a matrix.


I see a lot of questions in this topic, but most answers are at least 4-5 years old. I wonder if there is a more current solution that would allow me to gain a graph network from the OSM highways data.   Simplicity is key.   Previous discussions:

I spent days looking in all questions here and trying tutorials. I need to build a graph for a region (It will be my input in simulation) I downloaded Postgresql and Postgis and osm2pgsql. Now i can load .osm files into a database. I want to have a complete database with roads ids so i can generate a table of edges and nodes then build my graph  nodes = intersections and edges = roads for a city using python.  Please any detailed help with steps.I saw a lot of keywords (Postgresql/postgis, Networkx, QGIS ..) but i couldn't manage to assemble a good tutorial  I am a very beginner.


I remember watching an animated show during my childhood(I was born 2004 so must've been around 2008-2014). The main premise of the show was about a group of friends that each owned a unique cool car. And the show was sci-fi. With their cars they would fight against robots in different contests which used their cars. I remember there was a 'restaurant' type place in the middle of a desert and one of the characters from the main group of friends was always there eating pizza. I also remember one of the peoples' car had a front half that could flip/rotate (I think his car was red) around him while he stayed upright.

This is a cartoon/animation which aired between 2005-2010 ish. The teens would be like put into these mazes where they would race against aliens for keys to their dimension and I remember one of the main characters rode a yellow bike that kinda looked like a tron bike.  The thing is above is a vague outline of what the keys looked like but they did have weird symbols and they used to stick to the hood of the cars when collected.


I had four NTFS partitions on my drive. One on which Windows 7 was installed (C Drive) and others contained my data (D Drive) (E Drive) (F drive).  During Ubuntu installation I chose to install Ubuntu and erase my existing OS. When Ubuntu was installed, I was shocked to see no partitions. All my data was gone. I must have done something wrong in selecting my option during installation.  I tried testdisk in my other PC with the hard drive. I messed up with the thing I deleted the Ubuntu and made a single partition.  Is there any way I can recover my D Drive? I don't care about the other partitions - I just need my pictures and videos which I captured. I have almost all computer equipment so just name it  Thanks in advance.

I am on Ubuntu 12.04 64-bits  I accidentally deleted a NTFS 255 GB partition using Gparted, and yes it contains LOTS of important data.  Upon realizing the deletion I haven't yet created any file-system on it. So it still shows Unallocated.    I tried Testdisk , but it shows entire partitions created from the beginning.  This sdb is my secondary drive with Xubuntu and Kubuntu on it. And that 255 GB NTFS  partition was cross platform storage drive.  I am currently in sda with Ubuntu and Win7 in dual boot, which enables me to use it as Safe recovery option rather then Live USB drive.   First ,  should i allocate it to ? file-System for better recovery .  Second , i really need to recover data from this drive so please give me possible  suggestions and proven methods of data recovery.  Third ,does Testdisk requires deleted partition to be allocated for its recovery .  I am currently trying the answer seen here  with Testdisk scanning for partition second time, hoping to recover it.   It looks a duplicate but i can't confirm if the OP got it right. Since my first doubt is to allocate it or not.  If any clarification required please do comment ,i will add it.  Edit: TestDisk deeper search results.      The following partitions can't be recovered:          Partition               Start        End    Size in sectors     >  HPFS - NTFS          22241 107 11 55592   3 27  535777280        FAT32 LBA            274460 158 19 460576 228 16 2989957948  NTFS, 274 GB / 255 GiB & for FAT32 LBA 1530 GB / 1425 GiB


I installed some programm (xlsx2csv) using pip3. The executable of the software is in ~/.local/bin. My $PATH is defined in ~/.profile like this:  PATH="$HOME/bin:$HOME/.local/bin:$PATH"  echo $PATH /home/bruni/bin:/home/bruni/.local/bin:/home/bruni/bin:/home/bruni/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin   Permissions on the executable seem ok:  bruni@bruni-Inspiron-5547:~/.local/bin$ ls -l total 44 -rwxrwxr-x 1 bruni bruni 42501 Jul  2 12:39 xlsx2csv  bruni@bruni-Inspiron-5547:~/.local/bin$ type -a xlsx2csv  xlsx2csv is /home/bruni/.local/bin/xlsx2csv xlsx2csv is /home/bruni/.local/bin/xlsx2csv   Nonetheless, I cannot invoke the installed software without specifying the exact path.  :~$ xlsx2csv -bash: /usr/bin/xlsx2csv: No such file or directory

I've installed pytest for python testing, but I get No such file or directory error when simply trying to run it from a project folder.  It's in a location that should be accessible through the PATH variable, but (to the best of my ability to describe the problem) isn't being 'found'. For some reason when I type 'pytest' my shell is looking to the wrong location; if I specify the location then pytest will run fine.  Looking in /usr/bin  kirk@kirk:~/develop/foo$ pytest bash: /usr/bin/pytest: No such file or directory   It's actually in /usr/local/bin, which is part of the path, and works when I explicitly call that location.  kirk@kirk:~/develop/foo$ whereis pytest pytest: /usr/local/bin/pytest  kirk@kirk:~/develop/foo$ echo $PATH /home/kirk/bin:/home/kirk/.local/bin:/usr/local/sbin:/usr/local/bin:     /usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin  kirk@kirk:~/develop/foo$ /usr/local/bin/pytest ============================= test session starts ============================== platform linux2 -- Python 2.7.12, pytest-3.0.5, py-1.4.32, pluggy-0.4.0 rootdir: /home/kirk/develop/foo, inifile: pytest.ini collected 0 items   ========================= no tests ran in 0.00 seconds =========================   What can cause this behavior?


I'm on centos 7 using firewalld.  I've configured firewalld so 443 is open:  $ sudo firewall-cmd --zone=public --permanent --list-all public   target: default   icmp-block-inversion: no   interfaces:    sources:    services: couchdb2 dhcpv6-client http https ssh   ports: 443/tcp 5984/tcp   protocols:    masquerade: no   forward-ports:    sourceports:    icmp-blocks:    rich rules:   $ sudo firewall-cmd --zone=public --add-port=443/tcp --permanent Warning: ALREADY_ENABLED: 443:tcp success   apparently port 443 is open, but ...  $ curl https://127.0.0.1:443 curl: (7) Failed connect to 127.0.0.1:443; Connection refused   I also test it using the web tool at   I type in my IP address and port 443 and get: Closed Port 443 is closed on {my-ip}  What could be going wrong? It seems to open and yet it isn't.  I query netstat with this result:  $ sudo netstat -lnp | grep 443 udp        0      0 127.0.0.1:323           0.0.0.0:*                            443/chronyd          udp6       0      0 ::1:323                 :::*                                 443/chronyd   Once I fixed my nginx.conf to properly listen to 443 the result looked like:  $ sudo netstat -lnp | grep 443 tcp        0      0 0.0.0.0:443             0.0.0.0:*                LISTEN      10197/nginx: master  tcp6       0      0 :::443                  :::*                     LISTEN      10197/nginx: master  udp        0      0 127.0.0.1:323           0.0.0.0:*                            443/chronyd          udp6       0      0 ::1:323                 :::*                                 443/chronyd

This is a  about Connection Refused    We see a lot of questions to the effect      When I try to connect to a system I get a message      Connection refused      Why is this ?


I want to take an object that I have scaled in object mode and set the current scale to 1. I can find the current scale, clear the scale with Alt+S, and then switch to edit mode and scale to what it was before I cleared the scale. Is there a built in way to do this? Modifiers build off of the object scale, so it would be nice to set the current scale as 1 rather than just clearing the scale and resizing in edit mode.

I try to unwrap uv on first ever 3d model i made in blender which is Baymax., then that message shows up in upper right corner of screen. The uv map looks so grotesque. I already tried remove double but nothing changed.  Help me pls.  Thanks.  Im noob at blender btw.


Perhaps my question has been already answered but if it did, I haven´t be able to find it. I´ve updated the rgal package to version 1.5-23 (GDAL 3.2.1 & PROJ 7.2.1) and when I run the following line crs(res_data_PA) <- LAEA  I get the following warning message: Warning message: In showSRID(uprojargs, format = "PROJ", multiline = "NO", prefer_proj = prefer_proj) :   Discarded datum Unknown based on GRS80 ellipsoid in Proj4 definition  I´m aware that I  and since it´s not an error nothing should change in my data. I don´t like to suppress any type of message from R so, I would like to know how is it now the proper way to assign the CRS to my raster.

I have a script which contains several r objects which are CRSs that I use for transforming spatial objects. After updating R and many packages, there is a warning which wasn't there before. LCC <- CRS("+proj=lcc +lat_1=49 +lat_2=77 +lat_0=0 +lon_0=-95 +x_0=0 +y_0=0 +ellps=GRS80 +units=m +no_defs")  Warning message: In showSRID(uprojargs, format = "PROJ", multiline = "NO", prefer_proj = prefer_proj) :   Discarded datum Unknown based on GRS80 ellipsoid in CRS definition  I understand that this is due to a change in how spatial information is stored... PROJ4 to PROJ6 upgrade and "Discarded datum" warnings ..but beyond that, I don't understand what this error means or if I need to do anything in response. Any thoughts?


Can anyone show me how to get this font (both text and math formula) in LaTex.

Is it possible to identify the font used in a specific document/picture?  Answers to this question should identify:   Possible methods to do this (perhaps one answer per method) and adequately describe how to use it (as opposed to merely stating it); Ways of finding the identified fonts, if possible (free or not); and Any prerequisites associated with the method used, if required (for example, "In order to use method X, your document has to be in format Y").   This question is meant as an FAQ, based on an . Its aim is to facilitate the community with the general procedures involved in font identification. Similar cases are solved on a per-usage basis on 's  tag.


Well... kind of hard to translate in English so bare with me :).  Let's consider a wheel that spins in the void. Each point of the wheel has the speed $v = ω r$.  That means that for any $ω$, there is an $r$ sufficiently big that $c = ω r_c$. That would mean that for an $r > r_c$, the speed of the point would be higher than $c$.  But we also know that c is limit. So... where is the mistake?  I'm presuming that it has something to do with the "limit" between classic mechanic approach and relativistic approach.

Is it possible for information (like 1 and 0s) to be transmitted faster than light?   For instance, take a rigid pole of several AU in length. Now say you have a person on each end, and one of them starts pulling and pushing on his/her end.   The person on the opposite end should receive the pushes and pulls instantaneously as no particle is making the full journey.  Would this actually work?


Last night, I wanted to shutdown my PC after using it, but when I clicked the power icon, a tiny empty box showed with nothing in it (i.e. there's not Shutdown option)  So I thought rebooting will fix it, so I typed in my Terminal:     shutdown -P 1   After one minute, the PC got hung for few seconds, and then it suddenly shutdown, without closing any programs or anything, it did shutdown abnormally  Later, I turned my PC on and I was surprised that my user account was deleted! Plus the background and other settings were set back to their defaults, however the Wi-Fi connected automatically without asking for the password, seems like it was saved  There's the login button with Username/Password fields, I am sure that I typed them correctly but it says invalid credentials  I can sign in as Guest, but I can't do anything administrative, my user folder is still in place, but I can't access it due to being Guest  I have Ubuntu 13.04, dual-boot with windows 8

solution doesn't work. I'm using Guest account right now.  I was just working on VirtualBox and listening to some music with Rhythmbox when suddenly my computer became laggy, and seconds later, everything disappeared except my cursor and wallpaper. I ran terminal using CTRL+ALT+T and typed startx, sudo startx, and the last one sudo shutdown -h now. After booting up my computer again I could not login to my user account, after typing my password and hitting enter, black screen for 2 seconds, and login screen again.


I am looking for a way to evaluate (if not, then estimate) the following $$\int_0^x \dfrac {1}{\sqrt{\cos t - \cos x}}dt, \ 0 < x \leq \pi$$ Wolfram tells me that it blows up at $x = \pi$ and for lower values, it does not. (I tried $\pi/2$ and $\pi/3$.)  Edit 1 I have tried to make use of comparing the integrand with some other function, whose behaviour is known. For $\cos t - \cos x$, I am trying with $t-x$, but once it goes inside the root, then the range no longer stays real.

I once asked a  about how to integrate the reciprocal of the square root of cosine.  Is  there a general closed form for the integral $$\int_{0}^{\theta_0} \frac{1}{\sqrt{\cos \theta-\cos \theta_0}} d\theta$$   in terms of the gamma function?  Thank you.


The screen grab shows a notification that reappears seemingly at random. I have tried turning off Avast and MBAM in case they are blocking a web request but it didnt help. The image has scroll bars and scrolling down offers a 'Refresh this page' link but clicking it doesn't help. The notification does n ot time out and remains until I log out. I recently updated to Win10 2004 but had to roll back because it was unstable. Now rolled back to 1909. I also tried dism /online /cleanup-image /restorehealth - the log shows so problems were fixed. I also tried sfc/scannow which fixed some issues. However this still keeps appearing. Any help tracking down the app that is raising this notification would be much appreciated. I have tried to research checking what web pages are being requested - but didn't get anywhere. Image showing screen grab of lower right corner of screen: shows a customised 404 page:

A random popup appears in Windows 7 titled as Information with a progress bar and a clock. The window sometimes says Please wait a moment..., and the progress bar moves very slowly and disappears.     I don't know the source of this popup. I tried to search regarding this popup on the Internet, and some people had this problem. It also has a question on Yahoo! Answers, but everyone told to scan for malware and viruses.   Is there any way to know the source process for this window/popup?   The task manager shows nothing about this window The only tasks that are running are Google Chrome, etc. Right-click and left-click does not work on this window or its title bar.


I understand residuals intuitively in terms of linear regression as "the error in prediction". Mathematically I've seen residuals given by  $$\epsilon = y - \hat{y}$$  where $y$ is the true value and $\hat{y}$ is the estimated value.  But what are residuals with respect to PCA? Once we apply PCA to a matrix say, we are reducing its dimension by finding the directions with the most variation and projecting the data onto these directions (the principal components). I would guess that the residual here is the amount of variation left "unexplained" by the dimensionality reduction. But I haven't seen a formal definition for this so I can't be sure. Is there a more formal definition or better intuitive understanding to PCA residuals?

Given a PCA (or SVD) approximation of matrix $X$ with a matrix $\hat X$, we know that $\hat X$ is the best low-rank approximation of $X$.   Is this according to the  (i.e. the largest eigenvalue norm)  or according to the Frobenius $\parallel \cdot \parallel_F$ norm ?


To be clear, I am trying to find a closed form estimation for the $f(n)$, if $f(0)$ is defined to be $1$.   For example, this sequence would go as so: 1 is the starting value, and then add ${1\over1}$ to get the next value. $1+{1\over1}=2$, so the next value is 2. Iterating here, $2+{1\over2}=2.5$, so $f(2)=2.5$. $f(3)={2.5+{1\over2.5}}=2.9$.  $f(4)={2.9+{1\over2.9}}=3.2448...$  I am wondering whether there exists a closed-form expression that can either exactly output or accurately estimate $f(n)$.  So far, an interesting relation between $f(n)$ and $n$ seems to be that as $n$ increases, the number $a$ such that $f(n)^a=n$ approaches a number close to 2. This was tested with Mathematica, and $f(100,000,000)^{1.927471...}=100,000,000$. It could also be the case that the value $a$ diverges very slowly, but it is difficult to check for higher numbers as Mathematica is having trouble witht the calculations.  By assuming the value of $a$ was actually approaching 2, and playing around with the graph on desmos, I managed to come up with the expression $\log_{(2-{1\over n+1})}{(n+1)}+{n+1 \over 10.7}$. Or, using the change of  base formula to avoid the multi-term log base, ${\log{(n+1)} \over \log{(2-{1\over n+1})}}+ {n+1 \over 10.7}$. This expression seems to accurately estimate f(n) for the first 30 terms or so, but it soon becomes inaccurate for larger terms.  Is there any better formula that can accurately calculate the terms no matter how large? Or, is there some closed-form expression that is asymptotic with this function?

Today, we had a math class, where we had to show, that $a_{100} > 14$ for  $$a_0 = 1;\qquad a_{n+1} = a_n + a_n^{-1}$$  Apart from this task, I asked myself: Is there a closed form for this sequence? Since I didn't find an answer by myself, can somebody tell me, whether such a closed form exists, and if yes what it is?


I need this scenario based query.  SalesID Line    Noofitems   Category    Desc SID12345    1   1           Metal-SI    Strong iron SID12345    2   1           Plastic     Disposal SID12345    3   1           Plastic     Disposal   Expected Output  SalesID     Totitems    Category            Desc SID12345    3           Metal-SI,Plastic    Strong iron,Disposal

I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).  In the original app, we used almost entirely ANSI-SQL compliant statements, with one significant exception -- we used MySQL's group_concat function fairly frequently.  group_concat, by the way, does this: given a table of, say, employee names and projects...  SELECT empName, projID FROM project_members;   returns:  ANDY   |  A100 ANDY   |  B391 ANDY   |  X010 TOM    |  A100 TOM    |  A510   ... and here's what you get with group_concat:  SELECT      empName, group_concat(projID SEPARATOR ' / ')  FROM      project_members  GROUP BY      empName;   returns:  ANDY   |  A100 / B391 / X010 TOM    |  A100 / A510   So what I'd like to know is: Is it possible to write, say, a user-defined function in SQL Server which emulates the functionality of group_concat?   I have almost no experience using UDFs, stored procedures, or anything like that, just straight-up SQL, so please err on the side of too much explanation :)


I want to generate several point on a line, and this is the command:   \documentclass{article} \usepackage{tikz,pgf} \usetikzlibrary{calc} \begin{document} \begin{figure}   \begin{tikzpicture}     % this command generate a series of .0.0.0.0.0.0.0.     \foreach \i in {-2,...,1}{\fill ({random(-40,36)/10+0.2},0.2) circle (0.2cm); };       \end{tikzpicture} \end{figure} \end{document}   Very thanks!  =========================update======================================  Thanks for percusse, the problem is in the negative parameter of function random. Just change like this:    \foreach \i in {-2,...,1}{\fill ({(random(0,76)-40)/10+0.2},0.2) circle (0.2cm); };

\documentclass{minimal} \usepackage{tikz} \begin{document} \pgfmathparse{random(-5,5)} \pgfmathresult \end{document}   Works, but I have a .0.0 that not supposed to be here.


the code isn't working and I'm not sure where I've gone wrong any help would be much appreciated this is the details of the assignment create a class template by writing a template for a class named "Pair". This class will represent a pair of data members of a type that is parameterized in the template definition. For example, you could have a Pair of integers, a Pair of doubles, etc.  /* so I'm trying to implement this driver this is the driver.cpp file and  * I'm trying to do it with a template class */  int main() {    Pair<char> letters('a', 'd');    cout << "\nThe first letter is: " << letters.getFirst();    cout << "\nThe second letter is: " << letters.getSecond();     cout << endl;    cin.get(); }  //this is my .h file code template <class T> class Pair {    private:       T first;       T second;    public:       Pair(const T, const T);       T getFirst();       T getSecond(); };  //this is my Pair.cpp #include "Pair.h"   template<class T> Pair<T>::Pair(const T first, const T second) {    return first, second; }  template<class T> inline T Pair<T>::getFirst() {    return first; }  template<class T> inline T Pair<T>::getSecond() {    return second; }

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


I have an iPhone SE running iOS 12 with the beta profile installed. I don't always update to the next beta when it comes out.  Is there any way to stop updates form downloading as they can take up quite a bit of space?

I have a data plan for all of my smartphones, computers, and tablets, so I have to be very careful staying within my allotted usage.  When I discovered that my iPad downloaded a 3 GB software update (not apps, the iOS update), I am not happy. I do not know how to turn off the automatic downloading of iOS updates.  All of the answers I get on the Apple Support Communities tell me that iOS updates are not installed, only downloaded.  It is the automatic downloading of iOS updates that is the problem, because my data gets unintentionally used.  How do I turn off the automatic downloading of iOS updates?


I'm very new to Blender and I made a guy made out of blocks for a Game I'm working on in Unity. I made the armature and made it Parent with automated weights, now my Problem: When I for example move my right arm, it deforms the right side of my torso like it's glued to the arm, I dont know what to do please help.

I follow this  which uses rigify and I have run into some issues.    Not every vertex moves along the rig. Any idea what could cause this? I applied the location and rotation for every object.  The entire head is weight painted with blue.


Sometimes, a close-reason says it all, and while I also vote to close, I post the reason as a comment as well for faster feedback from new users.  Those close-reasons have some links for further reading for a reason though, so I suggest that if part of a comment, stripped of bold/italic/italic&bold-markers is identical to a close-reason, the site should add the links in automatically.

I know that that duplicate questions automatically post the duplicate to the comments on the question.     Would it be possible / a good idea to have this for all vote closes?  Possibly having a check box at the bottom of the vote close window to post reason as a comment to the question might work as well.   My reasoning for this is I tend to vote close questions for lack of effort.       unclear what you're asking - Please clarify your specific problem or   add additional details to highlight exactly what you need. As it's   currently written, it’s hard to tell exactly what you're asking. See   the How to Ask page for help clarifying this question.   Now in some cases the question could be improved, but a lot of times questions like this are by new users who don't always return.  If I feel it can be improved I like to let these new users know that it was vote closed and why.  I copy that to the comment. example:    Is this something we could consider adding?


I'm writing an AVL tree in Java, and I'm having trouble with the rotation methods. The Node class contains pointers to a parent, a left pointer, and a right pointer. Here is my leftRotate() method, for example:      private void leftRotate(Node<K,V> node) {         System.out.println("leftRotate(" + node.key + ")");         System.out.println(node.parent.key);         Node<K,V> newTop = node.rightChild;         if (node.parent != null) {             newTop.parent = node.parent;         } else {             newTop.parent = null;         }         node.rightChild = newTop.leftChild;         if (node.rightChild != null) {             node.rightChild.parent = node;         }         newTop.leftChild = node;         node.parent = newTop;         if (newTop.parent != null) {             if (newTop.parent.rightChild == node) {                 newTop.parent.rightChild = newTop;             } else {                 newTop.parent.leftChild = newTop;             }         }     }   Whenever this code runs, the System.outs will properly print the parameter node's key and then its parent's key. The parent's pointer obviously is not null, but a NullPointerException is thrown at newTop.parent = node.parent (line 6). I even tried wrapping it in an if/else, to no avail. Any ideas why this is happening and what I can do to 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?


the add options are greyed out (in all tabs) I can't use them. Any help? BLENDER VERSION: 2.78

I'm still learning, but I'm trying to follow a tutorial to apply texture to a model. I only want to apply the texture to one object in the scene, so I selected it, unwrapped it, and painted over it. Now I selected it in the Edit Mode (I can't select it in the Object mode because all is locked together) and went into Node Editor, but the nodes are greyed out.  Why?


I'm new to Blender, coming for 3DS Max, is it possible in Blender to copy an object along a path with specific parameters? Such as count of copies and orientation?

I want to outline a curve in the form of text with a mesh (UV-sphere, cube etc.). How can I do that while saving mesh geometry without using the Curve modifier?


I found a bug with select tag in IE 9... In IE 10 and 11, FF, Chrome, Safari everything works fine, but in IE 9 - when list with options become visible, it's going over , browser window and monitor display:    May I somehow manually set height of options list, or set count of visible options (before scrolling) using CSS and JS?   P.S. it's just select tag and many options inside.  Please, help. Thanks.

Can someone confirm that its not possible to change the height of a dropdown that is shown when you click on a select box.   The size attribute of the select makes it look like a list, the height attribute in the CSS doesnt do much good either.


I am programming a genetic algorithm so that this solves problems of linear programming, I am using C language, when I calculate the limit of the variables I keep the values in a float type array, I need to order that array but it deletes a data that I need to moment of ordering: I have used a shell_sort pogramed by me and the qsort that is implemented in the standard librarian and with both gives me the same result, I append the code of the algorithm that I use to order and the comparator function that I use for the qsort () :      void shell_sort(float *A, int n){     int gap = n/2;  //Se obtiene el gap dividiendo el tamaño de arreglo entre dos     int inner, outer, swap; //Variables auxiliares      while (gap > 0) { //Mientras gap sea mayor que zero entonces:         for(outer = gap; outer < n; outer++){ // Para outer igual a gap, siempre que outer sea menor a n, outer aumentara su valor en uno             inner = outer; // inner se iguala al valor de outer             swap = A[inner]; // Swap se iguala a la posiscion inner de A             while (inner > gap - 1 && A[inner - gap] > swap ) {  // Mientras inner sea mayor que gap menos 1 y que A en su posicion inner menos gap sea mayor a Swap                 A[inner] = A[inner - gap]; //La posicion inner de A tomara como nuevo valor la posicion inner menos  gap de A                 inner -= gap; //inner decrementa su valor en gap veces             }             A[inner] = swap; //La posicion inner de A tomo como nuevo valor swap         }         gap /=2; // se divide a gap entre dos     } }   Comparer function:  int comp(const void * a, const void * b){     if(*(float*)a < *(float*)b) return -1;     if(*(float*)a == *(float*)b) return 0;     if(*(float*)a > *(float*)b) return 1; }   Output:  I think when I sort the array the result will be 0,26,37 but the result is 26,37 and I need that zero I don't really know why is this happen.  Hope someone can help me.  This is the piece of code when I use the sorting.      Limites obtenerValoresLimites(lista *l,char var){         //This code works Limites lim;         restriccion r;         int i,j;         float *aux = (float*)malloc(sizeof(float));         for (i = 0; i < Size(l); i++)         {             r = Element(l,i+1);             for (j = 0; j < strlen(r.variables); j++)             {                 if(r.variables[j] == var){                     aux[i] = (r.limite/r.coeficientes[j]);                     }             }         }     //First print of the output that confirms the zero originally exist          //for (i = 0; i < sizeof(aux)/sizeof(*aux) ;i++)             //printf("%f\n",aux[i]);      //Sorting         //qsort(aux,sizeof(aux)/sizeof(*aux)+1,sizeof(float),comp);         shell_sort(aux,sizeof(aux)/sizeof(*aux));          //printf("\n");     //Second print of the output now the zero is no longer in the array         //for (i = 0; i < sizeof(aux)/sizeof(*aux) ;i++)         //{         //  printf("%f\n",aux[i]);         //}          lim.inferior = 0;         lim.superior = aux[(sizeof(aux)/sizeof(*aux))-1];         lim.variable = var;          return lim;     }   Thanks for answer and read.  I think the code is a little bit difficult to read, its because we are using some data structures to modelete the problem so if you are interested in we leave the gitHub repo below.  Complete code if you are interesed in:

First off, here is some code:  int main()  {     int days[] = {1,2,3,4,5};     int *ptr = days;     printf("%u\n", sizeof(days));     printf("%u\n", sizeof(ptr));      return 0; }   Is there a way to find out the size of the array that ptr is pointing to (instead of just giving its size, which is four bytes on a 32-bit system)?


I wiped my computer and need to install an OS. Unfortunately my computer does not have a CD drive so I need to boot from a USB. How do you do this?

My CD drive is broken,so I can't install Ubuntu from a CD.  Are there any workarounds for that?


Let $A$ be a commutative ring and $I$ a finitely generated ideal satisfying $I=I^2$. Prove that $I$ is generated by a single idempotent element.  Attempt: I know it exist an element $x \in A$ such that $x \equiv 1$ mod $I$ and $xI = 0$. By this I know that for this element $x$ we have $xy=0$ for all $y \in I$, and I can write $x + y_1 = 1$ for some $y_1 \in I$, multiplying this with $x$ gives $x^2=x$, thus I have found what I believe is our idempotent element we are looking for. Now i cant argue that $I=(x)$, what am I missing?

Exercise 2.1 in Matsumura's Commutative Ring Theory reads as follows: "Let $A$ be a commutative ring and $I$ an ideal that is finitely generated and $I=I^2$. Then $I$ is generated by an idempotent."   In trying to solve it, i first followed a constructive approach, where e.g. for the case of two generators i tried to construct an idempotent generator. However, it seemed difficult. Then i realized that i could apply Nakayama's lemma to the $A$-module $I$ and the existence of the idempotent generator follows.   My question is: How could one go about finding this idempotent generator? Is there a systematic way?


Which one of the two sentences - "Do I need mention that she is my wife" or "Do I need to mention that she is my wife" - is correct use.

Consider:  I need to do this. I need do this.  My English grammar knowledge tells me that "need" doesn't have the same status as the modal verbs "may", "can", "should" and what not. Hence the second usage where two verbs appear consecutively is incorrect. But yesterday, my native English speaking friends (Americans) told me that "I need compute this." is a perfectly grammatical sentence, and one is simply omitting the "to". How can this be? Is it a colloquial usage but grammatically incorrect, or is it grammatically correct? If it is grammatically correct, is it because "need" is a semi-modal verb? EDIT: in particular, is it okay to use "need compute" in a scientific paper? EDIT2: the exact phrase that raised the question was "The advantage of this representation is that we need only compute sums and products"


This morning i found movies inside my server (debian VPS, apache,webmin/virtualmin), files are located in /var/log/roundcube/./ and the user/group is www-data  I looked in my log (apache,proftp,auth) and i didn t found weird lines. rkhunter found nothing bad.  how can i check the history of a file (in hidden folder) or the way that the user uploaded movies in this folder.  i guess it s a backdoor but when i scan my website i found nothing bad.  i think i ll cut my website for a while and see if there is new movies in folder, if yes it means that the user have ftp/ssh access or that the backdoor is not in my var/www/  Thanks by advance

This is a  about Server Security - Responding to Breach Events (Hacking)   See Also:                  Canonical Version I suspect that one or more of my servers is compromised by a hacker, virus, or other mechanism:   What are my first steps? When I arrive on site should I disconnect the server, preserve "evidence", are there other initial considerations? How do I go about getting services back online? How do I prevent the same thing from happening immediately again? Are there best practices or methodologies for learning from this incident? If I wanted to put a Incident Response Plan together, where would I start? Should this be part of my Disaster Recovery or Business Continuity Planning?   Original Version       2011.01.02 - I'm on my way into work at 9.30 p.m. on a Sunday because our server has been compromised somehow and was resulting in a    attack on our provider. The servers access to the Internet   has been shut down which means over 5-600 of our clients sites are now   down. Now this could be an FTP hack, or some weakness in code   somewhere. I'm not sure till I get there.      How can I track this down quickly? We're in for a whole lot of   litigation if I don't get the server back up ASAP. Any help is   appreciated. We are running Open SUSE 11.0.            2011.01.03 - Thanks to everyone for your help. Luckily I WASN'T the only person responsible for this server, just the nearest. We managed   to resolve this problem, although it may not apply to many others in a   different situation. I'll detail what we did.      We unplugged the server from the net. It was performing (attempting to   perform) a Denial Of Service attack on another server in Indonesia,   and the guilty party was also based there.      We firstly tried to identify where on the server this was coming from,   considering we have over 500 sites on the server, we expected to be   moonlighting for some time. However, with SSH access still, we ran a   command to find all files edited or created in the time the attacks   started. Luckily, the offending file was created over the winter   holidays which meant that not many other files were created on the   server at that time.      We were then able to identify the offending file which was inside the   uploaded images folder within a  website.      After a short cigarette break we concluded that, due to the files   location, it must have been uploaded via a file upload facility that   was inadequetly secured. After some googling, we found that there was   a security vulnerability that allowed files to be uploaded, within the   ZenCart admin panel, for a picture for a record company. (The section   that it never really even used), posting this form just uploaded any   file, it did not check the extension of the file, and didn't even   check to see if the user was logged in.      This meant that any files could be uploaded, including a PHP file for   the attack. We secured the vulnerability with ZenCart on the infected   site, and removed the offending files.      The job was done, and I was home for 2 a.m.            The Moral   - Always apply security patches for ZenCart, or any other CMS system for that matter. As when security updates are released, the whole   world is made aware of the vulnerability.   - Always do backups, and backup your backups.   - Employ or arrange for someone that will be there in times like these. To prevent anyone from relying on a panicy post on Server   Fault.


Question is too push the zeroes at the end in relative order. I'm using a main class to call pushZerosAtEnd in solution class.  public static void printArray(int[] arr) {         for (int element : arr) {             System.out.print(element + " ");         }          System.out.println();     }      public static void main(String[] args) throws NumberFormatException, IOException {         int t = Integer.parseInt(br.readLine().trim());          while(t > 0) {              int[] input = takeInput();             Solution.pushZerosAtEnd(input);             printArray(input);                          t -= 1;         }  In which i am using another temp array to store only non-zero number after this i'm assigning temp pointer to arr(arr = temp). after completing call when i print the array using print function in main class. it print the initial array. initially arr = [0, 5, 7, 4, 0] in pushZerosAtEnd function temp become temp = [5, 7, 4, 0, 0] arr = temp; before returning to main class printing [0, 5, 7, 4, 0]. Why pointer changed to initial array?? public class Solution {        public static void pushZerosAtEnd(int[] arr) {         //Your code goes here         int j = 0;         int[] temp = new int[arr.length];         for(int i = 0; i < arr.length; i++){             if(arr[i] != 0){                 temp[j] = arr[i];                 j++;             }          }         arr = temp;     }  }

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


I can't get my Cognito form to load. It just keeps giving me this error message:  Invalid Form Our apologies, this form has been disabled due to suspicious content. If you believe you have received this message in error, please contact the original form author.  How do I solve this?

This appears:     Our apologies, this form has been disabled due to suspicious content. If you believe you have received this message in error, please contact the original form author.     How can I make my form code work?


So my Linux experience began a week ago. I thought that Ubuntu is a great project so switched to it instead of Windows  as I saw that just replacing it was easier and less tedious. So I made the backup image plus the Windows Recovery on a USB stick (I tested if it worked or not before installing Ubuntu and it worked) then I decided that it was time that I switch back to Windows. The USB stick is on the first slot of boot order in the BIOS but it still boots Ubuntu instead of the Windows recovery USB. So I tried to uninstall grub and now I'm stuck in grub rescue and the usb stick still doesn't boot even though it is supposed to boot first.

I installed Ubuntu (twice actually) onto the same drive. I wanted to 'try again' since one of them didn't install correctly and the other installed differently, but it worked.   I was getting frustrated with the GRUB menu because it was really sloppy (There were two Windows options - one with the Windows bootloader to go into Ubuntu, and two different versions of Ubuntu from the first install for some reason and memtest, etc.).  In my attempts at getting rid Ubuntu to do a fresh installation, I went ahead and deleted the partitions that weren't swap or main via Windows 7. As I said, I am a noob.  Now, even though I though I completely got rid of Ubuntu, including the GRUB menu, when I boot my PC I am brought directly to GRUB Rescue. And from what I've found from other forums, GRUB rescue isn't even completely functional for me (it doesn't recognize any commands that it should support besides ls. It also returns unknown filesystem for any partition I try to view or boot.)  Is there any way that I can boot straight into Windows? I fear I may have gone about deleting those partitions in the wrong way. If so, what are my options?


The issue is basically this - where should I mount SSD and where should I mount the HDD if what I want is the system to be installed on the SSD, but new software installed through apt-get and such will be installed on the HDD.  Assuming this setup is possible of course.   suggests moving parts to the HDD is possible but does not specify how.  My specific case is I've installed ubuntu on a multiboot machine, mounting a 10GB ssd partition on root(may be a bit too small in retrospect), and HDD on /home. But it seems I'm filling up the ssd partition quicker than I wanted as everything seems to be installed there.   is on the same topic but does not mention where applications are typically installed and does not suggest where to mount HDD for new applications to be installed there.

I have purchased a new SSD (120GB) and I had a HDD (1TB) already installed. I will install both Ubuntu and Windows on these drives. As the file space on the SSD is limited and I've read that writing to an SSD drive is discouraged, I would like to store most of the data on the HDD drive. I am aiming at faster system but also keeping the valuable data safe on the more reliable HDD and expanding the life span of the SSD.  I have already set up Windows on these drives (system files and applications on SSD, Users folder and ProgramData on HDD) and now it's time to set up Ubuntu.  So my question is which partitions I should create, on which drive should they be placed and how large they should be.  Based on my experience and articles I've read, I will probably create /swap, /home and / partitions.   Does it seem reasonable to place /swap and /home partitions on the HDD and / on the SSD?  And how large should / partition be?  Also, will the applications be installed in / partition? If so, is it rational to store the applications on separate partitions on the HDD instead of / on the SSD, and what should the size of the / partition be in this case?


Is it correct to use these expressions without commas (as written below)?        A finite simple group.   A finitely generated abelian group.   A finitely generated torsion-free abelian group.   A finitely generated periodic infinite group.      From my experience, I can't remember ever seeing commas in any expressions of this kind (in mathematical texts). But that could be because I simply wasn't paying attention to punctuation.  I've spent some time googling for the appropriate rule, and the rule says that commas should be avoided between cumulative adjectives, and should be used between coordinate adjectives. To distinguish between the two, the following test is usually suggested: if the adjectives can be rearranged, and also the phrase doesn't look weird when "and" is placed between them, then these adjectives are coordinate.  When I try to apply the rules to cases 1-3, I feel a certain amount of doubt. In case 1 I could agree that "a simple finite group" sounds unusual. In case 2 I could also agree that "abelian group" is a very common expression, so it feels natural to place "abelian" after all other adjectives.  But what about case 4? The three modifiers seem to be more or less on equal footing. It doesn't look weird at all when they are rearranged or when "and" is tossed in: "an infinite, periodic, and finitely generated group" - looks fine to me.  So, my questions are:   Are examples 1-4 above correct or not? Why? Is there a convention to avoid commas between adjectives in mathematical texts altogether (ignoring the general English rule)?   Thanks.

Is there a convention which rules that in mathematics an object with some properties should be referred to as a  "property 1 property 2 property 3 ...object"  rather than a  "property 1, property 2, property 3, ...object"?  Specific example is an "oriented compact smooth manifold". By  this question I found that it would appear the convention is without commas, but I could not find a source confirming that it actually was.  Can someone confirm this is the correct convention, and perhaps from which organization the convention comes from?  I hope this falls within the bounds of MathStack; although it is obviously not about mathematics per se, I'm guessing nearly everyone on this site has written something like what I'm asking about!


I want to have the function like the following  unit = "days" datetime.datetime.now() + datetime.timedelta(unit = 1)   Where in the unit could be days, hours, and minutes etc., which may be changed according to the the time shift unit.  Is there any way to do it in a fast way?

Does python have the ability to create dynamic keywords?  For example:  qset.filter(min_price__usd__range=(min_price, max_price))   I want to be able to change the usd part based on a selected currency.


Let's say I have cast 100 close votes.  How can I easily determine how many of those close votes are on questions which are currently closed? This would be useful for understanding how well my personal close voting preference matches a site's overall philosophy on when questions should be closed, reopened, etc.  Even more awesome would be:   Close votes on questions which were closed (even if reopened) Close votes on questions which are currently closed Close votes on questions which are deleted

How can I see the ratio of my previous close/reopen votes that were correct (i.e. resulted in the question being closed/reopened) or incorrect (i.e. resulted in the question left open/closed)?   I am interested in this statistic, because it would help self-educate about the correct use of close/reopen votes.


Generally it is considered to be "good practice" to write reports in the third person passive voice for a wide array of academic writing. It is even a requirement of publication in several journals.  However, I have been unable to find any sort of information for "why" this is the way it is. I can't find any studies on the effect of reports written in the passive vs active tenses nor the effect of 3rd vs 1st person.  Could anyone shed any light on why this is the way it is?

Are there written or unwritten rules for avoiding the use of first-person while writing research papers? I was advised at the beginning of my grad school to avoid use of first person - but I still don't know why I should do this.  I have seen that, at many places, authors refer to themselves are "the authors" and not "we". At the same time, I have also seen use of first-person to a good extent.    Do these things differ in different Journals and Conferences (and in different disciplines as well - mine happens to be CS)?


Can I make a wither skeleton farm in the over world? Or does it have to be in a nether fortress. Just wondering because I’m trying to get a stack of nether stars

What conditions are necessary for a Wither Skeleton to spawn naturally, and can I manipulate those conditions to increase the chance of them spawning?  I want to make a Wither Skeleton spawning pad in the Nether but I'm having trouble finding Wither Skeletons. I've only heard that they spawn in Nether Fortresses.


I have a troubleshoot with my blender file. I've upload a stl file in blender and when i apply a mirror modify to X axis i see 2 objects. I tried to change 3d cursor position, but not work.

When I add a mirror modifier it sometimes doesn't mirror correctly, giving me an overlapping mesh. How can I fix this?


So there's a feature request (I'm not the OP) which has recently been tagged status-declined.  I was/am highly in favor of the request.  Now I'm depressed.  I will probably drown my sorrows tonight in a case of dark English ale (nothing like the old world).  This particular feature-request had 72 upvotes on it and the reason given for declining was not all that great (IMHO).  How long do we wait (realistically) before asking for a highly-popular feature request which was declined to be reconsidered?  (ok, to save you some forensic time the feature in question is , but this is really just in general)

As I was browsing earlier today, I really happened to like an answer to a question. The question didn't interest me so much, and the answer was actually a tangential reply to some of the comments in the post, and was by far more valuable than the original question or the accepted answer. Now, my only options to favorite that answer are   Favorite the question. Add the link to the answer to my browser's bookmarks.   I was pretty sure others have had the need for this, and sure enough, I found a  and a , both nearly two years ago and a , nearly a year ago.  Now, there might have been several reasons why it (and several other old feature-requests) was denied. SO was pretty young back then, there probably weren't enough developers on board, perhaps they didn't have the resources to track favorite answers. But SO has grown since then from 1-3 sites to 30+ sites. Requests that might have at one point been too demanding, might now be easily implementable, which could greatly enhance user experience.  So, my question is: "Can we re-request features that were previously declined, provided the request and the denial are sufficiently old, so that the team can reconsider their decision?"  After how long is sufficient enough needs to be decided by the community and is only to prevent re-requesting a feature that was only declined say a week ago.


I'm trying to add some files from a file to another but at time to redirecting output the terminal returns me a message of "Denied permission" and I don't know where I should put sudo.  I tried with this:  sudo cat named.conf.default-zones >>named.conf.local

When using sudo to allow edits to files, I regularly get 'permission denied'.  For example, my mouse is jittery and sluggish, so I want to disable polling:  sudo echo "options drm_kms_helper poll=N">/etc/modprobe.d/local.conf   I'm prompted for a password, and then get:  bash: /etc/modprobe.d/local.conf: Permission denied   So I tried to do a temporary change to disable polling by using:  sudo echo N> /sys/module/drm_kms_helper/parameters/poll   Yet again the system responded with:  bash: /sys/module/drm_kms_helper/parameters/poll: Permission denied   Any ideas?


I'm trying to load a page and put it inside a div.  code :   $("#test").load("page.php");   The problem is that once it's loaded, sometimes when I re-execute this script, it seems that the file 'page.php' is not really reloaded, seems that this file is keep in a cache or something like this.  It's really a problem because I have a PHP request inside this file it doesn't execute it.

I have the following code making a GET request on a URL:  $('#searchButton').click(function() {     $('#inquiry').load('/portal/?f=searchBilling&pid=' + $('#query').val());             });   But the returned result is not always reflected. For example, I made a change in the response that spit out a stack trace but the stack trace did not appear when I clicked on the search button. I looked at the underlying PHP code that controls the ajax response and it had the correct code and visiting the page directly showed the correct result but the output returned by .load was old.  If I close the browser and reopen it it works once and then starts to return the stale information. Can I control this by jQuery or do I need to have my PHP script output headers to control caching?


I have settled WI-FI hotspot on Kali linux via hostapd+dnsmasq tools. For being able to access internet(which is accessible through different interface) I used masquerading:  iptables -P FORWARD ACCEPT iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE   But afterward another feature turned to be wanted: redirection of the incoming traffic to the tor's proxy. Could you help me to understand which rules I need to append to iptables in order to proxying through tor configured like this:  # configure tor with this configuration AutomapHostsOnResolve 1 TransPort 9040 TransListenAddress 10.0.0.1 DNSPort 5354 DNSListenAddress 10.0.0.1 SOCKSPort 0

On a Linux system, is there a way to block all in and outbound traffic unless it passes through the Tor network. This includes any form of IP communication, not just TCP connections. For example I want UDP to be completely blocked since it cannot pass through Tor.  I want this systems Internet usage to be entirely anonymous, and I don't want any applications leaking.  I realize this might be complicated because Tor itself needs to communicate with relay nodes somehow.


I have pushed a change in Git with a little mistake. How to add some modification in that same changelist? I heard that it's possible using cherrypick. I'm unable to find how.

When I've worked a bit with my source code, I did my usual thing commit and then I pushed to a remote repository. But then I noticed I forgot to organize my imports in the source code. So I do the amend command to replace the previous commit:  > git commit --amend   Unfortunately the commit can't be pushed back to the repository. It is rejected like this:  > git push origin To //my.remote.repo.com/stuff.git/  ! [rejected]        master -> master (non-fast forward) error: failed to push some refs to '//my.remote.repo.com/stuff.git/'   What should I do? (I can access the remote repository.)


I piped one echo command into the other   🌐 echo a b c d e f g h i | echo   🌐 echo $? 0   Contrary to my intuition, there was no output, however there was also no error returned. I expected, that echo a b c d | echo  is only an unnecessary redundant alternative to echo a b c d . But it is not the case, Why were the arguments lost on their way through the pipe?

I have a file named my_file.txt whose content is just the string Hello. How could I redirect its content to the command echo?  I know I have the commands less, cat, more... but I need to do it with echo.  I tried this:   $ cat my_file.txt | echo   and also this:  $ echo < my_file.txt   But in both cases it appears only a blank in the stdout, not the content of my_file.txt.  How could I do that?


Suppose I want to generate 100 apparently identical PDF files, where I hide some kind of key, in order to distribute them among 100 different people. Now I detect an online shared copy of the document and I need to track who of that 100 people uploaded it.  My first approach would be to compile them in some way (maybe ) to, for example, include among its hyperref PDF keywords some "UserNr001", "UserNr002", ... tags.  What I'm asking for is a more subtle way to mark a PDF from the .tex file.  Maybe related:  and .

I'd like to add an invisible watermark to each PDF document that I produce so that in case it leaks, I know where it leaked from. Anyone knows what would a good way for an invisible watermark be in a PDF document and how to add one?


Here is my javascript code:  var prevDate = new Date('1/25/2011'); // the string contains a date which                                       // comes from a server-side script                                       // may/may not be the same as current date  var currDate = new Date();            // this variable contains current date     currDate.setHours(0, 0, 0, 0);    // the time portion is zeroed-out  console.log(prevDate);                // Tue Jan 25 2011 00:00:00 GMT+0500 (West Asia Standard Time) console.log(currDate);                // Tue Jan 25 2011 00:00:00 GMT+0500 (West Asia Standard Time) console.log(prevDate == currDate);    // false -- why oh why   Notice that both dates are the same but comparing using == indicates they are not the same. Why?

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.


the default new form in my sharepoint online calendar got deleted and it won't let me create a new one I have tried creating it from sharepoint designer but it throws an error, i have deleted designer cache but it did not help

In SharePoint online the calendar default new form disappeared, and whenever I try to create a new one I keep getting:  I have tried clearing the SharePoint designer cache but I keep facing the same problem - any solutions out there for me to get my default newform back?


I am using ireport to design jasper reports. I want to have a report that can be dynamically generated based on user input. Means columns can be added/removed based on user input.  The one solution I know is to design the report that contains all the columns, Then based on the user input, Using "Print When Expression" can hide the column, But the empty column will still be there. Is there any way to remove the columns completely without leaving empty space in ireport.

I'd like to show/hide a column at runtime based on a particular condition. I'm using "Print when expression" to conditionally show/hide this column (and it's header) in my report. When the column is hidden, the space it would have occupied is left blank, which is not particularly attractive.  I would prefer if the extra space was used in a more effective manner, possibilities include:   the width of the report is reduced by the width of the hidden column the extra space is distributed among the remaining columns   In theory, I could achieve the first by setting the width of the column (and header) to 0, but also indicate that the column should resize to fit its contents. But JasperReports does not provide a "resize width to fit contents" option.  Another possibility is to generate reports using the Jasper API instead of defining the report template in XML. But that seems like a lot of effort for such a simple requirement.


How did Neo know that the "reality" Morpheus told him was the real world was not actually just another simulated reality? I mean if he believed Morpheus' explanation on simulation isnt it logical for him to assume that the real world was also simulated. Wouldnt it be the perfect prison designed by the machines. Design the prison world and a world for those who think they have escaped.

Can any of the "free humans" tell if they are in the Matrix or not? Does it feel different? Or is it only context (like if they remembered being put in there, or see familiar Matrix cities, etc.)?


I want to install this extension to my blender to get materials to save from blender render to cycles render. Anyways when I clicked on the installation link this is what appeared(picture). How do I use this to install the script to blender?

There is this addon that was built called Window Generator 2. It can be . However, when I go to the download link it shows up in a new tab as a bunch of code.  How can I download and use this addon in Blender?


The Panasonic GH5's sensor is suspended in a magnetic field when in use, allowing it to move on 5-axis to stabilise the image.   However when not in use it is completely loose and flops around in its space (it can move around by a good 3-4mm in all directions) and it can clearly be heard and felt knocking around, presumably it has some sort of rubber buffers around it.   However in the long term, being carried in a camera bag, rucksack, handbag, neck-strap etc etc... Is it likely to suffer any actual physical damage? Is the flexible cable to it likely to degrade in time?   I am fully aware that they are built like this, and have of course been thoroughly tested, but sometimes there are unforeseen issues later in the life of products.

I own a Panasonic DMC-G81 (same as G80/G85) with in-body Image Stabilization.  When turned on everything is just fine, but when turned off, the sensor is wobbling around in the body. When no lens attached, it's clearly visible moving about 1/2 cm in the body. I didn't find anything about it in the internet. Shouldn't the sensor be in a kind of parking position, should I worry about the sensor ?  I'm not sure if that is the usual behavior, maybe someone with the same or similar body can have a look.


I wonder if it can be mathematically demonstrated that   4k + 3 != n^2 where k,n are N (natural) numbers?   My daughter (6's grade) has a problem and the book's answer is just enumerating k elements  {3,7,11,19,23,27...}    saying that they cannot be perfect square.  Thank you,

This is a question from the free Harvard online abstract algebra .  I'm posting my solutions here to get some feedback on them.  For a fuller explanation, see  post.  This problem is from assignment 6.  The notes from this lecture can be found .     a) Prove that the square $a^2$ of an integer $a$ is congruent to 0 or 1 modulo 4.   b) What are the possible values of $a^2$ modulo 8?   a) Let $a$ be an integer. Then $a=4q+r, 0\leq r<4$ with $\bar{a}=\bar{r}$.  Then we have $a^2=a\cdot a=(4q+r)^2=16q^2+8qr+r^2=4(4q^2+2qr)+r^2, 0\leq r^2<4$ with $\bar{a^2}=\bar{r^2}$.  So then the possible values for $r$ with $r^2<4$ are 0,1.  Then $\bar{a^2}=\bar{0}$ or $\bar{1}$.  b) Let $a$ be an integer. Then $a=8q+r, 0\leq r<8$ with $\bar{a}=\bar{r}$.  Then we have $a^2=a\cdot a=(8q+r)^2=64q^2+16qr+r^2=8(8q^2+2qr)+r^2, 0\leq r^2<8$ with $\bar{a^2}=\bar{r^2}$.  So then the possible values for $r$ with $r^2<8$ are 0,1,and 2.  Then $\bar{a^2}=\bar{0}$, $\bar{1}$ or $\bar{4}$.  Again, I welcome any critique of my reasoning and/or my style as well as alternative solutions to the problem.  Thanks.


My Ubuntu version is 20.04 LTS. How can I remove the shortcut arrow emblems from the icons?

How do I turn off the arrow for desktop icons?


I do not understand why System.out.println(name) outputs Sam without being affected by the method's concat function, while System.out.println(names) outputs Sam4 as a result of the method's append method. Why is StringBuilder affected and not String? Normally, calling methods on a reference to an object affects the caller, so I do not understand why the String result remains unchanged. Thanks in advance  public static String speak(String name) {     name = name.concat("4");     return name; }  public static StringBuilder test(StringBuilder names) {     names = names.append("4");     return names;  }  public static void main(String[] args) {     String name = "Sam";     speak(name);     System.out.println(name); //Sam     StringBuilder names = new StringBuilder("Sam");     test(names);     System.out.println(names); //Sam4 }

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


Update, I made an honest mistake. I assumed the person who set the bounty was the person who asked the question, this was my mistake. Thanks to Kendra for pointing it out in the comments and how to find out who posted the bounty.

It's possible to offer and award bounties of reputation on questions.   What is a bounty? How can I find questions that have a bounty attached? How do I start a bounty? When can I start a bounty? Why is the system requiring me to choose a bounty amount that's higher than the minimum? Can I use Markdown formatting in the bounty remarks? Can I edit the remark? How long is the bounty period? How do I award a bounty? Can I award a bounty to my own answer? Can I award a bounty to an old answer? If I offer a bounty on someone else's question, can I award the bounty to their answer? After awarding the bounty, can I remove it or move it to another answer at a later time? What happens if there's no answer after the bounty period? What happens if I feel my question is still unanswered? What is automatic awarding? Are bounty awards exempt from the 200 points/day reputation limit? How does Community Wiki mode affect bounties? How does user deletion or post dissociation affect bounties? Can I award a bounty to an answer from a deleted user or one where the author was dissociated? Can I offer a second bounty after the first one has expired? Can I raise my bounty? What happens if a bounty question is closed or deleted? Why can't I vote to close or migrate a bounty question? What happens if I delete my account while I have an active bounty? Do I keep an awarded bounty when I delete my answer? What happens if a question where I awarded a bounty later gets deleted or migrated? Can I cancel my bounty? Can I affect / divide / share part of my bounty to two (or more) users? How many outstanding bounties can a single user have?      See also:  in the Help Center


I've seen some inconsistencies between the cron environment and my environment.  For example, I have installed paver (pip install paver) in my environment and calling paver works paver. Using paver in my cron doesn't work command not found. Everything is done through the same user root.  Any idea ?

This is a  about using cron & crontab.   You have been directed here because the community is fairly sure that the answer to your question can be found below. If your question is not answered below then the answers will help you gather information that will help the community help you. This information should be edited into your original question.  The answer for 'Why is my crontab not working, and how can I troubleshoot it?' can be seen below.  This addresses the cron system with the crontab highlighted.


I have a small icon called "favorite" and when I click on it I call a jquery event handler to change the icon and change the class name.  But when I click on it again it doesnt go to the event handler of the class that I have added to it, it goes back to its original event handler  This is the icon  <input style="float:right" type="image" name="unfavorite" id="unfavorite" class="unfavorite" src="images/unfavorite.png" />   and my jquery is:      $('.unfavorite').click(function()     {         $(this).removeClass('unfavorite');         $(this).addClass("favorite");         $(this).attr("src","images/favorite.png");     });      $('.favorite').click(function()     {         $(this).removeClass('favorite');         $(this).addClass("unfavorite");         $(this).attr("src","images/unfavorite.png");     });   so basically I want to change the icon each time is clicked. But when I addClass(favorite) the event handler for favorite class is never called, it always goes to unfavorite  What should I do?  thank you

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 have applied for a UK business visa with travel dates as 30th Oct - 5th Nov 2017. I have submitted the form and made the payment online. My travel dates have changed to a month later. I still have to go for my interview to VFS. Can my travel dates be changed on the form? At VFS?

After printing out a UK visa form, can you cross out planned arrival date with a pen and write a new one?


I have one keyword for my site and when I search for it , it is displaying my website at 9th result in first page in Google , Now I want to know that what improvement I need to do in SEO for same keyword to reach in top 3 result?

What are the best ways to improve a site's position in the Google search results?


I found this article:  and I have some question about part of the presented code:  First: I think that is something about dependent name but I am not sure what is a purpouse of this part:   template <typename T>     typename instance_counter<T>::counter instance_counter<T>::icounter{};   And second one:  template <typename T> struct counted : T, private instance_counter<T> {     using T::T; };   Could somebody give me an explanation about these codes?

In templates, where and why do I have to put typename and template on dependent names? What exactly are dependent names anyway?    I have the following code:  template <typename T, typename Tail> // Tail will be a UnionNode too. struct UnionNode : public Tail {     // ...     template<typename U> struct inUnion {         // Q: where to add typename/template here?         typedef Tail::inUnion<U> dummy;      };     template< > struct inUnion<T> {     }; }; template <typename T> // For the last node Tn. struct UnionNode<T, void> {     // ...     template<typename U> struct inUnion {         char fail[ -2 + (sizeof(U)%2) ]; // Cannot be instantiated for any U     };     template< > struct inUnion<T> {     }; };   The problem I have is in the typedef Tail::inUnion<U> dummy line. I'm fairly certain that inUnion is a dependent name, and VC++ is quite right in choking on it. I also know that I should be able to add template somewhere to tell the compiler that inUnion is a template-id. But where exactly? And should it then assume that inUnion is a class template, i.e. inUnion<U> names a type and not a function?


I used the Intel® Wireless WiFi Link 5300AGN card in my desktop, this wireless card transfer miniPCI to PCIE. Does the ubuntu support this type interface 5300AGN wireless card?  Thanks.

I am a bit financially strapped and received a Gateway GT5056 tower. The tower has an AMD dual core 64-bit processor in it. Will Ubuntu 12.04 run on this machine? I will not have any other application other than LibreOffice installed.


I submitted my revised manuscript to a mathematical journal since 12-04-2017. The status is "Waiting for reviewer assignment" since 24-4-2017. What does it mean? Have the reviewers started working on my manuscript yet?.

What steps does a manuscript typically go through from submission to publication (or rejection) in a typical journal? How are these steps referred to, in particular by editorial systems, and how long do they each typically take?  Note that this question is about the typical situation and hence not about:   Journals with an atypical workflow, e.g. those that allow for an instantaneous reviewer–author interaction. Exceptional steps or rare occurrences such as withdrawal or .   This is a canonical question on this topic as per . Due to its nature, it is rather broad and not exemplary for a regular question on this site. Please feel free to improve this question.


I need to "Safely" remove Unity 12.04 and replace it with something Different. I have looked and I have tried a couple of things (one which caused a complete re-install of Ubuntu). So maybe someone else can help.  I am a Tinkerer! I Love Customization! I get bored and have to constantly change things, and Unity just won't give me that FREEDOM!! Don't get me wrong, I love Unity for something else, and there are a lot of great things about it. But it is just NOT for me...  Any suggestions would be greatly appreciated...  What I am looking for:   "SAFE REMOVAL", of Unity, and install of "Something New"... As much customization as possible... Bells and Whistles!    Please Help!...

This question exists as it fills a specific criterion.  While you are encouraged to help maintain its answers, please understand that "big list" questions are not generally allowed on Ask Ubuntu and will likely be closed per the . More information on the .   What kind of desktop environments or shells are there for Ubuntu users to install?  Please list a desktop environment or shell for each:   a description on why you like or suggest it (features, performance, etc.). a good screenshot, preferably of it running on Ubuntu and showing off some of its features. the minimal requirement for it to be usable, If there's any setting to lower it's requirement (Like kde's low-fat profile); how to enable the said setting some instructions on how to set it up if in the repositories, please provide a software centre link


Let $f : \mathbb R \rightarrow \mathbb R$ be a continuous function such that $f(f(x)) + f(x) + x = 0$ for all $x \in \mathbb R$. Find all $f(x)$.    I already proved that $f(x)$ is injective. But I didn’t know how to use the fact that $f$ is continuous. Can anyone give a hint or a solution to this problem? Thank you.

Find the number of continous functions $f:\Bbb R\to\Bbb R$ which satisfy the following functional equation $$f(f(x))+f(x)+x=0$$


As I do not have enough reputation I can not edit questions and answers.  However I sometime wish to view the Markdown so I can see how someone has done some formatting etc.  So there is a hard (hack) way of doing this, should there be a direct link.  E.g. "view marked" link instead of an "edit link" when no edit rights?

I sometimes see a useful markup feature in a per-site meta answer. However, I cannot edit it to see how one did it, since editing (or suggesting edits) is disabled for users with less than 2k reputation on per-site metas.  Is there a way to see the source code of a per-site meta answer?


I'm planning to write my PhD thesis about the work I authored or co-authored in published journal. In this case, is it okay to simply copy and paste the paragraph from the paper to my thesis? Is this considered plagiarism if I am the author or co-author of the paper? I'm particular concerned for those papers that I'm not the first author.

I am writing my thesis currently and I want to include papers that I am included on as an author.  I will have a couple papers where I am 1st author, but there is one where I am third but did a lot of the work.  How do I go about integrating it into my thesis?  Can I copy/paste most of the text still or do I need to rewrite it?  I don't want to plagiarize but don't want to rewrite it if I don't have to.


I found the answers to be a=-1, b=0; a=1,b=0; a=0,b=1 and a=0,b=-1. Only 4 pairs, however the answer is 6. Please tell me how to proceed.

Consider the equation $a^2+ab+b^2=1$. How many integer pairs are solutions to this?  I found 4 pairs: $a=-1, b=0$; $a=0, b=-1$; $a=1,b=0$; $a=0, b=1$. But the solution says the answer is 6. Which other possibilities am I missing? Please post the answer with solution.


In regards to bypassing damage immunity to attacks not made by magic weapon, what are considered magical attacks besides spells/spell-like ability and magical weapon attacks?  Are summoned monsters considered magical?  What about bite/claw from dragons and high CR creatures or legendary creatures?  In the old AD&D, there was a rule that said that attacks from monsters of 4D+4 hit dice or higher are considered magical in regards to hitting creatures like werewolves. I also remember reading years ago that attacks from creatures from other planes and attacks from creatures immune to non-magical attacks are also magical. But I can find no such rule in 5e.  Does this mean that werewolves fighting in wolf form cannot hurt each other, and that a typical CR9 fire giant has no chance to defeat a CR2 wererat?  How about the bite of the Tarrasque?

For Druid Wild Shape:     PRIMAL STRIKE Starting at 6th level, your attacks in beast form count   as magical for the purpose of overcoming resistance and immunity to   nonmagical attacks and damage.   For the Monk:     KI-EMPOWERED STRIKES Starting at 6th leveI, your unarmed strikes count   as magical for the purpose of overcoming resistance and immunity to   nonmagical attacks and damage.   The text seems to indicate the ability to bypass magical immunity requires a feature.  Alternatively, I have read that natural attacks and unarmed attacks aren't "weapons," and therefore you should just be able to pummel the Werewolf with your hands if your sword fails:     Melee Attacks (PHB p.195 (or in errata), emphasis mine). The rule on unarmed strikes should read as   follows: “Instead of using a weapon to make a melee weapon attack, you   can use an unarmed strike: a punch, kick, head-butt, or similar   forceful blow (none of which count as weapons).    However the errata for Monster Manual I guess clears that loophole:     Global Damage Resistances/Immunities. Throughout the book, instances   of “nonmagical weapons” in Damage Resistances/Immunities entries have   been replaced with “nonmagical attacks.”   We temporarily ad hoc'd an answer in our game to say the Stirges summoned by the druid were magical creatures(Fey) and hence had magical attacks against the Werewolves, even though they were 1HD(d4).  Now I see the druid made the Fey part up, and they are beasts, but oh well.  What is the real rule here?


I'm using 18.04.3 I read previous answers but the GUI seems different than previous answers as previous answers talk about older version.  I don't want screensaver and auto lock. My system automatically locks itself after few minutes of inactivity and also there's a screensaver. I want to disable this.

I want that my monitor turns off when I am inactive for a while, but I do not want that I am prompted for a password when I revoke my pc. In Ubuntu 16.04 it was possible to disable the lock but still enable the screensaver as explained .  In Ubuntu 18.04 I entered the following in terminal:  dconf-editor   and disabled ubuntu-lock-on-suspend:    However, since I made this change, my monitor never suspends anymore. I tried restart but it didn't help.  Any ideas how I can disable lock but still enable suspend mode?


I'm not sure why in some situations articles are not going before a noun. E.g. I found this sentence:     The best time to go out for dinner.   Why is not here a dinner? This  says that we don't put articles in front of noun if is already some determiner before, like this and that. But for is not a determiner, so I'm wondering why it's not correct to say a dinner?

Does one need to use the article in this case?