I have this code which does not compile  public class MyClass<T> {     public bool AreEqual(T a, T b)     {         return a == b;     } }   The error is     Operator '==' cannot be applied to operands of type 'T' and 'T'   That makes sence because T could be something that does not implement any operators. Anyway, what do I have to do to make this work?  I know I could rewrite my code to avoid the == operator, but that's not the question.  Update  After reading the current answers, just to make it more clear. I know how I could rewrite my code but what I wanted to know was more like.  Is there a way that allows me to use the == operator in my generic class. Something like public class MyClass<T> where T : ==

According to the documentation of the == operator in ,      For predefined value types, the   equality operator (==) returns true if   the values of its operands are equal,   false otherwise. For reference types   other than string, == returns true if   its two operands refer to the same   object. For the string type, ==   compares the values of the strings.   User-defined value types can overload   the == operator (see operator). So can   user-defined reference types, although   by default == behaves as described   above for both predefined and   user-defined reference types.   So why does this code snippet fail to compile?  bool Compare<T>(T x, T y) { return x == y; }   I get the error Operator '==' cannot be applied to operands of type 'T' and 'T'. I wonder why, since as far as I understand the == operator is predefined for all types?  Edit: Thanks, everybody. I didn't notice at first that the statement was about reference types only. I also thought that bit-by-bit comparison is provided for all value types, which I now know is not correct.  But, in case I'm using a reference type, would the == operator use the predefined reference comparison, or would it use the overloaded version of the operator if a type defined one?  Edit 2: Through trial and error, we learned that the == operator will use the predefined reference comparison when using an unrestricted generic type. Actually, the compiler will use the best method it can find for the restricted type argument, but will look no further. For example, the code below will always print true, even when Test.test<B>(new B(), new B()) is called:  class A { public static bool operator==(A x, A y) { return true; } } class B : A { public static bool operator==(B x, B y) { return false; } } class Test { void test<T>(T a, T b) where T : A { Console.WriteLine(a == b); } }


It is probably a very elementary question but I cannot figure it out: my book gives a proof for the theorem that congruent matrices have the same determinant, characteristic polynomial ($\phi(X)$) and the same trace. However, I do not understand the second and third operation they conduct in the proof. How do they go from $(X \mathbb{I_n} - P^{-1}\cdot A \cdot P)$ to $(P^{-1}\cdot (X \mathbb{I_n} -  A) \cdot P)$ and why is $det(P^{-1})\cdot\det(X \mathbb{I_n} -  A) \cdot det(P)$ equal to $\phi_A(X)$?   Many thanks for your help in advance!  Consider two matrices $A$ and $B$ ($\in \mathbb{R^{m \times n}}$) to be congruent. If there is an invertible matrix $P$, such that $B = P^{-1} \cdot A \cdot P$, then: \begin{equation} \begin{aligned} \phi_B(X) &= det(X \mathbb{I_n} - P^{-1}\cdot A \cdot P) \\ &= det(P^{-1}\cdot (X \mathbb{I_n} -  A) \cdot P) \\ &= det(P^{-1})\cdot\det(X \mathbb{I_n} -  A) \cdot det(P) \\ &= \phi_A(X) \end{aligned} \end{equation}

It's a simple exercise to show that two similar matrices has the same eigenvalues and eigenvectors (my favorite way is noting that they represent the same linear transformation in different bases).   However, to show that two matrices has the same characteristic polynomial it does not suffice to show that they have the same eigenvalues and eigenvectors - one needs to say something smart about the algebraic multiplicities of the eigenvalues. Moreover, we might be working over a field which is not algebraically closed and hence simply "don't have" all the eigenvalues. This can be overcome, of course, by working in the algebraic closure of the field, but it complicates the explanation.  I'm looking for a proof that is simple and stand-alone as much as possible (the goal is writing an expository article about the subject, so clarity is the most important thing, not efficiency).


I need to use php5 (5.6) because I'm working on a Drupal 7 project which doesn't support php7. The problem is I recently updated to ubuntu 16.04 Xenial which seems to .   I tried to install it from , however when It try to install it with apt I always get similar errors.  $ sudo apt-get install php5-cli Cependant les paquets suivants le remplacent :   php7.0-cli:i386 php7.0-cli`   Which means it's obsolete. How can I install PHP 5.6 on Xenial?

I am trying to update to install PHP 5.5, 5.6 or 7.0 in Ubuntu 12.04/14.04/16.04 LTS, and I can only get PHP 5.3.10 for Ubuntu 12.04, PHP 5.5.9 for Ubuntu 14.04 or PHP 7.0.4 for Ubuntu 16.04 using official repositories (using apt-get).  I'm not really sure how to do a manual update – as I need:   to play around with the new(est) PHP features to install older PHP version due support in the software


Can a particle moving below the speed of light be accelerated more and more until it is travelling at say c/2? IF so does it behave like electro-magnetic radiation?

I'm in a freshmen level physics class now, so I don't know much, but something I heard today intrigued me. My TA was talking about how at the research facility he worked at, they were able to accelerate some certain particle to "99.99% the speed of light". I said why not 100%, and I didn't quite understand his explanation, but he said it wasn't possible. This confused me. Since the speed of light is a finite number, why can we go so close to its speed but not quite?  Edit: I read all the answers, and I think I'm sort of understanding it. Another silly question though: If we are getting this particle to 99.99% the speed of light by giving it some sort of finite acceleration, and increasing it more and more, why cant we increase it just a little more? Sorry I know this is a silly question. I totally accept the fact we cant reach 100%, but I'm just trying to break it down. If we've gotten so close by giving it larger and larger acceleration every time, why cant we just supply it with more acceleration? And how much of a difference is there between 99.99% the speed of light, and the speed of light? (I'm not really sure if "difference" is a good word to use, but hopefully you get what I'm asking).


I have a function that needs to be called and needs to pass the kwargs to another function after performing some logic, but this is'nt working, can someone please guide me where i am going wrong? My code is: def a(**kwargs):    #perform some logic and then call function c using the kwargs    c(kwargs)  def main:    a(a=1,b=2,c=3)  How should I succesfully forward these params to function c

I'd like to call a function in python using a dictionary.  Here is some code:  d = dict(param='test')  def f(param):     print(param)  f(d)   This prints {'param': 'test'} but I'd like it to just print test.  I'd like it to work similarly for more parameters:  d = dict(p1=1, p2=2) def f2(p1, p2):     print(p1, p2) f2(d)   Is this possible?


Is there a way for me to find all my installed programs in one place? When using the Launcher, I have to type in the letters of the alphabet to find installed programs.

Is there a way to see installed apps in a more conventional (to a Mac user!) way, like a folder with a load of app icons, or a list, or anything other than that odious semi-transparent flip out thing that's difficult to see (cos there's loads of crap showing through it), can't be resized and keeps disappearing when I click something..?


On my site I have a search bar like this:    The user types something in and presses enter. There is nothing they can click on to submit the search. I could make the icon on the right clickable but it certainly doesn't look like a button now and I quite like the way it looks. I could add something to the placeholder, e.g. "Search and press Enter" but again I like how minimal it is now and this will only help if they think to read the placeholder before typing something in.  Can I assume that the vast majority of people on the Internet have figured out when pressing Enter is likely to work?  The site aggregates search results from multiple online stores (linking directly to them) so the users already need some web proficiency to be able to accomplish anything.

On websites with a search box, should you add a button they can click on, or will users understand a search box like on this site?  The target group is not very technical, such as women aged 40-60.


I've upgraded my Windows 7 computer to Windows 10 using the free upgrade offer. Am I allowed to install Windows 7 again, alongside my new Windows 10 installation, or does the upgrade deal require me to choose which one I want to use, going forward?  Currently I still have the option to "Go back to Windows 7". Would I be right in thinking this "unlicenses" me for Windows 10?

Microsoft is offering "Microsoft Windows 8 Professional Upgrade" at a discounted price compared to the OEM version. However it states:     If you currently have a personal computer running Windows 7, Windows XP or Windows Vista then you can upgrade to Windows 8 Pro (Professional).   My question is what happens to the Windows 7 key that I use to upgrade? Will it become the Windows 8 key or will it generate a new Windows 8 key?  Basically if I upgrade using my Windows 7 key from my laptop for my desktop will I be able to continue using the laptop on Windows 7 while concurrently using Windows 8 upgrade on my Desktop?


My friend has a notebook with Windows XP Professional installed. I would like to understand which version exactly is and which license type is referred to. The sticker reports an OEM pre-installed XP Home Ed, so I just get infos by read some file or some pop-up by launch a command. For example I can read the serial number from system proprieties. I also can extract product key used for activation.  My goal is to provide all needed infos to, in case, be able to borrow the right version of WinXP CD and reinstall/reactivate the system on the same machine, reusing current extracted product key.  So I'd like to know which version is installed (localization included) and which CD version of XP I need to reuse its working product key.  Thanks in advance!  :)    EDIT  to explain why this question is not solved by answers of suggested topic ():  c:\windows\system32\prodspec.ini   on our system is just empty, I saw that answer before posting, thanks anyway for suggest.    EDIT2  In reply to who talked about absence of COA. If one loose an old CD with its COA sticker, his system remains still genuine. I think it should be possible to obtain info about license version from an installed system in that case, just it. This topic is not to discuss about cracking or so on. We have a system installed. We want to know more info as possible about its version and license version. That's all, nothing more.  Thanks for all your answers, even if I think they are not completely exhaustive, anyway... thanks again

I have a drive that I cannot boot, but it has an installation of Windows XP on it.  I need to know what type of XP it has, and MS's solution () presupposes I can load the OS.  Is there a folder or file I can look at that might give me a clue as to the flavor of XP (Home, Pro, MCE, etc) I need to use for a recovery installation? Thanks.


As you can see from the picture below, I have a box with a plating on one side. How do I copy/paste it so that I can get it placed precisely on the rest of the sides?

I want to create a cube with some general extrusions. This should be the same across all sides of the cube. Is there a way to make this mirrored across all six sides? I know that I could delete the rest of the cube, copy my changes, rotate it 90°, move it down and to the side, and repeat for all the sides, then remove doubles, but I'm wondering if there's a way to make this work in real time.  In the below image, all six sides should copy the changes shown here on the one side:


It seems that $i$ plays an important role in quantum mechanics (Q.M.). On the other hand, linear algebra plays such an important role in Q.M. too. So would linear algebra, such as a matrix be able to represent the formalism of Q.M. totally?  $i$ is the symmetric decoupling of $-1$, and in matrix representation, the $i$ is also a  requisite for Hamiltonian symmetric decoupling of the negative identity matrix.  On the other hand, $i$ could be viewed as a phase factor.  Would it be possible to replace $i$ by a $2\times 2$ matrix?

1.  Why is the wave function complex? I've collected some layman explanations but they are incomplete and unsatisfactory. However in the book by Merzbacher in the initial few pages he provides an explanation that I need some help with: that the de Broglie wavelength and the wavelength of an elastic wave do not show similar properties under a Galilean transformation. He basically says that both are equivalent under a gauge transform and also, separately by Lorentz transforms. This, accompanied with the observation that $\psi$ is not observable, so there is no "reason for it being real". Can someone give me an intuitive prelude by what is a gauge transform and why does it give the same result as a Lorentz tranformation in a non-relativistic setting? And eventually how in this "grand scheme" the complex nature of the wave function becomes evident.. in a way that a dummy like me can understand.  2.   A wavefunction can be thought of as a scalar field (has a scalar value in every point ($r,t$) given by $\psi:\mathbb{R^3}\times \mathbb{R}\rightarrow \mathbb{C}$ and also as a ray in Hilbert space (a vector). How are these two perspectives the same (this is possibly something elementary that I am missing out, or getting confused by definitions and terminology, if that is the case I am desperate for help ;)   3.   One way I have thought about the above question is that the wave function can be equivalently written in $\psi:\mathbb{R^3}\times \mathbb{R}\rightarrow \mathbb{R}^2 $ i.e, Since a wave function is complex, the Schroedinger equation could in principle be written equivalently as coupled differential equations in two real functions which staisfy the Cauchy-Riemann conditions. ie, if $$\psi(x,t) = u(x,t) + i v(x,t)$$ and $u_x=v_t$ ; $u_t = -v_x$ and we get $$\hbar \partial_t u  = -\frac{\hbar^2}{2m} \partial_x^2v + V v$$ $$\hbar \partial_t v  = \frac{\hbar^2}{2m} \partial_x^2u - V u$$ (..in 1-D) If this is correct what are the interpretations of the $u,v$.. and why isn't it useful. (I am assuming that physical problems always have an analytic $\psi(r,t)$).


Let p is a prime number.  Prove that:  $$ (p-1)! +1  \equiv 0 \:  \pmod p$$  Could you give me some advice?

How can I show that $(n-1)!\equiv-1 \pmod{n}$ if and only if $n$ is prime? Thanks.


I am working with a series of shapefiles of France, which were created privately by someone (as opposed to an official institution). We can call them the P-maps. There is no .prj file associated with them. When I open them in QGIS or ArcMap, and set their coordinate system to be WGS84, they "look alright". However, they don't overlay with a correct shapefile of France in WGS84 (a map in WGS84 from the IGN, let's call it IGN) , so another projection was used (you can see the picture, the IGN shapefile is circled in blue; one of the P-maps is pointed in red).  I know I could potentially try to identify the correct projection by trying each individual projection one by one, by I am weary of using this method, as I am not sure that this person correctly georeferenced these P-maps. I think that they establish them by creating the shapefile from an image that was not georeferenced.   Is there a way to define a transformation to each file (I have around 50 P-maps, and they all align to each other) so that  GIS would define the right coordinates systems, having the comparison point of the IGN shapefile in the WGS84 projection? Something like when you georeference a raster map. Since all the  maps align, I could apply this transformation to each one of them.   The layer extent:  top 590.9218000 right 620.0 bottom 30.0 left 20.02860  And the file you can

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


How does one calculate the age of a Time Lord?   Is it the time since he was born until the canon present? Or is it the sum of the days he lives?  Because if it is the latter, he could live billion of years in five seconds.  So, do they really have an age? Does The Doctor really have an age? Or does he say he is 900 or 2000 years old just to prove a point?

I've often wondered, how does the Doctor know how old he is? He not only travels through time, but also through space, and visits planets where days can be shorter or longer than 24 hours. How does he 'keep score'?  Also, does he count his age in Earth years or Gallifrey years? They might be completely different in length.


Related to this question:   I experienced similar problems with a PDF produced by XeLaTeX (v0.9998) with MiKTeX 2.9 and Adobe Acrobat Pro IX or XI:  The PDF produced by XeLaTeX and opened in Adobe Acrobat looks good and all fonts are embedded including Asana Math. However, after saving with another name or after editing (for example, extracting pages), a lot of Asana Math is replaced by questionmark symbols.   The only solution that worked so far is replacing Asana Math by XITS Math.   PS. I was not sure to post this as a new question or an answer to the question mentioned above. It was assumed in  that this is a bug in Adobe. If so, the issue has not been solved, even when using the newest versions of Adobe Acrobat, MiKTeX and XeLaTeX.

After recent update of Asana-Math (packaged for MiKTeX on 2011-10-11) I noted that Greek letters and various arrows disappear from PDF file after it was saved from within Adobe Acrobat 10 (via the menu File | Save As | PDF...). I use such method of saving file to reduce its size. Asana-math font is loaded as follows:  \usepackage[math-style=ISO,bold-style=ISO]{unicode-math} \setmathfont{Asana Math}   Note that the problem appears only if (1) my document is compiled with LuaLaTeX and only if (2) Asana-math font is loaded. XeLaTeX or STIX fonts work fine. I am sure that this problem did not exist before I updated Asana-Math a week ago (on 2011-10-28) since every week I compile new lecture for students and all previous lectures are OK.  Having opened PDF file in ordinary text editor, I see that the word asana disappears after saving PDF file from Acrobat. It means that Acrobat removes Asana-math font from the file.   But why?  Update: I located a table in my book that caused the trouble. Here is minimal example extracted from that table:  \documentclass{article} \usepackage{fontspec}     \defaultfontfeatures{Renderer=Basic,Ligatures={TeX}}     \setmainfont[Numbers={OldStyle}]{Minion Pro} \usepackage[math-style=ISO,bold-style=ISO]{unicode-math}     \setmathfont{Asana Math}    % damaged     %\setmathfont{STIXGeneral}  % OK     %\setmathfont{Cambria Math} % OK  \begin{document}%     Fuel $T_{Br}$ $T_{\min}$ $\min(P_{Br}/P_{fus})$ \\     ${D}{T}$ 2.7  39.4 $5{,}3\times 10^{-3}$ \\     ${D}{D}$ 57.7 553 $4{,}1\times 10^{-1}$   \\     ${D}[3]{He}$ 29.0 152 $1{,}4\times10^{-1}$ \\     ${p}[11]{B}$ 295 2{,}6  \end{document}   Originally, compiled PDF file looks fine:    However some latin and greek letters, math symbols disapper after it was saved from within Adobe Acrobat:    This damage does not occur if source file was compiled with the aid of xelatex or if other math fonts is loaded. Here is how saved PDF looks when Cambria Math was used:


I try to execute this command I got this warning.   root@sabresd_6dq:/system/etc/wifi # hostapd_cli                                 hostapd_cli v2.5-devel-6.0.1 Copyright (c) 2004-2015, Jouni Malinen <j@w1.fi> and contributors  This software may be distributed under the terms of the BSD license. See README for more details.   Could not connect to hostapd - re-trying   How to fix this?

I always got error. When i execute hostapd command. I was changed everything in my hostapd.conf file but i got error.  hostapd_cli wps_pbc Failed to connect to hostapd - wpa_ctrl_open: No such file or directory  Can anyone help to me.?


Show that the congruence equation  $x^8 \equiv 16 \pmod p$ has a solution for every prime $p$. Let $g$ be a primitive root， then the equation is equivalent to $8  \ ind_g(x)\equiv 4 \ ind_g(2) \pmod {p-1}$. It suffices to show that $2\mid ind_g(2)$.

I'm still making my way along in Niven's Intro to Number Theory, and the title problem is giving me a little trouble near the end, and I was hoping someone could help get me through it.  Now $x^8\equiv 16\pmod{2}$ is solvable with $x\equiv 0\pmod{2}$, so I assume $p$ is an odd prime. From a theorem earlier in the text,      If $p$ is a prime and $(a,p)=1$, then the congruence $x^n\equiv a\pmod{p}$ has $(n,p-1)$ solutions or no solution according as $a^{(p-1)/(n,p-1)}\equiv 1\pmod{p}$ or not.   So since $(16,p)=1$, the problem reduces to showing that $16^{(p-1)/(8,p-1)}\equiv 1\pmod{p}$ holds for all $p$. I note that $(8,p-1)$ can only take values $2,4,8$. For $2$, the above equivalence is then $4^{p-1}\equiv 1\pmod{p}$, which is true by Fermat's little Theorem. For $4$, it is then $2^{p-1}\equiv 1\pmod{p}$, which again holds by FlT. However, the case where $(8,p-1)=8$ is throwing me off. At best I see that $16^{(p-1)/8}\equiv 2^{(p-1)/2}\pmod{p}$, but I'm not sure how to show this is congruent to $1$ modulo $p$. Maybe there's a more elegant way to do it without looking at cases. Thanks for any insight.


I need to convert this multi-part form that contains some json and also uploads a file.  curl \ -F metadata='{"userID":"12345","mimeType":"image/jpeg","typeHint": "uploadedImage" }' \ -F contents=@$HOME/Downloads/photo.jpg \ http://localhost:8083/myservice/upload

I want to do an HTTP POST that looks like an HMTL form posted from a browser. Specifically, post some text fields and a file field.  Posting text fields is straightforward, there's an example right there in the net/http rdocs, but I can't figure out how to post a file along with it.  Net::HTTP doesn't look like the best idea.  is looking good.


My brother and I have used the 'Open to LAN' button before and it worked well, but I got a new computer and now it doesn't work at all.  When I host the game on my Windows 10 computer, my game won't pop up in the server list like it should, but when my brother hosts it on his windows 7 computer, his game appears in my server list.    However when I try and connect to his LAN world, it says "Java.net.connectException:Connection timed out:no further information"  How can I get LAN to work?

My LAN server won't let my cousin join me or me join my cousin. It won't show up on the multiplayer screen - it keeps saying "scanning for LAN servers" but it never finds it. I am at his house and we use different computers but it won't connect. How can I fix this?


Let $A$ be a rank 1 positive semidefinite matrix and $B$ a Hermitian matrix. Suppose I know the eigenvectors of both $A$ and $B$ and that $A-B$ is also positive semidefinite.  Apart from Weyl's inequality is there anything that can be deduced about the eigenvalues of $B$?

Let $A$ be a positive semidefinite matrix of rank $1$. Let $B$ be a general Hermitian matrix.  Under what conditions on $B$ (probably in terms of $A$) is $A-B$ positive semidefinite?  I was thinking that it may be along the lines of the generalized eigenvalue problem but can't quite see how.


How can I evaluate the following integral?     $$ \int_0^{\pi/2} \log\left(\frac{1 + a\cos\left(x\right)}{1 - a\cos\left(x\right)}\right)\, \frac{1}{\cos\left(x\right)}\,{\rm d}x\,, \qquad\left\vert\,a\,\right\vert \le 1$$   I tried differentiating under the integral with respect to the parameter $a$, and I also tried expanding the log term in a Taylor series and then switching the order of integration and summation. I ran into difficulties with both approaches.

Question: Evaluate the following definite integral:   $$ I= \int_{0}^{\pi/2} \ln\left(1 + a\cos\left(x\right) \over 1 - a\cos\left(x\right)\right)\, {{\rm d}x \over \cos\left(x\right)}\qquad \mbox{where}\qquad\left\vert\,a\,\right\vert < 1 $$   This is left as an exercise in my textbook. The book says that I should use the method of "differentiating parameters" by using the provided Leibniz Formula (?):     Prerequisite: Function $f(x,y)$ and its partial derivative $f_x(x,y)$ are both continuous on region $R=[a,b]\times[c,d]$. Function $\alpha(x)$ and $\beta(x)$ are both differentiable on intervl $[a,b]$ while   $$ c \le \alpha(x) \le d,\quad c \le \beta(x) \le d \quad (a\le x\le b),$$      Conclusion: The Function $\displaystyle\Phi(x)=\int_{\alpha(x)}^{\beta(x)} f(x,y) \,\mathrm d y$ is differentiable on interval $[a,b]$, and   $$\begin{align}   \Phi^\prime(x) &= \frac{\mathrm d}{\mathrm d x} \int_{\alpha(x)}^{\beta(x)} f(x,y) \,\mathrm d y \\    &= \int_{\alpha(x)}^{\beta(x)} f_x(x,y) \,\mathrm d y + f\left[x,\beta(x)\right]\beta^\prime(x)-f\left[x,\alpha(x)\right]\alpha^\prime(x).   \end{align}$$   First, I'd like to ask: What is the correct name of this theorem?  Next, here's my (failed?) attempts at solving the question.  Following one of the textbook examples on the same topic, I tried:  $$ \begin{align} I&=\int_0^\frac{\pi}{2} \left[\ln(1+y)\right]_{-a \cos x}^{a \cos x} \frac{\mathrm d x}{\cos x} \\ \\ &= \int_0^\frac{\pi}{2} \int_{-a \cos x}^{a \cos x} \frac{\mathrm d y}{1+y} \frac{\mathrm d x}{\cos x}. \\ &=\int_{-a}^{a} \frac{1}{1+y} \int_{0}^{\arccos\left|y/a\right|}\,\mathrm d x \mathrm d y \\ &=\int_{-a}^{a} \left.\left[\ln\left|\tan x + \sec x\right|\right]\right|_0^{\arccos(y/a)} \end{align} $$  And I don't know what to do next.  Also I tried to substitute $u=a \cos x$ but I don't know how to proceed.  Please help me with this (non-homework) problem by giving hints or solution, It's been a week since I first tried this problem. Thanks for helping!  P.S.: My MathJax doesn't render (or it may need hours of time), and I don't get preview for writing questions/answers. I'm relying on LaTeX now. How can I fix this problem? It used to work. I'm using IE 9.


In RecyclerView, the OnBindViewHolder method , I can not get the TextViews that are located in the ViewHolder class. Why? What is the problem? Please refer to the screenshot:  And my code below: public class MainActivity extends AppCompatActivity  {      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          ((CollapsingToolbarLayout) findViewById(R.id.collapsing_toolbar_layout)).setTitle("Screen Title");          RecyclerView rv = findViewById(R.id.recyclerview);         rv.setLayoutManager(new LinearLayoutManager(this));         rv.setAdapter(new RecyclerView.Adapter<RecyclerView.ViewHolder>() {             @Override             public RecyclerView.ViewHolder  onCreateViewHolder(ViewGroup parent, int position) {                 View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);                 return new ViewHolder(view);}              @Override             public void onBindViewHolder(RecyclerView.ViewHolder  viewHolder, int position) {                 viewHolder.text1.setText("Bacon");                 viewHolder.text2.setText("Bacon ipsum dolor amet pork belly meatball kevin spare ribs. Frankfurter swine corned beef meatloaf, strip steak.");             }              @Override             public int getItemCount() {                 return 30;             }         });     }// on create method END      private static class ViewHolder extends RecyclerView.ViewHolder {         TextView text1;         TextView text2;          public ViewHolder(View itemView) {             super(itemView);             text1 = itemView.findViewById(android.R.id.text1);             text2 = itemView.findViewById(android.R.id.text2);         }     } }

In Java, are there clear rules on when to use each of access modifiers, namely the default (package private), public, protected and private, while making class and interface and dealing with inheritance?


I'am new to QGIS and I run into a problem. I have two shapefiles, one with line data and one with polygon data. I would like to remove all the lines that do not overlap the polygon.    So remove all the green lines that do not overlap the blue polygon. What is the best way to do this? I tried the difference tool but I was not able to achieve what I intended.

I'm new to desktop GIS, and will try to ask while lacking the proper terms from the GIS lingo:  If QGIS was like Photoshop I would like to make a selection from one layer, and then match that selection to another layer to get the overlap between the two and create a new layer from this overlap.  Formulated in another way:  I want to select all land from each of the Norwegian municipalities. In the shapefile I have (you can download it here: ) municipality borders are found as "N5000_AdministrativGrense" (just the borders) and "N5000_AdministrativFlate" (borders and the land within each municipality). This data (borders and land per municipality) is too administrative - it includes ocean and we have a lot of fjords in Norway. I need the landmass minus ocean.  The landmass is found in the layer "N5000_ArealdekkeFlate" - or so it looks to a novice at least.   So - I want to find the intersection between the landmass (only land, no ocean) and municipality borders and make a new layer that is all municipalities without ocean.  I'm on a mac with QGIS as my installed tool. All tips, pointers and help is much appreciated.


I wonder if there is such a query on , similar to  on user base who cast the most downvotes.

How about introducing a badge that rewards downvoting, but only of the sensible kind?   A measure for sensible downvoting would be a high percentage  certain number of downvotes on content that has subsequently been   Deleted  Closed (except migrations and duplicates)   Bronze, Silver, and Gold badges would vary in numbers, say     Bronze: cast 50 downvotes on content that was subsequently closed or deleted   This would encourage downvoting (which is great and needed), but of the measurably sensible kind only.  What  good actual numbers would be for Bronze, Silver, and Gold would be a separate discussion. Feel free to suggest numbers in your answers, as well as name suggestions (the only I managed to come up with was Whistleblowerand that isn't really accurate. I'm more imagining the old lady calling the council over some abandoned litter in the streets, or broken windows... but in a good way of course.


Not much more than in the title except that when I took an astronomy class the professor said, Andromeda is 2 million lightyears away so it is safe to say humans will never reach there. But with time dilation, why would a human not only not be able to reach this galaxy but it could take from the passenger POV only a year or something? Or is this some practical issue like a propulsion system that received power from Earth lasers would eventually fail because the lasers would be too attenuated?

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


I installed a Ubuntu virtual machine that I need to use OOF 1 (available at this link:  ), a programme for microstructural analysis from the NIST. I have never used Ubuntu in my life and after a couple of hours of trying I still don't even understand the readme file given in the download folder. Could anybody help me? Thank you very much

I have downloaded tar.gz files. But I don't know how to install it. How do I install this kind of file?


I know we are to use “a” before words that start with a consonant sound and “an” before words that start with a vowel sound, but in the case of an initialism that have a vowel sound for first letter, but a consonant sound for the abbreviated word, which of the two indefinite articles are to be used? Example:  I have an SSD drive installed in my computer. I have a SSD drive installed in my computer.  In the example above SSD is an initialism for Solid State Drive. I'm inclined to think that there may be separate rules for speech and written approaches to this, as when speaking I would obviously use the first phrase in the example.

99% of the time, I'm clear on when I should use "a" versus "an." There's one case, though, where people & references I respect disagree.  Which of the following would you precede with "a" or "an," and why?   FAQ FUBAR SCUBA   [Note: I've read the questions  and , but the rules given there don't necessarily apply here.]    [Edited to add]  Here's a shorter (and hopefully clearer) version of the question…  In written English, which is correct (and why): "a FAQ" or "an FAQ"?  Some references with differing opinions:   an: the  and  a: the Microsoft Manual of Style for Tech Publications, 3e either: the  and


In the films, we only see male students from Durmstrang. Do we know if witches also attend that school?  If not, where do they go to school?

In the 4th Harry Potter book I read that Poliakoff (Durmstrang student) when he spotted Harry Potter he pointed Harry's scar to a girl standing next to him, this occurence happened when they first arrived at Hogwarts for the Triwizard tournament. The girl was never identified as a Hogwart, Beauxbaton or Durmstrang student. Is there canon evidence of what school she came from and can females attend Durmstrang?  Also the wikia says the girl is from Durmstrang, but they don't give evidence. Someone told me that Durmstrang was an all-male school, but I assumed it was since no females are known that have joined.


Do I need a visa or stamp to enter UK from the Republic of Ireland? I have a 90-day tourist visa stamped in my passport on arrival.  If I get the bus from Dublin to Belfast, and then a flight from Belfast to London, do I need anything in advance?  I read that Australians don't need anything ahead of time for a standard 90-day tourist entry. Is that right?  I also head that there is a 6-month visa for Australians. Does that exist? How do you get it?

I complied with the rules by leaving after 2 years in UK and didn't overstay.  It's been 3 months since I exited UK. I flew to the Republic of Ireland and have been a tourist doing unpaid writing and photography for a blog.  My partner lives in UK and is working. He's currently applying for residency rights and was just sent letter saying he now can apply for a National Insurance Number.  I'd like to come back to the UK as a visitor and see him. I have also registered a company in the UK so I will need to see an accountant to do the company's first tax return.  How long do I have to stay outside UK before I can come back on a tourist or any other short category visa?  I am Australian.  We noted that while flying from Belfast to London there is no passport control. What's the penalty for entering Northern Ireland and flying to London from there? What happens when you don't get a temporary passport stamp?   I have no intention of staying long term. I'm just planning on doing the tax and seeing my partner.


Is it  These occur naturally in the Balkan Peninsula, Iberian Peninsula, Pannonian basin, and northern sides of the Black Sea.  or  These occur naturally in the Iberian Peninsula, the Balkan Peninsula, the Pannonian basin, and the northern sides of the Black Sea.  There seems to be occurences of both in places I checked.

I am a bit confused about the rule of setting the definite article in a sentence when it is associated to two nouns.          The beginning and end of the channel.    The beginning and the end of the channel.           The arguments belong to the request and to data function.    The arguments belong to the request and to the data function.


I have two headers having cross-reference between each other. I did research and the solution is to pre-define the classes involved. For example, A.h and B.h cross-referencing each other. // A.h #ifndef A_H_ #define A_H_  #include "B.h"  class A {     friend class B; protected:     int data; public:     A(void) {data=1000;} }; #endif /* A_H_ */  // B.h #ifndef B_H_ #define B_H_  #include "A.h"  using namespace std;  class A; // adding the pre-definition of A works IF scr.data won't be called  class B {   friend class A; public:     B() {};          void setup(A &scr) {         scr.data = 0; // this line cause compile error     } };  #endif /* B_H_ */   If B is not a friend of A and scr.data is not called in setup(A &scr), the program compiles without any problem. How could I fix it cross-reference issue when friendship needed for both classes? Thanks.

I often find myself in a situation where I am facing multiple compilation/linker errors in a C++ project due to some bad design decisions (made by someone else :) ) which lead to circular dependencies between C++ classes in different header files (can happen also in the same file). But fortunately(?) this doesn't happen often enough for me to remember the solution to this problem for the next time it happens again.  So for the purposes of easy recall in the future I am going to post a representative problem and a solution along with it. Better solutions are of-course welcome.     A.h  class B; class A {     int _val;     B *_b; public:      A(int val)         :_val(val)     {     }      void SetB(B *b)     {         _b = b;         _b->Print(); // COMPILER ERROR: C2027: use of undefined type 'B'     }      void Print()     {         cout<<"Type:A val="<<_val<<endl;     } };       B.h  #include "A.h" class B {     double _val;     A* _a; public:      B(double val)         :_val(val)     {     }      void SetA(A *a)     {         _a = a;         _a->Print();     }      void Print()     {         cout<<"Type:B val="<<_val<<endl;     } };       main.cpp  #include "B.h" #include <iostream>  int main(int argc, char* argv[]) {     A a(10);     B b(3.14);     a.Print();     a.SetB(&b);     b.Print();     b.SetA(&a);     return 0; }


I am somehow a noobie in PHP and I want to learn. I am making a proyect, in which I use require('parts/header.php') statements to include functions and templates. My pages look like this:  <?php  include('core/checklogin.php'); //This will check if the user is logged in and can see this page or not include('parts/top.php'); //This loads the  tags and the header, including the navbar ?>

Hello <?php echo getUserNickname()?>

Some stuff

  <?php  include('parts/bottom.php'); //This loads the  tags and the header, including the navbar ?>   The problem is if someone enters myproyect.com/parts/top.php he would see the top part, and that file is going to be executed. I don't want that. I was thinking doing some stuff in a .htaccess file like:   #.htaccess inside parts directory  dont_serve_anything_inside_this_directory_and_return_forbidden();   But I don't know how without affecting the server side code. Another alternative is to use the equivalent of if __name__ == 'main':  of python, and do like:   //parts/top.php  if(__name__ == 'main'){      header('Location: /index.php');      exit();  }   What could I do?

I have a php file which I will be using as exclusively as an include. Therefore I would like to throw an error instead of executing it when it's accessed directly by typing in the URL instead of being included.  Basically I need to do a check as follows in the php file:  if ( $REQUEST_URL == $URL_OF_CURRENT_PAGE ) die ("Direct access not premitted");   Is there an easy way to do this?


Let $H$ be a separable Hilbert space and consider the strong operator topology (SOT) on $B(H)$, that is the topology on $B(H)$ generated by the seminorms $$p_x: u \mapsto \Vert ux \Vert, \quad x\in H$$ Is this topology first countable? Attempt: It suffices to find a countable neighborhood basis of $0$. Let $(x_n)_n$ be a dense sequence of $H$. Then I believe the topology generated by $$u \mapsto \Vert u x_n \Vert, \quad n \geq 1$$ agrees with SOT. Hence, the collection $$\left\{\bigcap_{i=1}^k p_{x_{n_i}}^{-1}([0, \epsilon[): k \geq 1; n_1, \dots, n_k \geq 1, \epsilon \in \Bbb{Q}\cap(0, \infty) \right\}$$ is a countable basis of $0$ of $SOT$. Is the above proof outline correct? EDIT: This question was accidentally closed by a misunderstanding. Please read the comments and reopen the question. Thanks!

The strong operator topology on a Banach space $X$ is usually defined via semi-norms:  For any $x \in X$, $|\cdot|_x: B(X) \to \mathbb R, A \mapsto \|A(x)\|$ is a semi-norm, the strong topology is the weakest/coarsest topology which makes these maps continuous.  Alternatively it is generated by the sub-base $\left\{B_\epsilon(A;x)=\{B\in X \mid |B-A|_x<\epsilon\}\phantom{\sum}\right\}$.  If we define this topology on a separable Hilbert space $\mathcal H$ and restrict it to the subset of unitary operators, a statement in a book I am reading is that this is then a metrisable topology.  My question is then, how can I prove this (especially, why do we need separability)? What does the metric look like (is it constructable)?  When can this result be extended to other bounded subsets of $B(\mathcal H)$?


I want to have a vector with objects "Rectangle" and "Triangle". I want to run a function from specific index of vector. Why it calls function from parent class? Code will explain my problem better than my description :)  #include <iostream> #include <vector>    class Shape {     public:     virtual void info() {std::cout << "IM BASE CLASS - SHAPE" <<std::endl;} }; class Rectangle: public Shape {     public:       void info () {std::cout << "IM RECTANGLE :" <<std::endl;} };  class Triangle: public Shape {    public:        void info () {std::cout << "IM TRIANGLE :" <<std::endl;} };  int main() {     Rectangle rec;    Triangle  tri;     std::vector<Shape> v;    v.push_back(rec);    v.push_back(tri);       std::vector<Shape>::iterator it;    for( it=v.begin(); it!=v.end(); ++it )    {      it->info();    }    return 0; }

Someone mentioned it in the IRC as the slicing problem.


\[\smile_{i\in I}\alpha_i\]   I write this code and the summation variable i comes as subscript, to the right of the smile (cup product symbol in algebraic topology). I wish to have the index i underneath the cup product symbol, like it does with union, intersection or summation operation in place of the cup product.  Any ideas?  Thanks in advance!

I want to define \ext to behave exactly like \lim.  I tried \newcommand{\ext}{{\mathrm{ext}}\,} but that doesn't behave exactly like \lim.


I am designing a network service in which clients connect and stay connected -- the model is not far off from IRC less the s2s connections.  I could use some help understanding how to do capacity planning, in particular with the system resource costs associated with handling messages from/to clients.  There's an article that tried to get 1 million clients connected to the same server [1].  Of course, most of these clients were completely idle in the test.  If the clients sent a message every 5 seconds or so the system would surely be brought to its knees.  But... How do you do less hand-waving and you know, measure such a breaking point?   We're talking about messages being sent by a client over a TCP socket, into the kernel, and read by an application. The data is shuffled around in memory from one buffer to another.  Do I need to consider memory throughput ("5 GT/s" [2], etc.)?  I'm pretty sure I have the ability to measure the basic memory requirements due to TCP/IP buffers, expected bandwidth, and CPU resources required to process messages.  I'm a little dim on what I'm calling "thoughput".  Help!  Also, does anyone really do this? Or, do most people sort of hand-wave and see what the real world offers, and then react appropriately?  [1]   [2]

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


I am wondering how to change the text that displays "Ubuntu 14.04 . . . ." on boot to a custom text.   Edit: I am talking about the ASCII text during the boot process, not the Ubuntu logo.

I am making a custom distribution, and have a question about the Ubuntu Logo with 5 dots displayed when booting up.  The Ubuntu-Logo-Script in the /lib/plymouth/themes/ubuntutext folder has the word Ubuntu and beneath that 5 progressing 'dots'. Is it possible to remove the progress bar dots, and instead replace it with a faded Ubuntu logo, that gradually colors up to full?


Something I've never understood with linux is why a status file is stored under /etc.  As far as I know /etc/ is for configuration (relatively static) configuration files.  But /etc/mtab shows the current status of mounts on the system.  Under debian this has even been replaced with a symbolic link to ../proc/self/mounts (ie: /proc/self/mounts).  This is actually important because with the creation of mount namespaces different processes can see different mounts.  Is there a particular historic reason for this and is there a good reason why it has not been removed entirely (in favor of /proc/self/mounts)?

What is /etc/mtab in Linux?   Why is it needed and advantages of having it?


Right now I can't differentiate my tags questions in Android app  So if it can be highlighted would be nice and readability will be improved.

It would be nice to show questions based on favorited tags on the Android App, just like the Web application.  The app doesn't handle it right now and this feature would be nice to have.


It's been many years since I studied maths, and I'm trying to figure out the half factorials $(7/2)!$ without a calculator.  I did $(7/2) \times (5/2) \times (3/2) \times (1/2) = (105/16) ^ \pi = 1.82$ (as per a little tutorial I'm doing).  However, if I put $(7/2)!$ in the calculate I get $11.631$  Am I completely off target here? Sorry if this is elementary - I'm basically starting from the beginning again.  ** UPDATE **  Despite the real issue being not knowing how to use the damn calculator properly - I now have a better understanding of this subject thanks to all your comments.

My TI-83 calculator doesnt allow me to do this, but using Windows calculator, I can compute the factorial of say 5.8. What does this mean and how does it work?


I'm using a Java program I made, to act as a client for rest platform called Firebase.  I have also an android app to read to coordinates from the Firebase platform, to update markers on google maps.  So my question is, if I have the latitude and longitude of both point A and point B, how can I calculate the coordinates between those both points?  Imagine this case scenario   Point A (left) lat: 39.091868 long: -9.263187  Point B (right) lat: 39.089815 long: -9.261857     How can I calculate, for example, 10 coordinates between those points?

How do I calculate distance between two GPS coordinates (using latitude and longitude)?


Let $X \subset \mathbb A^n$ be an affine variety that is also a vector space. In my algebraic geometry course we have seen that $X$ is a noetherian topological space so we can define the dimension of $X$ as the supremum over all $n \in \mathbb N$ such that there is a chain $$\varnothing \subsetneq Y_1 \subsetneq Y_2 \subsetneq \ldots \subsetneq Y_n \subseteq X$$ of length $n$ of irreducible closed subsets $Y_1, \ldots, Y_n$ of $X$. What is the link between this notion of dimension and the dimension of $X$ as a vector space ? It seems that they are equals, because we can always construct a chain like $$\{0\} \subsetneq \text{Vect }(\{e_1\}) \subsetneq \text{Vect }(\{e_1, e_2\}) \subsetneq \ldots \subsetneq \text{Vect }(\{e_1, \ldots, e_n\}) = X,$$ but I am not able to write a rigourous argument. Any help?

Suppose $Y=Z(f_1,\cdots ,f_r)\subseteq \mathbb{A}^n_k$ where each $f_i$'s are linear homogeneous polynomials which are $k$-linear independent. Then $Y$ is also a vector space over $k$. My question: Is the vector space dimension of $Y$ is same as the dimension of $Y$ as an affine variety? If yes how?    Thank you.


I know, in Mathematics all infinities are not same for example, cardinality of natural numbers and cardinality of real numbers are two different infinities. But I want to know, can two uncountable sets have two different infinities in terms of their size ?

Two sets $A$ and $B$ are called similar $\iff$ thee exists a one to one function $F$ whose domain is the set $A$ and whose range is the set $B$.  We know that two countably infinite sets should be similar to each other but what about uncountable sets?   Attempt: Let $a_1,a_2,a_3,\cdots$ be elements in $A$ and $b_1,b_2,b_3,\cdots$ in $B$.  Then, can we say that this mapping : $a_1 \rightarrow b_1, a_2 \rightarrow b_2, \cdots$ is a one one onto correspondence between $A$ and $B$?  I am a little confused.     EDIT: My query actually arose from this problem : If $B$ is uncountable and $A$ is uncountable, then we need to prove that $B$ is similar to $B-A$. I proved that $B-A$ is uncountable and $B$ is already uncountable. Now, I should prove that $B$ and $B-A$ are similar. Could you please give me a hint?   Thank you for your help.


I can't find this case in the board, so I'm asking the question.  This is input file:  module   x(a,b,c)   module   y(d,e,f,   g,h,i)   module   z(j,k,l)   And output file should be:  module x(a,b,c)   module y(d,e,f,   g,h,i)   module z(j,k,l)

I have more than 1000 lines in a file. The file starts as follows (line numbers added):  Station Name Station Code A N DEV NAGAR ACND ABHAIPUR AHA ABOHAR ABS ABU ROAD ABR   I need to convert this to a file, with comma separated entries by joining every two lines. The final data should look like  Station Name,Station Code A N DEV NAGAR,ACND ABHAIPUR,AHA ABOHAR,ABS ABU ROAD,ABR ...   What I was trying was - trying to write a shell script and then echo them with comma in between. But I guess a simpler effective one-liner would do the job here may be in sed/awk.  Any ideas?


I have a simple text of URLs in stdout. Part of the URL looks as below.  https://somedomain./xx?t=s&u=random other text   I wish to change this using sed or something from the command line to read  https://somedomain./xx?t=l&u=random other text   I have used sed -e 's/s&/l&/'  Instead of replacing s& with l& I am getting ls& in the string. Is there something wrong with my command?

Take the following script:  #!/bin/sh sed 's/(127\.0\.1\.1)\s/\1/' [some file]   If I try to run this in sh (dash here), it'll fail because of the parentheses, which need to be escaped. But I don't need to escape the backslashes themselves (between the octets, or in the \s or \1). What's the rule here? What about when I need to use {...} or [...]? Is there a list of what I do and don't need to escape?


Heres how i call the image  Icon logoOne = new ImageIcon("logo.png"); // LOGO JLabel imageLogo = new JLabel(logoOne);  imageLogo.setPreferredSize(new Dimension(200, 50));   Its just added to a panel in a JFrame and works fine when running in eclipse but doesnt show up when exported to JAR.  can anyone help ?

When running a Java app from eclipse my ImageIcon shows up just fine.  But after creating a jar the path to the image obviously gets screwed up.  Is there a way to extract an image from the jar at runtime so I can then open it up?  Or, is there a better way to do this?  I'd like to distribute a single jar file if possible.


I accidentally overwrote a blend file. I was making a small thing and instead of opening something else I saved new small unimportant file over one of my biggest projects. Can someone help me please?

I had just finished creating a realistic human head in blender that took me about four hours to make. I then tried to open it in a new file but I accidentally saved over it.  Someone please help, I'm really upset about losing all that time and effort.


Currently  I have a table row that contains a textarea for user input. The purpose of textarea is so user can input multiple lines.  Code:    table {   border-collapse: collapse;   width: 100%;   border: 1px solid black; }  th, td {   text-align: center;   border: 1px solid black;   padding: 10px; }  .container {   border: 1px solid blue; }  .text-area {   width: 100%;   box-sizing: border-box;   display: flex; }  .fixed-min {   min-width: 600px; } <!DOCTYPE html>

     Column 1	     Column 2

             <textarea class="text-area">Set width in this big column             </textarea>

             <textarea class="text-area">This contents of this column should always be visible i.e. no scroll bar, and instead the height of this row should adjust to show all content.             </textarea>

         Problem  I would like the textarea to show all content by auto-adjusting height rather than requiring the user to scroll.    Notes:   I saw a solution on , but there has to be a simpler solution through CSS that I am missing. I used to use an editable  rather than  before, but because I am using this html within a react component, there were other complications with using an editable  so I switched to a . I wanted to know if there is a  solution, but appreciate it if there is not, and will then refactor the code to use  once more.   EDIT: Seems there is no CSS only solution for  :'(

There was , which I've tried. But there is one problem: the textarea doesn't shrink if you delete the content. I can't find any way to shrink it to the correct size - the clientHeight value comes back as the full size of the textarea, not its contents.  The code from that page is below:  function FitToContent(id, maxHeight) {    var text = id && id.style ? id : document.getElementById(id);    if ( !text )       return;     var adjustedHeight = text.clientHeight;    if ( !maxHeight || maxHeight > adjustedHeight )    {       adjustedHeight = Math.max(text.scrollHeight, adjustedHeight);       if ( maxHeight )          adjustedHeight = Math.min(maxHeight, adjustedHeight);       if ( adjustedHeight > text.clientHeight )          text.style.height = adjustedHeight + "px";    } }  window.onload = function() {     document.getElementById("ta").onkeyup = function() {       FitToContent( this, 500 )     }; }


How can we show that $$\sum_{n=1}^{+\infty} \frac{1}{n^n} = \int_0^1 \frac{1}{x^x}dx$$   Could you give me some hints??

I need help with this exercise.  I need to prove $$\int_{0}^{1}x^{-x}\ dx=\sum_{n=1}^{\infty}n^{-n}$$  I think I should use some convergence theorem, but I'm stuck.  Thanks a lot!


First I asked this at AskUbuntu:     I've been trying to install .deb chrome file google-chrome-stable_current_amd.64.deb. It is saved in my Downloads, so I tried this command      sudo apt-get install ~/Downloads/google-chrome-stable_current_amd.64.deb   After reading the package list it responds:      E: Unsupported file /home/stockton/Downloads/google-chrome-stable_current_amd.64.deb given on command line   I don't know why it says E: file, I though Linux drives and files are not named after letters like Windows drives, for example 'C:' but idk I can still be wrong. I did have Windows 10 before I booted Ubuntu.      Any help will be great.   And then someone suggested I perform this command:      The conventional way is to install using dpkg. It is a new feature of apt to install from deb files. That's why the correct syntax is not always clear. man apt doesn't tell much either.      So a guaranteed way is to copy the deb file to your Home directory and running      sudo dpkg -i google-chrome-stable_current_amd64.deb   If it is the first time you install Chrome, you will get some error messages regarding missing dependencies. You can fix it by      sudo apt install -f   Instead of copying to Home you can use the path      sudo dpkg -i ~/Downloads/google-chrome-stable_current_amd64.deb    Now when I tired the sudo apt -i command, the computer was processing the downloaded chrome files and puts on the screen: Errors were encountered while processing: google-chrome-stable I don't know what to do now please help me.

I've been trying to install .deb chrome file (google-chrome-stable_current_amd.64.deb). It is saved in my Downloads, so I tried this command   sudo apt-get install ~/Downloads/google-chrome-stable_current_amd.64.deb    After reading the package list it responds:  E: Unsupported file /home/stockton/Downloads/google-chrome-stable_current_amd.64.deb given on command line   I don't know why it says E: file, I though Linux drives and files are not named after letters like Windows drives, for example 'C:' but idk I can still be wrong. I did have Windows 10 before I booted Ubuntu.  Any help will be great.


$$\int e^{2\theta}\sin(3\theta)\ d\theta$$   I don't know where to stop when it comes to questions such as this? Can you make me aware? I believe there was a possible prior person who answered the same question but they failed to indicate what the       I was and in the larger scheme of things why there was no need to further integrate or utilize another method to integrate.

Integration by parts - unless I'm not thinking straight - doesn't seem to help here.. If I pick either of the functions $e^{2x}$ or $\sin(3x)$ to be $u$ or $dv$, they don't change to anything easier... $e^{2x}$ stays in the form $e^x$ and $\sin(3x)$ flip-flops between $\sin(3x)$ and $\cos(3x)$, neglecting the constant that gets introduced.  So how can I approach solving this? $u$-substitution doesn't seem to be something I can use either.


Every time I reboot my Ubuntu 14.10, my touchpad drive(synaptics) resets to default configuration. Is there a way to restore my sysclient settings after rebooting? Alternatively; how can I configure a command to execute every time I log in?  The command to set my touchpad correctly is:   synclient VertScrollDelta=-120 && synclient HorizScrollDelta=-120

I want to run a simple bash script automatically when I log in. For example  #!/bin/bash echo "start spotify" gnome-terminal -e spotify --title spotify   When I run this command, one gnome-terminal shows up and spotify show up. I also want the gnome-terminal to popup "hidden" in a different virtual desktop. (one of the other four virtual desktops you can choose from taskbar)   I tried to add this to /home/me/.bash_login or something, but that didn't work..


I have an XML with the following structure:  <mrk mtype="seg" mid="12">line 1 <x id="211"/>             <x id="212"/> line 2 <x id="213"/>             <x id="214"/> line 3 <x id="215"/> </mrk>   My code:  node = tree.find("mrk") print(node.text)   yields:     line 1   How do I get the full text ("line 1 line 2 line 3") using Python 3.5 and ElementTree?  UPDATE  This is a bit different from  because I need the text without any child tags.   The easiest SOLUTION I found is:  "".join(node.itertext())

That is, all text and subtags, without the tag of an element itself?  Having
blah bleh blih
   I want   blah bleh blih   element.text returns "blah " and etree.tostring(element) returns:
blah bleh blih


I have often noticed that, whenever a race bike is running with free wheel (so no active pedals movements), I can hear a distinct "tick tick tick tick" coming from the rear wheel, sounding more or less like a speedy clock.  That doesn't happen neither on my cheap city bike, nor on my more expensive tourism bike. Is it a matter of proper lubrication, or is it also an indirect index of how good the gear is?  I would guess that if I hear a sound, some energy is being spent to generate it, and that energy comes from the bike motion. Therefore I would assume that a better bike with lower resistance would be more silent.

I tend to ride relatively modest gear (Tiagra/Ultegra), but when I'm riding near higher-end bikes, I sometimes notice that the clicking sound that comes from their cassette/free-wheel while coasting seems to be much louder and more distinct than on my bike.  Why is this?  Intuitively, one would expect that a quieter drive-train would be an indicator of greater efficiency, but that doesn't seem to be the case here.  Is it something to do with different construction, or materials?  Can you get 'quiet' high-end cassettes, or is being noisy while coasting the price you must pay for being efficient while pedaling?


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

Suppose $k$ is a field that is finitely generated as a ${\mathbb Z}$-algebra.  (That is, $k$ is a quotient of ${\mathbb Z}[X_1,\dots,X_n]$ for some $n$). Does it follow that $k$ is finite?


I am working with php to insert a line in sql server with odbc but I have this problem with french accents ( é , â , ô , î , è ,...), when I insert inside sql server it works and also php reads it well, but when inserting using odbc it is read as a special character   Example:  $sujet = 'BEM relevé bancaire';  $sql ="INSERT into matrice values('$groupe','$sujet','$nom','$ref','$ref','$next')";  odbc_exec($connection, $sql);   Output:          ID:           542          groupe:         Groupe_name     CI:             BEM relevÃ© bancaire //THE PROBLEM      Nom:            Name     affectationRef: 1     restAffect:     1     nextAffect:     0      How can I make it reads the french accents ?  The possible duplicate doesn't answer my question unfortunately

I'm looking for the alternative of mysql_real_escape_string() for SQL Server. Is addslashes() my best option or there is another alternative function that can be used?  An alternative for mysql_error() would also be useful.


I have noticed that in order to describe 3-dimensional space you need at least three variables in every Koordinate-System. My question is whether it is possible to assign every single point in n-dimensional space a unique number - in other words whether any bijective function $f:\Bbb{R^n}\rightarrow\Bbb{R} , n\in\Bbb{N}/\{1\}$ exists. If $f$ does exist - what would it look like - and if it doesnt - how would you prove it?

How does one create an explicit bijection from the reals to the set of all sequences of reals? I know how to make a .  I have an idea but I am not sure if it will work. I will post it as my own answer because I don't want to anchor your answers and I want to see what other possible ways of doing this are.


When n and k are positive integers.   Would this be a correct proof?  Description: Suppose how many ways can we choose k people from a group of n + 1.  LHS: The left-hand side gives us the number of ways to do this by definition, on how to select k from n+1.   RHS: The right-hand side gives us the number of ways to do this as well, but instead, it first counts the number of elements plus one (n+1) times the number of ways to choose an element a subset of k - 1 in n over the number of elements k.

Suppose we want to prove $$ k \binom{n}{k} = n \binom{n-1}{k-1}$$   In the LHS we are choosing a team of $k$ players from $n$ players. Then we are choosing a captain. In the RHS we are choosing a captain from the $n$ players. Then we are choosing the remaining $k-1$ players from the $n-1$ players.   Is this a correct interpretation?


Let $A:X\rightarrow X$ be a linear transformation, where $X$ is a finite-dimensional complex inner product space. Show that $A$ is self-adjoint if and only if $(Ax,x)\in\mathbb{R}$ for all $x\in X$.

I have having trouble with the following question:  Let $V$ be a finite-dimensional complex inner product space, and let $T$ be a linear operator on $V$. Prove that if $\langle T\alpha, \alpha\rangle$ is real for every $\alpha$ in $V$ then $T$ is self-adjoint.   I have been focusing on trying to show that if $\langle T\alpha, \alpha\rangle = \langle T^*\alpha, \alpha\rangle$ for all $\alpha$ then  $T = T^*$, but have been unable to do so. I also feel like I'm missing something really obvious. How should I proceed.


How to calculate days between two dates by using JavaScript?        How to get only 'day' from the date.   How to get only 'month' from the date.   How to get only 'Year' from the date.   How to calculate 'year' from the 'days'      This type of questions are have Answer is below refer it

How do I get the number of days between two dates in JavaScript? For example, given two dates in input boxes:  <input id="first" value="1/1/2000"/> <input id="second" value="1/1/2001"/>  <script>   alert(datediff("day", first, second)); // what goes here? </script>


I'm really sorry that I can't word my question properly. So I want to create an if-else scenario where you take string input from user and to print "Oh, so your name is xyz" if the input is correct, and to print "Oh, so your name is not xyz" if the input is wrong. String name = "xyz"; String lol = input.nextLine();             if (lol == name) {                 System.out.println("Oh, so your name is xyz");             } else {                 System.out.println("Oh, so your name is not xyz");             }             input.nextLine();             input.close();     }  But after I run the file I got something like this instead: What's your name? xyz Oh, so your name is not xyz  I've changed the if (lol == name) to if (lol != name) but it prints "Oh, so your name is xyz" even though the input is false. What's your name? asd Oh, so your name is xyz  This is the whole code: import java.util.Scanner;  public class MyClass {     static void myMethod() {                  Scanner input = new Scanner(System.in);                  System.out.println("Hello World");         System.out.println("What's your name?");                  String name = "xyz";         String lol = input.nextLine();             if (lol == name) {                 System.out.println("Oh, so your name is xyz");             } else {                 System.out.println("Oh, so your name is not xyz");             }             input.nextLine();             input.close();     }          public static void main(String[] args) {         myMethod();     }  }  Thanks in advance.

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


Shared DNA: 1,655 cM across 46 segments.   Can someone that shows this as one of my matches on AncestryDNA be a half sibling?

Given two tests that share some cM of autosomal DNA, how can I easily find the predicted relationships that such shared cM would suggest? For example, a 2,200 cM match suggests it could be either: grandparent, half-sibling, or grandchild.


I am setting the umask to a new value as below.   However although I am applying rxw to the user, this does not seem to be respected (?)  /home/pkaramol $ umask u=rxw,g=rw,o=r /home/pkaramol $ umask -S u=rwx,g=rw,o=r /home/pkaramol $ rm -rf afile && touch afile; /home/pkaramol $ ls -l afile  -rw-rw-r-- 1 pkaramol pkaramol 0 Μar   2 10:30 afile   edit:  $ mount | grep -E '\s/\s' /dev/sda3 on / type ext4 (rw,relatime,errors=remount-ro,data=ordered)  $ mount | grep -i home /home/pkaramol

It seems that whenever I create a file with touch the permissions are set to: -rw-r--r--.   Is there some way that I can configure the permissions with touch or does this have to be done after with a different command?


I have a problem regarding the Copy Editor badge. I have edited more than 500 posts in total. Still, I cannot receive Copy Editor badge in my account. And also, Copy Editor badge track (progress bar) also disappears from next badge track window.

Formerly List of all badges with full descriptions.  What are badge name's requirements? Why didn't I get badge name ? Which badges can I earn multiple times?    Jump to:                    Note: Some badges are awarded based on score. The term score means the total number of upvotes minus the total number of downvotes.  Any badge with a *** next to it is one of 20 badges that count towards the  displayed on a moderator candidate in an election. The candidate score is a total of 40 points: the first 20 are awarded based on the user's rep divided by 1000 and rounded down; the second 20 represents the total number of unique badges earned of the 20 that count. Note that if the same badge is earned multiple times, it will only count once towards the candidate score.  Any badge with a "(retired)" next to it is no longer awarded, but is retained by users who previously earned them. See  for more info on what it means for a badge to be retired.       Visit the  of the  on any site to see a complete list of badges that you can filter by earned, unearned, or type.


Let S be a nonempty finite semigroup. Suppose that, for all a, b ∈ S, the equation ax = b has a solution and that the equation xa = b also has a solution. Show that S is a group

It is easy to prove: in a finite semigroup if for all $a$ and $b$, $ax=b$ and $ya=b$ has unique solution. then it is group. But if in a finite semigroup, if for all $a$ and $b$, $ax=b$ and $ya=b$ has solution(not necessarily unique given) would it be a group?


How to evaluate this? $$\prod_{k=1}^m \tan \frac{k\pi}{2m+1}$$  My work I couldn't figure out a method to solve this product. I thought that this identity could help. $$\frac{e^{i\theta}-1}{e^{i\theta}+1}=i\tan \frac{\theta}{2}$$ By supposing $z=e^{\frac{2k\pi}{2m+1}i}$, then, $$i\tan \frac{k\pi}{2m+1}=\frac{z-1}{z+1}$$ So, the product $$\displaystyle\prod_{k=1}^m \tan\frac{k\pi}{2m+1}=\displaystyle\prod_{k=1}^m \frac{z-1}{i(z+1)}=\displaystyle\prod_{k=1}^m \frac{e^{\frac{2k\pi}{2m+1}i}-1}{i(e^{\frac{2k\pi}{2m+1}i}+1)}$$ which is getting more complicated. Answer is $\sqrt{2m+1}$. Any help is appreciated.

I have to prove that the following holds. A hint to use complex numbers has been given. I have tried to make a start but not to any result.      $$\prod_{k=1}^{n}\tan\left(\frac{\pi k}{2n+1}\right)=\sqrt{2n+1}$$     My Attempt:  Let us consider $(2n+1)^{\text{th}}$ roots of unity, $z_k=\exp\left(\frac{2k\pi i}{2n+1}\right)$. We can rewrite the product in terms of $\arg(z_k)$ as $\prod_{k=1}^{n}\tan\left(\frac{1}{2}\arg(z_k)\right)$. Or equivalently so, if we consider $(4n+2)^{\text{th}}$ roots of unity, we get this product as $\prod_{k=1}^{n}\tan(\arg(\zeta _k))$, where $\zeta_k= \exp\left(\frac{2k\pi i}{4n+2}\right)$.     I know it can be proved by proving the expression for $\prod\sin(\frac{1}{2}\arg(z_k))$. But I was wondering, is there a way to use telescopic products or purely the geometry of the complex roots of unity to arrive at this


I have a Javascript/Typescript code that looks like this:  for (let item of itemList) {   this.myService.myMethodReturningPromise(item.id).then(success => {     item.value = success;   }); }   By the time my Promise resolves, I have already exited the loop and I no longer have reference to item.  Why is it able to correctly set the value of each item in itemList?

How would you explain JavaScript closures to someone with a knowledge of the concepts they consist of (for example functions, variables and the like), but does not understand closures themselves?  I have seen  given on Wikipedia, but unfortunately it did not help.


Can someone explain why this block of code is valid syntax? Why does it compile?  void foo(){} enum class X { X1, X2 };  int main() {     auto s = X::X1;     foo(),s = X::X2;     return 0; }   Using Apple LLVM version 9.0.0 (clang-900.0.38).  Edit:  The line in question as Some Programmer Dude mentioned       foo(),s = X::X2;

How does the comma operator work in C++?  For instance, if I do:  a = b, c;     Does a end up equaling b or c?   (Yes, I know this is easy to test - just documenting on here for someone to find the answer quickly.)  Update:  This question has exposed a nuance when using the comma operator.  Just to document this:  a = b, c;    // a is set to the value of b!  a = (b, c);  // a is set to the value of c!   This question was actually inspired by a typo in code.  What was intended to be  a = b; c = d;   Turned into  a = b,    //  <-  Note comma typo! c = d;


I'm using Dell laptop with Windows 7 ( 32 bit ) with 2 GB RAM where memory usage is always high. Please suggest if I increase RAM to make laptop work faster and how much max RAM I can increase to ? Configuration  High Memory Usage  Note: As per youtube videos, I have tried most of things to reduce max memory usage but it didn't help and I've kaspersky antivirus running as well.

Possible Duplicate:             According to , Win 7 only supports 4 GB of RAM. I, however have been reading some forums and some say they are using 8 GB RAM with good performance. I am wondering if I can use 8 GB before I purchase.


As far as I understand,Confidence Interval of a parameter is an interval which contains the true value of the parameter at a certain level of confidence. But, why do we need it?

If I understand correctly a confidence interval of a parameter is an interval constructed by a method which yields intervals containing the true value for a specified proportion of samples. So the 'confidence' is about the method rather than the interval I compute from a particular sample.   As a user of statistics I have always felt cheated by this since the space of all samples is hypothetical. All I have is one sample and I want to know what that sample tells me about a parameter.  Is this judgement wrong? Are there ways of looking at confidence intervals, at least in some circumstances, which would be meaningful to users of statistics?  [This question arises from second thoughts after dissing confidence intervals in a math.se answer  ]


As far as I understand ECDSA keys are smaller than RSA because all of the value of the ECDSA (up to a high number) are valid private keys.  Is there any method of compressing RSA keys, based on some form of description of the key?  e.g. This is the $M^{\text{th}}$ possible value of $n$, given that $e = E$ and $A \leq n < B$.

I am wondering to what degree we can define an RSA variant, with a security argument that it is as safe as regular RSA with a given modulus size $m$ (e.g. $m=2048$), in which the public key has a compact representation of $k \ll m$ bits.  We can fix the public exponent to our favorite customary value, e.g. $e=2^{16}+1$ or $e=3$, thus need to store only the public modulus $n$. We need not store the leftmost bit of $n$, which is always set by definition; nor the rightmost bit, which is always set since $n$ is odd. With a little effort, we could save (very) few more bits noticing $n$ has no small divisors, but that will still be $k \sim m$ bits.  We can do better by forcing the $\left\lfloor m/2-\log_2(m)-2\right\rfloor$ high bits of $n$ to some arbitrary constant such as $\left\lfloor\pi \cdot 2^{\left\lfloor m/2-log_2(m)-4\right\rfloor}\right\rfloor$. Observe that we can chose the smallest prime factor $p$ of $n$ just as we would do in regular RSA, then find the maximum integer interval $[q_0,q_1]$ such that any $q$ in that interval cause $n=p\cdot q$ to have the right high bits, then pick a random prime $q$ in that interval (most often there will be at least one, if not we try another $p$). Some of the security argument is that   generating an RSA key $(p,q')$ using a regular method, with random huge primes in some appropriate range and no other criteria beside the number of bits in $n'=p\cdot q'$, and $p<q$; then deciding the high bits of $n$ from those in $n'$; then finding $[q_0,q_1]$, generating $q$ as a random prime in that interval, and setting $n=p\cdot q$;   demonstrably gives the same distribution of $(p,q)$ as said regular generation method, hence is as secure; then we remark that the high bits of $n$ are random (with some distribution not too far from uniform), and public, thus fixing it can't much help an attack (I think this can be made rigorous).  This is now $k \sim m/2+\log_2(m)$ bits to express the public key. We can save a few more bits, each one at worse doubles the amount of work to generate the private key (we can repeat the generation process outlined above until we find a key with these bits equal to some public arbitrary constant; or equal to bits from a hash of the other bits if we want a tighter assurance that the scheme is not weakened).  Can we do better, and what's the practical limit?  Update: In , Marc Joye discuses this, and reaches $k \sim m/3$ (without claim of optimality). I'm worried that I do not see an argument that the manner in which $(p,q)$ are selected in Algorithm 3 does not weaken $n$ against a dedicated factoring algorithm.


I've created a small form that acts like the office notifications (fades in\out above the notification icon tray)  I'm having problems showing this form, I want to display it without the focus being taken from my main application (or any other form), I've managed to get the attached code doing roughly this, (using Me.Activate to take back focus) But this isn't great - focus switches for an instant plus I want to show the form from various areas in my application...    Dim frm2 As New frmNotification()     frm2.TopMost = True     frm2.Show()     Me.Activate()   Any Ideas?

I'm using a Form to show notifications (it appears at the bottom right of the screen), but when I show this form it steals the focus from the main Form. Is there a way to show this "notification" form without stealing focus?


What's the fastest speed I can move until Pokemon Go no longer considers me to be walking?

I have a couple of eggs that I've picked up from some Pokestops (I'm lucky enough to live above one).   I walk a lot. I get to work through a 2 mile walk / train journey every day, so I should be picking up loads of steps for the eggs I have. However, because I'm normally always running late... for everything, I have to rush everywhere, so I walk at an above average pace.   Today I've walked around 5 miles, but the game has registered 100 metres. Is this because I walk too fast, or because of something else?  It's worth pointing out that I have the app open when walking... mostly because I have to catch them all. (This made me miss a train this morning... luckily I was early :D)


Find all the positive natural solutions of $x^2+y^2=3z^2$. I guess it has something to do with Pythagorean triples, but I don't know how to relate it properly. Suggestions, hints, or any sort of assisting is welcome.

I tried to solve this question but without success:     Find all the integer solutions of the equation: $x^2+y^2=3z^2$   I know that if the sum of two squares is divided by $3$ then the two numbers are divided by $3$, hence if $(x,y,z)$ is a solution then $x=3a,y=3b$. I have $3a^2+3b^2=z^2$ and that implies $$ \left(\frac{a}{z}\right)^2+\left(\frac{b}{z}\right)^2=\frac{1}{3} $$ so I need to find the rational solutions of the equation $u^2+v^2=\frac{1}{3}$ and I think that there are no solutions for that because $\frac{1}{3}$ doesn't have a rational root, but I dont know how to explain it.  Thanks


I want to convert 8874M to GIGA so I did this    echo $(( 8874 / 1024 ))   but actually we get 8 ( while exactly results is 8.6 )  so what need to change in order to get the 8.6?

how to calculate float numbers: with bash  example        DRIVER_MEMORY=$(( 5 * 0.6 * 0.9 )) -bash: 5 * 0.6 * 0.9 : syntax error: invalid arithmetic operator (error token is ".6 * 0.9 ")   remark - results must be integer number  - so we can round the number to down


I have an account in Stack Exchange communities. I use OpenID login, but apparently I can't do this any more. I add Google address as they asked, but it creates this new account and I lose all my previous work.  So, how can I access to my previous account?

NOTE: Signing up or Logging in via OpenID is no longer officially supported from any of our sites. Currently,  is still on the internet, but we are in the process of completely removing it.    Stack Overflow was an early and strong supporter of . We built our sign up/log in flow around it. We were idealistic and had , but these hopes weren't realized. Over the years people have wondered if  is . We've had to remove support as OpenID providers  or .  The time has come to part ways. The reality is OpenID support has created a ton of complexity in our codebase and the number of users actively using OpenID simply don't justify that cost. Users have spoken with their actions. You prefer Google, Facebook and Stack Exchange (aka email/PW) based account auth.     Of our 9,813,747 accounts around one-tenth of a percent are actively using OpenID (defined as having visited a site in the past 12 months). If you include all the inactive accounts it is still less than 2.9% of all accounts.  So, what is the plan?   DONE - Remove the ability to create a new account with most OpenID providers DONE - Add the ability to  DONE - Convert Launchpad (used on  ) to OAuth DONE - Remove creating new accounts with Steam from  (Steam removed support for OAuth. Only 454 accounts that use Steam have visited Arqade in the past 6 months.) DONE - We will email all users that rely on deprecated OpenID credentials and request that they  DONE - Run an announcement banner for any user who signs in with deprecated OpenID credentials urging them to  DONE - End support for logging in via OpenID  In progress - Remove  (note: only 0.2% of authorized sites in the last year have been non-Stack Exchange sites.)   Obviously, if your account relies on OpenID, then make life easy and go now and .   If you've forgotten what you credentials you use to login, then  to refresh your memory. If you don't see one of the three account types shown in the image below (Google, Facebook or Stack Exchange) then click the "add more logins" button to add one of them to your account.    Remember, SE OpenID accounts are really email/pw accounts handled through complicated OpenID code path. They will be migrated to a simpler email/pw only code path as a part of this change. No extra work required on your part.


So I got an att galaxy s5 that is being used on tmobile service.  Am I out of luck as to getting either the att 4.4.4 update or the tmobile lollipop update?  Checked through settings and version is 4.4.2 and shows as no new update is available for att and I do not see an option for tmobile.

Android 5.0 (Lollipop) was officially announced on October 15th, 2014.  You can review the high-level changes at the  and the announcement on the official .  Of course, not all devices will get this update right away and others won't get it at all. Each manufacturer and carrier often choose to add their custom modifications which tend to delay the official release.  When will each device get Android 5.0, either officially or unofficially, if ever?  See also:


I'm looking for a scifi book with an old guy and a group of youngsters that find an anomaly on a planet that looks like a massive pit but ends up being a gate to another world created by this race of aliens that are top shaped with tentacles coming from their mouths.  The old man turns out to be one of them but had forgotten everything until it started to come back when he came to that world. also the world has a seemingly infinite number of land types that cycle randomly, and when a person goes through this gate they get send to a specific land type and their body is changed in order to fit that space.  I think the plot revealed that the planet was a control device used to rebuild the universe. if anyone could help me that would be awesome.

I read this book at least ten years ago.  Any help identifying it would be appreciated.  Characters are teleported to an artificial world where each take over the mind of a different species.  I remember a moving sentient plant, a faun-like character, and a wasp-like character.  The planet is subdivided into different zones designed for each species.  One of the characters had long sharp fingernails with poison in them.  Thanks for any help, steve


I have been looking everywhere and I found the ways of doing this with images with \usepackage{float} for \includegraphics. But I also have texts from .txt files that I have as in \lstinputlisting that I would also like to force.  I don't really understand the documentation of how placement works.     5.1 Space and placement      float=[*] <subset of tbphi> or float     floatplacement   makes sense on individual displayed listings only and   lets them float. The argument controls where LATEX is allowed to put   the float: at the top or bottom of the current/next page, on a   separate page, or here where the listing is. The optional star can be   used to get a double-column float in a two-column document      floatplacement=<place specifiers>   tbp   is used as place specifier if   float is used without value.   Any ideas how I force the code below with \lstinputlisting?  \lstinputlisting[float=h,frame=tb,     caption=Iteration: 2. Variable importance for unpruned decision tree ,captionpos=b, belowcaptionskip=2cm ,label=zebra]{results/maybe_80_20.txt}

Is there any package or a method to force LaTeX to keep floating environments like table and figure closer to where they are declared?


I see weird behaviour of the sort command (in Debian 10.6 and Fedora 32) Content of a file is ced )cd cad )cd  If I sort it (without any flags), I get cad )cd )cd ced  Now logically, either c comes before ), or after it. How are the ')' characters fitting between two 'c' characters ? This is not even using any sort flag, though :  There is no change in behaviour if I use the flag -n, for numeric sort The weirdness is resolved if I use the flag -f, for case insensitive sort, though everything in the file is lower case.

While trying to answer , I noticed a sort order I did not expect:  $ export LC_ALL=en_US.UTF-8   $ echo "T-700A Grouped" > sort.txt $ echo "T-700 AGrouped" >> sort.txt $ echo "T-700A Halved" >> sort.txt $ echo "T-700 Whole" >> sort.txt $ cat sort.txt | sort T-700 AGrouped T-700A Grouped T-700A Halved T-700 Whole $    Why is 700 A sorted above 700A, while 700A is above 700 W ?  I would expect a space to come before A consistently, independent of the characters following it.  It works fine if you use the C locale:  $ export LC_ALL=C $ echo "T-700A Grouped" > sort.txt $ echo "T-700 AGrouped" >> sort.txt $ echo "T-700A Halved" >> sort.txt $ echo "T-700 Whole" >> sort.txt $ cat sort.txt | sort T-700 AGrouped T-700 Whole T-700A Grouped T-700A Halved $


I'm trying to run games through Lutris and followed  on installing wine-staging.  When running:  $ sudo apt install --install-recommends winehq-staging   I get the error they predict, but then when running:  $ sudo apt install --install-recommends winehq-staging wine-staging wine-staging-i386   I still have the unmet dependencies error (output below).  Could anyone direct me to a solution?  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  wine-staging : Depends: wine-staging-amd64 (= 4.13~bionic) but it is not going to be installed  wine-staging-i386:i386 : Depends: libfaudio0:i386 but it is not installable                           Recommends: libcairo2:i386 but it is not going to be installed                           Recommends: libcapi20-3:i386 but it is not going to be installed                           Recommends: libcups2:i386 but it is not going to be installed                           Recommends: libglu1-mesa:i386 but it is not going to be installed or                                       libglu1:i386                           Recommends: libgsm1:i386 but it is not going to be installed                           Recommends: libgssapi-krb5-2:i386 but it is not going to be installed                           Recommends: libgtk-3-0:i386 but it is not going to be installed                           Recommends: libkrb5-3:i386 but it is not going to be installed                           Recommends: libodbc1:i386 but it is not going to be installed                           Recommends: libosmesa6:i386 but it is not going to be installed                           Recommends: libpcap0.8:i386 but it is not going to be installed                           Recommends: libsane:i386 or                                   libsane1:i386 but it is not going to be installed                           Recommends: libv4l-0:i386 but it is not going to be installed                           Recommends: libva-drm2:i386 but it is not going to be installed or                                       libva-drm1:i386 but it is not installable                           Recommends: libva-x11-2:i386 but it is not going to be installed or                                       libva-x11-1:i386 but it is not installable                           Recommends: libva2:i386 but it is not going to be installed or                                       libva1:i386 but it is not installable                           Recommends: libxcomposite1:i386 but it is not going to be installed                           Recommends: libxslt1.1:i386 but it is not going to be installed E: Unable to correct problems, you have held broken packages.

After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


I don't know how range hood is fixed under panel. By way, what do you call this fixation under panel?

My home range hood is . Plz see pictures that post. I never clean . It's probably greasy and clogged.  How can I clean it, but not access it? I don't want remove range hood or open exhaust duct. I see no Access Panel like picture below.  Are there safe chemicals I can spray at range hood? Then when I turn on range hood fans, these chemicals suck into exhaust duct, destroy grease?


I'm getting the following error:    $ sudo apt-get update  # partial output Reading package lists... Done  W: GPG error: https://download.01.org trusty Release: The following signatures couldn't be verified because the public key is not available:  NO_PUBKEY A902DDA375E52366 W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty/InRelease  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/InRelease  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-backports/InRelease  W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/trusty/InRelease W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/InRelease  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty/Release.gpg Could not resolve 'us.archive.ubuntu.com'  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/Release.gpg Could not resolve 'us.archive.ubuntu.com'  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-backports/Release.gpg Could not resolve 'us.archive.ubuntu.com'  W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release.gpg Could not resolve 'dl.google.com'  W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/trusty/Release.gpg Could not resolve 'extras.ubuntu.com'  W: Some index files failed to download. They have been ignored, or old ones used instead.

There is an error sign on my Ubuntu panel which states the error given in the title. I used sudo apt-get update but it gave me no errors. However the error sign persists.   How do I fix this?


If $f(x,y)$ is harmonic then so is the function $g(x,y) = f(\frac{x}{x^2+y^2},\frac{y}{x^2+y^2})$. Since $f$ is harmonic we have $\frac{\partial^2 f}{\partial x^2} + \frac{\partial^2 f}{\partial y^2} = 0$. Then I tried changing to polar coordinated. But  I am unable to prove it.

Suppose we have $f(x,y)$, which satisfies Laplaces equation: $\frac{\delta^2f}{\delta x^2}+\frac{\delta^2f}{\delta y^2}=0$  Does $f(\frac{x}{x^2+y^2},\frac{y}{x^2+y^2})$ also satisfy Laplace equation?


I am trying to set up a fallback connection on a Linux machine that has access to two different routers on different subnets on running on the same network.  I have been reading several other posts related to this but am struggling to get it to work.  The setup is as follows:      Internet 1                 Internet 2           ^                          ^           |                          | --------------------     ------------------------ [Router 1: 10.1.1.1]     [Router 2: 192.168.2.10] --------------------     ------------------------           ^                          ^           |                          |            \                        /            --------------------------            [eth0              eth0:1]            [10.1.1.14   192.168.2.50]            [     linux machine      ]            --------------------------  In this example, eth0 is configured with DHCP, and eth0:1 is configured as a static IP.   I want to connect via the internet on the router at 192.168.2.10, but fall back to the router at 10.1.1.1 if 192.168.2.10 is unreachable.  According to some other posts I was reading, it seemed setting route metrics on the default routes should do the trick.  I ran the following on the linux machine and tested by unplugging the router at 192.168.2.10 to ensure that it would fallback to 10.1.1.1: ip route add default via 192.168.2.50 dev eth0 metric 100 ip route add default via 10.1.1.1 dev eth0 metric 200  Running a route -n showed: Destination     Gateway         Genmask         Flags Metric Ref    Use Iface 0.0.0.0         192.168.2.10    0.0.0.0         UG    100    0        0 eth0 0.0.0.0         10.1.1.1        0.0.0.0         UG    200    0        0 eth0 10.1.1.0        0.0.0.0         255.255.255.0   U     0      0        0 eth0 192.168.2.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0  But a simple ping to Google DNS failed.  Removing the 192.168.2.10 route allows it to work just fine. What am I missing, or am I interpreting the route metric wrong?  Is there a better way to do this? I have seen other cases where the routes are added to different tables, and then ip rules are setup for certain IPs to use different connections, but I want all connections to try to go out Router 2 but to go out Router 1 if Router 2 is down. Thanks!

I have two internet connection from two different ISP. ADSL on eth0 and 4G on wlan0. Is there any way that if one ISP fails, the other take over automatically without a physical router and by Host OS (Ubuntu 18.04)?


I`m trying to move left, or right the text and ImageView on Android Studio, but I want to do this programatically.   @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     getSupportActionBar().setTitle("new title");     getSupportActionBar().setDisplayShowHomeEnabled(true);     getSupportActionBar().setLogo(R.drawable.bible1);     getSupportActionBar().setDisplayUseLogoEnabled(true);     setContentView(R.layout.activity_main);

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


Let $\cal{H}$ be a separable Hilbert space and $\cal{K(\cal{H})}$ the algebra of compact operators acting on $\cal{H}$. Then $$\cal{K(\cal{H})}\otimes\cal{K}(\cal{H})\cong\cal{K}(\cal{H}\otimes H).$$  How to prove it? I can find a mapping $\phi$ from  $\cal{K(\cal{H})}\otimes\cal{K}(\cal{H})$ to $\cal{B}(H\otimes\cal{H})$, but there is some difficult to prove the range of $\phi$ is justly $\cal{K}(\cal{H}\otimes H)$.  P.S.: Is $\mathbb{M}_n(\mathbb{C})\otimes\mathbb{M}_n(\mathbb{C})\cong\mathbb{M}_{n^2}(\mathbb{C})$?  Thanks a lot!

QUESTION: Is it true that for the algebra of compact operators:  $\mathcal{K}(L^2(\mathbb{R}^m \times \mathbb{R}^n))$ is as a $C^{\ast}$-algebra isomorphic to  $\mathcal{K}(L^2(\mathbb{R}^m)) \otimes \mathcal{K}(L^2(\mathbb{R}^n))$?  The latter tensor product is any $C^{\ast}$-tensor product (because the compact operators are nuclear it doesn't matter). On $L^2$ we use the ($\sigma$-finite) Lebesgue measure, but of course the algebra $\mathcal{K}(L^2)$ no longer depends on the measure. Clearly, $L^2(\mathbb{R}^{m} \times \mathbb{R}^n)$ can be identified with $L^2(\mathbb{R}^m) \otimes L^2(\mathbb{R}^n)$ by Fubini's theorem. This makes me think that $L^2$ has a better chance than other Hilbert spaces to make $\mathcal{K}(\mathcal{H}_1 \otimes \mathcal{H}_2) = \mathcal{K}(\mathcal{H}_1) \otimes \mathcal{K}(\mathcal{H}_2)$ hold.  Thanks for your help.  EDIT: Of course $\mathcal{K}(\mathcal{H})$ denotes the compact operators on the Hilbert space $\mathcal{H}$.