Android Eclipse - MediaPlayer in Fragments NullPointer

I'm having an issue with MediaPlayer code in fragments. Logcat is suggesting it's down to the OnClickListener in this passage of code within the SoundsFragment.java class.  Can anyone tell me what I'm doing wrong?  public void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.fragment_sounds);  setVolumeControlStream(AudioManager.STREAM_MUSIC);  Button button1=(Button)findViewById(R.id.button_1);  Button button2=(Button)findViewById(R.id.button_2);  button1.setOnClickListener(this);  button2.setOnClickListener(this); }   SoundsFragment.java file which hosts the mediaplayer code that was recently inserted and has causes these issues.  import android.app.Fragment; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.app.Activity; import android.media.AudioManager; import android.media.MediaPlayer; import android.view.Menu; import android.view.View.OnClickListener; import android.widget.Button;   public class SoundsFragment extends Fragment implements OnClickListener{      public SoundsFragment(){}      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container,             Bundle savedInstanceState) {          View rootView = inflater.inflate(R.layout.fragment_sounds, container, false);          return rootView;     }      private MediaPlayer mp;     @Override     public void onCreate(Bundle savedInstanceState) {      super.onCreate(savedInstanceState);  setContentView(R.layout.fragment_sounds);      setVolumeControlStream(AudioManager.STREAM_MUSIC);      Button button1=(Button)findViewById(R.id.button_1);      Button button2=(Button)findViewById(R.id.button_2);      button1.setOnClickListener(this);      button2.setOnClickListener(this);     }      private Button findViewById(int button1) {         // TODO Auto-generated method stub         return null;     }      private void setVolumeControlStream(int streamMusic) {         // TODO Auto-generated method stub      }      private void setContentView(int activityMain) {         // TODO Auto-generated method stub      }      public void onClick(View v) {      int resId;      switch (v.getId()) {      case R.id.button_1:        resId = R.raw.a;        break;      case R.id.button_2:         resId = R.raw.b;        break;      default:        resId = R.raw.a;        break;      }      // Release any resources from previous MediaPlayer      if (mp != null) {         mp.release();      }      // Create a new MediaPlayer to play this sound      mp = MediaPlayer.create(getActivity(), resId);      mp.start();     }       @Override     public void onDestroy() {       if(null!=mp){      mp.release();       }       super.onDestroy();     } }   fragment_sound.xml This is the xml file the manages the layout of the sounds fragment and is hosting the buttons.  <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:background="@color/sounds_fragment">          <Button         android:id="@+id/button_1"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignParentTop="true"         android:layout_marginRight="22dp"         android:layout_marginTop="36dp"         android:text="Play audio a.mp3" />      <Button         android:id="@+id/button_2"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignLeft="@+id/button_1"         android:layout_below="@+id/button_1"         android:text="Play audio b.mp3" />  </RelativeLayout>


Integrate $\sin(\cos(x))$ with respect to $x$

Solve this:     $$\int\sin(\cos x)dx$$   I checked on Maxima, mathematica but both cannot find its integral though numerical approximation is available in later. Has someone faced similar problem? Also, I saw that such problems are not stated in books also, no function can be expected to be invalid to integrate !!


Does there exist a self-adjoint operator whose spectrum is just the continuous spectrum?

Does there exist a self-adjoint operator whose spectrum is just the continuous spectrum, i.e. no point spectrum and no residue spectrum?  If not, please prove it.


long delay while opening folder files in ubuntu14.04

Folder file appears empty for few minutes even though it contains file in it. any solutions to get rid of this. os is ubuntu 14.04


Data transfer from Microcontroller to computer

I'm looking for a good link to data from Microcontroller to computer. I do not know what kind of communications is suitable for me.  I need a link which has a bit rate more than 50 Mbit/sec. and also it should be good enough reliable.  Moreover, I have not chosen the uC yet. What about these choices?   1-(uC side) USB to USB (PC side)  2-(uC side) SPI to USB (PC side)  3-(uC side) ethernet to ethernet (PC side)  Data is in fact received from a 16 channel ADC with a rate of 100 K. Data is processed in the uC and then would be sent continuously to PC.


Do I need a visa to walk over the Rainbow bridge?

Suppose I'm in Canada visiting the Niagara Falls. Now I want to walk over the Rainbow bridge to visit the American side of the falls. Do I need a visa for this? Or is there any special onsite visa for this purpose?  So I general: Do the same visa rules apply when walking over the Rainbow bridge as entering USA on a normal border?


On a QA server I need to give access to specific login  from  just one IP to log to this server.    I wrote This login  trigger    Create   TRIGGER tr_CheckIP ON ALL SERVER FOR LOGON AS BEGIN     DECLARE @IPAddress NVARCHAR(50) ;     If ORIGINAL_LOGIN()='test'       --print ORIGINAL_LOGIN()      begin       SET @IPAddress = convert(NVARCHAR(50),ConnectionProperty('client_net_address'))     --print @IPAddress     IF NOT EXISTS ( SELECT  IP                     FROM    master..IPAddress                     WHERE   IP = @IPAddress )         BEGIN               ROLLBACK          END     End END   However the trigger is preventing  the user from log although the IP exists in the IPAddress table.  Any idea where in the problem in the trigger


Why didn't I get the Java bronze tag badge?

According to the Help Center, the requirement of earning the Java bronze tag badge is:     Earned at least 100 total score for at least 20 non-community wiki answers in the java tag.   I've answered many questions with the  tag and gained more than 500 reputation, but I haven't gotten the Java bronze tag badge.  Could someone tell me why?  Am I misunderstanding some of the rules?


Write something to text field when any item from combobox is selected

I want to write something to a text field when I select any item from combo box.  But I couldn't do this.  Java code:  comboBox.addItemListener(new ItemListener() {     public void itemStateChanged(ItemEvent arg0) {             if(comboBox.getSelectedItem()=="apple") {                 tfbf.setText("apple selected");             }         }     });


Postgresql: Does autovacuum impact query performance? Does it apply locks which impact the performance of other queries?

Postgres recommends using the autovacuum to remove the dead tuples. But does running the autovacuum end up making other queries to the same table slow? Does it add locks (row or table level) which impact performance? Is there a significant load on CPU or does it consume lot of memory.   This will help us decide if we should turn on autovacuum for one of our tables which has very high amount of writes and deletes or if we should rather run a manual vacuum regularly during off peak hours.


Coloring the *text* of the entire row in a table

I can use colortbl to color the background of a row by setting \rowcolor{Gray}. How can I set only the text to gray and keep the white background instead?


What would have happened if Voldemort died a natural death?

According to , if Voldemort's natural body were to die he'd be rendered a spirit, in need of a body. We see this in Philosopher's Stone, where... well, where this happens. Voldemort accidentally kills his mortal body due to Lily's protection, and his spirit (somehow) flies to Albania, where it, eventually, meets Quirrel.   My question is this: If Voldemort had succeeded, and had lived a long long life with his Horcruxes intact, would his body eventually wither away (edit: due to natural aging), leaving his spirit lost and looking for a way to create a body as in Philosopher's Stone?  Edit: I'd just like to point out that this ISN'T a duplicate question. The answer to the question I linked clearly states that "even if [someone with a horcrux]'s body is attacked or destroyed, one cannot die". Now we see Voldemort die, his Avada Kedabra spell backfired and hit HIM. This reduced him to that "ghost"-like form. My question is asking about the natural death of the body case. Some mentioned that having horcruxes prevents natural death, but that isn't stated anywhere. Horcruxes seem to only prevent death in that they keep the soul "earthbound and undamaged".


What if my flight is delayed/cancelled leaving South Africa on my 90th day?

Planning a trip to South Africa but leaving on day 90.  I know that I don't need a visa when traveling 90 days or less, but what would happen if my flight is delayed or cancelled on that 90th day?


Is there a way to prove  $$1+\frac{1}{2}+\frac {1}{3}+...+\frac{1}{n-1} = \ln(n)+c+o(n)$$ where c is a constant? Any idea will be appreciated, thanks!


How do I install Adobe flash player on ubuntu 16.04?

I have google chrome and terminal always write: you cannot translate the name of the machine. Command not found...  What I must to do?


When using the quick smoke effect the bake option is not showing

I used Eevee. I only changed the Border Collision and Vorticity (followed YouTube tutorial).


My laptop fan is making a rattling sound

so 2 weeks ago I heard this very very loud rattling fan noise and the next day I opened my laptop and used some compressed air 1 week later the sound returned but it fixed itself somehow now today I woke up and guess what the sound is back and this time it doesnt fix itself I really dont know what to do now I'm setting my pc on very very low powerplan but this is honestly just unusable can anybody give me any advice on what to do also if you wanna hear the sound I could send it on discord or something


Wrong order of reference number in latex

I have 3 references in my report, below is my bibtex file. The problem is when I do \cite{article1} in my first citation, it showed [2]. And the second \cite{article2} showed [3] and the last showed [1].   @article{ article1, Author = {Jie, Ding and Ning, Li.}, Title = {A Distributed Adaptation Management Framework in Content Delivery Networks}, Journal = {Wireless Communications, Networking and Mobile Computing (WiCOM)}, Pages = {23-25}, Year = {2011} }  @article{ article2, Author = {Molina, B. and Ruiz, V. and Alonso, I. and Palau, C.E. and Guerri, J.C. and Esteve, M.}, Title = {A closer look at a content delivery network implementation}, Journal = {Electrotechnical Conference}, Pages = {685-688}, Year = {2004} }  @article{ article3, Author = {Chen, Y. and Katz, R.H. and Kubiatowicz, J.D.}, Title = {Dynamic Replica Placement for Scalable Content Delivery}, Journal = {Intel workshop on Peer-to-Peer Systems}, Pages = {306-318}, Year = {2002} }


Do All The Warnings of Dual Booting Apply to Me If I am Using a Separate Drive?

On my computer I have a typical SATA SSD (with my current Windows 10 installation) and and another separate M.2 SSD. I have more than enough space on my normal SSD and would like to install KUbuntu on my M.2 SSD. As I read through questions about dual booting, I see warnings about things like UEFI, Secure Boot, and Fast Startup and wonder if they apply to me since most of the time it seems as if they are all talking about dual booting from the same drive. I have the installer flashed to a USB drive right now but I would like to know if I should be worried about anything such as corrupting my Windows installation. I would like to know if I can keep fast startup on, if I have to change anything with UEFI or secure boot, and if I have to unplug anything like the people on this discussion are talking about;  Also feel free to give me some simple partition layouts geared towards programming for my KUbuntu  installation :)


I have always had problems with my windows directory's growing to a huge size.  It started with windows 95 then 98 then 2000 and xp.  Windows 7 however is absolutely huge.  The windows folder itself with out program files is 21.4 gigs...add the program files and other windows files and it is a whopping 32 gigs.  My question is why is it so large and what can I do about it.  At the rate this is going I will be out of space in now time.


biblatex: \parencite in note field prints spurious ; with authoryear-icomp style

I have a book and two of its translation in my bibliography list. Each book has a note that cites the other translation. For that, I use a \parencite command in the note field.  If I use the authoryear-icomp style a spurious ; appears in the notes; as shown in the image. With the authoryear style this is not happenning.     What should I do to remove the unwanted ;?  \documentclass{article}  % \usepackage[style=authoryear]{biblatex} \usepackage[style=authoryear-icomp]{biblatex}   \usepackage{filecontents} \addbibresource{biblio.bib}   \begin{filecontents}{biblio.bib} @book {b11,      MRKEY = {MR0113788},     AUTHOR = {Bourbaki, Nicolas},      TITLE = {Éléments d'histoire des mathématiques},     SERIES = {Histoire de la Pensée, IV},  PUBLISHER = {Hermann, Paris},       YEAR = {1960},      PAGES = {277},    MRCLASS = {01.00},   MRNUMBER = {0113788}, MRREVIEWER = {C. J. Scriba},       note = {Também disponivel em Inglês em \parencite{b11en} e Espanhol em \parencite{b11es}}, } %%%% @book {b11en,     AUTHOR = {Bourbaki, Nicolas},      title = {Elements of the History of Mathematics},       isbn = {9783540647676},       lccn = {98039221},        url = {http://dx.doi.org/10.1007/978-3-642-61693-8},       year = {1998},      PAGES = {301},  publisher = {Springer-Verlag},    address = {Berlin Heidelberg},       note = {Traduzido por J. Meldrum do original em Francês \parencite{b11}, também disponivel em Espanhol em \parencite{b11es}}, } %%%%  @book {b11es,     AUTHOR = {Bourbaki, Nicolas},      title = {Elementos de historia de las mathemáticas},       isbn = {84-206-2018-1},       year = {1972},      PAGES = {401},  publisher = {Alianza Editorial},    address = {Madrid},       note = {Traduzido por Jesús Hernández do original em Francês \parencite{b11}, também disponivel em Inglês em \parencite{b11en}}, } %%%% \end{filecontents}   \begin{document} \pagestyle{empty} \parencite{b11} \nocite{*}  \printbibliography{} \end{document}


I have a sticky situation and I'm not quite sure how to deal with it.  As part of branding a company for a friend/client I have created some cartoon type characters (as well a logo, fonts, colours, feel and all the other branding stuff). Now this is a good friend so I'm not necessarily concerned about losing business but he's involved someone else to do some facebook marketing. This third party wants all the individual assets.  I'm doing all this work at a reasonable rate and would like to retain control of the artwork used.  As this is a friend I have offered to create backgrounds for the ads for free when ordinarily I would be negotiating a better rate for handing over the constituent parts of my design work.  The third party is pressing for the parts so I would welcome any input on how to proceed and what my expectations should be.  Thanks.


In the beginning of mathematics, Number system was restricted to only integers.  then solutions of equations like $2x=5$ Needed us to extend it to rationals.  then solution of $x^2=\frac{1}{2}$ needed us to extend it to irrational.  Then solutions of $x^2=-1$ needed us to extend it too complex as well.    So considering this analogy solution of $f(x)=a,a \in A$ may not belong to A necessarily, Thus can we not say that numbers beyond complex numbers may exist.       ie. If $f(x)=z,z \in C$ but $x \notin C$     Is there any fundamental theorem which restricts this extension, Are there any clues of this extension, Please discuss and help.


I download the code file (tex) of articles on . But I can not open it by texmaker. Do you know how to do this? For example,    Go to this   See on the right corner  Choose Download: other formats  Choose Download source   Then how can I open the file I have downloaded?


Do not capture Ctrl + F/B/K keyboard events when editing in Stack Overflow Editor on Mac OS X

On Mac OS X, these shortcuts Ctrl + B, Ctrl + K belong to Mac's readline shortcut:  Since Stack Overflow's editor has used Cmd + B/K as a shortcut for editing, there isn't any need to take up the shortcut keys of the Mac system. I recommend the following shortcuts for Mac OS X users.  Ctrl + B       Move Cursor Backwards Cmd + B        Bold Text Ctrl + K       Delete Text Forwards Line Cmd + K        Code Sample


How do I install the Fortran 9x compiler?

I want to install a program called OSIRIS but, I need to get the Fortran 9x compiler. I was wondering how do I install it? I am using a Ubuntu 16


I use the mobile SE app a lot; it is my primary access to SE. So, what bugs me is that when I find a question with a bounty, all we get is this:   Which is compared to users of browsers, who see this:   Although not much more detail in this case, it still has more; unlike on mobile, Browser users can see why the bounty was set, along with the comment from the bounty-setter. Why can't we have this as a feature in Mobile SE?


Indicate Journal name for "under review" and "accepted/in press" publications on CV

there are similar questions on how to list on CV publications that have not passed the accepted or in press stage when applying to junior research positions ( PhD/postdoc).  I am not clear if such publications should include the journal name or not, and what would be the reason for either choice.


I know that a semicolon should be used before a transitional phrase and a comma after, but what about in a sentence like this:  "This study has; however, demonstrated comparable rate, further supporting the use of traps"  or  "Abundance was; however, higher in the BGS trap"  Is this incorrect? If so, would it be correct to remove the semicolon and comma completely?


Find FreeBSD ports that depend on another port

I have a headless FreeBSD server where some port has installed tons of X11-related packages. I would like to find out what these ports are so I can get rid of the unwanted X-related packages. Is there a way to figure this out?


How to write properly math accent for letter i?

When it is requested to write letter "í" in math mode, it happens that $\acute{i}$ is not the right answer as it could be expected: the accent (´) is written over the letter (i), without deleting/overwriting the upper dot (^{.}) Another possiblity to solve the problem: $\acute{\imath}$, not always works satisfactorily. Is there another way to do it, obtaining an acceptable/appropriate character?


Need span in middle of image but not working

I am trying bring text in middle regarding image but it's not working.  I tried this but not working either    HTML

          Some Text

   CSS  .cz {      width:100%;      height: 30%;     float:left;     position:relative; }  .ca {      margin: 5px 0px 0px 30px; }  .cb {   position:absolute;     text-align: center;     vertical-align: middle;     right:0;     top:0;     margin: 20px 20px 0px 0px; }


Given a matrix A, return the transpose of A. The transpose of a matrix is the matrix flipped over it's main diagonal, switching the row and column indices of the matrix. Example Input: [[1,2,3],[4,5,6]] Output: [[1,4],[2,5],[3,6]] my code: def transpose( A):     length = len(A)     width = len(A[0])     res = [[0] * length] * width     for i in range(length):         for j in range(width):             res[j][i] = A[i][j]     return res        transpose([[1,2,3],[4,5,6]])  my code's result : [[3, 6], [3, 6], [3, 6]] I track in the double loop, every time the res is updated, the value of a column is updated. def transpose( A):     length = len(A)     width = len(A[0])     res = [[0] * length] * width     for i in range(length):         for j in range(width):             res[j][i] = A[i][j]             print(i,j,'->',j,i)             print(res)     return res        transpose([[1,2,3],[4,5,6]])  The output information is as follows: 0 0 -> 0 0 [[1, 0], [1, 0], [1, 0]] 0 1 -> 1 0 [[2, 0], [2, 0], [2, 0]] 0 2 -> 2 0 [[3, 0], [3, 0], [3, 0]] 1 0 -> 0 1 [[3, 4], [3, 4], [3, 4]] 1 1 -> 1 1 [[3, 5], [3, 5], [3, 5]] 1 2 -> 2 1 [[3, 6], [3, 6], [3, 6]]  But the following code gets the correct result： def transpose( A):         length, width = len(A), len(A[0])         res = [[0] * length for _ in range(width)]         for r, row in enumerate(A):             for c, val in enumerate(row):                 res[c][r] = val         return res  transpose([[1,2,3],[4,5,6]])  It's confusing!Is there any difference between the two ways of loop？ Is it caused by the underlying code optimization during compilation?


If product of two sets $A\times B$ is closed, are $A$ and $B$ closed?

If $A\times B$ is closed in $X\times Y$, then are $A$ and $B$ closed in $X$ and $Y$ respectively?


Generating a single TeX file by merging different TeX files

I have a main TeX file which inputs many other TeX files i.e. for example  \documentclass{article} \begin{document} \input{input1.tex} \input{input2.tex} \input{input3.tex} \end{document}   Let's call the above file say main.tex I want a single TeX file which imports contents from input1.tex,input2.tex and input3.tex, so that I have only one single TeX file instead of the above four TeX files.


Trying to create a blackboard texture and gradient in Photoshop

I'm trying to create a wedding invitation but I'm struggling to get the same effect as the example one I've seen on a website.  How would I create the same background effect? I've tried using the gradient tool in Photoshop, but it doesn't seem to create the same effect.    Thanks!


I need to parse my HTML page to replace some links, this is the form of a link Mauris nec. The problem is that my regex expression doesn't end properly, I think it's because of the ".  This is my Regex expression :  Regex r= new Regex("(.*)");   That regex doesn't end after each link, and the third group doesn't contain the title property but almost all the html until the last  of my html.  I tested it with this site :      So, why doesn't the third group end directly after Bas-Rhin" ?


When quoting a lyric or line of poetry in running prose, should the original capitalisation be preserved?


Ways to provide list of parameters to options in shell scripts?

Basically I am making a script where I would like to give a list of parameters to some option, say -l, eg: usr@domain:$./somescript -l hi bye cry nigh  The list specified to -l would be then stored into a specific array and iterated over. So far, I have been using these lines from Arch linux's mkinitcpio script to do so. This allows one to specify a comma-separated list to an option: _optaddhooks()  while :; do     case $1 in         -A|--add|--addhooks)             shift             IFS=, read -r -a add <<< "$1"             _optaddhooks+=("${add[@]}")             unset add             ;;  What are some other methods to do this, particularly when other options/parameters will be used? Can the list provided to an option be space separated? Or is specifying a list by "," (or some other character") easier to manage?


What is the value of the sum $$\sum\limits_{n=0}^{\infty}(-1)^{n-1}\frac1{(2n+1)^3}$$ I think the sum evaluates to $\frac{7\zeta(3)}{8}-\frac1{32}\zeta(3,-\frac1{4})$, where the last zeta is the Hurwitz zeta function. But, Hurwitz zeta is defined only for $\operatorname{Re}(q)>0$ as a Dirichlet series in this manner. Am I right? Any hints? Thanks beforehand.


How to call the default Exit button (the on next to the minimize/fullscreen buttons)? SOLVED

I want the user to be able to get an alert / warning if the Default Exit button of the Tkinter Window is getting clicked (the one next to the 2 others for minimizing and fullscreen mode). . Have searched, read, and looked many places for finding how to call this default button. Can anyone help?


Is JavaScript's "new" keyword considered harmful?

In another , a user pointed out that the new keyword was dangerous to use and proposed a solution to object creation that did not use new. I didn't believe that was true, mostly because I've used Prototype, Scriptaculous and other excellent JavaScript libraries, and everyone of them used the new keyword.  In spite of that, yesterday I was watching Douglas Crockford's talk at YUI theater and he said the exactly same thing, that he didn't use the new keyword anymore in his code ().  Is it 'bad' to use the new keyword? What are the advantages and disadvantages of using it?


I was wondering about a problem which i could reduce to asking the following   Does there exist a set $a,b,c$ of prime numbers such that $$a^a+b^b=c^c$$  Is it really a tough problem or do you think it can be solved with some amount of work .  Thank you for your ideas and help .


How do I remove a broken software source?

I accidentally added this in a terminal:  sudo wget http://www.medibuntu.org/sources.list.d/gutsy.list -0 /etc/apt/sources.list.d/medibuntu.list   after which I get this error:  E:not known on line 1 file /etc/apt/sources.list.d/medibuntu.list E:Could not read source list etc...etc...   I saw that you already 'solved a similar problem ... can you help me  Original (italian):  gestore pacchetti bloccato   Ho inserito per sbaglio questo comando nel terminale:   sudo wget http://www.medibuntu.org/sources.list.d/gutsy.list -0 /etc/apt/sources.list.d/medibuntu.list dopodiche si e'bloccato gestione pacchetto e ricevo questo errore: E:non riconosciuto alla riga 1nel file /etc/apt/sources.list.d/medibuntu.list E:impossibile leggere elenco sorgenti etc...etc...   ho visto che hai gia' risolto un problema simile... mi puoi aiutare


Where do I report a bug about touchpad behaviour?

I found a bug (or probably: unimplemented behaviour) in how the touchpad operates in GNOME 3. I'd like to report it in the appropriate channels (or at least check if it's already reported), but I have no idea with software is responsible for its behaviour. Who knows?  Note that I do not want to report an Ubuntu-specific bug, as described in , and the Wiki page  also does not describe which package is appropriate for the touchpad handling.


Cannot install Ubuntu 16.04 in BIOS mode

I'm new to Linux and i have encountered a somewhat difficult problem for me. I currently run my system on Windows 10 installed in BIOS mode. I am trying to dual-boot by installing Ubuntu 16.04 x64 (from a USB stick made bootable with Rufus) on a separate partition to the Windows one (i have 4 : 2 for storage, one for Windows and a free one for Ubuntu) I've tried installing it by booting in legacy mode and with CPM enabled in bios but probably due to the fact that my video card has no VGA port, everytime, after the purple ubuntu loading screen, my monitor stays black. I managed to bypass this by disabling CPM and inserting in the grub command window the parameter "nomodeset" before launching the installer but what is bugging me is that by disabling CPM, my installer goes into UEFI mode due to my boot order being resetted and i'm being warned not to force an UEFI install while having the Windows in BIOS. Can you help me, pretty please? ^_^   Motherboard : asrock b85 pro4 Video card : nvidia gtx 970 oc CPU : i5 4460


If $a^2+b^2=c^2$ then $a$ or $b$ is even.

I am having trouble proving this directly. I know that it is easy to prove by contradiction by assuming both $a$ and $b$ to be odd, but how should I start to try to prove this? This is a homework problem and I am just looking for help getting started, not the full answer.


What is BODMAS and why is it useful in programming?


When Garou fights heroes does he actually kill them or just severly injure them. If he killed them then that will leave the Hero Association at a huge loss and in previous episodes     When Garou fought the 8 heroes in Gatling Gunner's squad it seemed like some of them died.   Does he actually kill heroes?


Regular expression to select only first substring from multiline text

I need to replace multiline substring in Notepad++  Text:  some text-123 first time occurrence1 blah-blah-blah some other text -blah end of selection1 abc -blah-blah 123 second time occurrence2 blah-blah-blah -blah-blah end of selection2 def some other text   So, I need to select:  123 first time occurrence1 blah-blah-blah some other text -blah end of selection1 abc   but Regex  (?im)123 [\S\s]*end of.*$   selects   123 first time occurrence1 blah-blah-blah some other text -blah end of selection1 abc -blah-blah 123 second time occurrence2 blah-blah-blah -blah-blah end of selection2 def   How can I select only first occurrence, except "second time occurrence2"?


Since Windows 10 (or earlier?). It has become standard to store the license product key in the UEFI/BIOS.  I am in the market for buying a new (custom build, individual parts) PC with a new Windows 10 License.  However I was wondering (and can't find clear information on this subject). What the differences between the licenses are when it comes to OEM and Retail.  If in the far future I were to sell this PC:   Would the license (whether OEM or Retail), be stored in the UEFI/BIOS, where it could be used by the new owner? If so, can I remove the license key from the UEFI/BIOS?   I want to know this because I don't want to buy Windows 10 every single time I buy a new PC (since no new versions of Windows will be created, only updates).


What is the best control to use to select from a list of thousands of possible options?

I have a field which needs to be populated from a large list of items (many thousands). These items have unique numbers as identifiers, and there can be many thousands of them. (Similar to the way that bug tracking software will label 1000 items from #1 -> #1000). The field must be populated with a valid value.   A dropdown is obviously not a suitable control here. I've thought of five possible solutions:   Free text input, with some kind of validation on input blur. As (1) but with a manual 'check' button which manually validates input instead of doing it automatically. As (1), but with a 'search' button which overlays a form allowing user to search on various item properties (ie. item title), and then select from a list of valid options? An inline sortable/filterable/pageable grid showing all items and some properties (such as identifier, Title, Date Created). As (4), but the grid is hidden by default. A 'search' button opens the grid in an overlay.    The first two options require the user to already know the ID of the item they are selecting or navigate away from the page and search for it. The inline grid might take up quite a lot of space for what is supposed to be a fairly simple selection. The overlays again seem quite complex for a simple control.  Are any of the options I've detailed appropriate? Is there a better way?


How to prove that $n$ is a prime if $2^n-1$ is a prime

I got this by watching a video on youtube and they said that this is always true but I am wondering why. I have tried to use Fermat's little theorem (FLT) but got nowhere bcs it says that if p is a prime then $p|{a^p-a}$.


Is it possible to protect oneself from a lightsaber with bare hands?

held Anakin's lightsabers with his hands. Ok he's really powerful.   But the point is, as maybe using the same Force protection from Force lightnings, one could hold the light of a lightsaber or defend using their own arms, or even protect their own body from it.  We see Vader using his own hands to defend from blasters on Lando's planet.  At this episode on the Clone Wars, when the Father holds it you can see the same glow around his hands.  What are your thoughts? Is it possible and common?


A positive integer is divisible by $3$ iff 3 divides the sum of its digits

I am having trouble proving the two following questions:    If $p|N$, $q|N$ and gcd(p,q)=1, then prove that $pq|N$ If $x$ is non zero positive integer number, then prove that $3|x$ if and only if 3 divides the sum of all digits of $x$.   For both questions I tried to use theorems of discrete mathematics, but I could not find the way to solve them.


When a character with no fly speed ends their turn in the air, when should they start falling?

We had a situation last session where I (sorcerer/monk) ended my turn mid air after striking a flying monster trying to flee. It was already 100 feet high so I used a quickened Thunder Step to teleport 90 feet up on the wall and step of the wind to jump from it and strike the monster with two melee attacks. It wasn't enough to finish it and I was left mid air. I thought that I would immediately fall down and be okay since it's a forced movements and thus does not trigger an Opportunity Attack and thanks to the Slow Fall feat I wouldn't take too much damages. But The DM ruled it as the monster getting to hit me before I fall since his turn was next so I was knocked unconscious and died of the fall (no Slow Fall when you're unconscious). I'm not mad at the DM for making this choice, I knew it was a reckless action when I took it, but it got me thinking when should a character start falling when they ends their turn in the air.


Do vacuum bubbles exist in theories with normal ordered Hamiltonian?

When we calculate the Hamiltonian in the free theory, we notice that it contains an infinitely large term  \begin{align}  H   &=  \int_V \mathrm{d }k^3  \frac{\omega_k}{(2\pi)^3 }   a^\dagger(\vec k) a(\vec k)+ \frac{1}{2} \int_V \mathrm{d }k^3  \omega_k  \delta(\vec 0)    \, . \end{align} We can get rid of this term by claiming that nature only uses normal ordered operators, in which case there is no infinitely large term.  As soon as add an interaction term like $\phi^4$, we encounter the same problem. If we switch the operators around using the commutation relations we find infinitely large terms that are all related to field commutators evaluated at the same spacetime point $[\phi_{-}(x) ,\phi_{+}(x)]  \sim \infty $. In diagrammatic form, these terms are given by self-loop diagrams     Again, the problem can be solved by demanding that the Hamiltonian is brought into normal form before we quantize it. If we work with a normal ordered Hamiltonian there are no self-loop diagrams.  This seems to suggest that if we work with normal ordered Hamiltonians, at least some of the vacuum bubble diagrams no longer exist. Does normal ordering remove all vacuum bubble diagrams or are there some remnant diagrams that are not removed through the process of normal ordering?


C++: writing a function for a struct outside that struct?

For classes, you could just say:  class Test{     int a;     Test(int a); }  Test::Test(int a) {     this->a=a; }   Function names get "classname::" in front of them when declared outside of class.  How would I do this for structs?  struct Test {     int a;     Test(int a); }   How would I write the function for this struct Test outside of struct declaration so that it can be only be called by a Test struct?


Can't delete file with strange characters in name

I have an old file named ˇ¡␀␀ˇ¡␀␀␀"9 ␀"9 which is not deleted when I empty the trash. I have tried renaming it but it does not accept any changes. Using the Terminal didn't work either so far:  Mac-Pro:deletethisfolder me$ find . -inum 425884608 -delete find: -delete: rmdir(./ˇ¡␀␀ˇ¡␀␀␀"9\006␀"9): Invalid argument   what can I do? Thanks!


how to proof that $1,9999.... \in \mathbb{Z}$?

I want to prove that $1,999\dots$ Is an element of $\mathbb{Z}$. Here is my try :   $x = 1,9999\dots \\  10x = 19,9999\dots \\ 10x - x = 18  \\ 9x = 18  \\ x = 18/9  \\ x = 2 $    So $x \in \mathbb{Z}$   I know something is wrong but where ?


A question regarding existence and uniqueness in IVP

Consider the IVP $$y'(t)=f(y(t)), \ \ \ \ y(0)=a \in \mathbb{R}$$ $$f : \mathbb{R} \rightarrow \mathbb{R}$$ Which of the following is/are true $(A)$  There exists a continuous function $f : \mathbb{R} \rightarrow \mathbb{R}$ and $a \in \mathbb{R}$ such that the above problem does not have a solution in any nbd of $0$. $(B)$  The problem has unique solution for every $a \in \mathbb{R}$ when $f$ is Lipschitz continuous $(C)$ When $f$ is twice continuously differentiable the maximal interval of existence for the above IVP is $\mathbb{R}$ $(D)$ The maximum interval of existence  for the IVP is $\mathbb{R}$ when $f$ is bounded and continuously differentiable.  It is obvious to me that $A \ \& \ B$ are false from traditional existance and uniqueness theorems (viz Picards Theorem). I am not sure about $C \ \& \ D$ and this is really bugging me. Please could anyone shed light on this. PS: Multiple correct options are allowed.


I recently moved to Linux from OSx and in there I had mapped Caps lock to Ctrl+b. This was mostly done because of tmux.   How can I do this in Ubuntu 14?  There is a very comprehensive answer here how to remap keys:   But this doesn't cover a key combination like Ctrl+b. It only covers remaping a single key to another key.


Prove ${2n\choose n}=\sum\limits_{k=0}^n {n\choose k}^2$     My Approach: I will be making use of $$\tag 1\quad{m+n\choose r} = {m\choose 0}{n \choose r} + {m\choose 1}{n\choose r- 1} + \cdot\cdot\cdot + {m\choose r}{n \choose 0}$$ and $$\tag 2{a \choose b}={a\choose a-b}$$     By (1) $${2n\choose n} = {n+n\choose n}= {n\choose 0}{n\choose n}+{n\choose 1}{n\choose n-1}+\cdot\cdot\cdot + {n\choose n}{n\choose 0}$$  By (2) $${2n\choose n} = {n\choose 0}^2 + {n\choose 1}^2 + \cdot\cdot\cdot + {n\choose n}^2$$  Then $${2n\choose n}=\sum\limits_{k=0}^n {n\choose k}^2$$    Please have a look at my solution and give me any hints and\or suggestions you may have.


Handling names with leading dash in bash shell

How can I handle (e.g. apply mv command) in a command shell the files with leading dash (-) in names? The command  mv -weirdfilename.zip normalfilename.zip    naturally accepts - at the beginning of a filename as an argument.


Is the set of all strings of finite length $\Sigma^*$ from a infinite alphabet $\Sigma$ uncountable?  The usual procedure in these types of proof is that you   list strings of length 1 list strings of length 2 list strings of length 3 .......  .......  ....... and so on   But now even the first line has infinite length so the construction can never stop. What is wrong?


I am looking for title of Book about a kid or kids who build a rocket or space ship

I read it when I was a kid maybe 25 to 30 years ago. I remember details about how he built it, but not if he/they flew anywhere. Maybe it was built/stored in a cave at the beach??  I don't think it is "Welcome to Mars" or "Rocket Boys". I've google searched quite a bit. Any hints? Thanks


Function pow() does not work correctly when using big numbers?

Please explain why pow() doesn't work for the big number such as 2^63?(if you write a pow function with the prototype of pow(long long int a, long long int b) instead of pow(double a, double b) it works fine.)  here is the code:  #include <stdio.h> #include <math.h> int main() {     printf("%.0lf\n" ,pow((double)2,63)); }   output:  9223372036854775800   true answer:  9223372036854775808   thanks.


Is it possible to communicate with other VisualForce pages/components from a VF component?

I have a VisualForce page that is made up of different components. One of my components is passed in a Case and displays the case fields.   If there is an edit to the case I would like to save it with associated controller to that component. If saving produces an error I would like to pass that error to the parent VisualForce page/controller and display the error message there.   Is it possible to communicate with other components/VisualForce pages? I am looking for something similar to an event in lightning components.


Does $\sum_{n=1}^{\infty}\frac {\sin{\frac 1 n}} {\sqrt n}$ converge?

So my teacher gave a pretty tough (for me) problem in class today: Does the series $$ \sum_{n=1}^{\infty}\frac {\sin{\frac 1 n}} {\sqrt n} $$ converge or diverge?  So far I've thought of trying the Comparison Test and Ratio Test but couldn't really get anywhere. Intuitively I think it should converge, but how do I actually show this?


How to mount an unmounted USB device Ubuntu using command?

I first eject device using sudo eject /dev/sr1. And then sudo umount /dev/sr1. But now it's not showing me the device which i'm unmounted. I want to mount it using command.


What will be the direction of motion of a test charge released at a point in an electrostatic field?

I have recently come across a statement in my book that,  "when a test charge is released at a point in an electrostatic field, the direction of traversal of the test charge will not be along the field line passing through the point at which the test charge is released." Why is this so?  Wouldn't the charge travel along the electric field line passing through the point?? Could someone explain my why the above mentioned statement is true ?


Why didn't Michonne's tied-up zombies try to eat her?

Just because she chopped off their arms and de-toothed them, wouldn't they still be clamoring to eat her, like all the other walkers?


How do we know that nuclear decay is truly random and spontaneous?

Nuclear decay is said to be random and spontaneous but how do we know for certain, that it is not just a lack of understanding of some other unknown force.  Doesn't everything in the universe just depend on the starting conditions, arguably nothing is random.


Inline formatting in the Stack Exchange apps and mobile web eats spaces

contains several lines with inline formatted code. It looks aligned in web:        But it looks like spaces are eaten in the Android app:        Same buggy behavior in iOS app:         And mobile web:         App Version: 1.0.95 Device Manufacturer: LGE Device Model: LG-H860 OS Version: 7.0 (1710300506712)      App Version: 1.7.0.1 Device: Unknown (iPad7,3) / iPad Pro 10.5" OS Version: Version 10.3.3 (Build 14G60)


Young adult time travel novel where the hero is recruited by a good scientist and tempted by his evil doppelganger

A teenager meets a scientist and his daughter, and discovers that they can travel in time.  In the book, time travel into the past can create overlapping branches, potentially leading towards chaos. An evil (or just self-serving and corrupt) version of the scientist and his daughter show up, and tempt the young man into working for them.  Part of the plot involves a hideout far in the past, in the arctic, where there's no chance of affecting causality. The young man is abandoned there for awhile, then rescued... There's a nightmarish scene involving elevators stopping on multiple floors at the same time, and a sequence where the young man sees the scientist doing an elaborate exercise routine with leaps and hurdles, that turns out to be practice for a heist of some kind.


Accuracy in neural network for regression

I want to measure the accuracy in neural network that performs regression. I have two outputs. Is the root-mean-square deviation ( ) the right way to go?   From wikipedia     RMSD is a good measure of accuracy[...]   How do I use it? I want to show how the accuracy is changing over epochs.  In classification measuring accuracy is simple. $$ accuracy = \frac{TP+FN}{TP+FP+TN+FN} $$


Having read the threads  and  I am wondering for classes such as SqlConnection or one of the several classes inheriting from the Stream class does it matter if I close Dispose rather than Close?


Why does separating plastic from a cough drop create flashes?

I was tearing open individually-wrapped cough drops in the dark, and noticed that when I pulled apart two adhesive-joined pieces of silvery plastic film, small flashes of light were produced. It was not a reflection--it was pitch dark.  What causes this?  The product is Bee M.D. Organic Honey Throat Drops--kind of gooey, old ones (laugh). They contain menthol and eucalyptus oil. I did some more experimenting and think the the flash could actually be separating the plastic from the cough drop itself rather than pulling apart the adhesive. The item is small, the room is dark, my finger has a wound, and all in all it's hard to tell for sure.  I don't know if this is a physics or chemistry question--it depends on the answer.


Circular arrangements of identical objects

Q> In how many ways can 5 identical red beads, 3 identical green beads and 2 identical blue beads be arranged in a necklace?


He swam slowly to the island.  He slowly swam to the island.    Some experts say that there is a “slight difference” in meaning. Would you please tell me that difference?


For my cryptology class, we're asked to prove this statement:  Let $p$ be prime and $a, b$ be integers such that $p \nmid a$. Prove that if $p^2 \mid ab$, then $p^2 \mid b$.  I'm not sure where to even begin with this proof. I think it must rely on some property of $p$ as a prime number since the next question was to give a counterexample to show it's not necessarily true for composite $p$, but since $p^2$ is no longer a prime number (since it would be divisible by at least 1, itself, and $p$), I'm not sure where this comes in. I thought to try the definition of divisibility and say there exists a $k \in \mathbb{Z}$ such that $p^2 k = ab$, but I don't see where to go from there. Since $p^2$ isn't prime, I can't use that $p \mid ab \implies p \mid m \,\text{or}\, p \mid n$. Edited to add: we have covered the fundamental theorem of arithmetic, but I don't see how to apply that either. Perhaps to say that $k$ is either a prime or a product of primes? I'm not sure whether that produces any progress. Any hints as to first steps I could take or a sketch of the proof would be very much appreciated.


Enthusiast and Fanatic badges should be counted in the user's local time

I am trying to get the Enthusiast badge. However, trying to coordinate my visits to the site with UTC time is hard.   There is no reason why you can't time these badges in the user's local time, either by IP address or a setting in the Profile. (If there is, comment.)


In C# check that filename is *possibly* valid (not that it exists)

Is there a method in the System.IO namespace that checks the validity of a filename?  For example, C:\foo\bar would validate and :"~-* would not  Or a little trickier, X:\foo\bar would validate is there is an X: drive on the system, but wouldn't otherwise.  I suppose I could write such a method myself, but I'm more interested in a built-in one.


How to move AdSense block in responsive website?

Making my website responsive I've faced the challenge - I need to move AdSense block, for examlpe: in desktop version of website AdSense adblock is located below the first post of my blog, but in the mobile version - above the first post of my blog.  Usually it's easily solved by using css @media queries  for hiding/showing one of blocks (the one above or the one below). But can I make it with AdSense blocks?  These blocks will have the same slot-id. I think that is breaking the adsense google policy. What alternatives are there to fix this?


Is it possible to add a variable reference to an execute method that implemnets SchedulableContext sc

I need to pass a reference to a string variable to a method that implements (SchedulableContext sc) I tried:   global void execute(SchedulableContext sc, loginstring){   but I'm getting a compile error "Compile Error: unexpected token: ')'" What am I missing here?


Eliminating non-integer solutions to $ab / (2\sqrt{ab} + a + b)$

I am writing a program to output all $a,b \in \mathbb{N}$, where $a \le b \le n$ (for a given $n \in \mathbb{N}$), such that  $$ \frac{ab}{2\sqrt{ab}+a+b}=c\in \mathbb{N} $$  For example, $a=9$, $b=36$, and $c=4$ satisfy this equation.    My program runs at a tolerable speed for values of $n<10^5$, but is not efficient enough for higher values.  Is there anything of value from number theory that I can use to eliminate my options?  For instance, I know that $\sqrt{ab} \in \mathbb{N}$ is a necessary (but not sufficient) condition.


Is there a group $G$ such that $\mathrm{Aut}(G)\simeq (\mathbb{Q},+)$?

My guess is that no such $G$ exists. All I know is that if $\mathrm{Aut}(G)$ is abelian, then $G$ is two-step nilpotent. Since $\mathbb{Q}$ is locally cyclic (i.e. every f.g. subgroup is cyclic), can we say more about $G$ in this case? Must it polycyclic-by-finite?  What I can show is that there is no group whose automorphism group is $\mathbb{Z}$.     Proposition. There is no group $G$ such that $\mathrm{Aut}(G)\simeq \mathbb{Z}$.   Proof. If $\mathrm{Aut}(G)\simeq \mathbb{Z}$, then $G/Z(G)$ is cyclic (because it is isomorphic to $\mathrm{Inn}(G)$, and is therefore isomorphic to a subgroup of $\mathbb{Z}$), and this implies that $G$ is actually abelian. Let's write $G$ additively: then the inversion map $\sigma(x):=-x$ is an automorphism $\sigma:G\rightarrow G$ with $\sigma^2=1$. Since $\mathbb{Z}$ has no elements of order $2$, the only possibility is $\sigma=1$, which means $2x=0$ for all $x\in G$. Therefore $G=V$ is actually an $\mathbb{F}_2$-vector space, infinite-dimensional since $G$ has to have infinite cardinality. But then $\mathrm{Aut}(G)=\mathrm{GL}(V)$ is not abelian (e.g. it contains finite symmetric groups). QED    Now I want to show the same result with $\mathbb{Z}$ replaced by $\mathbb{Q}$.  If $G$ is a group with $\mathrm{Aut}(G)\simeq \mathbb{Q}$, then perhaps by mimicking some Galois theory, we can find a group $H$ so that $\mathrm{Aut}(H)\simeq \mathbb{Z}$? This would contradict the above proposition.  (Sorry if this is a duplicate, but I did a lot of searching and found nothing before deciding to post.)    Here is another attempt along the same lines.     Proposition. There is no finitely-generated group $G$ such that $\mathrm{Aut}(G)\simeq \mathbb{Z}$.   Proof. Same technique as above. If $G$ is finitely-generated, then $G/Z(G)\simeq \mathrm{Inn}(G)$ is a finitely-generated subgroup of $\mathbb{Q}$. Since $\mathbb{Q}$ is locally cyclic, it follows that $G/Z(G)$ is cyclic, so $G$ is abelian and we're done. QED


Is there a generalized solution to the birthday problem?

The problem of the calculating the probability that there is a birthday shared by at least 2 people in a group of size n is well known. I am wondering if there is a way of finding the probability of there being a birthday shared by m people in a group of size n. I couldn't find any info about this online and was unable to solve it myself.  The particular question asked by a friend of mine was on the chances of there being some day which is at least 4 peoples birthday from a group of 50. I was able to get the answer through a monte-carlo simulation, but am still interested in an analytic solution.  Edit: I have since solved the problem, using Bernoulli trials, a technique I just learned in my discrete math class. The general formula is  $1-\left(\sum_{i=0}^{m-1}\operatorname{nCr}\left(n,i\right)\cdot\frac{1}{365}^{i}\cdot\frac{364}{365}^{\left(50-i\right)}\right)^{365}$. The part inside the sum is the chance of, for a fixed day, that there are exactly i shared birthdays. The sum finds the chance that there are less than m shared birthdays. Raising this to the power of 365 finds the chance that there are less than m shared birthdays every day. Subtracting this from 1 gets the chance that there are m or more shared birthdays. The answer I got for the specific case agreed with my simulation within +-.000001.


Can a Simple Metric be Used to Construct the Required Unbounded, Continuous Function that Exists if the Space is not Compact?

I have tried unsuccessfully to follow a hint in Gamelin & Greene's Topology, 2nd Edition, Dover, ex.9 in Section 6, that is written to demonstrate the existence of a continuous, real valued, continuous but unbounded function on a metric space that is not complete and therefore not compact.   The author of the hint uses the real metric to create a function from it using a Cauchy sequence that does not converge.  I don't want to detail the hint, because there are frequent typos in the book, most regrettably, and I don't know if I reading it as the author intended.   The author does seem to show that the inverse of the function is unbounded and continuous using the Cauchy sequence. Does anyone know such a construction, using the inverse of d($x,x_n$) ?


Footnote citation superscript in square brackets

I'm using biblatex to build my citations and my bibliography for a math paper. However, I have certain portions like this:    As you can see, I am trying to say "as d tends towards 1" but with the superscript citation it seems like I'm saying "as d tends towards 1 to the power of 17". To prevent misinterpretation, I have decided to enclose each superscript in square brackets. How can I do this?  Here is my MWE:  \documentclass[british, 11pt, reqno]{amsart} \usepackage[utf8]{inputenc}  \usepackage{babel} \usepackage{csquotes} \usepackage{amsmath, amssymb} \usepackage[backend=biber, style=apa]{biblatex} \DeclareLanguageMapping{british}{british-apa} \addbibresource{Biblio.bib}   This is a test script\footcite{BrinPage1998}. As $d \longrightarrow                          1$\footcite{BrinPage1998}.   Here is the Biblio.bib:  @article{BrinPage1998, author={Brin, Sergey and Page, Lawrence}, title={The Anatomy of a Large-scale Hypertextual Web Search Engine}, journaltitle={Computer Networks and ISDN Systems}, volume={30}, issue={1-7}, pages={107--117}, date={1998-04-01}, url={http://dx.doi.org/10.1016/S0169-7552(98)00110-X}, urldate={2017-04-02}, publisher={Elsevier Science Publishers B. V.}, address={Amsterdam, The Netherlands, The Netherlands}, }


How can I disable a stock app that has its Disable button greyed out?

There is a pesky bloatware app (specificlly VUDU Version 1.0) that came preinstalled on my device.  Whenever I boot my device, it starts up an app process, so every time I boot I have to open up the App Switcher and swipe it away.  I went into the Settings app and tried to Force Stop and then Disable the app, but the Disable button is disabled ("greyed-out") itself.  Some other apps also don't allow me to disable them.  Is there any other way that I can enable the button or disable the app without rooting?  I am running 4.4.2.


In/at when we're talking about being physically present somewhere

I was in her housing complex yesterday.  I was at her housing complex yesterday.  I was at college when you called.  I was in college when you called.   In both cases, I'm talking about physically being present there. So, which preposition should I use in both cases?


I know that there's a relation between the rank of matrix and whether it is invertible or not. What should the rank of the matrix equal to in order for the matrix to be invertible ? The other small question is what's an Nonsingular matrix ?


What's the definition of a linux distro?

Disclamer: the question i am asking is what determines what linux distro i'm using not "am i still useing ubuntu" now for the question. I use to think that a linux distro was defined by its desktop environment, but now I have 7 desktop environments. Am I still useing ubuntu? Have I made a ubuntu dirivitive? I know some distros have difrent ways you install stuff like debien & ubuntu use apt-get, & arch uses pacman. So what i'm asking is what determins which linux distro you are useing?


Motivation for Wigner phase space distribution

Most sources say that  acts like a joint phase-space distribution in quantum mechanics and this is justified by the formula   $$\int_{\mathbb{R}^6}w(x,p)a(x,p)dxdp= \langle \psi|\hat{a}\psi\rangle$$  as this allows us to compute the expectation value for the operator $\hat{a}$ corresponding to the physical quantity $a$. However, without the knowledge of this formula, how did Wigner come up with this definition:  $$w(x,p)=\frac{1}{(2\pi)^3}\int_{\mathbb{R}^3}\psi\left(x-\frac{v}{2}\right)\psi^*\left(x+\frac{v}{2}\right)e^{iv \cdot p}dv \quad ?$$  I would be greatly indebted for any mathematical motivation that anyone could provide. Similarly, I also wonder at the mathematical motivation for the Weyl quantization.


What is a ppa? I tried installing vlc 2.2.1 but I found two PPAs and both of them seem to work? Is there no difference between them? Which one is better for future releases?   sudo add-apt-repository ppa:mc3man/trusty-media sudo apt-get install vlc vlc-plugin-*  sudo add-apt-repository ppa:videolan/stable-daily sudo apt-get install vlc    Also, why is sudo apt-get update always included in the steps of installing new software? Isn't Ubuntu supposed to be updated by its nature ?


I try to display the help pages of unset command line , i get as a result the following output:  No manual entry for unset  I see  since they are  similar , however , it cannot be solution for this issue . Indeed , that issue has been resolved by installing some packages using this cmd : sudo apt-get install manpages-posix manpages-posix-dev  So , i try to do the same thing ;except modifying posix by unset , so i do this : sudo apt-get install manpages-unset  The result was :  Unable to locate package manpages-unset  The  explicit question is : How to display manual of unset


How do I mount ejected external USB flash Via terminal

After safely remove or eject it, i want to remount it without unplug it, and re-plug it again .. so Any suggestion pls?  PS  after using eject all usb memories are out of fdisk command scope i don't think it is that easy   `       Device Boot      Start         End      Blocks   Id  System /dev/sda1       109473792  1953525167   922025688   83  Linux /dev/sda3         2050048    99706297    48828125   83  Linux /dev/sda4        99708926   109471743     4881409    5  Extended Partition 4 does not start on physical sector boundary. /dev/sda5        99708928   109471743     4881408   82  Linux swap / Solaris  Partition table entries are not in disk order`   None of them is the usb memory


Lograthmic equation $ \frac {1}{\log_2(x-2)^2} + \frac{1}{\log_2(x+2) ^2} =\frac5{12}$ solutions

$$ \frac {1}{\log_2(x-2)^2} + \frac{1}{\log_2(x+2) ^2} =\frac5{12}.$$  I made the graph using wolfram alpha it is giving answer as  6. But how to solve it algebraically? base of logarithm is 2.  Tried using taking Lcm but then two different log terms  are getting formed.


You are a pie maker and you are holding a fair to display your pies. You have 1000 pies. You have 10 workers to help you. The fair is in two hours. Unfortunately you discover that a rival pie maker has poisoned one of your pies with a form of norovirus that makes people violently ill one and a half hours after even consuming a tiny bit of it. You know if any single person who visits your fair gets ill, your business will collapse but you need all the non poisoned pies for the fair. You can take small samples from the pies without spoiling them and your workers are prepared to do anything to help you. How do you find the poisoned pie?


Given N sets and all pairs of non-empty intersections between those sets, can those N sets be real number intervals?

Thanks to @LordSharkOfTheUnknown, I now realize that I wish to recognize if a graph is an interval graph. He had linked this  of the subject, but I have not understood the recognition algorithm described there   I was solving a question in Stack Overflow in Portuguese about a particular problem that could be modeled as graph-colouring. The problem was something like this:     I have n machines. Those machines needs to work at continuous intervals: I_1 for the first machine, I_2 for the second and so on. Each machine needs one operator to work properly, and each operator can only handle a single machine at a given time. What is the minimum number of operators needed?   So, I have modeled this as a graph:   each vertex k is a machine k/time interval I_k each edge connecting vertex j and k is a time overlap between intervals I_j and I_k; or equaly it is a non-empty intersection between I_j and I_k each vertex colour is an operator, so no operator can operate two similtaneous machines, thus one colour cannot be it's own neighbor   So far, everything is fine. But, given a graph, can it have the semantics above? This can also be asked as the title question:   Given n sets and a list of all pairs of sets that has non-empty intersections, can all of those sets be continuous intervals of real numbers?   So far, I know that this problem lies in NP, because if I have a list of intervals for each set, than I can test if all the intersections apply and validate if is a correct input.    For example, a valid input:  Given 4 sets (A,B,C,D) with the following intersections:   A,B B,C C,D A,D B,D   It is a valid graph. Because I can have this values:   A = [1,10] B = [8,15] D = [8,14] C = [12,18]   All the intersections above occurs, thus these intervals represents a valid input     For example, an invalid input:  Given 4 sets (A,B,C,D) with the following intersections:   A,B B,C C,D A,D   There are no such values for A, B, C and D so that they are continuous intervals ou real numbers and there exista only those 4 non-empty intersections     Original question that I was solving:  SOpt question of this same open question:


What happens if I don't close a System.Diagnostics.Process in my C# console app?

I have a C# app which uses a System.Diagnostics.Process to run another exe.  I ran into some example code where the process is started in a try block and closed in a finally block.  I also saw example code where the process is not closed.  What happens when the process is not closed?    Are the resources used by the process reclaimed when the console app that created the process is closed?    Is it bad to open lots of processes and not close any of them in a console app that's open for long periods of time?  Cheers!


How to disable boot sound that comes while starting MacBook pro

I have macbook pro mid 2012 edition. I want to disable sound at the time of boot that comes while turning on..


Windows - permission automatically changes to Read-Only

I have some files/directories on an external hard drive connected using USB to my Windows XP laptop. I am trying to delete those files but every time I try, I get an error "Cannot delete ....: Access Denied. Make sure disk is not full or write protected and that the file is not currently in use".  I checked that the directory is not is use. However, the permissions are set to read-only. Even if I remove the "read-only" checkbox, in Properties->Attributes, it automatically comes back again. How do I fix this? Is it a virus that is automatically changing it back to read-only?  regards,  JP


where to put /home missing on 3 TB storage?

Due to various trials and errors and installation of Kubuntu 18.04 LTS, I have a clean install on a 120 GB SSD but I do not see the 3 TB HD where I would like to put /home.  I'm ready to reinstall if more efficient. Indeed, the HDD is only visible when installing. It is not visible with Kubuntu Partition Manager (KPM).  $ lsblk -a NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT loop0    7:0    0         0 loop  loop1    7:1    0         0 loop  loop2    7:2    0         0 loop  loop3    7:3    0         0 loop  loop4    7:4    0         0 loop  loop5    7:5    0         0 loop  loop6    7:6    0         0 loop  loop7    7:7    0         0 loop  sda      8:0    0 111,8G  0 disk  ├─sda1   8:1    0   512M  0 part /boot/efi └─sda2   8:2    0 111,3G  0 part / sdb      8:16   1         0 disk  sdc      8:32   0         0 disk  sr0     11:0    1  1024M  0 rom  $ df -a Sys. de fichiers blocs de 1K  Utilisé Disponible Uti% Monté sur sysfs                      0        0          0    - /sys proc                       0        0          0    - /proc udev                 8152164        0    8152164   0% /dev devpts                     0        0          0    - /dev/pts tmpfs                1637404     1416    1635988   1% /run /dev/sda2          114337956 17937500   90549320  17% / securityfs                 0        0          0    - /sys/kernel/security tmpfs                8187000   163692    8023308   2% /dev/shm tmpfs                   5120        4       5116   1% /run/lock tmpfs                8187000        0    8187000   0% /sys/fs/cgroup cgroup                     0        0          0    - /sys/fs/cgroup/unified cgroup                     0        0          0    - /sys/fs/cgroup/systemd pstore                     0        0          0    - /sys/fs/pstore efivarfs                   0        0          0    - /sys/firmware/efi/efivars cgroup                     0        0          0    - /sys/fs/cgroup/cpu,cpuacct cgroup                     0        0          0    - /sys/fs/cgroup/pids cgroup                     0        0          0    - /sys/fs/cgroup/cpuset cgroup                     0        0          0    - /sys/fs/cgroup/net_cls,net_prio cgroup                     0        0          0    - /sys/fs/cgroup/perf_event cgroup                     0        0          0    - /sys/fs/cgroup/freezer cgroup                     0        0          0    - /sys/fs/cgroup/devices cgroup                     0        0          0    - /sys/fs/cgroup/memory cgroup                     0        0          0    - /sys/fs/cgroup/rdma cgroup                     0        0          0    - /sys/fs/cgroup/blkio cgroup                     0        0          0    - /sys/fs/cgroup/hugetlb systemd-1                  0        0          0    - /proc/sys/fs/binfmt_misc mqueue                     0        0          0    - /dev/mqueue debugfs                    0        0          0    - /sys/kernel/debug hugetlbfs                  0        0          0    - /dev/hugepages configfs                   0        0          0    - /sys/kernel/config fusectl                    0        0          0    - /sys/fs/fuse/connections /dev/sda1             523248     6232     517016   2% /boot/efi tmpfs                1637400       16    1637384   1% /run/user/1000 /dev/fuse                  0        0          0    - /run/user/1000/doc   [edit] Now visible with Gnome Utility Disk but not in Dolphin


Why is ++i considered an l-value, but i++ is not?


I am an Indian citizen residing in the USA. I have an expired H1B visa with an approved I-797 until 2021.   I am planning to travel from USA to India with a stopover in London (intend to get my H1B stamped while in India). I have an approved 6-month UK Visitor Visa.   Would i face any problems boarding the flight from USA to London given that I have an expired H1B?


Site position and its rectangle area on grid view

The full list of the Stack Exchange sites can be displayed as :        How are the size and position of the site icon calculated in this view mode?


Germany family visit visa refusal and new tourist visa application

I had applied for a family visit visa to Germany to visit my husband who is a student there. The basis of rejection were  8) the information submitted regarding the justification for the purpose and conditions of the intended stay was not reliable.   your declared travel purpose is not understandable regarding your submitted documents or your information during the interview. the existence of your family relationship is not proved   9) your intention to leave the territory of the member states before the expiry of the visa could not be ascertained.  -you did not submit documents which confirm stable financial background    -the documents you submitted do not allow a positive conclusion as to the existence of a secured background or sufficient family relationship.  also i received comments stating  as per my information:  BE ADVISED THAT YOU MAY APPLY FOR FAMILY REUNION WITH YOUR HUSBAND WHEN IT IS LEGALLY POSSIBLE. IN THAT PROCESS YOUR MARRIAGE DOCUMENTS WILL BE CHECKED. UNTIL THEN IT WILL NOT BE POSSIBLE TO ISSUE A SCHENGEN VISA.  with all this being stated the reason i applied for family visit and not tourism since i felt that applying for a tourism could create a red flag earlier since my husband was already in Germany. I worry that if i apply for a tourist visa now it will get rejected too since somehow they feel i have intentions to stay with my husband and not return whereas the only reason i wish to go is to enjoy my stay for a few days n come back since I am already enrolled a student in my home country. Should i apply for a new application for a tourist visa or sit back ! i fear of getting rejected also it shouldn't look for my desperation. Please help  I am still confused whether i should reply them through remonstrance or apply for a new visa.... Also i have only a few days to go for remonstrance since i received the rejection quite later than the issuance I do not have a lot of time only a week maybe.....  I do not wish to ask the details for rejection instead i wish to know the best practice in reply as to go for a new category or stay stay stick to it


Nullpointer exception comes in onpostexcute

Plz help me When we get data from server and save in a string variable, it is store in a variable but cantnot retrive.   public class Profile extends Activity {     ListView list;     Activity act;     String[] username = { "Pankaj", "Aaa" };     TextView name;     JSONObject object;     String url = "http://thinksl.com/taughtable/profile.php?user_email=pank@gmail.com";      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.profile);         list = (ListView) findViewById(R.id.list);         name = (TextView) findViewById(R.id.mailid);         Custom_Profile pro = new Custom_Profile(Profile.this, username);         list.setAdapter(pro);         new Userdata().execute(url);     }      public class Userdata extends AsyncTask<String, Void, String> {         public static final int connection_type = 1500;         Profile p = new Profile();         ProgressDialog dialog;         String resul;         HashMap<String, String> user;          @Override         protected void onPreExecute() {             // TODO Auto-generated method stub             dialog = new ProgressDialog(Profile.this);             dialog.setTitle("Processing");             dialog.setMessage("Loading Data.Please wait....");             dialog.setCancelable(false);             dialog.show();          }          @Override         protected String doInBackground(String... url) {             // TODO Auto-generated method stub             Log.e("result", "Do in background");             HttpParams params = new BasicHttpParams();             HttpConnectionParams.setConnectionTimeout(params, connection_type);             HttpConnectionParams.setSoTimeout(params, connection_type);             HttpClient client = new DefaultHttpClient(params);              ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();             param.add(new BasicNameValuePair("user_email", "pank@gmail.com"));              HttpGet get = new HttpGet(url[0]);             try {                 Log.e("result", "Try");                 HttpResponse response = client.execute(get);                 Log.e("result", "Response" + response);                 HttpEntity entity = response.getEntity();                 String result = EntityUtils.toString(entity);                 Log.e("result", "result" + result);                 JSONObject jobject = new JSONObject(result);                 object = jobject.getJSONObject("userdetail");                 Log.e("result", "result" + object);                  String name = object.getString("user_login");                 int post = object.getInt("month");                 Log.e("name", "name" + name);                 Log.e("name", "post" + post);                 Log.e("result", "result" + resul);                 user = new HashMap<String, String>();                 user.put("name", name);              } catch (IOException e) {                 // TODO Auto-generated catch block                 e.printStackTrace();             } catch (JSONException e) {                 // TODO Auto-generated catch block                 e.printStackTrace();             }              return null;         }          @Override         protected void onPostExecute(String result) {             // TODO Auto-generated method stub             super.onPostExecute(result);             dialog.dismiss();             String s = user.get("name").toString();             p.name.setText(s);          }     } }


How do you tell if the correlations at different lags obtained from the cross-correlation (ccf function) of two time series are significant.


How to prove that A is normal if and only if there's a unitary matrix V,s.t. A*=AV?

This can be found at , but I don't know how to prove it:  $A$ is normal if and only if there's a unitary matrix V,s.t. $A^*=AV$


I have textured my object in Quixel and have an opacity map due to a portion of this object being glass. The issue is that when I try to use the opacity map my entire object has transparency and not just the glass. Could someone please show me a node set up (using principled shader) with an opacity map included?


I'm currently running Ubuntu GNOME 16.10 on my pc, and unfortunately, I don't have an internet connection. I really really need to be able to run java programs on it, because I've started learning java. My phone has an internet connection. Is there any way that I can download java onto my phone and then install it on my pc manually without an internet connection?


How do I explain D&D's rules, but you can do whatever you want, to new players?

I recently brought up the fact that I play D&D to a friend, and a few days later he came back to me and said that he wanted to play.  I was excited at the idea and said that I would be willing to run a one-off session for him and some other friends.  The first friend used to play somewhere around 15-20 years ago (certainly before 5e), but the other people have never played.  RPGs are fun to me because of the idea of being able to go anywhere and do anything.  I don't want to make a group of people read the entire PHB before they play for the first time, especially before a one shot game.  Even further than that, I will be making their character sheets for them so new players don't get bored by filling out sheets of paper.  Now I am presented with a challenge: I am new to GMing, and relatively new to RPGs in general.  How do I explain the rules of D&D to new players?  What should I explain before we play so that they understand that they can do whatever they want, but are still constrained by rules and rolls of the dice?


How to edit system files with the Kate editor?

If I try to use sudo kate to edit a system file, I get the message:  Executing Kate as root is not possible.  So how can I edit a system file? I put up this question so that I could answer it myself.  As far as I can tell, none of the suggestions involving gksudo have any advantage over the solution I proposed: just edit the file as a non-root user, save it when you're done, and provide the root password at that time.


Do pressure-cooked vegetables really have nothing else to give?

Yesterday, I watched an episode of Good Eats, where Alton Brown made broth by pressure-cooking mirpoix and beef for about 50 minutes.  At the end of that time, he discarded the vegetables, stated that they had "given their all," and citing (as proof) the significantly higher level of liquid post-cooking.  This seems to me like a waste. Do these vegetables have any value left (texture, nutrition, something)?  On the other hand, he also stated that the difference between soup and broth can be the addition of chunks of the ingredients.


Evaluate the Integral: $\int e^{2\theta}\ \sin 3\theta\ d\theta$

$\int e^{2\theta}\ \sin 3\theta\ d\theta$  After Integrating by parts a second time, It seems that the problem will repeat for ever. Am I doing something wrong. I would love for someone to show me using the method I am using in a clean and clear fashion. Thanks.


How to show that $\mathbb R^n$ with the $1$-norm is not isometric to $\mathbb R^n$ with the infinity norm for $n>2$?

Could you please give me a hint to prove that $\mathbb{R}^n$ with the 1-norm $\lvert x\rvert_1=\lvert x_1\rvert+\cdots+\lvert x_n\rvert$ is not isometric to $\mathbb{R}^n$ with the infinity-norm $\lvert x\rvert_\infty = \max_{i=1,\ldots,n}(\lvert x_i\rvert)$ for $n\gt2$.  I do not see how the critical case $n=2$ enters the picture.  Thank you!


I tried to work with timeout decorator(using signal) to timeout a function,But it results in main thread error  Any other solution to timeout a function after some seconds  Thanks


Insert a node at any position in Linked List implementation in Java

I have written this code to insert a new node at any position of the "Linked List"     I know there is build-in library in Java; I am writing this as a practice for Java.  But I get error      java.lang.NullPointerException    I don't know where the problem. Here is my code:   public void insertAtPos(int val , int pos) {          Node nptr = new Node(val, null);                         Node current = start;          /*  Crawl to the requested index */         for (int i = 0; i < pos; i++){             current = current.getLink();         }          /*  Set the new node's next-node reference to this node's next-node reference  */         nptr.setLink(current.getLink());          /*  Set the new node's next-node reference to the new node  */         current.setLink(nptr);          size++ ;   }       /*  Function to set link to next Node  */ public void setLink(Node n) {     link = n; }   /*  Function to get link to next node  */ public Node getLink() {     return link; }


There are 50 light bulbs in a room each with its own switch. If a light bulb is on, Dick turns it off and if it is off, he turns it on. Initially all light bulbs are off. After 50  flips and assuming that Dick chooses switches to be  flipped randomly, what is the expected number of light bulbs on in the room rounded to the nearest natural number?  how would you attempt to find the expected value? Any help on this will be highly appreciated Thanks


Use LaTeX to simulate old typewriter written texts

This question led to a new package:      I'm giving my students an old exam and barely remembered to change the date at the top. A colleague and I joked about how long we could reuse the same exam, and it made me wonder if I could use LaTeX to create an exam that looked like it was written in 1963 on a typewriter.  Here's what I'd like to see:   Typewriter font even in math mode. (Several ways to accomplish this; is there a "best" way?) Slight inconsistencies in the printing of each letter. I attempt this below adapting code taken from . Each word has a random vertical shift, though I'd like to see it reduced to each letter having its own vertical shift. Other typewriter-like irregularities would be great. It would be great if math-mode delimeters \left(, \right}, etc., can be created in a piece-meal fashion as they did in days of old. Fraction bars, tops of square-root symbols -- any horizontal line, really -- is made up of a series of en-dashes that don't quite match up.   Here is what I've come up with so far:  \documentclass[10pt]{article}% This is a document class providing more font size options \usepackage{graphicx} \usepackage{ifthen} \usepackage[textwidth=7.5in,textheight=9.5in]{geometry} \pagestyle{empty}  % thanks to Bruno Le Floch: https://tex.stackexchange.com/q/9331/4012 % and in his comments to https://tex.stackexchange.com/a/29458/4012 \usepackage[first=-1,last=1]{lcg}% you can play around with these values \makeatletter \newcommand{\globalrand}{\rand\global\cr@nd\cr@nd} \makeatother  \newcommand{\randomvshift}[1]{\globalrand\raisebox{\value{rand}pt}{#1}}  %%% thanks to Martin Scharrer: https://tex.stackexchange.com/q/11598/4012 \makeatletter \def\typewriter#1{%     \@typewriter#1 \@empty } \def\@typewriter#1 #2{%    \randomvshift{#1}\space    \ifx #2\@empty\else     \expandafter\@typewriter    \fi    #2% } \makeatother \begin{document}\tt  \typewriter{Math 101 Fall 1963}  \begin{enumerate} \item   \typewriter{$\frac{\texttt{d}}{\texttt{dx}}\texttt{(x)}^2$}  \item \typewriter{State the Fundamental Theorem of Calculus.}  \end{enumerate}  \end{document}


I just made a batch of macarons. This is my third total batch of them, and they become increasingly better - alas compared to my previous batch, these don't show much if any improvement even though I've changed how much I mix the macaron mass and how I pipe them.  Recipe:     ~150g egg-whites   ~70g finest sugar (not powdered!)   Mix with an older Kenwood chef until stiff and glossy   1 very flat teaspoon of vanilla extract (so about half a deep spoon)   ~3g of powdered green food coloring   More mixing with the Kenwood until well mixed, still stiff and glossy        ~150g sifted almond meal   ~250g sifted powdered sugar   pinch of salt   Mix well         Mix the almond/sugar stuff into the egg-whites using a rubber spatula until the consistence allows me to pour a figure-eight without globs breaking off        Pipe onto trays, let sit some 10-15min and rap every ~5min (rap 4 times, turning tray 90 deg after a few hits/raps)        Bake for 20min, middle height of oven1, at 150C   The first tray went into the oven as soon as the latter hit 150C:   The second tray had to wait for some ~20min while the other baked, during that time I rapped it a few times more but mostly let it sit:   What can I do to prevent my macarons cracking / how to change my recipe and/or process?  I see that there are positive results by letting them sit for more time, so I'm thinking about letting them sit ~1 hour next time I make a batch, and def rap them every 15min or so. What other changes/improvements should I make to my recipe?    1what's that called in english? I call it "Mittlere Backofenrille" in German


Typed in deno upgrade and after telling me new version was found, displayed error: No such file or directory (os error 2) Originally installed from snap if that matters. I'm new to Ubuntu, so any pointers in the right direction would be much appreciated.


Close vote review header not alway top element

I was just going through the close vote review queue and noticed that when I scroll down through the post, there are some elements that cover up the review bar as I go. Notable things appearing above the bar include   Tabs on posts flagged as dupes   Quote blocks    Other items behaving this way are question tags, and the post timeline icon. Additionally, quote blocks and tabs being hovered appear to have no background, so the test of the review bar jumbles on top of them.


so I'm very new to all this, so I don't know a lot. My mountain bike will no longer shift gears, I've been told this is because my cables need lubricated, but I have no idea how to do this, so, how would I do that with a spray lubricant?  And please keep in mind, I don't really know anything about bikes.


I'm having a problem with my code I don't know why isn't making the comparison but prints it well. These is my code...    public void read() throws IOException {         String entered = one.next(); // Read from the console         try (BufferedReader reader = new BufferedReader(new FileReader("file.csv"))) {             while (true) {                 String line = reader.readLine(); // Read file line                 if (line == null) {                     break;                 } //Break if there is no more lines                 String[] lineTwo = line.split(","); // Split into Array the line to compare it                 if (lineTwo[1].replaceAll(" ", "") == entered.replaceAll(" ", "")) {                     // compare record 1 with the entered value replace all is not needed I was testing if it have some spaces                     System.out.println("entered");                 }                 System.out.println(lineTwo[0]);             }         }     }   It print all the information of the file but when I'm going to to compare it the condition never gets printed. First read from the console and then read the file line .. line and compare if the record [1] = entered from the console. For some reason print all but it doesn't enter that if statement.


I can't find my bin folder. Where is it located?

The other day I was trying to download something for Minecraft and it involved my bin folder. So I was looking for it and couldn't find it. I then thought that I might have accidentally deleted it, but didn't find it in the trash. I have no idea how to get the bin folder back with all the Minecraft binary files in them.


So im generating few input fields and that works. But i cant get the value of this generated input fields. I can make onchange work, but i still can't catch any value. So i have tried a bunch of stuff with jQuery but nothing works. I alywas get undified.  jQuery(document).on('change', function (){         var id = "";         alert( this.value); }  jQuery(document).on('change', function (){         var id = "";         alert( jQuery(this).attr('id')); }  This is the field that gets generated <input class="mb-1 ml-2" style="transform: scale(1.3);" type="radio" id="input-'+counter+'">'  which will look like <input class="mb-1 ml-2" style="transform: scale(1.3);" type="radio" id="input-1">'  That works aswell. But i cant get the id of this input field


"Open in terminal" not working on nautilus as root

When using natilus as root, open in terminal used to work as using with any user. However, when I press open in terminal when using nautilus as root now, it does nothing.  How to solve it?  The error:  GLib-GObject-CRITICAL **: g_object_set_data: assertion 'G_IS_OBJECT (object)' failed


I got a samsung galaxy folder 2:  It runs Android 6.0.1 Anyways I am not new to ABD and have used it to uninstall system apps on my other phone (Samsung S10) with no problems. So when I got the folder 2 and started removing system apps using pm unistall -k --user 0 as I did with my other phone. Then I decided to remove the contacts app (com.android.contacts) because I installed google contacts. Well apparently, in doing so that contacts app actually housed the phone app as well. So now I have no phone app on my phone. That's kind of a big deal. How do I re enable the contacts app using ADB? My device is not rooted and I don't want to root it. Also I know factory resetting should fix this, but I'd prefer not to do that either. Thanks.


Retrieve my Minecraft world after forcing to shut down my PC

Yesterday I was playing on one of my Minecraft worlds. After a few minutes, my PC froze and nothing on the screen would move. After about 40 minutes, my screen was  completely frozen and I decided to force my PC to shut down. When I started Minecraft again, my world had disappeared off the list. I then went on the "%appdata%" files, under ".minecraft" and "saves," and saw my world in the list! How can I get the world file shown in that folder to appear in the list of worlds in the game?


Having difficulty proving that the set of nth degree monic polynomials that split on R is closed in Rn(X) with supremum norm using topological methods

Let $\Bbb R_n[X]$ be the metric space of $n$-th degree polynomials with real coefficients and polynomial height (supremum norm) as norm. Then, let $E_n$ be the subset of all monic polynomials in $\Bbb R_n[X]$ that split over $\Bbb R$. Show that $E_n$ is closed in $\Bbb R_n[X]$. I have no idea how to progress. Just giving a hint on how to solve to me would be fine.


I have heard in multiple locations that in the case of a flat universe, the universe is infinite. This seems to present multiple issues:  a) If a flat universe were infinite, would would the space of the Big Bang then not be infinite?  b) If the above is not the case, that seems to suggest that the geometry of the universe can evolve over time?  c) If the space of the Big Bang was infinite, and since space, time, matter, and energy came from the Big Bang, wouldn't the density of the universe at the start of the universe be equal to that of the universe now?  d) If the above is true, why are we told that the universe began in a very dense state? And also, if the universe indeed was more dense initially, would this not suggest that space must not be flat?  Note: Some of these questions depend on the answer to previous questions.


I installed Ubuntu 17.10 but there's a very annoying bug. When I'm watching videos (streaming or YouTube, not only in full-screen) the monitor goes to sleep. Some solution? Thanks you!


Friend of mine got a new phone number that came linked to an iMessage account. He can’t see text messages (iMessages) sent from iPhones because the account is linked to the phone and iPhones send the messages to the account by default. He doesn’t have access to the Apple ID nor does he have an iPhone.   How would he unlink the account? Apple conviently doesn’t list this information anywhere.


Singular or Plural (has/have vs was/were)?

1) There has been a funeral, two weddings and three thefts since you left.  OR  1) There have been a funeral, two weddings and three thefts since you left.  2) There was a boy and two girls inside the room.  OR  2) There were a boy and two girls inside the room.  3) Two girls and a boy was murdered.  OR  3)Two girls and a boy were murdered.


Doesn’t gravity violate the first law of thermodynamics?

So gravity is a force, and when it pulls on an object the object gains kinetic energy. However, doesn’t this mean that energy is being “created”, since the object gains kinetic energy?  Why doesn’t this violate the first law? It seems that energy is just created and then destroyed (when the object stops moving). Please don’t be too complex in explaining, as I do have some knowledge but am not an expert.  Also, isn’t potential energy not really energy, just a way of keeping track of the energy an object has? Doesn’t that make it not a justifiable response for this?


Why won't apt-get update/upgrade install ALL outstanding security packages

When I login to my 14.04.4 LTS VPS I see the standard system info along with:  7 packages can be updated 7 updates are security updates   When I run apt-get update/upgrade these packages remain uninstalled.   How do I install these packages? Do I need to install these packages? What's the deal?  Thanks!


package acro does not work with biblatex anymore

I used to use the acro package for managing my acronyms and I also used acronyms in my bibliography which I compile with biblatex/biber. After updating MikTeX packages this doesn't work anymore. Here is my minimal example:  \RequirePackage{filecontents} \begin{filecontents}{\jobname-bib.bib} @Book{TEST,   author    = {{\acs{ISO} X}},   title     = {You name it},   year      = {2015}, } \end{filecontents}  \documentclass{scrbook}  \usepackage[backend=biber]{biblatex} \usepackage[printonlyused]{acronym} \usepackage{zref,             xkeyval,             ifpdf,             ifthen,             calc,             marginnote,             datetime2,             refcount,             soulpos}%suggested to use with acronym  \addbibresource{\jobname-bib.bib}  \begin{document} \begin{acronym}     \acro{ISO}{International Organization for Standardization} \end{acronym}  This is text and I want to cite with acronyms: \cite{TEST}  \printbibliography  \end{document}   Compiling ends with:  ! Extra }, or forgotten \endgroup. l.27       }   ?


Monolithic Reference Collection, vs Per Paper Reference Collection, or Both?

When managing References, seem to me to be two-ish, options:  Either for each Project, I maintain a database of the relevant resources (In say a bibtex file), and for each new piece of work I start a new one.  Or I maintain a single "Monolithic" collection of resources (still in a bibtex file),  for everything I do, and I carry that around with me for years.  There are some in-betweens, such as having a Monolithic Collection, which I copy references from at the start of a project into a Project Collection, which I then use (and update) during the project, then copy either all or some of it back into the main collection.  What are the Pros and Cons of each approach? Am I thinking about this in the wrong way?


Ubuntu (16.04 LTS 64-bit) keeps disconnections from WiFi

I installed Ubuntu on my PC, updated everything and it seemed everything will be fine.  But WiFi keeps disconnecting. When PC is just turned on everything is fine, signal is strong and everything works as should.   But then it just disconnects, at random times.  Sometimes after 3 minutes, sometimes after 10.  That little drop down menu you get when clicking on WiFi signal also sometimes gets mostly grayed out, you can't select "connect to hidden WiFi" for example.  Other times it's not grayed out, it's just constantly trying to reconnect without success. Rebooting is the only option.  I don't know anything about Ubuntu, or Linux in general. I tried googling, but every solution starts with terminal and a lot of commands which I'm not comfortable trying out since I have no idea what they do. I might mess up things even more.  Like I was saying, I did see that you guys usually ask for several commands and results, so I did that and here they are listed. I hope this can be solved.  Link to results:   Link to script results from :   Thanks in advance!


What happens to argument in alias after using it once?

Why does this only print arg out once?  $ alias test="echo $1 $1 $1" $ test arg arg   This is on GNU bash, version 4.2.25(1)-release (x86_64-pc-linux-gnu).


If the bed you last slept in is destroyed or mined, where do you respawn when you die?

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


How to tell if a Journal is peer reviewed and/or legitimate?

I am working through my dissertation and was just wondering, how would you know if a journal is peer reviewed or actually legitimate? If a journal etc has an ISSN number on them, does this mean the journal is peer reviewed and good to use?


My site  is very slow, this is the server status page of  My guess is that the iptables are slowing it down, as there is no reason from the hardware side, there are enough free resources. I have 8 GB Ram and 4 CPUs.


When half-elvens choose mortal life, how would their bodies behave?  Half-elven are always elves by nature. Ever since they're born, their physical body and behaviour would be elvish - they have keen senses, they don't get physically weary, no illness, and so on.  Half-elvens are then offered a choice - Immortal elvish lives or mortal fate of men. When they choose the latter, like Elros and Arwen did, what would happen to their elvish nature? Would they lose it? I don't think they would lose their pointy ears, but what about the other elvish features that I mentioned before?  Are there any canonical references?


Evaluate combinations of page dimensions

For any given class and its specified page layout, I'd like to be able to combine (sum or subtract) a subset of the page dimensions, to obtain a length to work with, without specifying absolute values.  For example: I'd like to set the width of a figure equal to \textwidth + \marginparsep + \marginparwidth  I don't have a MWE yet, because I'm trying to figure out if this is possible somehow.   is related, but applicable only to KOMA


List executions of a particular Windows process / application

I want to get a usage log for a particular application during the last 30 days.  Does Windows have a log I can access for that?


Please provide the possibility to retract a flag

You can delete a question you posted, you can delete a comment you posted, it's absolutely ridiculous that you cannot undo flagging a comment if you flagged it by mistake.  Please implement this feature.


API request at the beginning of each minute of the day

I am using json.load to make an API request. I'd like to automate it so that it makes the request on the first second of every minute starting at 9:30am and ending at 4pm, ie. 9:30:01am, 9:31:01am ... 4:30:01pm and then stop.


How are NaN and Infinity of a float or double stored in memory?

As I understand it java will store a float in memory as a 32 bit integer with the following properties:   The first bit is used to determine the sign The next 8 bits represent the exponent The final 23 bits are used to store the fraction   This leaves no spare bits for the three special cases:   NaN Positive Infinity Negative Infinity   I can guess that negative 0 could be used to store one of these.  How are these actually represented in memory?


Proof that $f(z) = cosec(\pi z)$ has simple poles

In my book they say that $$f(z) = \csc(\pi z)=\frac{1}{\sin(\pi z)}$$ has simple poles, however doesn't explain why.  I tried do to the following: I know it should have simple poles where $g(z) = \sin(\pi z)$ has zeroes, i.e. $z = k\in\mathbb{Z}$. Then I can check if they are indeed simple poles with the following:$$\lim_{z\to k}(z-k)\csc(\pi z) = \lim_{z\to k}\frac{z-k}{\sin(\pi z)} = \lim_{z\to k}\frac{1}{\pi\cos(\pi z)}=\begin{cases}        \frac{1}{\pi} & k \,\,\text{even} \\       -\frac{1}{\pi} & k \,\, \text{odd}     \end{cases} \neq 0$$ hence a simple poles at $z = k\in\mathbb{Z}$? I am not sure this is correct or if this is the shorter/best way to show this.   Are there other options?


Is there a canonical metric for a Lie group manifold?

A Lie group can be defined as a differentiable manifold. Is it possible to import the notion of Riemannian metric on differentiable manifolds to define a canonical metric on a Lie group?


An Introduction to LaTeX in beamer documentclass in TeX format

Sorry if this is a off topic or duplicate question. I'm looking for An Introduction to LaTeX  in beamer documetclass in tex format. Any help will be highly appreciated. Thanks    Edited    I'm looking for a document in Tex format similar to . So that I don't have to type everything.


Reading a double precision values yields not exactly the same value in memory watch in C

I am reading some numbers from a file in C.  For example,  0.00632, 0.02731...  I store these numbers in double type variables.  This is how I read them:  fscanf(fp_ptr, "%lg", &num);   However when I check the value of the num via the watch window of the program I use (Visual Studio Express), I see the values as 0.0063200000000000001, 0.027310000000000001...  Is this normal? How can I read the exact value in the file?