Do I really need to add "useless" questions in order to interact?

I have decades of coding history in my pocket. Still I have many of areas in which I am looking for answers.  When Google sends me here to this platform its mostly a good result. Thus that means someone else has already had a similar question - and even the answers.  Sometimes I want to rate an answer as "best" or "not that helpful", or I want to contribute with my own answer to that. The current rules state a minimum of 15 points reputation for up voting an answer and even more for down voting and responding with a comment.  But guess what? When registering I start with just 1 reputation - that is not enough to do anything. Do I really have to fill up your platform (each flavour?) with some 3 "dummy" questions first, before I am able to interact in a human being meaningful fashion? At least I can not see any other way of achieving the system of accepting me with all my knowledge and understanding of the topics I have dealt with in the past decades.


Is it possible to open bottomSheetDialog with bottomNavigationBar?

I want to open bottom sheet dialog when i clicked bottom navigation item (Yandex Maps android app like. There is map on background always. Bottom navigation items just open bottom sheet dialog).   However i can not do that. Is it possible and if it is how?  I tried some fragment methods but app is crashing.  activity_main.xml  <?xml version="1.0" encoding="utf-8"?> <RelativeLayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context=".MainActivity" >      <com.mapbox.mapboxsdk.maps.MapView         android:id="@+id/berkay"         android:layout_width="match_parent"         android:layout_height="match_parent">     </com.mapbox.mapboxsdk.maps.MapView>      <FrameLayout         android:id="@+id/frame_main"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:layout_above="@+id/main_bottom">      </FrameLayout>      <android.support.design.widget.BottomNavigationView         android:id="@+id/main_bottom"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_alignParentBottom="true"         app:menu="@menu/navigation"         android:background="?android:attr/windowBackground">     </android.support.design.widget.BottomNavigationView>   </RelativeLayout>    Bottom navigation item selection  private BottomNavigationView.OnNavigationItemSelectedListener navListener = new BottomNavigationView.OnNavigationItemSelectedListener() {         @Override         public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {              Fragment selectedFragment = null;              switch (menuItem.getItemId()){                 case R.id.navigation_map:                      break;                 case R.id.navigation_search:                     SearchFragment searchFragment = new SearchFragment();                     searchFragment.show(getSupportFragmentManager(),"SearchFragment");                     break;                 case R.id.navigation_event:                     selectedFragment = new EventsFragment();                     break;                 case R.id.navigation_profile:                     selectedFragment = new ProfileFragment();                     break;             }              getSupportFragmentManager().beginTransaction().replace(R.id.frame_main,selectedFragment).commit();              return true;         }     };   SearchFragment.java  import android.os.Bundle; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.design.widget.BottomSheetDialogFragment; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup;  import com.mapbox.mapboxsdk.Mapbox; import com.mapbox.mapboxsdk.maps.MapboxMap;  public class SearchFragment extends BottomSheetDialogFragment {     @Nullable     @Override     public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {         View v = inflater.inflate(R.layout.fragment_search,container,false);         return v;     } }    Logcat Error for SearchFragment case     java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference


Book recommendation for second look at GR

Between Hawking & Ellis and Wald, which one would be the better choice to follow up a graduate-level course in GR (based off of Carroll's book)?  If not either of those two, does anyone have any suggestions? I'm interested in those two not only because of the physics they present but also because of their rigor (I'm a post-grad mathematician).


How to delete files from my indestructable memory card?

A week ago I started getting intermittent IO errors accessing the SD card on my rooted Evo 4g. I eventually plugged it into my windows machine and tried to format it. It appeared to work, but when I unmounted and remounted the card all the files came back. I tried formatting on my phone with the same result, and had a coworker try with the Mac diskutils suite. All the formats claimed to work, but the files came back when the card was remounted. Finally I ran dd if=/dev/zero of=/dev/block/mmcblk0; it completed, and the same thing happened again.  But here is where it gets crazy. I put a new recovery file on the sd card -- and it added the file without any issue. But now it can't be deleted, just like everything else. So I can write to the SD card, but I can't delete anything.  How can I fix this? Or if I can't, at least why is it happening?


How to download a source code of code.google.com

I am stuck with downloading project code for an android application on code.google.com.   My college have proxy settings issues while trying to download via terminal using Git.  Could somebody provide a link or way to do so.


Are there any travel experiences in Australia that offer aboriginal (or Torres Strait) “cultural immersion”?

I am wondering if it's possible for a traveller in Australia to immerse in aboriginal culture, or Torres Strait Islander culture.  By "immerse" I mean stay in a traditional aboriginal area where people speak the language on an everyday basis and generally live to some degree or other in a traditional way. Maybe including staying with a family and being taught some traditional skills or otherwise participating in daily life.  I'm from Australia and work in tourism and I think it's safe to say most Aussies would have no idea if you can do this. But it's a big country and we're pretty ignorant of our native culture.  For me the language aspect is important. I do know the most actively maintained indigenous languages in Australia are in Central Australia (Pitjantjara, Arrernte, Warlpiri) and Torres Strait (Kala Lagaw Ya). I also believe that traditional culture and language is practiced in Arnhem Land by the Yolngu people. But I have no idea about the state of tourism in those areas.


Why do we say "run apps" and not "walk" them?

I was recently working on an application and it was showing its status as "Running", and this thought popped up in my head: why "run" and not "walk"?   What's the origin of this difference?  Tried to search but couldn't find an explanation.


I'm working on a C# application.   I have an object used like a dialog box :  public partial class MyDialog : Form   The main windows is :  public class MyForm : Form   I can use it by :  public class ProgramApp {     public static MyForm MainForm { get { return _mainForm;  } } }   In one function I can use both with :  MyDialog dlg = new MyDialog(); dlg.ShowDialog(ProgramApp.MainForm);   First call works good, but at the second one I have a System.InvalidOperationException with HResult = 0x80131509 and message :     Cross-thread operation not valid: Control 'MainForm' accessed from a   thread other than the thread it was created on.   (translated from french, original message :)     "Opération inter-threads non valide : le contrôle 'MainForm' a   fait l'objet d'un accès à partir d'un thread autre que celui sur   lequel il a été créé."   What can I do to fix that ?  Edit :  I added this piece of code :  MyDialog dlg = new MyDialog(); bool needInvokeDlg = dlg.InvokeRequired; bool needInvokeForm = ProgramApp.MainForm.InvokeRequired; dlg.ShowDialog(ProgramApp.MainForm);   First attempt both are false. On second, needInvokeForm is true. How can I do an Invoke to set ProgramApp.MainForm as a parameter ?


Evaluate $\lim_{n\to \infty} \sum_{r=1}^n \frac {1}{2^r}\tan \left(\frac {1}{2^r}\right)$

Evaluate $$\lim_{n\to \infty} \sum_{r=1}^n \frac {1}{2^r}\tan \left(\frac {1}{2^r}\right)$$   I tried to create a telescoping sum but I couldn't. The last step I could reach was turning the limit into $$\lim_{n\to \infty} \sum_{r=1}^n \left(\frac {1}{2^r(1-\tan (2^{-r+1})} -\frac {1}{2^r(1+\tan (2^{-r+1})}\right) $$  But couldn't proceed further. Also I thought about Riemann sums but it was a pure dead end.  Any help would be greatly appreciated


Is there is metric to know how far we are from the nearest prime number. For example if my number is 38, then we are 3 numbers away from 41?  If such a metric doesn't exist, is there an upper bound saying that we must find a prime number before (say) the next 300 numbers?


Suppose I have a data structure like this:  const list = [   {"hello": "world"},   {"goodbye": "cruel world"} ]   and I want to join it into:  {"hello": "world",  "goodbye": "cruel world"}   I can do it semi-elegantly like so:  const union = l.reduce((acc, o) => {   Object.keys(o).forEach((k) => acc[k] = o[k]);   return acc; }, {})   But is there a more elegant way, perhaps built into the JS standard library?


Do I need 10/2 or 10/3 wire for a 220V heater?

I am wiring a receptacle for a 4800 watt (220) construction heater ( the standard type found in home stores). Do I need a neutral wire or not?  Do I use 10 awg wire 10/3 or 10/2.


Unable to follow an Area 51 proposal after turning from Guest into logged in user and unfollowing

I am trying to follow Prestashop under Area 51. I clicked follow, it gave me an email, I confirmed it, and it made a guest account. I didn't want to follow as a guest, so I unfollowed it, and then I logged in. It turned my guest example question into a question from me. Issue is, I am not unable to follow it. I can follow it, but it doesn't show me as a follower, and the number of followers stay the same, where as before I logged in with my stack account, I was affecting the number. I'd like to support a Prestashop stack site. Am I doing something wrong, or can this be fixed?


Seeking Python tools/modules/add-ins for GIS?

With ArcGIS 10, Python has become the de-facto scripting language for ESRI. While leading Open source software like QGIS, GeoServer, PostGIS all supports Python. Thus it became important to know/learn Python for GIS developers a well as users.  Can anybody make a list of such tools/modules/add-ins in Python that are crucial in GIS?


What's the meaning of a dot before a command in shell?

While following android eclipse debug tutorial, I encounter following commands.  cd /path/to/android/root  . build/envsetup.sh  lunch 1     make        emulator   My problem is what the dot before build/envsetup.sh means?


Which one seems correct?  non-xx domains (those that are not prefixed with "xx" sub-domains)   Or  non-xx domains (those that are not prefixed by "xx" sub-domains)


Let $f:[0,\infty) \to \mathbb R$ be a twice differentiable function, such that  $\,f''(x) \ge f(x)$, for all $x\in\ [0,\infty)$, and $ f(0)=f'(0)=1$. Can we deduce that $f$ is increasing?   I feel like it is, but I cannot see it. I can only show that to get it increasing it is enough to show that $f$ is non negative .


Why is this appearing in my c# strings: Â£

I have a a string in c# initialised as follows:  string strVal = "£2000";   However whenever I write this string out the following is written:  Â£2000  It does not do this with dollars.  An example bit of code I am using to write out the value:  System.IO.File.AppendAllText(HttpContext.Current.Server.MapPath("/logging.txt"), strVal);   I'm guessing it's something to do with localization but if c# strings are just unicode surely this should just work?  CLARIFICATION: Just a bit more info, Jon Skeet's answer is correct, however I also get the issue when I URLEncode the string. Is there a way of preventing this?  So the URL encoded string looks like this:  "%c2%a32000"  %c2 = Â %a3 = £  If I encode as ASCII the £ comes out as ?  Any more ideas?


I am currently using file_get_contents() to get the title of a webpage, given the URL. On wamp, this works perfectly fine. However, when I shifted this to my web server, I came across a problem which lead me to  answer. (Which is to set allow_url_fopen to 1).  Is there a major security risk in setting this on? If yes, are there any alternate ways to grab the title of a webpage from the URL itself?  (Also, unsure of tags for this so please feel free to add/remove if appropriate!)  Edit (1) : Further research lead me to  question, which pretty much says that it is a risk as well, and to disable it if the application does not need it. Unfortunately this does not tell me enough about the risk involved.  Edit (2) : Quick note, I will be using this function with user input (the URL), and not internally, which is why I want to ensure there is absolutely no security risk involved


He said " I had a car " when this is converted into a reported speech, which of these is correct? a) He said he had a car, or b) He said he had had a car.


I have the following scenario: I have uploaded a video to YouTube and I am logged in, but each time I refresh the page or "view" the video, the count does not change.   How does the video count work? If I load it once, play it 2-3 times, will it still count as 1? Does it count my own viewings?


Creating instance of type without default constructor in C# using reflection

Take the following class as an example:  class Sometype {     int someValue;      public Sometype(int someValue)     {         this.someValue = someValue;     } }   I then want to create an instance of this type using reflection:  Type t = typeof(Sometype); object o = Activator.CreateInstance(t);   Normally this will work, however because SomeType has not defined a parameterless constructor, the call to Activator.CreateInstance will throw an exception of type MissingMethodException with the message "No parameterless constructor defined for this object." Is there an alternative way to still create an instance of this type? It'd be kinda sucky to add parameterless constructors to all my classes.


How Can I create a bootable USB for Ubuntu on Windows 10 from an iso image?

I have downloaded the Ubuntu .iso and now I want to make a bootable USB from it on my Windows 10 system, can anyone help me, I am a noob at programming so I expect it to be explained in layman's terms. :)


Bug? LaTeX misparses nested optional arguments

LaTeX seems to be having problems handling nested optional arguments. I've included a minimal code example that generates the error:  \documentclass[12pt,oneside]{book} \begin{document}  \newcommand{\termbad}[2][]{#2#1} \newcommand{\termgood}[2][]{#2#1}  \newcommand{\up}[1]{#1} \newcommand{\dd}[1][]{#1}  \termgood{\up{Tart}}{Pop} \termbad[\up{Tart}]{Pop}      \termgood{\dd[Tart]}{Pop} \termbad[{\dd[Tart]}]{Pop} %\termbad[\dd[Tart]]{Pop}   \end{document}   If you run this code, it works. If you remove the % in the second to last line, it fails with:  Runaway argument?  Tart{Pop} \par \par \end {document}  !File ended while scanning use of \dd.   After further tinkering, I have discovered the problem: LaTeX is reading the ] for the inner optional argument as the end of the outer optional argument and then passing a malformed argument in. So it is passing in \dd[Tart as the optional argument to \termbad instead of \dd[Tart].  This still feels like a bug to me. Nesting braces in arguments works, brackets should as well. The following are workarounds:   Enclose the inner optional argument in braces (as in the line before %). Redefine your inner function to require its argument instead of using optional arguments. Redefine your outer function to require its argument instead of using optional arguments.   Any one of the three works around the issue.  (Reposted here; question was originally posted to stackexchange and then closed instead of being migrated.)


"Remote host identification has changed" warning when connecting over SSH

I got this message today when trying to log into my server. What should I do? Whats going on?  $ ssh 10.10.10.69 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that the RSA host key has just been changed. The fingerprint for the RSA key sent by the remote host is 3d:1b:02:9e:b2:b8:f0:f7:c6:4f:94:96:f6:e3:c0:d1. Please contact your system administrator. Add correct host key in /root/.ssh/known_hosts to get rid of this message. Offending key in /root/.ssh/known_hosts:8 RSA host key for 10.10.10.69 has changed and you have requested strict checking.Host key verification failed.


Generalized Poincaré Inequality on H1 proof

let's see if someone can help me with this proof.  Let $\Omega\subset\mathbb{R}^n$ be a bounded domain. And let $L^2\left(\Omega\right)$ be the space of equivalence classes of square integrable functions in $\Omega$ given by the equivalence relation $u\sim v \iff u(x)=v(x)\, \text{a.e.}$ being a.e. almost everywhere, in other words, two functions belong to the same equivalence classes if they only are different in a zero meassure set.  This space is a Hilbert space and its norm is:  $$ \Vert v \Vert ^2_{L^2 \left( \Omega \right) }= \int_\Omega v(x)^2\,\mathrm{d}x $$  Let $H^1\left(\Omega\right)=\left\{ v\in L^2\left( \Omega \right);\,\vert\mathbf{grad}(v)\vert \in L^2\left( \Omega \right ) \right\}$ be also a Hilbert space and its norm :  $$ \Vert v \Vert ^2_{H^1 \left( \Omega \right) }= \Vert v \Vert ^2_{L^2 \left( \Omega \right) } + \Vert \vert\mathbf{grad}(v)\vert \Vert ^2_{L^2 \left( \Omega \right) } $$   I've been asked to proove that:  $$ \Vert v \Vert ^2_{H^1 \left( \Omega \right) } \le C\left( \Omega\right) \left( \Vert \vert\mathbf{grad}(v)\vert \Vert ^2_{L^2 \left( \Omega \right) } + \int_\Gamma \left ( \gamma v(x) \right) ^2\,\mathrm{d}\sigma \right) \quad \forall v\in H^1 \left( \Omega \right) $$  where $\Gamma = \partial \Omega $, $\Omega $ is smooth enough, $\mathrm{d}\sigma$ is a meassure on the boundary of $\Omega$, and the operator $\gamma: L^2\left( \Omega\right )\mapsto L^2\left( \Gamma\right )$ is the trace operator. ( if it is needed I can define it also )  Sincerely, I just don't know how to begin, and maybe someone could give me some clue about it.(by the way the $C$ is a positive constant depending only on the domain $\Omega$).  Thank you very much!


When do I pronounce a non-existent “r” between adjacent vowel sounds?

If I say two words consecutively, with the first ending in a vowel sound and the second starting with one, when is it correct to include a non-existent r between those two words?  Examples from phrases I've heard:        I saw (r)a movie   They saw (r)us   Law (r)and order   That's the idea, (r)anyway.      I heard the last one in the movie Edge of Tomorrow yesterday.  Is this grammatically correct? If so, is the omission of the r grammatically incorrect? Are there any rules regarding this?


I'm looking for examples of quantum mechanical systems which have evenly spaced energy levels. A couple of them are -  Quantum Harmonic Oscillator; Inverted Quantum Harmonic Oscillator.  It appears to me that no more such systems are possible. Is that true? If not, what are the examples of that?


I try to export a QGIS 3 model (.model3) to Python but the functionality that was available in QGIS 2 doesn't exist anymore. Is there a way to export it ?


I found a misbehavior of the function summary.lm that might be a bug.  Data  d = structure(   list(     Treatment = structure(       c(1L, 1L, 3L, 1L, 2L, 1L, 3L, 2L, 1L, 1L, 2L, 3L, 2L, 2L, 3L, 3L, 3L, 1L, 2L, 3L, 1L, 3L, 2L, 3L, 2L),        .Label = c("A", "B", "C"), class = "factor"),      Elapsed = c(108L, 110L, 108L, 90L, 100L, 105L, 103L, 120L, 120L, 119L, 45L, 119L, 100L, 80L, 70L, 120L, 112L, 45L, 103L, 85L, 120L, 110L, 110L, 120L, 120L),      Correct = c(TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, FALSE, TRUE, TRUE, FALSE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, FALSE)),   row.names = c(NA, 25L),    class = "data.frame")   MWE  I perform an OLS regression of Elapsed vs. Treatment and Correct that gives rise to a degenerate model:  mdl = lm(Elapsed ~ Treatment:Correct + 0,data=d)  summary(mdl)   Then I obtain the following summary:  ##  ## Call: ## lm(formula = Elapsed ~ Treatment:Correct + 0, data = d) ##  ## Residuals: ##     Min      1Q  Median      3Q     Max  ## -54.571  -8.000   6.429  10.429  20.429  ##  ## Coefficients: ##                         Estimate Std. Error t value Pr(>|t|)     ## TreatmentA:CorrectFALSE  120.000     22.051   5.442 2.99e-05 *** ## TreatmentB:CorrectFALSE  120.000     15.592   7.696 2.97e-07 *** ## TreatmentC:CorrectFALSE  111.000     15.592   7.119 9.06e-07 *** ## TreatmentA:CorrectTRUE    99.571      8.335  11.947 2.79e-10 *** ## TreatmentB:CorrectTRUE    89.667      9.002   9.960 5.61e-09 *** ## TreatmentC:CorrectTRUE   103.571      8.335  12.427 1.43e-10 *** ## --- ## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 ##  ## Residual standard error: 22.05 on 19 degrees of freedom ## Multiple R-squared:  0.9658, Adjusted R-squared:  0.9549  ## F-statistic: 89.31 on 6 and 19 DF,  p-value: 6.789e-13   The coefficients computed by the lm() are correct. Actually they can be computed, e,g., with with(d,aggregate(Elapsed,list(Treatment,Correct),mean)).  Unfortunately the R-squared value is completely wrong as well as the p-values.  For instance, if I compute the R-squared manually  SSy = sum( (d$Elapsed - mean(d$Elapsed))^2) SSerr = sum( mdl$residuals^2 ) Rsq = (SSy-SSerr) / SSy   I obtain Rsq = 0.1853978, which is correct if I look at the plot  Any thought on that?


How to prove that $f$ surjective, if $g$ is injective and $g \circ f$ is surjective?

$X, Y$ and $Z$ are non-empty sets. $f : X \to Y$ and $g: Y \to Z$ are functions.   Prove that $f$ is surjective, if $g$ is injective and $g \circ f$ is surjective.  I'm aware of the surjective and injective definitions, but how would I prove that $f$ is surjective under the given conditions?


ProveUpper Riemann Integral is equal to Lower Riemann Integral, $U(f) = L(f)$

If $f$ is Riemann integrable, prove Upper Riemann Integral is equal to Lower Riemann Integral, $U(f) = L(f)$, where  $$U(f) = \inf \{ U(f, P) \mid P \text{ is a partition of } [a,b] \}$$  $$L(f) = \sup \{ L(f, P) \mid P \text{ is a partition of } [a,b] \}.$$  My professor asks us to prove this in parts.  (a) If $\varepsilon \gt 0 $, show that there is a partition of $P_1$ with width $W(P_1) \lt \delta$ and sample points for $P_1$ such that Riemann Sum $S_1 \gt U(f) -\frac{\varepsilon}{2}$ . (Hint: choose the partition based on denition of greatest lower bound, add points to make the width less than $\delta$)  points to make the width less  (b) show that there is a partition of $P_2$ with width $W(P_2) \lt \delta$ and sample points for $P_2$ such that Riemann Sum $S_2 \lt L(f) +\frac{\varepsilon}{2}$.  And another two parts..  I am having problems with proving both (a) and (b).  Edit: While it seems similar to , I am supposed to show that $U(f) = L(f)$ and in the addressed question, I don't think $U(f) = L(f)$ was proven.


We have witnessed (heard or read) about the birth of new academic journals many times. I have a vague idea how that happens:   A scientist or a group of scientists recognize the need for an academic journal in a specific field or a new scientific society considers to publish a journal,  they choose a group of experts as founders and/or chief editors,  they determine a scope and some basic rules for the journal,  they decide about the number of issues in each year and similar things,  they find a publisher or decide to publish the journal entirely on web, they establish a web site for the journal,  and then they announce the new journal in the related scientific community.    Did I miss any stage? But I suspect there are lots of discussions, negotiations, arrangements and cooperations behind the curtain, which public (the rest of the related scientific community) doesn't know. So my questions are:   What is a typical procedure for establishing a respectful academic journal?  Do financial considerations play a key role?  Should the founders be top experts (to some degree) in the field?  Is it important the new journal be affiliated to a scientific society or be published by a recognized publisher?  Why are some new journals published only on-line?   What are the influential factors for the success of a new journal?  How do the founders choose the editors?  What else should one consider for initiating a new academic journal?   Please share your partial answers too if you don't have all the answers.  Disclaimer: I am just curious and I don't intend to initiate any new journals in the near future.;)


How come I have the ability to edit questions and answers without the edit being reviewed, but if someone else’s edit is pending review, my approval of it is insufficient? Is this a bug or a feature?


Changing the passed-in list within a function

Consider the Python code below: def change_list(in_list):     in_list = [1,2,3]  def change_list_append(in_list):     in_list.append(7)   my_list = [1,2,3,4,5,6]  change_list(my_list) print(my_list)  change_list_append(my_list) print(my_list)  The output is: [1, 2, 3, 4, 5, 6] [1, 2, 3, 4, 5, 6, 7]  I don't understand why the first call (change_list) did not result in my_list to become [1,2,3]. Can someone explain? Look at what happens with the call to change_list_append: number 7 is appended to my_list.


This, that and it as a reaction to what was said/happened

Can I use these pronouns as a reaction immediately after something was said or happened, in order to express my opinion?        This is/was amazing.   That is/was amazing.   It is/was amazing.      And by the way, is it more appropriate to use "This" when using a noun instead of an adjective?For instance "This is madness" compared to "That's crazy".


Arrow Functions don't works. Regular ones do. Why?

I have a piece of code, that is just vanilla javascript. When I use arrow functions I get this error:  Uncaught ReferenceError: loadEventListeners is not defined   When I use regular function, syntax, it works fine.  Here is my code:  const form = document.querySelector('#task-form'); const taskList = document.querySelector('.collection'); const clearBtn = document.querySelector('.clear-tasks'); const filter = document.querySelector('#filter'); const taskInput = document.querySelector('#task');  // Load all event listeners loadEventListeners();  // Load all event listeners const loadEventListeners = () => {   // Add task event   form.addEventListener('submit', addTask); }  // Add Task const addTask = (e) => {   if(taskInput.value === '') {     alert('Add a task');   }    // Create li element   const li = document.createElement('li');   // Add class   li.className = 'collection-item';   // Create text node and append to li   li.appendChild(document.createTextNode(taskInput.value));   // Create new link element   const link = document.createElement('a');   // Add class   link.className = 'delete-item secondary-content';   // Add icon html   link.innerHTML = '<i class="fa fa-remove"></i>';   // Append the link to li   li.appendChild(link);    // Append li to ul   taskList.appendChild(li);    // Clear input   taskInput.value = '';    e.preventDefault(); }   My question is this. Do I need to do something that enables arrow functions, in my code? Maybe I need to setup Webpack or Parcel for this? I do not know why this is. Just replace the const <functionName> = () => {} with function <functionName>() {} and it works. Would really like a more thorough explanation why this is happening, if it is possible.  Thanks for your time..


I came across this problem :  Let $f\colon [a,b]\rightarrow \mathbb{R}^n$ a continuous vector valued function. Then it is true that:  $$\left\Vert\int \limits_a ^b f(t) dt\right\Vert \leq \int \limits_a^b \left\Vert f(t)\right\Vert dt$$  I consider that the integral of $f$ is given by integrating each component and then I am trying to reduce it to having an integral inequality for $n$ single valued functions but I am stuck.  I would appreciate some help.  Thank you!


We have below code being called from Cancel button on a Lightning component. We have used this lightning component on VF page.  navHome : function (component, event, helper) {      var urlEvent = $A.get("e.force:navigateToURL");     urlEvent.setParams({       "url": "/home/home.jsp"     });      urlEvent.fire();  }   Above is throwing JS error,     This page has an error. You might just need to refresh it. Action   failed: CsApp:ConfigSettings$controller$navHome [urlEvent is   undefined] Failing descriptor:   {CsApp:ConfigSettings$controller$navHome}   What should be the correct way to navigate Home page?


Is it true that for every regular language $L \subseteq \{0,1\}^*$, language $\big\{ w^{|w|} \big| w \in L \big\}$ is regular? I don't know how to prove that.Could you give me a hint? Thank you


Display the number of users elaborating answers to the question

Many users decide to ask questions on SE sites when they are done spending time googling for the answer. That would explain why it's no rare to see question demonstrating  or even . Wouldn't it be great, specially on those cases, if we could know when someone is working on our questions? It's worth mentioning that some answers does take time to be written.  We can see how many people have seen our questions and the number of answers it's gotten, but we lack a mechanism saying: "2 users are elaborating answers to this question".  Another side effect of that would be users prioritizing questions that have no one working on them avoiding duplicate answers.  I hope I made myself clear.


Can we make a POST request without using AJAX and without page refresh?

Actually, I have to send a huge array of jsons to download a file. If we can do that, we can have huge array of jsons in request body.  I know 2 ways so far: 1. Using simple form submit POST request, which reloads page. 2. Using AJAX POST request, which makes us to hold whole file bytes formatted data from response.data at client side and then, save the file using BLOB, etc from third party js frameworks.  I have another approach, which can send huge json array in GET request using anchor tag or window.location. Is it reliable? where huge json array is appended to GET request URL. How much data, can URL hold?  Hope someone help me out. Thanks in advance.


Very confused.  I'm using inSSiDer, WiFi Overview 360 and Wifi Analyzer apps to try to determine the best wifi channel to use. Assuming all channels are in use and there are about 20 different users in close proximity...  Q1: Signal Strength    If all channels are in equal use, do you select a channel where others that use it have the lowest signal strength?  I'm guessing that a higher signal strength means that it's from a router from your closest neighbour and you want to avoid that.  Is that the case?  Does lower signal strength mean the person using it is further away and therefore less likely to interfere with your signal? If 2 people are on channel 1 and have high signal strength and 2 people are on channel 11 and have low signal strength, do you choose channel 11?  Assume 6 cannot be used.    Q2: Signal Strength Weighted Against Number of People    What is the impact of signal strength compared to number of people using channel?  If 1 person is on channel 1 with very high signal strength and 2 people are on channel 11 with low signal strength, do you choose channel 11 over 1?  Assume 6 cannot be used?    Q3: Channel Overlap    If, for example, I had 11 routers sitting on top of each other, each set to a different channel, I'm guessing channel 1 and 11 would be the least interferred.  Is that right?  People go on about the fact that only channel 1, 6 or 11 should be used (in US) as they don't overlap but surely that statement is wrong.  Yes, if only 3 people were using Wifi, the best channels to use would be 1, 6 and 11 as they don't overlap but in practice, there are about 20 people using the channels in the same area.  What do you do in that scenerio.  Do you go for the shoulder channels if all channels are being used equally with equal strength?    Q4: Auto Channel Select    Do routers set to auto channel select only choose between 1, 6 and 11?  How do they make the choice?  Do they select by choosing channel with lowest other routers and do they factor in signal strengths.  My router auto chooses channel 1 but my closest neighbour is on that channel.  Is that correct.      Q5: Baby Monitors and Wireless Phones    What channels do 2.4 GHz baby monitors and wireless phones use?  No useful info on the internet for them.  Do inSSiDer, etc. pick them up?    Q6: I have access to channel 13.  All other things being equal, am I better to use this over channel 11 as it is further away from the other channels?    Those questions have puzzled me for a number of years and Google is not helping!!  Would really be grateful if someone could give sensible answers to one or all of them.  Thanks, Mike.


SQL Server IN with multiple values as a parameter

I have a SP as below (example only) and want to filter the City based on values passed in as a parameter.  SELECT * FROM Customers WHERE City IN (@cities_as_a_parameter);   In my C# code, I have the below   cmd.Connection = con; cmd.CommandType = System.Data.CommandType.StoredProcedure; cmd.CommandText = "MY_SPNAME"; cmd.Parameters.AddWithValue("@cities_as_a_parameter", "'Paris','London', 'xxx', 'yyyy'");   My question is how to pass multiple values to the SP parameter @cities_as_a_parameter ? Above code does not work and want to know what is the correct way of doing this.  What is the best way to do this ?   OR is there any other way to do this (without using multiple where conditions)?


When bit-banging I2C using 2 PIO lines do these lines still need to be pulled high? Obviously using a dedicated I2C bus the lines must be pulled high as the pins are open-drain outputs but PIO pins aren't open-drain.


How to make an Excel formula which totals several adjacent rows based on cell values

I have an Excel sheet with three columns: date, person and percentage. I would like to put in a data validation that flags cells if the total for a given data/person combination do not equal 100%. Is that possible?  In other words, in the custom formula of a data validation, I would like to make the following type of formula.   =if(sum( cells with a (date = the date on this row, person = person on this row))=1)   Is there a function which will return the cells in a range conditioned on certain values, or will sum the cells.  Note that if it is not possible to do two cells, I have no issue adding a cell which combines both values for the purpose of affecting the lookup.


Why we use const array in a function, even the original array are not const?

I hope that these code  express my question more clearly.  double xxxx(const double* const array){ //... } int main(){ double* array = new double [5]; xxxx(array); }   Is it actually create a new const array in the stack and heap by the input of the function?


What is the right site to post a question about why a particular language does or doesn't support certain features?

What is the right site to post a question about why a particular language does or doesn't support certain features, for example:      Why doesn't GoLang support inheritance? What were technological/language design factors involved in this decision?


What is the most efficient way to sort an Html Select's Options by value, while preserving the currently selected item?

I have jQuery but I'm not sure if it has any built-in sorting helpers. I could make a 2d array of each item's text, value, and selected properties, but I don't think that javascript's built in Array.sort() would work correctly.


B2B application: users has its own users

B2B Scenario I am trying is that:  The following Roles exists in the system:  Super Admin Super Admin Staff Owner (client) Admin (owner i.e. client and creates admin to define sales counters) Sales Counters  That means there are users who'll create their own sub users e.g.  [FLAG-A] ROLE "SUPER ADMIN" creates a ROLE "Owner" and "OWNER" creates its own sub users ROLES i.e. "ADMN" & "SALES COUNTER". Each role obviously has its info to login to the system I tried to design database as following:  In this diagram I am assuming that main user creates sub user that in my view many to many relationship so I have to add table between them as "USER_PERSON". Problem is to set "WHO CREATED USER" in the system. I mean which user has created sub user as described in [FLAG-A]  Please check this diagram


I'm developing a multilanguage software. As far as the application code goes, localizability is not an issue. We can use language specific resources and have all kinds of tools that work well with them.  But what is the best approach in defining a multilanguage database schema? Let's say we have a lot of tables (100 or more), and each table can have multiple columns that can be localized (most of nvarchar columns should be localizable). For instance one of the tables might hold product information:  CREATE TABLE T_PRODUCT (   NAME        NVARCHAR(50),   DESCRIPTION NTEXT,   PRICE       NUMBER(18, 2) )   I can think of three approaches to support multilingual text in NAME and DESCRIPTION columns:   Separate column for each language  When we add a new language to the system, we must create additional columns to store the translated text, like this:  CREATE TABLE T_PRODUCT (   NAME_EN        NVARCHAR(50),   NAME_DE        NVARCHAR(50),   NAME_SP        NVARCHAR(50),   DESCRIPTION_EN NTEXT,   DESCRIPTION_DE NTEXT,   DESCRIPTION_SP NTEXT,   PRICE          NUMBER(18,2) )  Translation table with columns for each language  Instead of storing translated text, only a foreign key to the translations table is stored. The translations table contains a column for each language.  CREATE TABLE T_PRODUCT (   NAME_FK        int,   DESCRIPTION_FK int,   PRICE          NUMBER(18, 2) )  CREATE TABLE T_TRANSLATION (   TRANSLATION_ID,   TEXT_EN NTEXT,   TEXT_DE NTEXT,   TEXT_SP NTEXT )  Translation tables with rows for each language  Instead of storing translated text, only a foreign key to the translations table is stored. The translations table contains only a key, and a separate table contains a row for each translation to a language.  CREATE TABLE T_PRODUCT (   NAME_FK        int,   DESCRIPTION_FK int,   PRICE          NUMBER(18, 2) )  CREATE TABLE T_TRANSLATION (   TRANSLATION_ID )  CREATE TABLE T_TRANSLATION_ENTRY (   TRANSLATION_FK,   LANGUAGE_FK,   TRANSLATED_TEXT NTEXT )  CREATE TABLE T_TRANSLATION_LANGUAGE (   LANGUAGE_ID,   LANGUAGE_CODE CHAR(2) )    There are pros and cons to each solution, and I would like to know what are your experiences with these approaches, what do you recommend and how would you go about designing a multilanguage database schema.


Omiting salt in baking recipes that use chemical leaveners?

I'm trying to reduce my salt intake.  I've noticed in baking recipes where baking powder is used they add salt.  Can I omit the salt or would the recipe fail?


I struggle to proof that:  $2n+1<2^n$  By using induction.  The base case is for $n\ge3$.  Any help will be appreciated!


How can I use CompareValidator for times without dates?

When I enter 9:00 into the Start control, and 16:00 into Finish; the code below fails validation.  Does anybody know a way I can use the ASP.NET validator for times without the dates?  Start <asp:TextBox ID="txtStart" runat="server" /> (hh:mm)
 Finish <asp:TextBox ID="txtFinish" runat="server" /> (hh:mm)
 <asp:CompareValidator     id="cpvFinish"     ControlToValidate="txtFinish"     ControlToCompare="txtStart"     Operator="GreaterThanEqual"     Type="Date"     Display="Static"     EnableClientScript="true"     ErrorMessage="Finish time must be later than the start time."     runat="server" />   PS-I know I can easily use CustomValidator instead, it just seems like something this validator should be able to handle.


String not converting to lowercase correctly

I wanted to make my own function that converts a string to lowercase,s and I want to be able to convert the result of tolower to a char but whenever I typecast it, it crashes. How would I fix this?  My function is as follows:  void stringToLower(char **str){     char *val = *str;      int i = 0;     int n;      for ( i = 0; val[i] != NULL; i++){          val[i] = (char)(tolower(val[i]) );          printf("%c", val[i]);     }      printf("\n");      return;  } int main(){       char *name = "BILLY";     stringToLower(&name);      printf("%s", name);       return 0; }


Roll out 10k tools gradually between 3k and 10k reputation for users who have shown interest in helping the site

I. Short Version Make it easier for lesser rep users who actually contribute in janitorial work, by giving them access to some of these tools between 3k and 10k. II. Long Version A. Pre-ramble Preamble Upon reaching 10k, a user has access to a "tools" page which lets them view questions with close votes, delete votes, edit queues, migration stats, etc. The last meaningful privilege that a user earns is at 3k, which is the ability to vote to close/reopen. The 5k privilege of approving tag wiki edits is absolutely worthless because there is no way of knowing which tags have been edited and are waiting for approval! So effectively, it's a barren stretch from 3k to 10k, and given that privileges feed our hidden masochistic desire to clean up the muck, my request in this post is to gradually rollout the different 10k tools for users who help keep the site clean. B. Recognize users who actually contribute in janitorial work   who are of tremendous help to the community and have been working hard without access to any of these tools. We should stop placing 10k users on a pedestal and start making it easier for lesser rep users who actually contribute in janitorial work by giving them access to tools.  For example:  Let users who also have the Strunk & White badge earn the privilege to view edit queues at 3k#. This way, the badges count for something other than merely being show pieces on your profile and there is a motivation to work towards something. If they have successfully closed/reopened (not cast votes) say 50 posts, they can be granted access to the close queue at 5k#. I understand that this might be a harder number to track (maybe not...). Let users who have the Deputy badge review flags in the queue at 7.5k# rep.  This way, SE can recognize the efforts of these users with something more than a measly badge and they too, in turn, will be more than happy to be able to assist in cleaning up with the help of shiny new tools. C. Possible extension to other users While II-B above is the primary intent of this post, it might not be a bad idea to ponder about extending this to other users. For example, for users without the respective badges, you could grant access to the edit queue at 5k, close queue at 7.5k and flag review page at 10k. So here, the incubation time is 2.5x the rep at which they earn the right to edit/close (as opposed to roughly 1.5x for those with badges). D. Advantages Currently, the 10k tools are a big dump of statistics and queues, which actually end up disappointing a lot of folks who think they get access to mod hammers. As  notes, there could also be the possibility of people going berserk when they see a big list to burn all 50 close votes. By rolling out the tools one by one, the least harmful first, we can greatly minimize this and perhaps even train them the right way.  A user first learns to use the tools with the edit queue. This is the least harmful of all, because a bad edit approval/rejection can be trivially fixed by just a single user with 2k rep. On the other hand, a wrong closure requires 5 other users with 3k rep to reopen. In the period it takes for them to get from 5k to 7.5k, hopefully they'd have learned to not go crazy and review and act only on those that they know for sure are correct. A lot of the flags are for dupes/not constructive/etc., which are flagged by <3k rep users. This unnecessarily adds to the mod queue. By letting more users see the close queue and act on it, such flags get resolved sooner, and the mods can utilize their time for more important flags. By the time they reach 10k, users have an idea of what to expect and won't have their hopes too high or too low. They'd also figure out how much time is worth spending on each and perhaps learn to use the tools better. More users involved in clean up ==> less crap to stink up the place.  #The actual thresholds and nitty-gritties are up for debate or left to the discretion of the dev team.


Rewrite Autodiscover to autodiscover with apache

How can I use modrewrite to rewrite the requests made by testconnectivity microsoft com  I want to rewrite   Redirect URL:  myhost com/Autodiscover/Autodiscover.xml  to   Redirect URL:  myhost com/autodiscover/autodiscover.xml  BEFORE it would get proxypassed:  <IfModule mod_proxy.c>   ProxyRequests Off   SetEnv proxy-nokeepalive 1   ProxyPreserveHost On    #RewriteEngine on   #RewriteRule   ^/Autodiscover  /autodiscover  [R]   <<< DOESNT WORK     ProxyPass /autodiscover http://127.0.0.1:5000/autodiscover retry=0   ProxyPass /ews http://127.0.0.1:5000/ews retry=0   ProxyPass /_debug http://127.0.0.1:5000/_debug retry=0    <Proxy http://127.0.0.1:5000>     Order allow,deny     Allow from all   </Proxy> </IfModule>


Compute $\mathrm{Aut}(S)$ of the ring $S=\mathbb{Q}[x]/(x^2)$

This problem once again is from a previous exam.  The problem is to compute the group of automorphisms of the ring $S$ where $S=\mathbb{Q}[x]/(x^2)$  My thoughts: Well $x^2$ is reducible over $\mathbb{Q}$ so I am completely stuck. Also what exactly is the theory I need to know to solve this problem?. I don't even know where to look in the text book to find the relevant theory for this. In particular  I have not learned Galois Theory. In fact we don't need to know Galois' theory for my exam. So I'm hoping this doesn't use any of that heavy machinery.  Can you guys help?  Thanks for your help and answers.


Is there a way to copy over the ssh passwordless authentication to a new RHEL linux server w/o being prompted on the initial login?

We will be migrating to a new server and copying all our accounts over to it. The issue we are encountering is now: There is a large number of ssh accounts and they require us typing yes on the initial connection from the new server. Is there a way to copy over the accounts to the new linux server so that we aren't prompted to type 'yes' on the initial connection?


If one would just read the question, one could easily understand that this is not a duplicate.  Previously in  question, it was asked how to typeset a column vector. Two answers were present,   First one used such syntax: \colvec{1}{2}{3}  and the second one was like this: \colvec{1;2;3}    Now I like the second one, because it seems shorter are more concise. Regarding this, another user had asked . The answer given to that question had a syntax similar to the first bullet. I would like some help converting the one which uses semicolons into a row vector function, (original is given below):  \documentclass{article}  \makeatletter \newcommand{\Spvek}[2][r]{%   \gdef\@VORNE{1}   \left(\hskip-\arraycolsep%     \begin{array}{#1}\vekSp@lten{#2}\end{array}%   \hskip-\arraycolsep\right)}  \def\vekSp@lten#1{\xvekSp@lten#1;vekL@stLine;} \def\vekL@stLine{vekL@stLine} \def\xvekSp@lten#1;{\def\temp{#1}%   \ifx\temp\vekL@stLine   \else     \ifnum\@VORNE=1\gdef\@VORNE{0}     \else\@arraycr\fi%     #1%     \expandafter\xvekSp@lten   \fi} \makeatother   \begin{document} \[ \Spvek{1;-2} \quad \Spvek[l]{1;-2;3}\quad \Spvek[c]{1;-2;-3}\quad\Spvek{1;2;-3;4} \] \end{document}


How to use lastrees on a catalog with a function requiring a CHM raster?

I'm still fairly new to using LiDAR data and R, so please let me know if this isn't clear.  I am using the lidR package to segment individual trees over a large landscape. I have been using the catalog function to process the data in reasonable chunks, and have created and saved the CHMs for each chunk.  What I can't figure out is how to use the lastrees function on the catalog and call the correct CHM to use with the algorithm. Is there a way to do this within the package, maybe using catalog apply (still haven't figured that out), or am I better off attacking it some other way?  If there is a way to process the CHMs to make this easier, I'm willing to try that as well!


Wave–particle duality is kinda bothering me... I read that electrons can act like waves, but I know that electrons are actually particles.  The theory says that if you have not observed the particle it acts like a wave and can explore all classically available particle trajectories simultaneously and when you observe it it ends up in just one place. But doesn't that just mean that this particle is a particle the whole time, but you can't know it's location without observing it and the wave just presents a range of possible locations where it might be if you do observe it?  And if so why would you call it "Wave–particle duality" if this particle is just a particle doing it's thing and a wave is just a best guess of where it is?


Have Google index different languages at the same URL instead of just the default (English)

I have a multilingual PHP site. I have set English as the default language.  The language changes automatically according to the browser settings. If it is French, the site will be seen in French.  However in the Google search results, even if I have the browser in French, the English language appears in the results. How can I fix that?  To be clear I don't want to use subdomains or URLs like www.example.com/fr/. I would like it to work like Facebook.


Show that it is possible that the limit $\displaystyle{\lim_{x \rightarrow +\infty} f'(x)} $ does not exist.

Let $f: \mathbb{R} \rightarrow \mathbb{R}$ a differentiable function with continuous derivative and the limit $\displaystyle{\lim_{x \rightarrow +\infty} f(x) }$ exists. Show  with an example that it is possible that the limit $\displaystyle{\lim_{x \rightarrow +\infty} f'(x)} $ does not exist.  My attempt:  $$f(x)=\int_{-\infty}^{x} e^{t^2}dt$$  $$\lim_{x \to +\infty} f(x)=\lim_{x \to +\infty} \int_{-\infty}^{+\infty} e^{t^2}dt=\frac{\sqrt{\pi}}{2}$$  $$\lim_{x \to +\infty} f'(x) =\lim_{x \to +\infty} e^{x^2}= +\infty \notin \mathbb{R}$$  Is my attempt right?


If we accept a false statement, can we prove anything?

I think that the question is contained in the title. Suppose we begin from something that is false for example $1=0$. Is it possible using only $\Rightarrow$ (and of course $\lnot ,\wedge,\lor$)  to prove any possible statement? It has been ages since i studied logic at the university so i would prefer a simple explanation (if possible)


Do users have veto power over suggested edits to their post?

If reviewers make a decision to accept/reject a suggested edit, does the original poster have a way to overturn their decision?  I've made a few edits that were rejected by reviewers. I thought they were improvements to the site that would help others in the future, but it seems they did not fit within SO policy.  It is my impression that the OP is in the best position to decide whether or not an edit is an improvement because rather than being responsible for impartially interpreting a policy, they need only to decide whether the change improves their question or answer.  So, I would like to know if the OP is notified of edits and given an opportunity to accept or reject them, should they have an interest in doing so.


How to find out which (not installed) Debian package a file belongs to?

On Debian systems (and derivatives):  $ dpkg --search /bin/ls coreutils: /bin/ls   That is, the file /bin/ls belongs to the Debian package named coreutils.  But this only works if the package is installed. What if it's not?


Launching native Windows 10 applications from a custimizable key on Logitech Keyboard

Using the Logitech Options software, I am trying to change the screenshot customizable key to instead open the Snip & Sketch tool. While you are able to customize the key to launch an application, it requires the path to the file, however, Snip & Sketch is a Windows 10 application and does not have a file location. Is there a work around to customize the key to launch native Windows 10 applications that do not have a file path?


will buying new domain and redirect it 301 to my website affects my website somehow?

I want to buy a new domain with a name that is so similar to my original website domain and redirect it in a 301 redirect to the original website. will this somehow affect the original website traffic?? Thanks


Is every positive definite matrix symmetric?

whether every positive definite matrix has to be symmetric? If not, what will be the example?


I'd like your feedback on a situation I'm facing with my stakeholders with regards to a particular web form design. I'm new to my role as a UX Designer and hope to learn from experienced folks here.  Currently, we have a long form that we cannot break into multiple pages. This is a solution I've brought forth to the stakeholder, but unfortunately, did not take off.  I went with a multi-column form field design. I'm aware that multi-column forms are bad in terms of readability and where possible, we should stick to a single column form (this is not possible due to the length of the form and that we cannot break them into multiple pages). I accept these risks - at least in the first product iteration till we get more user feedback on this, but for now, let's assume the following:   We've a multi-column form design. Each row in the form will have at most 3-4 form fields. The entire form is placed within a modal (again, this is something we can't move away from due to technical constraints)   Currently, our form looks something like below (information masked):    One of the key issues from our stakeholders was that:   For dropdowns and calendars, where there is normally a visual indicator (i.e. an arrow pointing down, calendar icon) accompanying the field: if we stretch it all the way out at 100% of modal width, users may not know that the field is a dropdown or a calendar. It was suggested that we avoid fields that stretch out all the way at 90% modal width and keep it short in length (e.g. see nationality field in the screenshot, suggestion is to keep it at the same length as gender, given name, etc)   My thoughts on it are:   It is a desktop based app and people are viewing this on a normal-sized monitor screen. They'll be able to see within their peripheral vision that the fields (that are currently stretched at 90% modal width) is actually a dropdown or a calendar. I would assume that people would normally click on the "currently active/default value" in the dropdown or the date in the datefield, and they don't bring their cursor all the way to the edges of the field where the "down arrow" (in dropdown) or "calendar icon" (in datefield) are to click; hence, it is OK to stretch the fields at 90% modal width.   Unfortunately, due to the nature of the project, we are unable to run usability tests until after the product launches... These are very real constraints we're facing as UX designers in the organisation we're at, and would like to tap in the experiences of other designers for advice.


1.Etiquette requires that the bride's father makes a speech. 2.The situation requires that he go there.  UPDATED: These are two different sentences. My questions are about those, not only one of them. No one has explained anything as to the latter. I am wondering the reason for--in the first sentence -- there has been used the s on makes. Basically, I meant although the two sentences are subjunctive, in fact, why the first one has used s.


What tags do developers look through on localized meta sites?

I know that developers view questions tagged by  but what about other kinds of tags like  or ?  If not only  questions are viewed, why  to write only bugs in both languages - Russian and English. Does it apply to feature requests too? Or how developers differentiate which proposals require development and which don't?


If $0<a<b$, prove that $a<\sqrt{ab}<\frac{a+b}{2}<b$  So far I've got:  $a<b$  $a^2<ba$  $a<\sqrt{ab}$  And:  $a<b$  $a+b<2b$  $\frac{a+b}{2}<b$  So I need to prove that $\sqrt{ab}<\frac{a+b}{2}$  How can I do it?


What is the etymological justification for taking the grammatical term "pluperfect" and turning it into an adjective meaning 'more than perfect"?

I'm interested in the usage of the word pluperfect in the following passage from Thomas Harris’s crime thriller, The Silence of the Lambs.  Jerry Burroughs of the National Crime Information Center makes a comment to Jack Crawford, an FBI special agent, regarding Dr. Frederick Chilton, the administrator of the Baltimore State Hospital for the Criminally Insane:     “Chilton was blowing off about “The Search for Billy Rubin.” Then he   went to dinner with a television reporter. That’s where he was when   (Hannibal) Lector took a walk. What a pluperfect asshole.” - Page   272.   Though several online dictionaries define pluperfect only as a grammatical term equivalent to “past perfect tense”, Readers-Plus English-Japanese Dictionary defines it as        (grammar) n.a. past perfect. 2.(slang) a. perfect, extraordinary.      I’m curious to know how the slang usage of pluperfect to mean “perfect, extraordinary” came about. What is the etymological background for the appropriation of the grammatical term to this slangy use? Is it common to use the word like this?


Explanation of python reference behavior when creating list of lists

When creating a new nested list the following way:  test_list = [[""]]*5   unexpected behavior happens, appending to an index the following modifications happens:  test_list[1].append(2) [['', 2], ['', 2], ['', 2], ['', 2], ['', 2]]   when doing the following it works as I would expect:  test_list[1] = test_list[1] + [0] [[''], ['', 0], [''], [''], ['']]   but when using the += operator the same odd thing happens  test_list[1] += [0] [['', 0], ['', 0], ['', 0], ['', 0], ['', 0]]   when the list is defined as following: [[""] for i in range(len(5))] all the examples return the expected output.   What is going on? Is it some reference thing I am not understanding?


Use of magic by underaged students. Harry Potter

I've been rereading the HP books and something keeps bugging me. In Chamber of Secrets the Ministry assumes Harry used magic, because he was the only magical being around, so basically that was their explanation. They couldn't actually trace the spell to him and not Dobby.   So I was wondering what if Ron or Ginny or the twins used magic at home? Could they have been traced because they are underaged or would the Ministry just assume that Mr or Mrs Weasley used magic instead?   Sorry if anyone else asked the same thing, but honestly, I couldn't find an answer.


Swapping first letters of different words

What is it called when you swap the first letters of two words?, for example - red truck is what is intended...instead ted ruck is what comes out.


Did Palpatine have contingency plans for the death of the Sith Order?

In new canon novels, it is shown that Palpatine has contingency plans in the event of his own premature death at the hands of his enemies. In the case of the Rebel Alliance it comes in the form of Operation Cinder:     It is intended to be issued in the event of the Emperor's death - Imperial forces are to use climate-control tech like satellites etc to render countless worlds, including Rebel-sympathetic ones like Naboo, permanently inhospitable in retaliation to the Rebels' murder of the Emperor.   It is known that Palpatine is disappointed with how Vader's half-machine transformation at the end of RotS has significantly diminished his potential in the Force and suitability to be his successor. It is certainly the reason why he pressed on with plans to turn Luke to the dark side by defeating and killing Vader: Luke is essentially the same as the good old Anakin that Palpatine had wanted - the perfect apprentice that Vader no longer is.  All in all, Palpatine feels Vader is not infallible and is eventually disposable. Considering he has some form of contingency for the Empire's future in the event of his own death, I don't see how having one for the Sith's future is not even more crucial, especially considering his impression of Vader, his immediate successor. So, does Palpatine have plans for the Sith Order's survival in the event of his own death, whether to Vader in accordance to the Rule of Two or otherwise, or of both Sith Lords' deaths as has happened at the end of RotJ?


I've been using Ubuntu 16.04 on my desktop for about 4 months now, and everything was fine until about a week ago. Now I can't log in my anymore.  Every time I type my password and click enter, the screen turns black for about 2 to 3 seconds, and then goes back to the login screen again.  There's no password error message just back to the login prompt.  I'm also 100% sure I'm entering the correct password.  this problem started just after I installed an update, could this have something to do with it?


Cannot update pacman using sudo pacman -Syu under proxy network. I tried exporting environment variables using  export http_proxy='http://uem:12345@172.16.0.1:3128/'   as my workplace network uses proxy and authenticaton.  and then updating using   sudo -E pacman -Syu   but it returns error 407and error: failed to synchronize any databases


Title of old Sci-fi movie, doctor goes to strange world

I trying to find the title of a science fiction movie I watched some years ago. Unfortunately I don't know how old the movie might be (or was at the time).   All I have to go on is a few memory fragments:   A doctor travels to a strange world There is some sort of strife on this world, a war I believe Some people (at least one is shown as I remember) have the power to shout, or scream, at animals (and possibly humans) and thereby kill them. The scene I remember a dark skinned man uses this ability to kill a threatening leopard (or similar). (He inhales deeply and roars wordlessly.) There is a prison with a special prisoner, a woman I think. The prison guard is a large alien being There is a red ocean. I think the prisoner is brough there at some point though I can't remember why   I will add to this if I can remember any more details, but chances are slim since it was quite long ago that I watched it.   If you have any idea what the movie might be, I'd be very grateful.  Edit: At the request of  who pointed out that there is a previously answered question for the same title .    This question adds details about some scenes and occurances that are not mentioned in the older question. Notably, voice powers, aliens and red ocean. Some of these details would likely have led me to find the previous question before posting my own.


word choice - realize notice find out figure out

The other day, I was at the bookstore and I noticed there was a woman surrounded by a large crowd. It was hard to tell what was going on. So, at first, I figured it was an employee handing out free stuff. But when I got a little closer, it looked like she was signing autographs. Since it was a bookstore,   I (knew/noticed/found/found out/figured/figured out/realized) that it could be a famous writer signing books.  I don't want to ask a lot but, could you choose the right word?  And could you let me know which one is right/not right and why and why not?


Every single mirror is missing the Quantal dists.  NOTICE:  Before you comment, I do realize 12.10 is in End of Life status!  But to totally restrict further usage?  Unacceptable!


how to exclude some properties of object

I'm new in JavaScript I have this object that want to exclude 2 keys :  "age":20 and "university":"HCC".   As a result, I want to see "name:"Sam" and "class":55 as the only properties in the object.  var b = {      "name":"Sam",     "age":20,     "university":"HCC",     "class":55 }


Pasting from several rows into a single row every 6th cell

I need to copy every 6 cells down horizontal to a new column  So that D3/E3/F3/G3/H3/I3 goes to J2/K2/L2/M2/N2/O2 And that D4/E4/F4/G4/H4/I4 goes to P2/Q2/R2/S2/T2/U2   And so on for sets of 20 rows  I swear I did it before, do not know VBA but am stumped other than manual paste


I've just finished re-reading Chamber of Secrets and this stuck with me. Once it becomes clear that the Chamber of Secrets has been opened again and the attacks have resumed, The Ministry of Magic arrive and send Hagrid straight to Azkaban.  I just can't get my head around why. Even if Hagrid had opened the Chamber the first time, what evidence did the Ministry have that he was involved in the latest round of attacks? I can understand why they'd want to question him at least, but sending him straight to Azkaban (without even a trial, as far as I'm aware) seems a little extreme.  Was there some other factor involved that I've missed, or was the Ministry just looking for a scapegoat?  There's a similar question regarding , but the accepted answer doesn't seem to apply to Hagrid's situation.


Disprove by giving a counter example for all real numbers a and b, if $a < b$ then $a^2 < b^2$  Context:The instructor just gave this question without the method to prove it


Does the order in which methods are written matter?

I know that some programming languages require methods that are referenced/called by other methods to be declared before the caller in the code. For example:  private Method1(in){   Return in *5; } Private Method2(paycheck){   Return Method1(paycheck); }   would be OK but,  Private Method1(paycheck){   Return Method2(paycheck); } Private Method2 (in){   Return in *5; }   Would fail.  Is Java, and/or Android specific Java, one of these languages?


Not able to set value to a variable by calling it inside a method

I want to set a boolean execute as true by passing it into a method set_Execute.Can someone help on solving this?   Here is code:   public boolean canExecute(){     boolean execute=false;     set_Execute(execute);     log("can execute"+execute); //it is going inside method set_Execute but it is always printing execute as false     return execute;     }      private boolean set_Execute(boolean setExecute){     return setExecute=true;     }


I remember reading a Science Fiction book during my youth (1980 ish) that was multiple books, had some Native American themes and the end puzzle all revolved around using twelve rings in a specific order to unlock some great machine or something.  I cannot remember the name or the author.  I am hoping someone here can help me out.


I recently discovered terminal's feature, you can set the keys emacs or vi style  I prefer the second. so if you do   set -o vi   You can use k j l h keys to navigate on the command line. And you can switch between 'Normal' and 'Insert' modes like in vim.  However there's no way to visually distinguish one mode from another, even cursor doesn't change. Which makes vi-style pretty much useless. Is there a way to make it truly vim-like?


What are the easy and possible ways to upgrade the operating system from 12.04 to 13.04? Are there  any option except booting the system with 13.04?


Two formulations of Lagrangian for Maxwell's equations in the vacuum (revised question)

I've started working my way through David Tong's excellent lecture notes in an effort to teach myself QFT and in his first lecture on classical fields he observes that the Lagrangian density for Maxwell's equations in a vacuum: $$\mathcal{L}=-\frac{1}{2}({\partial_\mu}{A_\nu})({\partial^\nu}{A^\mu})+\frac{1}{2}({\partial_\mu}{A^\mu})^2$$ can also "up to an integration by parts" be written as: $$\mathcal{L}=-\frac{1}{4}({\partial_\mu}{A_\nu}-{\partial_\nu}{A_\mu})({\partial^\mu}{A^\nu}-{\partial^\nu}{A^\mu})$$ I'm failing to manage to show this. Working in reverse, it's clear that: $$-\frac{1}{4}({\partial_\mu}{A_\nu}-{\partial_\nu}{A_\mu})({\partial^\mu}{A^\nu}-{\partial^\nu}{A^\mu})\\ =-\frac{1}{2}({\partial_\mu}{A_\nu})({\partial^\nu}{A^\mu})+\frac{1}{2}({\partial_\mu}{A_\nu})({\partial^\nu}{A^\mu})$$ but I can't resolve the second term. I clearly need to brush up my tensor calculus skills - can someone show how to derive this?


LIGO discovery: if the space "time" metric is changed, how is it measured?

Regarding the wonderful 2016 news about gravitational waves.  Travel time in one arm of the LIGO is ~ 30μs.  A gravitational wave affects the arm for some few hundred of these laps.  Then for example as  "the arm changes length ... subsequent wavecrests will have had successively further to travel and so there is a phase lag that builds up ..."  But we always use the language that gravitational waves are affecting the spacetime metric.  I just don't see how the phase ("speed") can change if the spacetime metric is changing.  Let me put it this way:  Say I said (A) "gravitational waves stretch and squash objects - amazing!".  Say a physicist says (B) "gravitational waves stretch and squash the spacetime metric - amazing!"  What really is the difference between saying "A" versus "B", and, what is it in the experiment that shows us "B" happened, not "A"?  In other words, say we deliberately merely did "A" - using say a really precise bulldozer chained to one end of the tube - what specifically would we look at in the signal and conclude "oh, that was merely 'A' - not actually 'B'".  Or indeed are "A" and "B" indistinguishable?


Wireless Keyboard: SHIFT-P suddenly not working

(This question is NOT about Macbook Pro keyboards. It is about an Apple Wireless Keyboard)  I'm using an old Apple Wireless Keyboard (can't find model number - it's the white and clear plastic model).  Yesterday the SHIFT-P (capital 'P') functionality suddenly stopped working. I didn't spill anything or otherwise mess with the keyboard (that I am aware of).  The "p" key works fine but in order to type a capital 'P', I need to set the caps lock. I looked at the 'keyboard viewer' and SHIFT-P doesn't trigger an event. No other keys appear to be affected.  Anyone seen this before?  UPDATE ok, so it's the left SHIFT key which is failing with the letter "P" but the right SHIFT key works fine with it. Weird. I understand total hardware failure but why would the left SHIFT key only fail with the letter "P"?  (the irony here: I am using the wireless keyboard because my MacBook Pro laptop battery swelled up and knocked out the Y, U, I, O keys. I replaced the battery but that didn't fix the keyboard issue)


So I'm revising definitions of algebra for my exam and I'm wondering what an Ideal actually is?  I believe the definition is:  $I$ is an ideal of $R$ if $xr,rx\in I$ where $r\in R$ and $x\in I$  However, after looking about the web, I'm finding that unity has a lot to do with it. I'm struggling to find out how though. I know a unit is an element which can be multiplied by another element in the set (is set the right word?) to get 1.  Essentially I'm asking what it means for a ring to have unity? and what doe an Ideal mean/tell you  I'm just looking for some clarification on this, so any explanation would help, and an example would be great. We were asked to find all Ideals in $Z_6$ today and I didn't understand at the time, so this as an example explained would help me a lot.  Thanks a bunch.


How can I batch create curved linear features i.e. using 3 points in ArcPY?   The real question is, whether we can create curved linear feature through arcpy or we have to use ArcObjects! Because, to me, it seems we can not do that in ArcPy.   to create linear (non-curved) features we can use:  arcpy.Polyline(Array([arcpy.Point(*coords) for coords in feature])))   This question is a duplicate of  New comers, note that curves are only supported on 10.3 and above. see


Issue in evaluating the performance of my "clustering algorithm" using NMI, ARI when the "ground truth" is available?

(**Edited the question after the initial comments)  Suppose,  Ground_truth_data = [1, 1, 1, 1, 1, 1, 1];  Clustering_result = [1, 1, 1, 1, 1, 1, 2];  Here, as you can see, there are "7" instances of data and two classes with labels "1" and "2".   Q1) Looking at this result, what can be said about the performance of my clustering algorithm that produces the "Clustering_result"?  Here's what 'two' of the widely used (have seen in many reseach papers) external clustering measures says :  ARI = metrics.adjusted_rand_score(Ground_truth_data, Clustering_result) ARI = 0.0 #Adjusted Rand Index Result  AMI = metrics.adjusted_mutual_info_score(Ground_truth_data, Clustering_result) AMI = -1.4018874593092454e-15 #Adjusted Normalized Mutual Information   Q2) Does these results mean my clustering algorithm is performing badly?  According to me, NO!! Since out of "7" instances "6" are clustered correctly. (Please correct me if I  am wrong)  Q3) Why ARI, NMI result in values close to ZERO in the above case?  Q4) In my dataset of 300 different types of data, the maximum value possible for the no. of clusters is "8". Also, in this dataset, there are many instances where a situation similar to the above example have been noticed. In such a case, what are the suitable performance measures (that are consistent) to evaluate the performance of my clustering algorithm?


Can we have the spoiler text show on click too?

On my iPhone, in order to view spoiler text, I have to double click it, copy it, and paste it into a note or something similar.  Could we make it show on click since on that device there is no such thing as a mouse over?      Please?


Solving equation involving Euler's totient function

Given $m\in\mathbb{N}$, is there a general way to solve the equation \begin{equation} \varphi(n)=m \end{equation} where $\varphi$ is the Euler's totient function? For example, I want to solve for all the $n$'s such that $\varphi(n)=4$. Is there any way to solve it that are also applicable to many (if not general) cases?


What does mtp://[usb:002,003]/Storage/ mean?

Recently that I connect my Windows phone mobile to my Xubuntu laptop I see mtp://[usb:002,003]/Storage/ alongside the other drives.It shows my phone media files! That actually I can not find it in terminal!   So can I access to its file system information at all? and also I want to know is there any way that I could access other data on my phone like documents or messages or ... ?


Ideas on how to measure the time to get 45th Fibonacci number

I'm working on a variation of a problem noted in Problem 19 Chapter 12 of the textbook "Building Java Programs". Essentially, I'm doing a recursion problem using a Fibonacci sequence. Though the program I've made works, part of the problem I'm working on is I also need to measure the time to get 45th Fibonacci number by using the implementations by 1, 2 and the one given in problem, print out how many times your implementations are faster than the one given in the problem . While I've looked at this page (), I was wondering is there was a way implement this without a lot of code change. This is the original method used:  public static int fibonacci (int n) {       if(n <= 2){         return 1;       } else {          return fib (n - 1) + fib(n - 2);       } }   And this is what I've done I did the problem using two java files: one that serves as a test main class with and the other with the recursion algorithm :  PrintValues.java  import java.util.Scanner;  public class PrintValues {      public static void main(String[] args) {         Scanner scan = new Scanner(System.in);         System.out.print("Enter the number value: ");         int n = scan.nextInt();         HelperBinary.countBinary(n);         //fib(double nth);     } }   HelperBinary.Java:  public class HelperBinary {      public static void countBinary(int n) {         if (n < 0) {             throw new IllegalArgumentException();         }         countBinary(new char[n], n);     }      private static void countBinary(char[] preFx, int n) {         if (n == 0) {             /* This is the base case             */             System.out.println(preFx);         } else {             /* This is the "recursive" case.             */             final int i = preFx.length - n;              /* Assign a '0' preFx and recurse             */             preFx[i] = '0';             countBinary(preFx, n - 1);              /*Assign a '1' preFx  and recurse             */             preFx[i] = '1';             countBinary(preFx, n - 1);         }     } }   Any help would be seriously appreciated.


Intuition of pdf of a continuous random variable

What is the intuition behind the probability density function of a continuous random variable? Integrating it within two points provides the probability that is associated between two points, but if you plug a single value into $f(X=x)$, it outputs a value. What is the intuitive understanding of this value for a given x?   For example, in the above image, the value of the red curve at x=0 is 0.4. How can 0.4 be interpreted?


How can I showcase my user research in an UX portfolio?

I'm a beginning in a UX field and currently building up my portfolio. In portfolio projects how do I include the research element of the UX process when I have no money to spend on formal UX research?  My research background (in psychology) is a big part of my interest in UX and a significant portion of my resume so I feel like I should include a research element to my projects, but I'm not sure how. The only "users" I have access to is my friends and family, and this is obviously biased. Any advice or guidance is extremely appreciated, I'm completely at a loss and I have no idea how others have solved for this problem.


At the moment I am using beamer and have a table in a frame: Everything works fine except that where I put this color filled circle the table breaks apart but I want to have the circle just within the table field not the table left and right to it if you know what I mean.  \documentclass[leqno,8pt,fleqn,table]{beamer} \usepackage{tikz} \usetikzlibrary{matrix}  \tikzset{ table/.style={     matrix of nodes,     row sep=-\pgflinewidth,     column sep=-\pgflinewidth,     nodes={         rectangle,         draw=black,         align=center,                },                     %baseline={([yshift=-0.5ex]current bounding box.center)},     minimum height=1.5em,     text depth=0.5em,     text height=1em,             text centered,     nodes in empty cells,     %%                             row 1/.style={         nodes={             fill=black,             text=white,             %font=\bfseries         }     },             rows/.style={nodes={fill=gray!10}},             columns/.style={nodes={text width = 10em}},             %myrowstyle/.style={                 %row #1/.style={nodes={fill=gray!10}}     %},    } }  \begin{document} \begin{frame} \begin{center} \begin{tiny}     \begin{tikzpicture}     \matrix[table, rows={2,...,3}{fill=grey!10}, columns={1,...,5}{text width = 10em}, ampersand replacement=\&] (first)     {          card \# \& date \& 1 \& 2 \& 3 \\         ghul \& 01.01.2016 \& \fill[green] (1,0) circle (0.05); \& \fill[red] (1,0) circle (0.05); \& \fill[red] (1,0) circle (0.05); \\ }; \end{tikzpicture} \end{tiny} %\vspace{4mm} \end{center} \end{frame} \end{document}


What action do I take when a more acceptable answer is posted?

I asked a question on an Stack Exchange site and at the time got an answer which I marked as such ()  Since accepting the answer, a new answer has been submitted which is now more accurate than the original answer (I only noticed as I stumbled across the question in error when going through my account).  Should I be changing my accepted answer or leaving it as it is? Logic says I should update it, but it seems unfair that the original user who answered the question will now lose reputation points (I'm assuming they will anyway once I un-mark their answer) when originally they answered the question correctly.


How do I find the distribution of sum of Two Dependant Random Variables?

So, I have this question (as seen in the picture) and I am curious how would I go about approaching it. Initially, I thought to use convolution but I don't think this is a valid approach because after finding the marginals, I found that they didn't satisfy a condition of independence. What are other things I could do? I read about change of variables, but I don't really have a great understanding of it... if someone could provide an example or something on how to do the question, it would be great]


$A,B\in M_n(F)$ where $F$ is a field. Prove that $(AB)^*=B^*A^*$.  I know it's correct if $A,B$ are both invertible. But how to prove the general case? I think it can be proved by Cauchy–Binet formula, but there should be better approaches.  $A^*$ means the adjugate of $A$.


Story set in Glasgow about a trainee lawyer whose body is taken over by a scout for an alien invasion

I read this novel in the early 1990's. I think it is written in first person diary form, and it's as much a satirical comment on urban life in Scotland as a science fiction story. The protagonist is an alien who has taken over the body of a Scottish trainee solicitor. The aim is to spy out Earth's defences, but the irony of him not being well placed to do that is commented on. I can't remember if he is in contact with any fellow alien spies or not. I think that very gradually the characters of the alien and the host body merge and in the end the alien ends up in a happy relationship with his girlfriend and has more or less become human and has abandoned his role as a spy.   Some random things I remember:    The host body's mother is not very bright and keeps making the same exclamations over and over again, much to the puzzlement of the alien. This detail for some strange reason is the thing I remember best: in his work as a trainee solicitor the protagonist has dumped on him the legal job everyone in the practice hates most, that of untangling the immensely complicated ownership of the lease of a little shack used for meetings by (I think) the Kelvinside Old Comrades Association, a war veterans' group. He finally does it, a personal triumph, only to find out that the land had been bought at a handsome price for redevelopment so he needn't have bothered.


Basically, I'm looking for a word for "wearables". Example:  Mary put on the __ she wasn't wearing yet: panties, pants, pumps.  Maybe accessories?


This question is specific to the errors faced by installing a corrupted ArangoDB Enterprise version, this prevents further installation of other packages and my aim is to solve it.  I get the following error when I try to install / remove packages:  dpkg: warning: overriding problem because --force enabled: dpkg: warning: package is in a very bad inconsistent state; you should  reinstall it before attempting a removal (Reading database ... 252333 files and directories currently installed.) Removing arangodb3e (3.3.3) ... Failed to stop arangodb3e.service: Unit arangodb3e.service not loaded. dpkg: error processing package arangodb3e (--remove):  subprocess installed pre-removal script returned error exit status 5 failed to locate javascript.app-path directory, its neither available in '/var/lib/arangodb3-apps' nor in '//var/lib/arangodb3-apps' FATAL ERROR: EXIT_FAILED - "exit with error" dpkg: error while cleaning up:  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  arangodb3e   and I've tried the following, still no luck:  sudo dpkg --remove --force-remove-reinstreq arangodb3e


Can I shrink the transaction log file on a mirror database?

This is a followup question to  about why I couldn't shrink the log file on the principal database.  To make a long story short, I setup database mirroring but forgot to make sure the job that backed up the transaction log was running again, and the transaction log grew to almost 60GB.   Since mirroring was set up, this size increase was duplicated on the mirrored server, and eventually took up all the disk space and made the mirror database unusable.  Per  about transaction log maintenance on a mirror database, you can't back up the log on the mirror, but when asked specifically in  about how to shrink an overgrown log file on a mirror database, a  was left that      One way to do this would be to failover to the mirrored database and   do the shrink there. Thoroughly test this out in a non-production   environment to ensure it has the behavior you want/expect.   This seems to suggest that there might be other ways to shrink the log file on a mirror, and this method might not necessarily be safe to do on a production server.  Is there a way to safely shrink the transaction log file on a database mirror?


There's a Wiki page for PLS "Path Modeling" and another one for PLS "Regression"... they seem to be saying the same thing, except the first link says PLS is great, and the second says that PLS is controversial and some journals no longer accept papers based on PLS:  1)   2)   Are PLS "Path Modeling" and PLS "Regression" pretty much the same thing?


$K/F$ of degree $n \implies$ There is a ring homomorphism of $K$ into $F^{n\times n}$

Let $K$ be an extension of the field $F$ of degree $n$, $K = \{c_0 b0 + c_1 b_1 + \dots + c_{n-1} b_{n-1} : c_i \in F \}$. Then for any $a \in K$, $\phi_a : K \to K : x \mapsto ax$ is an $F$-linear transformation of $K$, so the matrix for $\phi_a$ would be $A_a = \begin{pmatrix} \phi_a(b_0) & \phi_a(b_1) & \dots & \phi_a(b_{n-1})\end{pmatrix}$ where $\phi_a(b_k)$ is understood to be the column vector at the basis vector $b_k$.  I've shown that $\Phi : a \to A_a$ is additive, but how do you show that it is multiplicative?  The purpose is to show that $K$ is isomorphic to a subfield of the ring $F^{n\times n}$.  My attempt: $\Phi(ad) = \begin{pmatrix} ad b_0 & ad b_1 &\dots & ad b_{n-1}\end{pmatrix}$.  I've also tried working with a $2\times 2$ example and don't see where to take it.  Thanks.  EDIT:  The answers in the comments don't answer my general question, they only give an example. Therfore, this question is NOT a duplicate!  In fact, I was already aware of the content of those answers!  (See above!)


What was the reason for some plant and animals to become giant in course of evolution?

The dinosaurs, mammoths, giant plants etc are known to be bigger than modern animals. I wonder why they had been lived and why they are not living now? I really don't know much but is it something about oxygen balance or something similar?


Apt update failing after updating appstream

this issue is linked to  I had similar problem as described in issue and the approved solution stated that we should update appstream to version 0.10.1+ But after updating to version 0.10.6 I am getting this error regularly after apt get update command     AppStream system cache was updated, but problems were found: Metadata   files have   errors: /var/cache/app-info/xmls/fwupd.xml Reading package lists...   Done E: Problem executing scripts APT::Update::Post-Invoke-Success 'if   /usr/bin/test   -w /var/cache/app-info -a -e /usr/bin/appstreamcli; then appstreamcli refresh-ca   che > /dev/null; fi'   all I have to do is run apt get update again and it works. How to solved this?   cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=16.04 DISTRIB_CODENAME=xenial DISTRIB_DESCRIPTION="Ubuntu 16.04.5 LTS"   Update 23/07/2018  Actually its happening still again. Reinstalling didnt helped. Also tried purge:     apt-get purge libappstream3   But still same error.


Find $\mathbb{E} \bigg[ \frac{\textbf{h}^{H} \textbf{y}\textbf{y}^{H} \textbf{h}}{ \| \textbf{y} \|^{4} } \bigg]$ with Mathematica?

Considering the following complex random vectors (Complex Gaussian random variables): \begin{align} \textbf{h} &= [h_{1}, h_{2}, \ldots, h_{M}]^{T}\ \ \sim \mathcal{CN}(\textbf{0}_{M},d\textbf{I}_{M \times M}),  \\ \textbf{w} &= [w_{1}, w_{2}, \ldots, w_{M}]^{T} \sim \mathcal{CN}(\textbf{0}_{M},(\frac{1}{p})\textbf{I}_{M \times M}),  \\ \textbf{y} &= [y_{1}, y_{2}, \ldots, y_{M}]^{T}\ \ \ \sim \mathcal{CN}(\textbf{0}_{M},(d + \frac{1}{p})\textbf{I}_{M \times M}),  \end{align}  where $\textbf{y} = \textbf{h} + \textbf{w}$ and therefore,  $\textbf{y}$ and $\textbf{h}$ are not independent.   I'm trying to find the following expectation:  $$\mathbb{E} \left[ \frac{\textbf{h}^{H} \textbf{y}\textbf{y}^{H}   \textbf{h}}{ \| \textbf{y} \|^{4} } \right]$$   where $\| \textbf{y} \|^{4} = (\textbf{y}^{H} \textbf{y}) (\textbf{y}^{H} \textbf{y}$).  In order to find the desired expectation, I'm applying the following approximation:  $$\mathbb{E} \left[ \frac{\textbf{x}}{\textbf{z}} \right] \approx \frac{\mathbb{E}[\textbf{x}]}{\mathbb{E}[\textbf{z}]} - \frac{\text{cov}(\textbf{x},\textbf{z})}{\mathbb{E}[\textbf{z}]^{2}} + \frac{\mathbb{E}[\textbf{x}]}{\mathbb{E}[\textbf{z}]^{3}}\text{var}(\mathbb{E}[\textbf{z}])$$  However, applying this approximation to the desired expectation is time consuming and prone to errors as it involves expansions with lots of terms.  I have been wondering whether it is possible or not to use Mathematica to find the desired expectation.  Would it be possible?  $\textbf{UPDATE 21-04-2018}$: I've created a simulation in order to identify the pdf shape of the ratio inside of the expectation operator and as can be seen below it seems much like the pdf of a Gaussian random variable. Additionally, I've also noticed that the ratio results in real valued terms, the imaginary part is always equal to zero.  Is there another kind of approximation that can be used to find the expectation (one analytical/closed form result and not only the simulated value of the expection) given that the pdf looks like a Gaussian and probably can be approximated as such?      $\textbf{UPDATE 24-04-2018}$: I've found an approximation to the case where $\textbf{h}$ and $\textbf{y}$ are independent.  $$\mathbb{E} \left[ \frac{\textbf{h}^{H}_{l} \textbf{y}_{k} \textbf{y}^{H}   _{k} \textbf{h}_{l} }{ \| \textbf{y}_{k}  \|^{4} } \right] = \frac{d_{l}[(M+1)(M-2)+4M+6]}{\zeta_{k}M(M+1)^{2}}$$  where $\zeta_{k} = d_{k} + \frac{1}{p}$, $\textbf{h}_{l} \sim \mathcal{CN}\left(\textbf{0}_{M},d_{l}\textbf{I}_{M \times M}\right)$ and $\textbf{h}_{k} \sim \mathcal{CN}\left(\textbf{0}_{M},d_{k}\textbf{I}_{M \times M}\right)$. Note that $\textbf{y}_{k} = \textbf{h}_{k} + w$ and that $\textbf{h}_{k}$ and $\textbf{h}_{l}$ are independent.  I have used the following approximation: $$\mathbb{E} \left[ \frac{\textbf{x}}{\textbf{z}} \right] \approx \frac{\mathbb{E}[\textbf{x}]}{\mathbb{E}[\textbf{z}]} - \frac{\text{cov}(\textbf{x},\textbf{z})}{\mathbb{E}[\textbf{z}]^{2}} + \frac{\mathbb{E}[\textbf{x}]}{\mathbb{E}[\textbf{z}]^{3}}\text{var}(\mathbb{E}[\textbf{z}]).$$


How do you delay the launch of an application in Windows 7 at startup?

I'd like to delay the launch of some startup apps to give it some time to load the other ones before the one I want.


Ubuntu 14.04. Lost wired connection and will not connect wireless, lost nm-applet and laptop will not shut down, now lost cd rom connection

I have been using Ubuntu 10.04 for a couple of years and I am new to Ubuntu terminal.  I performed my first Ubuntu OS installation a couple of weeks. 14.04  It is now my 4th installation because while I have fixed one thing, I have broken another.  First I was not able to connect to my wireless access point.  Now I cannot connect using a wired, or a wireless connection. I also managed to lose the nm-applet, and my laptop will not shut down unless I hold down the power key.   I was able to establish a connection using an wireless external USB. I also have access to a desktop to perform all checks.  I am loving the learning curve and Ubuntu, however now require some help to see what I have done as I have spent endless nights troubleshooting with no success.  My laptop is a HP dv6700 running Ubuntu 14.04.  Just to add after performing an upgrade I have also lost my cd rom. So I cant even do a re install. My start up disk creator doesn't seem to be functioning either.  I am not giving up. PLEASE HELP


Show that if $x^d -1$ divides $x^n -1$ if and only if $d$ divides $n$

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I'm using  Git 2.1.60 for Windows and I want to push my directory to my github URL  Suppose I have a directory: Mydir  and there is "a.txt" in Mydir.  I want to commit only Directory. But when I type like this:  git add Mydir git commit -m "Mydirectory" git push origin master   Then in my github, commit message is updated not only directory but also files in Mydir.  I just want to show commit message only Mydir.  So I changed  a.txt file and i tried this:  git add Mydir/a.txt git commit -m "this is a.txt"   What I want is   Mydir     "Mydirectory"  And if I click Mydir in github,  a.txt     "this is a.txt"  But When I type like this(same as above code):  git add Mydir/a.txt git commit -m "this is a.txt"   The resuls is  Mydir     "this is a.txt"  And if I click Mydir in github,  a.txt     "this is a.txt"  How can I just commit only directory?  or How can I just commit only a.txt file?  Is it impossible?


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If $-1<x<1$ show that $\lim\limits_{n \to \infty}{n\,x^n} = 0$. I don't have idea. I only prove that $n\,x^n$ is decreasing.


During my study to gamma function I find this form but I try to prove but I can't $$\Gamma(x) = \lim_{n\to \infty} \frac {n! n^{x-1}}{x(x-1)(x-2)........(x+n-1)} $$ So I want to know how I can prove this limit ?


I have made a virtual installation of Ubuntu64bit via VMWare Workstation 16, then I wanted to install KDE Plasma so I searched on the Ubuntu Software app but I couldn't find the KDE. I also tried to download directly from Mozilla and get the ISO but I don't have any sofware to read the ISO on Ubuntu. What should I do to find KDE? Thanks for the help ^^


Let $M$ be Noetherian $R$-module(where $R$ contains $1$) and $\phi:M \to M$ be $R$ -module homomorphism . Suppose $\phi$ is surjective, how do I show that $\phi$ is injective ?   Hints will suffice, thank you.


C# operator '==' cannot be applied to operands of type 'TKey' and 'TKey' in generic classes

Hello I'm trying to create a generic repository pattern class that uses 2 generics in its implementation. The entity type itself (TEntity) and the key/identifier type (TKey).  Problem occurs whenever I try to check for equality of TKey's.  Error: Operator '==' cannot be applied to operands of type 'TKey' and 'TKey'.  Entity.cs  public class Entity<TKey> where TKey : struct, IComparable, IFormattable, IConvertible, IComparable<TKey>, IEquatable<TKey> {     public TKey Id { get; set; } }   IRepository.cs  public interface IRepository<TEntity, in TKey> : IDisposable          where TEntity : Entity<TKey>          where TKey : struct, IComparable, IFormattable, IConvertible, IComparable<TKey>, IEquatable<TKey>     {         /// <summary>         /// Get the <typeparamref name="TEntity"/> by id.         /// </summary>         /// <returns>The entity.</returns>         /// <param name="id">Identifier.</param>         TEntity Get(TKey id);     }   Repository.cs  public class NoSQLRepository<TEntity, TKey> : IRepository<TEntity, TKey>          where TEntity : Entity<TKey>          where TKey : struct, IComparable, IFormattable, IConvertible, IComparable<TKey>, IEquatable<TKey>     {             public TEntity Get(TKey id)         {             // error occurs in the line below.             return _context.Get<TEntity>(typeof(TEntity).Name).Find(entity => entity.Id == id).FirstOrDefault();         }     }   This being said, I need my TKey generic to not be constrained to a class. I rather use primitive types (i.e Int).  Can this be achieved or am I doing something wrong ?


Getting buffer wizard-like speed in Python (vs using MultipleRingBuffer_analysis)

I've got a script that takes a single input polygon feature, throws 10 buffers around it at tenths of a specified input distance, and then symbolises the output based on an existing layer file.  Pretty simple.  However, the arcpy.MultipleRingBuffer_analysis operation is amazingly slow.  It takes upwards of two minutes to generate the buffers, even for very basic polygon inputs - the same result can be had in about two seconds by using the buffer wizard tool.  Problem is, the buffer wizard can't be accessed through arcpy.    So obviously it's possible to quickly generate multiple ring buffers - does anyone have any insight as to how the buffer wizard tool is doing it, and how that might be replicated in Python?


GR. Einstein's 1911 Paper: On the Influence of Gravitation on the Propagation of Light

Regarding the paper, what does Einstein means when he says:     "If we call the velocity of light at the origin of co-ordinates $c_0$, then the velocity of light $c$ at a location with the gravitation potential $\Phi$ will be given by the relation: $c = c_0\cdot\left(1+\frac{\Phi}{c^2}\right).$ The principle of the constancy of the velocity of light holds good according to this theory in a different form from that which usually underlies the ordinary theory of"   relativity"   Does the velocity of light is constant only into a space where the gravitation potential is constant either?


Is there some way to embed LaTeX source code in a PDF file?

Several times now I have inadvertently lost the .tex file that generated a PDF file with pdflatex. Given what I know of the internal structure of PDF files, it should be possible to embed a text file containing the original LaTeX file into the PDF file so that it can be extracted later.   I am aware of no technology for doing this, but perhaps you are. Does anybody have something like this?


I wrote a DLL in .NET and I want to access it in VBScript. I don't want to add it to the assembly directory.   Is there a way to point too the DLL and create an instance of it?