Pdo parameter error in prepared statement

Sorry for my english I'm french :D,  Okay, i use pdo for my connexion with MySQL, but i have one error with PDO prepare statement.  I try to include my table name into the prepare request but i have an error :  Error : SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''NbClient' LIMIT 2) as sr' at line 1 Error Code : 42000   My code :   <html>     <head>     </head>      <body>     <?php      const HOST='localhost';     const DBNAME='GameWave';     const USER='';     const PASSWORD='';     const TABLE='NbClient';      echo GetNbClientByHour(2);       function GetNbClientByHour($nb_heure)     {                $hookConstTable = TABLE;           try         {             $pdo_options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;             $connexion = new PDO('mysql:host='.HOST.';dbname='.DBNAME, USER, PASSWORD, $pdo_options);              $prepare=$connexion->prepare('select SUM(record) from (select v_tot as record from :tab LIMIT :nb_heure) as sr;');             $prepare->bindParam(':tab', $hookConstTable, PDO::PARAM_STR);             $prepare->bindParam(':nb_heure', $nb_heure, PDO::PARAM_INT);             $prepare->execute();              $resultat = $prepare->fetch();             $prepare->closeCursor();              return $resultat[0];         }                     catch(Exception $e)         {             echo 'Error : '.$e->getMessage().'<br />';             echo 'Error Code : '.$e->getCode();         }     }     ?>     </body> </html>   But if i try to write table name in request, its work ...  $prepare=$connexion->prepare('select SUM(record) from (select v_tot as record from NbClient LIMIT :nb_heure) as sr;'); $prepare->bindParam(':nb_heure', $nb_heure, PDO::PARAM_INT);   Could you help me please ?


How is relativity related to anti-particles?

I have heard that a positron is like an electron moving backward through time. Can someone elucidate this statement for me. I would like to hear a deeper explanation of what we believe anti-matter to be, why it annihilates with matter and how this relates to relativity.


proof verification: $f(x) = 1/x$ is not uniformly continuous on the open interval (0,1).

I've written a proof that $f\left(x\right)=\frac{1}{x}$ is not uniformly continuous on the interval $(0,1)$ and would like to know if it is correct. Here's what I've got.      In order to show a function $f$ is not uniformly continuous on $A$, it   suffices to show there exist two sequences $(x_n)$ and $(y_n)$ in $A$   and an $\epsilon_0>0$ satisfying $\lim(|x_n-y_n|)=0$ but   $|f(x_n)-f(y_n)|\ge\epsilon_0$.      Let $x_n=\frac{1}{n}$ and $y_n=\frac{2}{n}$, with $n\ge3$, and set   $\epsilon_0=\frac{3}{2}$. Then $\lim(|x_n-y_n|)=0$, but       $\left|\frac{1}{x_n}-\frac{1}{y_n}\right|=\left|n-\frac{n}{2}\right|=\frac{n}{2}\ge\epsilon_0=\frac{3}{2}$,   as desired.


The current high school debate resolution is “Resolved: In the United States criminal justice system, jury nullification ought to be used in the face of perceived injustice.”   Although the resolution doesn’t seem to have a generic bare plural, is it correct to only talk about one kind of injustice? For example, if a debater decided to only focus on racial injustice, would this be a semantically correct interpretation of the topic? Is the word injustice an example of a mass noun?


How can I find the transfer function of a quadcopter's motor?

I want a model of a quadcopter and, thus, I need the transfer function of the motor.   Any suggestions on how to do it will be very helpful for me. Thanks.


Is it necessary to connect all power pins to power pic16f877a

I am using a pic16f877a for a project and I noticed that there are two VDD and VSS pins.  I wanted to know weather all 4 pins had to be connected to power or just one VDD and one VSS pin.  A circuit I was working on seemed to work fine with just one connected but I wasn't sure if it was a good idea.


How to disable .txt content icon preview?

I wish to permanently disable the process that generates a preview of any file content (specially text files) and generates an new icon for it. Sometimes my programs quickly update several files and this keep jamming the folder window during the process. I disabled evince-thumbnailer but I don't think it's what I'm actually looking for.


Workplace switcher stopped working in Ubuntu 16.04

I was using workplace switching for a long time and it suddenly stopped working today.  Even after a fresh install, (some config left over as I preserved my /home folder).  Super + S still raises to show all work-spaces.  Clicking on a task-bar icon representing a window in another work-space no longer switches to that workspace + window.  Ctrl + Alt + ⟵ (any direction) no longer works.  Ctrl + Shift - Alt - ⟵ (any direction) no longer works.  I've verified that those key combos are registering by redundantly re-assigning the shortcut mappings.


I am trying to create a latex class that allows sectioning below subparagraph. For doing that, I modified the article.cls class of the texlive distribution adding two more options \thesubsubsubsection and \thesubsubsubsubsection. So now, the sectioning tree goes as follows:  \thesection   \thesubsection   \thesubsubsection   \thesubsubsubsection   \thesubsubsubsubsection \theparagraph   \thesubparagraph   Please see below myarticle.cls, mysectioning.tex and the resulting mysectioning.pdf.  I achieved the wanted effects in terms of numbering, table of contents and section formatting. The only problem that I have is that in the new two headings, \thesubsubsubsection and \thesubsubsubsubsection, the heading title is repeated in the following paragraph as indented text (see Sections 1.1.1.1  and 1.1.1.1.1 below).  Do you know how can I avoid this behavior?  Many thanks in advance for your help and ideas! Sebastian


Please help me . I am interested to learn linux. Can I install linux in any Laptop ❔ My laptop asus x556u Am I able to install linux ?


Is it possible to get the class calling a function in JavaScript?  For example:  function Foo(){ this.alertCaller = alertCaller; } function Bar(){ this.alertCaller = alertCaller; }  function alertCaller(){     alert(*calling object*); }   When calling the Foo().alertCaller() i want to output the class Foo() and when calling Bar().alertCaller() I want to outbut Bar(). Is there any way I can do this?


Flotation of a body which is submersed into a incompressible fluid using Archimedes principal

There is a small boat in a water tank and the boat is loaded with a huge piece of rock .The water tank is totally filled with water .If the rock is taken off from the boat and totally submerged in the tank water then what will happen to the water level of the tank?


Using php, how to insert text without overwriting to the beginning of a text file

I have:  <?php  $file=fopen(date("Y-m-d").".txt","r+") or exit("Unable to open file!");  if ($_POST["lastname"] <> "") {    fwrite($file,$_POST["lastname"]."\n"); }  fclose($file);  ?>   but it overwrites the beginning of the file.  How do I make it insert?


Excel 2015 auto increment the cell reference by 5

I have data in an Excel worksheet called "Data Sheet" in the below format.  F7:  ID1 F8:  Amt1 F9:  Units1 F10: Status1 F11: <blank> F12: ID2 F13: Amt2 F14: Units2 F15: Status2 F16: <blank> F17: ID3 F18: Amt3 F19: Units3 F20: Status3 F21: <blank>        ⋮   I want to obtain the below details in another sheet ("Result Sheet"):  E12:    =Data Sheet'!F7 E13:    =Data Sheet'!F12 E14:    =Data Sheet'!F17                ⋮   How can I make the reference to auto increment by custom multiples instead of the default increment by 1? Here I need the reference cell to be incremented by 5 while dragging the formula.  The answer in the "how to customize autofill in excel2010" thread is referring to the same sheet. But, here my requirement is referring to different work sheet. I tried modifying the  formula in the other thread, but it didn't helped me.


How can I reset a counter when calling two different environments?

I defined my own counter which resets every time I call the environment ``environment1''. It works as expected.  \newcounter{ado}[environment1]   I wanted it to be reseted as well when I call the environment ``environment2''. Is there a simple way like the following?  \newcounter{ado}[environment1,environment2]   I am using  \setcounter{ado}{0}   prior to evironment2 environments but i was looking for anything more appropriate.


How is number of conjugacy class related to the order of a group?

Let $c(G)$ denote the number of conjugacy classes of a group $G$. I have to show that  $$\lim_{n \to \infty} \inf _{|G|=n}c(G)=\infty.$$ That is, I have to show that $\exists $ a function $f:\mathbb{N} \to \mathbb{N}$ such that if $c(g)\leq n, $ then $|G|\leq f(n).$   I know that if $G$ is a finite group such that any two non-identity elements in $G$ are conjugate, then $G$ is isomorphic to $\mathbb{Z}_2$. The proof is simple, infact:      It can easily be shown that $G$ acts transitively by conjugation on $G \setminus \{e\}$. Then, by  orbit-stabilizer theorem, the claim follows.    I wonder if similar idea could be useful somehow. But I can't think of any to prove the claim above. Please help!


Can quadric surfaces be made by cutting a 4-dimensional cone?

In my high school multivariable calculus class, we recently learned of quadric surfaces. Since they appeared to be a generalization of conic sections to 3 dimensions, I wondered if they could be generated by finding the intersection of a 3-dimensional plane with a 4-dimensional cone similarly to how a conic section is the intersection of a 2-dimensional plane with a 3-dimensional cone. What follows is my attempt at experimenting with this idea. Although I was able to obtain some interesting results, I was not entirely successful in my endeavour which is why I am posting here.  I was able to deduce that a fourth dimensional equivalent of a circular cone is:  $$x^2+y^2+z^2=w^2$$  With this, I was able to get a few quadric surfaces with minor effort by simply plugging in a constant for one of the variables. For example, by setting $w=3$, I got the equation of a sphere:  $$x^2+y^2+z^2=9$$  And by setting $z=3$, I was able to derive the equation of a hyperboloid of two sheets:  $$x^2+y^2+9=w^2$$ $$w^2-x^2-y^2=9$$  I wanted to see if I could get the rest of the quadric surfaces by picking less mundane planes than just those aligned with the axes. So then I attempted to define a 3-dimensional plane in a 4-dimensional space with a point and a normal. I remembered that one definition for a plane is:  $$\vec{n} \cdot (\vec{P_0} - \vec{P})=0$$  Where $\vec{n}$ is the normal of the plane, $\vec{P_0}$ is the initial point, and $\vec{P}$ is any arbitrary point that lies on the plane. Armed with this knowledge, I plugged in  $\vec{n}=\langle A,B,C,D \rangle$ and $\vec{P}=\langle x,y,z,w \rangle$ to arrive at:  $$Ax+By+Cz+Dw=\vec{n} \cdot \vec{P_0}$$  Since the cone should have rotational symmetry (admittedly I am not sure what this means in four dimensions so this could be a faulty assumption), I figured that any point would yield the same results as long as it does not lie on the plane $w=0$. With this knowledge, I picked the point $(1,0,0,1)$ because it seemed to be easy to work with.  Then, I tried various normals that I thought would yield interesting results. With this method, I was able to generate most quadric surfaces (including elliptic paraboloids). However, no matter what I tried, I was not able to generate a hyperbolic paraboloid or a hyperboloid of one sheet. Am I not picking the right normals for this? Or is my reasoning flawed? Could it be the case that it is actually not possible to generate these quadric surfaces by cutting a 4-dimensional cone with a plane?


How do I start skype in the system tray?

I have skype version 4 is set as one of my startup programs. Whenever skype starts, it pops up in it's full window mode. I would preferably like it to start as just an icon in the system tray.


Does javascript implement lexical scoping?

Why does this return 2 instead of 1? Seems the second "var" is silently ignored.  function foo() {   var local = 1;   {     var local = 2;   }   return local; } foo() /* 2 */


Estimating parameters of Student's t-distribution

What are the maximum-likelihood estimators for the parameters of Student's t-distribution? Do they exist in closed form? A quick Google search didn't give me any results.  Today I am interested in the univariate case, but probably I will have to extend the model to multiple dimensions.  EDIT: I am actually mostly interested in the location and scale parameters. For now I can assume that the degrees of freedom parameter is fixed, and possibly use some numeric scheme to find the optimal value later.


Need fonts of a different language to show up on android or atleast Instapaper

My family is residing in USA and we are from India. Now my mom gets super bored at home! And loves to read the regional online newspaper and magazines from India on the Internet; problem is she doesn't know how to use a computer! Me or my dad has to sit with her and click links for her, I have never heard anyone say a simple back in a browser in so many ways!.   Interestingly, she didn't have a hard time in using my dad's iPhone 4, in which he managed to lose!    I already own a Asus Transformer 300t and I tried to instapaper the websites she visits  this she doesnt miss at any chance.  Problem is, those turn up beautifully on the desktop/webapp but the fonts aren't rendered properly on my tablet or any Android device, before I go ahead and get a Nexus 7 or Galaxy Tab 7, can I have this font show up on Android or at least, instapaper.  All I need to do is instapaper every article when I come home in evening (morning time in India, meaning the newspaper just came out), so that she can read it next day and as a trial run on my tablet!,   Also, those websites, at least the one mentioned above, don't implement RSS feeds or else I could have had my Calibre auto generate/fetch daily news and make an e-book every day and download it on the tab. But I also don't know if those fonts will be detected on Kindle app or any app for that matter!  I know I can try having it outputted as PDF but teaching her to go to PDF and then browse; that's too much for me to teach! The instapaper works smoothly, open instapaper, read headlines, tap that and read/scroll/read , press back next article... plus I still got to download that PDF for her to the tablet  Also reason I'm saying Instapaper often is cause only that will detect the actual title of article  Some screenshots: for following  Android Apps:        Web Version:


Why doesn't someone try to turn ON/OFF enemy's lightsaber using the Force?

Lightsabers turn OFF when its wielder drops it or he/she dies. It means there's some kind of pressure button on lightsabers which needs to be always pressed to keep is ON.  In case of lightsaber throw, one uses the Force for that. It means, lightsabers can be turned ON using the Force.  Why doesn't someone try to turn ON enemy's lightsaber to do some lethal damage to someone nearby? Or, has this happened in any canon?


Random Forest Regression - Coping with extreme values

I'm not sure if I used the concept "extreme values" right. Anyhow, I'm trying to produce a model that estimates maximum tree heights / $\text{km}^2$. I have a database of around 24000 points ($\text{km}^2$), each has the max tree height value and 33 predictors. After playing around with random forest I manage to achieve a correlation of 0.67 between the real height and the estimated height on the test sample (20%). A MSE of around 1.6 meters. But Maximum errors of up to 33 meters. What I can see is that patches with very tall trees or very short trees (50 meters - 1 meters) are out of the scope of the model. Thinking in linear regression it is analogous to losing prediction power as you move away from the center of gravity of the observations. Right? How can I cope with this if at all?  p.s. this was implemented in R


the output when I start firefox from Terminal

I was curious and wanted to see if I could start Firefox using Terminal. So I typed   firefox   in Terminal, and it displayed the message below  (process:5199): GLib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed   And Firefox started running. But I am a little worried because the message above looks like an error message to me. Can anyone tell me what it means?


Hi so I have an object that has an array in it however when i try to print the the array itself it prints [Ljava.lang.String;@7637f22 I assume i am not calling it right and would like to know how i may go about doing so?


abhigenie92@ubuntu:~$ (sleep 2; echo $BASH_SUBSHELL ;sleep 2) 1 abhigenie92@ubuntu:~$ (sleep 2; echo $BASH_SUBSHELL ;sleep 2)& [1] 3297 abhigenie92@ubuntu:~$ 1  [1]+  Done                    ( sleep 2; echo $BASH_SUBSHELL; sleep 2 )   What happens when launch it as a background process, why don't I get the prompt back and I have to press Enter? In both cases it launches a child shell.


Looking for the cardinality of a collection of subsets of an infinite set

Let $A$ be an infinite set and ${\mathcal C}$ be the collection of all the subsets of $A$ which have the same cardinality with $A$. Does ${\mathcal C}$ have the same cardinality with the power set of $A$?


What was the original motivation for matrix multiplication?

When I took linear algebra class in my freshman year, the multiplication operation for matrices was defined without any apparent motivation. Given an $m$-times-$n$ matrix $A$ and an $n$-times-$p$ matrix $B$, define $(AB)_{ij} := \sum_{k=1}^n A_{ik}B_{kj}$.   I recently read a book which treats linear algebra more abstractly, introducing the notion of a matrix after it introduces linear maps. (The book is Linear Algebra Done Right by .)  Let $V$ and $U$ be vector spaces with bases $\{v_1,\ldots,v_n\}$ and $\{u_1,\ldots,u_m\}$. Notice that once we know how a linear map $T:U\to V$ acts on the basis elements of $U$, there is a unique way to extend it to the map on the whole space. The author then goes on to argue that we can thus associate with each linear map a matrix of that map. They are a very compact way of specifying linear maps relative to a given pair of bases.  We can define operations of addition and scalar multiplication on matrices so that they coincide with how these two operations act on the set of linear maps: $M(S+T)=M(S)+M(T)$ and $M(cT)=cM(T)$ for a scalar $c$ and linear maps $S,T:U\to V$.  What I like the most about the book is the next step.  Let $M(T)$ denote the matrix of the linear map $T:U\to V$ (relative, say, to standard basis). We know how to compose two linear maps $S:U\to V$ and $T:V\to W$ to get a linear map $ST:U\to W$.  What is more natural than to define matrix multiplication so that the equation $M(ST)=M(S)M(T)$ is satisfied? And we get the non-obvious rule for matrix multiplication. Despite not being simple it feels natural. I like it. I know where it came from. It makes sense.  Was this the original motivation for matrix multiplication? Who introduced it and when? (If not, when did people realize that is satisfies this rule?)  Edit (July 19th 2015). There is a substantial overlap with the question  but that answer does not have a satisfactory answer. In particular, the URL in the accepted answer is dead.


How to generate sample XML documents from their DTD or XSD?

We are developing an application that involves a substantial amount of XML transformations. We do not have any proper input test data per se, only DTD or XSD files. We'd like to generate our test data ourselves from these files. Is there an easy/free way to do that?  Edit  There are apparently no free tools for this, and I agree that OxygenXML is one of the best tools for this.


I'm building a php website with a limited number of users at all time (20 max). I've spend quite some time securing it and have done a lot of research on the topic.  I've run into a problem considering a secure password-reset-system. I'd like to use the most convenient way, that is sending an email to the user with an url that contains a token to reset the password. The token is bound to a certain user and is only valid for a certain amount of time. Alas this doesn't seem to be secure as email-traffic can be intercepted. I've been thinking of additional checks on the token, such as ip and browser (http_user_agent), but this too can be bypassed.  I could use a security question or link a code to the token that has to be given by the admin in order to use the token-url (is manageable because of the limited number of users), but I'd rather avoid that.  I've noticed that Facebook, Tumblr and probably many more use the convenient way of sending an email with an url without further security questions or such. Considering that security is one of the top priorities of these companies, how do they manage to make this process secure (I assume it is)? Are there any special security checks that they run? Or is the email-traffic-interception-security-leak a bit over-exaggerated?  Thanks in advance.


I had the extra wire in the wires run from my thermostat to my A/C, but the old thermostat did not need the C wire, so it was cut and stuff on both ends.  While installing the new thermostat I realized that a C wire is needed, so I pulled out the stuff wire in the wall and attached it to the C on the thermostat.  Went down stairs, opened the A/C unit and found that there isn't a C connection on the board.  There is a W, R and G and it appears the Y goes out to the A/C compressor outside.  My question is, am I able to cut one of the wires from the transformer on the 24v side that I think is the common side, it's grounded, and simply use a wire nut to connect everything back together while splicing in the wire that was unused, now making it the C wire?  here is a picture.   I was going to cut 1 of the 3 blue wires.  It's hard to see in the pic, but there are 3 square terminals on the blue side that 3 wires attach to.  Please help and thank you =)    side note, only terminals on the a/c board are W, R and G.  The yellow wire doesn't even attach to the board, but connects to another wire that looks like it runs out to my a/c compressor outside.


How does searching a file (locate) or autocompletion work?

I am a Windows user and coming from Windows with all the indexing and eternal wait times when searching for files, I find it surprising how fast does locate work or the autocompletion (that I know) work in linux.  Is there any indexing being done in the background or how is this achieved? I still have a pretty clean installation, so maybe this goes bad with time, but in Windows the moment you want to search on a folder which is not indexed you have to wait for some seconds.


The Visual Studio refactoring support  for C# is quite good nowadays (though not half as good as some Java IDE's I've seen already) but I'm really missing C++ support.  I have seen  and am currently trying it out, but maybe one of you guys know a better tool or plugin?  I've been working with  now for a week or two and got totally addicted. Thanks for the tip, I'll try to convince my boss to get me a license at work too.  I've been bughunting for a few days since Visual Assist X kept messing up my Visual Studio after a few specific refactorings, It took me (and customer support) a week to hunt down but let's say for now that Visual Assist X is not a good combination with .


I'm a new user of LyX. I'm using it to write math lectures.  How can I make a new symbol from two existing ones? To be more precise, how can I create this:    It's a subset with a circle in it (\subset, \circ).


Why did ubuntu overwrite windows when I installed it from a USB stick?

I'm trying to learn linux, so I installed ubuntu onto a 64 gigabyte USB and restarted my computer and booted from the usb. When it was loaded it asked me if I wanted to "try without installing"(which is kind of like a trial right?). The second option was to "install ubuntu". I clicked this option and it said "no operating systems detected", so I assumed it would install onto the USB since I don't have windows or any other operating system on the USB stick. When it was all done I rebooted my computer and tried booting windows but it had been completely overwritten. I unplugged the USB stick with ubuntu on it and ubuntu had been installed onto my main HDD from the USB stick.   Luckily, I have recovery USB sticks that lenovo sent me, so when I get back to college I'll be able to recover windows, but I want to know what I did wrong, and what I need to do next time, so that I can learn from my mistake.


I'd like to use the Greek letter qoppa in a formula in an otherwise non-Greek document. I tried using the greekoption for babelbut that turned my document into Greek letters. By default, \qoppadoesn't seem to be defined.


Will redirecting expired domains to my website help or attract penalties?

I am developing a entertainment website and have found more than 4 entertainment domains (expired domains). Domain authority of these domains are 25 or more.   If I will redirect these domain to my site then will this help my site or will penalize website?


Find the file extension of the given file name

How to find the extension of given file name:  See code below:     $file_name = "sample.jpg";   Output will be: .jpg   I need to find the extension of the file name  Example: If we parse sample.jpg i should return .jpg


Construction of addition and multiplication table for GF(4)

I am dealing with finite fields and somehow got stuck. The construction of a prime field $GF(p),  p \in \mathbb{P}$ is pretty easy because every operation is modulo p. In other words $GF(p)$ contains all integers ranging from 0 to $p-1$.  However, non prime fields are a bit trickier. Given the power $q = p^n$ with $p \in \mathbb{P}$ and $n \in \mathbb{N}$, one has to find an irreducable polynom g(x) of degree n. Then the construction of $GF(p^n)$ is the following:  $GF(p^n) = \frac{GF(p)[x]}{g}$  Theoretically I get along with this definition. Unfortunately I fail to construct addition and multiplication tables for any GF(q). Though I can easily find the wanted table on the internet, I have not found an explication yet that really made me understand.  I would like to know how to create the addition and multiplication table for $GF(2^2)$ with the above knowledge. $GF(2^2)$ contains four elements. Let's call them $\{0,1, \alpha, \beta \}$. $g$ must be $x^2 + x + 1$ as there no other irreducable polynom of degree 2. So far I am able to construct the addition table partly (question marks indicating despair...):  | + | 0  1  $\alpha$  $\beta$ |  0 | 0  1  $\alpha$  $\beta$ |  1 | 1  0  ?  ? |  $\alpha$ | $\alpha$ ?  ?  ? |  $\beta$ | $\beta$  ? ? ? |  I don't understand how to calculate for example $1+\alpha$. The result is $\beta$, but I don't know why. Concerning the above short explanation, I have to divide $1+\alpha$ by $g$. But how can I do this?   Thanks for your help


I can't seem to input the syntax for an umlaut.  Here is what I write  \documentclass[12pt]{article}  \setlength\parindent{0pt}  \usepackage{amsmath} \numberwithin{equation}{section} \usepackage{color} \usepackage{amssymb} \usepackage[margin=2.0cm]{geometry} \usepackage{graphicx} \usepackage{float} \usepackage{array} \usepackage{url} \usepackage{braket} \usepackage{hyperref} \usepackage{tensor} \usepackage{titlesec}  \usepackage{amsthm}  \begin{document} {\''o} \end{document}   Now when I copy and paste {\''o} from the internet it works fine and I get the first thing, but if I type it in manually then I get the second. Texworks automatically changes my ' to a \rq{}, so I have to do ctrl+shift+' or alt+' to get the character -- I think that this will have something to do with it but I don't know what.


Relation between water flow and pressure

Is there any equation that states the relation between pressure and water flow.  I.e. Let's say that in 1 hour with 8mca (water collum meters) pressure I obtain 50m3. What if (giving the same contditions) I execute the same test but now with 15mca?  Is that just proportional?


I have read on a lot of places that the crop sensor bodies give you an extra reach over the full frame bodies when using the same lens. For example over here:  - "For example, this can be very useful when shooting sports, wildlife, and other types of photojournalism. Just imagine that on a Canon crop frame body such as a Canon 7D; your Canon 70-200mm f/2.8 lens is effectively a 112-320mm lens!"  So, after reading all of that, I have got the following setup:   Canon 5D MKIII, 70-200L IS and Canon 2x extender Canon 450D, 70-200L IS and Canon 2x extender   But my question is - on both of those setups the maximum reach I'm getting is 400mm - should I not be getting more on my cropped 450D?  I'm checking the EXIF data in Lightroom.


What is the name of a sci-fi movie where an alien vehicle collects sample of living beings on different planets?

Name of a sci-fi movie where an alien vehicle collects sample of living beings on different planets. When it comes to Earth a boy becomes its friend. I don't remember much of the movie but one scene is that earthlings get a hold of the vehicle and keeps it in captive using big chains and heavy weights. Vehicle is silver in color and almond shaped.


How to control switch mode power supply feedback voltage through optocoupler?

The larger design is for a 170 V input, 500 V 2 mA output using a flyback converter. I will refer to the schematic on page 29 of the  switching controller, also found below.  The feedback pin of the switch controller controls the mode of operation: CHARGE MODE, REGULATION, NO LOAD (Fig 1 page 10 LT3751), also included below. I wish to avoid exceeding 1.34 V on this pin as that pushes it into NO LOAD, and the output voltage can increase up to 10% above nominal (page 14 LT3751).  Using the Isolated 282 V Voltage Regulator on page 29 LT3751, wouldn't this result in the voltage on the LT3751 switching between 0 V and Vcc?  If this is the case, how can I avoid this? I wish to operate in REGULATION mode. Is there a analog optocoupler type device, like a isolated operational amplifier what would pass the voltage sensed between R17 and R18 to the LT3751 FB?  Note the FB pin is internally regulated to 1.22 V (page 8 LT3751), so it would be acceptable to apply a voltage between 1.16 V and 1.22 V when the output is low, and between 1.22 and 1.34 V when the output is high. How could I achieve this using the optocoupler? Also, would the optocoupler present any significant resistance itself into a voltage divider circuit (ON/OFF).


How to disable Mac's generic Option-Command-W?

I end up accidentally hitting it because I have a similar shortcut for something else. I was hoping to disable Option-Cmd-W. I am fine disabling it only for one app specifically, or for all apps, whichever is easier. I'm on MacBook Pro, Catalina. What software can I buy that could do it? (Or maybe I just missed some menu option?) Note: I'm talking about the shortcut that is set by Apple, not by any application. It's mentioned here: . Chrome is not showing this key assignment in its menu (it has Close All listed in the menu, but it seems as if it's unassigned). And yet, when I followed the accepted answer, I did manage to disable this.


How to change the user specific PATH on windows 10 HOME?

On windows home we have several users (mostly family members). These users have different path requirements. Can they set their respective path ( without affecting others)? If that is not possible, how can the admin change the path for a particular user?


Recall the mean value theorem: If $f:\mathbb{R}\rightarrow \mathbb{R}$ is continuous and differentiable on $[a,b]$ then there exists $c\in(a,b)$ such that $f'(c) = \frac{f(b)-f(a)}{b-a}$ I am wondering if we can make our choice in reverse. In other words for each $c\in\mathbb{R}$ does there exist an $(a,b)\in\mathbb{R}^2$ such that $c\in(a,b)$ and $\frac{f(b)-f(a)}{b-a}=f'(c)$.


Short story/novella wherein everyone's following patterns like parts of a machine

...but an office worker has some sort of perceptual shift, and stops following his pattern--wakes up.    Other people keep speaking as though he's replying with the preset line, but he's just listening in horrified silence.  They also move in preset patterns--disrupting their movement makes them have seizures.  Eventually the protagonist meets others who've woken up: a woman whom he likes, as well as a gang of thugs (who have a large/evil hound) who run around pillaging and (I think it's implied) raping the unknowing "machine part" people.  At the end the protagonist and his lady friend decide to rejoin their patterns, by relaxing, dropping back into their routines.    I think it's from the 50s/60s, but I can't for the life of me remember who wrote it, or the title.  I think I might've run across it in an anthology of short stories.  Any help is greatly appreciated!


probability that exactly two accidents happen in any day of a week if 7 accidents happen in a week

If 7 accidents happen in a week, what is the probability that exactly 2 accidents happen in any day of the week.  I tried to work it this way.  2 accidents out of 7 can be taken in ${7}\choose{2}$$= 21$.  Now this can happen in any of the 7 days, so we have $7 \times 21$.  Now, the remaining 5 can happen in $6^5$ ways.  So the probability is  $\frac{7\times 21 \times 6^5}{7^7} = \frac{3 \times 6^5}{7^5}$   But this gives me a value greater than 1.   I know I am doing something wrong.  Can anyone help me ?


Compactness Theorem (Propositional Logic) and Compactness (Metric spaces).

Definition. A subset $E$ of a metric space $(X,\tau)$ is compact if every open cover of $E$ has a finite subcover.    Theorem (Compactness Theorem). A set $\Gamma$ of formulas is satisfiable if and only if every finite subset $\hat \Gamma\subseteq \Gamma$ is satisfiable.  I've recently began studying metric spaces, and I remembered about the compactness theorem for propositional logic, so I wanted to know what's the connnection between it and the notion of compactness. Could someone explain this in rather simple terms?


I want to draw this digram below in Latex and thank you .


How to get the value of a textbox using jQuery?

I can get the element like this $("#name") but I'm not sure how to get the actual value.


In a two months I will have a bachelors degree from a German University with an degree average (Notendurchschnitt) of 1.8 or 1.9 . My programme uses ECTS Credit Points. I am in the process of applying to British MSc programmes. They mostly require a Honours degree of "2:1" which, according to one university, is equivalent to "GPA 3.0".   Do I pass these requirements? And is it legit for me to say in my application that I have a GPA of 1.9?  I tried to get my head around these degree specifications but was unable to.


Date on the bottom of the page without drafting option in ClassicThesis

I'm using classicthesis to write my document. I don't use the option drafting but I can see on the bottom of the page the date (there is a part of the date that is not readable, but when I copy and paste this part I obtain [ December 1, 2011 at 20:50 ]). This is my code:  \documentclass[a4paper]{scrreprt}   % classe report di KOMA-Script  \usepackage[english]{babel}     % Per scrivere in inglese \usepackage[T1]{fontenc}        % Imposta la codifica dei font \usepackage[utf8]{inputenc}     % Lettere accentate da tastiera \usepackage{classicthesis-preamble} % Preambolo classicthesis \usepackage{classicthesis}      % Classicthesis  \begin{document}  \input{Chapters/0_Introduction} [...]  \end{document}   I would like to avoid this little issue.  I use TeXworks in Windows7 x64.


How can I determine if an NPC is available for marriage?

In the vein of  - Pete Hines, Bethesda's VP of PR and Marketing, when asked if Skyrim would support gay marriage :     You can marry anyone...Not any NPC, just mean any male or female.   So obviously some NPCs are off the list.  I assume I can't marry Jarl Balgruuf, but what about Irileth?  What about the Graybeards?  What about already-married NPCs?  Is it any "important" NPC, or is it more or less than that?  Has the Skyrim Creation Kit shed any light on how to determine this?


Part of model disappears when zooming out

When I go into camera lock mode and zoom out on my model. The distant parts grey out and disappear. Why is that?  Kind regards,  Maarten


Theorem 5.1. Chapter I in Hartshorne Book's

I find difficulty to understand the proof of this theorem :  Theorem : Let $Y\subseteq\mathbb A^n$ be an affine variety. Let $Ρ\in Y$ be a point. Then $Y$ is nonsingular at $Ρ$ if and only if the local ring $\mathcal O_P$ is a regular local ring.  Let $P$ be the point $(a_1,\dots,a_n)$ in $\mathbb A^n,$ and let $\frak {a}$$=(x_1-a_1,\dots,x_n-a_n)$  be the corresponding maximal ideal in $A = k[x_1,\dots,x_n].$ We define a  $\theta : A\longrightarrow k^n$ by $$\theta(f)=\left(\frac{\partial f}{\partial x_1},\dots,\frac{\partial f}{\partial x_n}\right).$$ So $\theta$ induce an isomorphism $\theta':\frak{a}/\frak{a}^2\longrightarrow$$k.$   Now let $\frak b$ be the ideal of $Y$ in $A,$ and let $f_1,\dots,f_n,$ be a set of generators of $\frak b.$ Then the rank of the Jacobian matrix $\left(\frac{\partial f_i}{\partial x_j}\right)_{i,j}$ is just the dimension of $\theta(\frak b)$ as a subspace of $k^n.$ Using the isomorphism $\theta'$ this is the same as the  dimension of the subspace $\frak a^2+b/a^2$ of $\frak a/a^2,$ if $\frak m$ is the maximal ideal of $\mathcal{O}_Р,$ we have $$\frak m/m^2\cong a/(b+a^2).$$   I don't understand how I can use $\theta'$ to get $\dim_k \theta(\frak b)$$=\dim_k(\frak a^2+b/a^2)$ and why  $$\frak m/m^2\cong a/(b+a^2).$$   Thank you for any help.


Brand new laptop, two years in storage, will the battery be ok?

I have an opportunity to buy a brand new (sealed box) EliteBook 8470p laptop for a good price.  The date of manufacture goes back to around March 2013, which is bang on two years ago.  Given that it's been two years, what state will the supplied Lithium-Ion battery be in? Still usable?


This is sort of a multi-part question that adds up to one larger question:   Can Sauron get to the Undying Lands? ( seems to have produced the answer to this - "No") Is the One Ring still dangerous even if Sauron can't possibly get to it? Is Elrond strong enough to resist the Ring? Could the Ring be taken to the Undying Lands, perhaps by Frodo, Bilbo, or Elrond?   Assuming the answers to these questions are 1. no, 2. not really, 3. yes, and 4. yes, then wouldn't it be feasible for someone to just bring the Ring to the Undying Lands and give/send it to someone who could safely hold on to it?  Say, perhaps, Eru Iluvatar, Manwe, Elbereth, Cirdan, etc?  This wouldn't require the person in question to actively intercede in worldly affairs - they would merely have to accept a gift and keep it forever.  Since humans (and/or elves and/or hobbits or whoever took the initiative in getting the Ring there, it would be more or less the same as bringing it to Mordor and destroying it, but less suffering and loss of life would be required in the process.  So basically, the overall question is:  Why not send the Ring to the Undying Lands?  *Note - since sea monsters never seem to attack ships carrying Elves, Valar, or Maiar to the Undying Lands, despite Sauron's hatred of them, the sea monster issue is irrelevant.  In any case, this question isn't about whether the ship would get there safely if passage were granted - it is about whether passage WOULD be granted and whether it would solve the problem.   *Note 2 - granted, this wouldn't get rid of Sauron, but Aragorn was free to set the terms of the Army of the Dead's deployment.  If he said "You must serve for a thousand years" instead of "You have to fight one battle", then the Army of the Dead could have roamed through Middle-earth and Mordor killing off every Orc and goblin Sauron enlisted.  Sauron would still exist, but he would be a more or less powerless eye stuck on top of a tower, with no hope of raising and army for a thousand years. If Aragorn said "You must serve forever", Sauron would be deprived of an army forever.


Why does English spelling use silent letters?

Why have a letter in a word when it’s silent in pronunciation, like the b in debt?  Can anyone please clarify my uncertainty here?


"Highly active question" banner text has a couple of stray asterisks

The banner text for protected questions currently reads:     .** You have enough reputation to answer this question. The reputation requirement helps protect this question from spam and non-answer activity.   What are those two asterisks doing there? Looks like someone made a Markdown typo.


I'm not a native english speaker, so even though I'm decently proficient at it, I don't really "know the rules" sometimes, and this is one that's been confusing me for a long time.  Which one is correct in each sentence?     If the movement [was/were] to continue uncorrected, the tower would   one day topple.      If I [was/were] rich, I would buy a yacht.   NOTE: I care not only about the case of "I", but also "she", "them", "it", etc, as in the example of the tower. Would it be any different if instead of the tower, it'd be me who'd topple if uncorrected?  I'm pretty sure it's "were" in both cases. That's what they taught me, I think. I started to doubt when I saw a lot of "was", but it sounded like the typical intentional mistake used "stylistically". ("If I was a rich girl...")  Then I saw it some more and thought it came down to an American/British English difference (I was taught British, in theory, and most of what I read is American).    But that tower sentence came straight from "The Guardian"...  When do you use was and when do you use were?


Currently running Ubuntu 15.10 on azure and Installed vnc4server and gnome group packages but still screen showing gray out. configuration file is define below:  $cat .vnc/xstartup unset SESSION_MANAGER exec /etc/X11/xinit/xinitrc [ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup [ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources xsetroot -solid grey vncconfig -iconic & x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" & x-window-manager &  gnome-panel & gnome-settings-daemon & metacity & nautilus -n & gnome-terminal &  $cat /etc/vncserver/vncservers.conf VNCSERVERS="1:adminuser" VNCSERVERARGS[1]="-geometry 1024x768"


Recently I ran across the sentence:     "Just why the law prescribed thirty-nine lashes instead of forty or forty-one and so on, must needs remain unanswered."   How did a plural verb like "needs" wind up as an adverb?  Is it alone in this phenomenon, or are there other examples that appear to be an odd misplacement of a second verb, but are actually adverbs as well?


Someone is duplicating/reproducing my site what can I do?

Someone has created an exact copy of my site.   At first, the code of his pages were identical to mine.  A few days later he just replaced my internal links with the same links to his own domain. At the top of his source code he uses some "Vodafone securenet" script connecting to my site.  At first I thought he was using embed or iframes or something to reproduce my site, but I have posted a new post and it doesn't show on his domain.  I have contacted the company that protects his whois info and I plan to issue a dmca with Google.  What else can I do?  Btw, this is obviously a neg seo case, since his site has no chance to appear on the search, yet it can hurt mine as duplicate content.


chown file changes back to root after reboot

having to chown chuck ttyUSB0    on each boot so that programs can access ttyUSB0    they don't work without the chown, how can i make the ownership stay as chuck or whatever on reboots, shut downs etc.


Footer of the first page of every chapter is not bold, but it should be. All the others are bold.       \usepackage{fancyhdr}      \setlength{\headheight}{40pt}     \setlength{\parindent}{0pt}      \makeatletter     \setlength{\@fptop}{0pt}     \makeatother     \renewcommand{\topfraction}{1.0}     \renewcommand{\bottomfraction}{1.0}     \renewcommand{\textfraction}{0.0}     \pagestyle{fancy}     \renewcommand{\chaptermark}[1]{\markboth{#1}{}}      \renewcommand{\sectionmark}[1]{\markright{#1}}      \clubpenalty = 10000      \widowpenalty = 10000      \displaywidowpenalty = 10000      \fancyhf{}     \fancyhead[EL]{\textsc{\leftmark}}     \fancyhead[OR]{\textsc{\rightmark}}      \fancyhead[ER]{}     \fancyhead[OL]{}     \rfoot{}     \lfoot{}     \cfoot{\bf \thepage}


I am working on a lightning component where on click contact link I have to open that contact in edit mode. But throwing this error:   Please find my code below:     I am using it in :                         <aura:component >      <aura:attribute name="showcontact" type="Contact[]"/>

             Selected Contacts

Contact Name

Phone

Email

         <aura:iteration items="{!v.showcontact}" var="con">
                                                                {!con.Name}
                             {!con.Phone}

                         {!con.Email}

          </aura:iteration>

 </aura:component>   Controller:  ({     editContact: function (component, event, helper) {         var rectarget = event.currentTarget;         var idstr = rectarget.getAttribute("data-value");          console.log('****'+idstr)         var editRecordEvent = $A.get("e.force:editRecord");         editRecordEvent.setParams({             "recordId": idstr         });         editRecordEvent.fire();             } })


How many users are there on Stack Overflow?

I'm just curious: how many users are there on Stack Overflow altogether?


PDF of normalized gaussian random vector

let $X$ be a Gaussian random vector in $R^n$ such that   $$X \sim \mathcal{N}(\mathbf{0}, \mathbf{I_n}),$$  How can I find the PDF of $\frac{X}{\|X\|}$?


Trying to benchmark Java 8 parallelSetAll() vs setAll()

Despite "warming up" via repetitions, and a bit of complexity added to the algorithm, parallelSetAll() seems consistently slower here. I'm not really trying to micro-benchmark here, just getting a rough feel for what's happening.  import java.util.*; import java.time.*;  public class SlowParallelSetAll {   static final int SIZE = 20_000_000;   static long timeIt(Runnable test) {     Instant start = Instant.now();     test.run();     long millis = Duration.between(start, Instant.now()).toMillis();     System.out.println(millis);     return millis;   }   public static void main(String[] args) {     int reps = 10;     long[] la = new long[SIZE];     for(int i = 0; i < reps; i++)       timeIt(() -> Arrays.setAll(la, n -> n * n * 11 + n * 7));     System.out.println("###");     for(int i = 0; i < reps; i++)       timeIt(() -> Arrays.parallelSetAll(la, n -> n * n * 11 + n * 7));   } } /* Output: 38 37 35 34 35 34 35 34 34 35 ### 52 42 43 44 46 46 44 44 43 43 */   The (lambda expression) algorithm should be independent as it only relies on the index value n, and therefore seems like it should be easily parallelizable.  Moving the calls around, alternating the two approaches, etc. does produce different results, but it also seems like there's something more here than just micro-benchmarking noise. For one thing, I was expecting bigger time differences between the normal and parallel versions. Also, it seems like one might stumble across situations where the parallel version might seem like the right choice but the normal version would actually be more appropriate. Basically I'm looking for some insights on this---including whether there's some easy way to show that what I'm seeing is purely a micro-benchmarking phenomenon.  For what it's worth, here it's rewritten to use System.nanoTime() and just alternating the tests. These results seem reasonable, although the whole microbenchmarking issue is daunting:  import java.util.*; import java.time.*; import java.util.concurrent.*;  public class SlowParallelSetAll {   static final int SIZE = 20_000_000;   static long timeIt(Runnable test) {     long start = System.nanoTime();     test.run();     long delta = System.nanoTime() - start;     long millis = TimeUnit.NANOSECONDS.toMillis(delta);     System.out.println(millis);     return millis;   }   public static void main(String[] args) {     int reps = 10;     long[] la = new long[SIZE];     for(int i = 0; i < reps; i++) {       timeIt(() -> Arrays.parallelSetAll(la, n -> n * n * 11 + n * 7));       timeIt(() -> Arrays.setAll(la, n -> n * n * 11 + n * 7));     }   } } /* Output: 41 74 41 73 41 67 40 67 40 67 41 67 41 67 40 67 40 67 40 67 */


How do I create bookmarks with pdfLaTeX?

I'm using MiKTeX and using pdfLaTeX. I can generate the PDF, but there are no bookmarks. In the .tex-file it is using:  \chapter \section \subsection   (with labels)  I originally used make with sphinx to output LaTeX. It must work somewhat or I wouldn't get the PDF. When I say bookmarks, I mean when you are in Acrobat and the left side has the Bookmarks panel.  I am reading   But I am not sure where to apply this.  EDIT:  I applied this, \usepackage{bookmark}, and got bookmarks, but I never get the subsection bookmarks.


I am using the packages xcolor and tikz.  I have defined my own color in rgb which name is MyColor1. I am using multiple times in TikZ MyColor1!50!white and I want to define it as Mycolor2 so that if I want to modify the percentage of white I don't have to do it manually each time I am using MyColor1!50!white. I don't know if I can do it in xcolor or in TikZ.  Thank you in advance for your help!


A "nativelog" application shows up in my Desktop

Question, whenever I start up my Minecraft a notepad application appears on my desktop called "nativelog", how do I remove that from ever popping up? Thanks.


Entire functions satisfying a given condition

"n" is a given positive integer. Find all entire functions satisfying $f^n(z)=z$ for every z in $\mathbb C$ Not getting any ideas. Can someone help please?


Logistic Regression : 10 events per predictor rule

I am building a marketing model based on logistic regression. It's a customer attrition model. The event rate is very low i.e 0.1%. I have more than 1000 predictors. I know there is a rule - Minimum 10 events per predictor. I want to know - Does this rule exist before dimensionality reduction (feature extraction) with PCA and Information value? Should i consider this rule based on my original 1500 variables or does it exist for significant variables that came after applying variable selection techniques such as Stepwise Regression , PCA etc?


I have a pendrive with the ubuntu root partition encrypted with LUKS, and it's inside a lvm volume. How could I read the data from Windows 10?


I asked a question and added a 50 point bounty (my first bounty question) but none of the answers actually provided anything solid and only tried to point me in the right direction with links I had already found myself.  I ended up solving the problem on my own and posted my code as an answer and accepted it.  I don't feel like either of the other answers showed significant knowledge or research and doubt they would be helpful for anyone in the future.  Since I can't award myself the points should I pick one of the other answers or just let them go into the void?  The question:


Occupancy problem with balls and boxes. Suppose there are $N$ balls and $M$ boxes. The balls are thrown to the boxes at random. What is the probability of $k$ boxes contain exactly $1$ ball? where $k=1,2,...\min(N,M)$


My Ubuntu used to go fast, recently it started going slow, any helpful tips?

Okay, it used to go fast, just like it should, but yesterday, everything started to slow drastically. It's gotten to the point I can't even watch an entire episode of something on Hulu without the page crashing. Has this happened to anyone before? No, I haven't installed anything new recently, and after it slowed down, I even uninstalled unnecessary items such as Wine and Perl. It's gotten even slower since then, but when I'm off for a while and then get back on, it goes at least a little faster for awhile, but not long enough to do much.  Should I just wait longer between uses, or is this an actual problem I should fix?  Note: Disregard the tag, I couldn't find one that really fit.  It's in Ubuntu 14.04  Probably is, but I'm not 100% sure on the hardware, was bought for my birthday and I wasn't really told the Hardware Specs. (I can try to find the name of the model and look it up, but as of now that's all the information I have). And I haven't tried booting an old kernel, though that might be one of my next courses that I take. The RAM and the rest of it, not that I know of.


PDFs looking different in Yosemite Preview.app

I've just installed Yosemite on my iMac and noticed that my PDF files viewed with the Preview.app don't look the same as in Mavericks. If I view the PDF files directly in Safari, all looks like it should. Against this in the Preview.app it looks kinda trashy.  Is there anyone who can confirm this? And if it's so, how can I make Preview.app show the PDFs like Safari does?


How to run an application on a headless Ubuntu?

I have an Intel NUC running 3.13.11.6; and I have written an application that runs some simple data polling (cpu, memory usage, disk usage etc ...).  The NUC is headless, so I connect via SSH (putty) and can execute the program.  My issue is that I need the program to run for days; and if I close the putty session, the process is killed.  I do not have cron on the system, or some way to remote execute the application (that I am aware of).  *** edit - some recommendations for using screen and tmux were great, however I am learning this is a custom implementation of Ubuntu and these are not available.  Does anyone have any suggestions on the best way to run an application on a headless Ubuntu system and not have the process killed when the ssh session disconnects?  Appreciate any help!  Thank you,  Dan.


The meaning of tensors in the neural network community

In the neural network community, is a tensor pretty much always just a multi-dimensional array?


Google Drive doesn't appear on my Finder

I can see Dropbox but I can't find Google Drive on my Finder. If I want to sync a file to GDrive, I have to open the folder GDrive by click on the symbol of Gdrive. It's very inconvenient.   I'm wondering if there is a way to display GDrive on the Finder, just like where Dropbox is?


I have installed Apache2 MariaDB and PHP7 for use on localhost, but PHP does not work. The Apache webside looks as normal while phpinfo.php only gives me a blank page. I used to install with 'apt-get install lamp-server^', but I wanted MariaDB, so I installed every single package including some PHP extensions and phpmyadmin. I have no idea of how to get php working. Any clues?   ~ # php -v PHP 7.0.13-0ubuntu0.16.04.1 (cli) ( NTS )   phpinfo.php:  <? phpinfo(); ?>


Failure to boot in Ubuntu for only-Ubuntu + Nvidia laptop

Problem  I just received the Nvidia laptop I ordered specifically for coding and deep learning. So I just erased Windows while installing Ubuntu.  The installation procedures follow Ubuntu community listed below.        I initially thought there would be no much pain since I do not need dual boot (as I said, I ordered this machine solely for coding and deep learning). However, I am get stuck in purple screen that looks like    It seems that this issue is releated to Nvidia GPU driver, which governs the display. However, all the workarounds I could find assume users could access GRUB, which is not my case since I erased Windows.  Could some help me? Thank you in advance!  Update  I would like to clarify several things   I burned the USB correctly, and could see GRUB like the following, and finally could boot into USB by setting nouveau.modeset=0   I completed all the steps in the Ubuntu installation and probably installed it correctly. After the Ubuntu installation, I tried to reboot the machine but initially it is all purple, and then the image shown before.


Functional Equation in the rationals: $f(xy)=f(x)f(y)-f(x+y)+1$

Find all the possible functions $f:\mathbb{Q}\to\mathbb{Q}$ such that $$f(1)=2$$ and $$f(xy)=f(x)f(y)-f(x+y)+1\text.$$  I managed to find the function for the set of natural number, by putting $x=1$ and $y=n$. From it, I have that $$f(n+1)=f(n)+1\text,$$ which means that $f(n)$ is an arithmetic progression of natural numbers. I am stuck with generalizing this into the set of rational number, any hit will be appreciated.


Hi i want to transfer few file (which is very big in size ) from A server to B server via  ftp.  I have credentials of Server A's ftp and Server B's ftp - server B is my own server running  unix.  so can anyone suggest me  the way to direct transfer files via ftp from server A to Server B


How to get remainder of 2 double using % operator?

I am trying to get remainder of 2 double using % operator  double x = 965.606698735538; double y = 482.803349367769; var mod = x % y;   Expected value is 0  Actual value is 482.803349367769  Can someone help why its behaving so strange.


Hyphenating compound adjectives with more than two parts

my question is about hyphenating adjectives that have more than two parts. For this example, I can find four different options:   working life oriented working-life oriented working life-oriented working-life-oriented   Which one is correct, according to the finest rules of British English grammar? Thanks!


I'm working on a multiclass classifier with 6 classes on the target column and I was thinking about Hot Encoding the classes, thus having 6 target columns. Will this improve efficiency? I am using sklearn. L.E: improve efficiency compared to just label encode


Dual Booting Windows 10 and Ubuntu 14.04.2 on Lenovo Yoga 2 Pro

as a preface - my only experience with Ubuntu is playing around on VM's, so I apologize in advance for any naivety.  I've just updated my Yoga 2 Pro from Windows 8.1 to 10, and am trying to install Ubuntu 14.04.2 along side. I created a UEFI bootable USB with Ubuntu 14.04.2 using rufus .  I disabled secure boot and fast boot and enabled USB boot in the BIOS menu. I was able to get 'try Ubuntu' running, but when I go to install, I get errors with the grub install.  When I select /dev/sda as the pointer for the boot loader, I get the error:  The 'grub-efi-amd64-signed' package failed to install into /target/. Without the GRUB boot loader, the installed system will not boot.   This is followed by the installation crashing.  Looking online, it seems like others had this issue, but it was resolved when they pointed the boot loader to /dev/sda2 (which is where the Windows Boot Manager is). Unfortunately, I get another error when I do this:  Executing 'grub-install /dev/sda2' failed. This is a fatal error.   If it matters, I elected to not have separate root and home partitions due to a smaller SSD. So I have a partition, sda8, that is a 8gb swap partition and a ~25gb root partition, sda9, formated in Ext4 and mounted at /.  EDIT: I've tried going through  to no avail. I tried to install 15.04 as well (the above link seems to indicate that alone could resolve some UEFI related issues) but got the same errors. Ubuntu seems to be installing (the installer sees a previous install in the correct partition), but crashes at the boot loader.  EDIT 2 - SOLUTION: I'm not sure what solved it, but here is what I did in case anyone else has the same issue. Some how the EFI partition corrupted. I deleted the ubuntu partitions using a live USB, then deleted /EFI/boot/Ubuntu. This lead to a failure to boot windows as well, so I used a windows recovery USB to repair windows boot manager. Then, in windows, I created the partitions for a clean ubuntu install. Finally, I reinstalled with no problem.


Arriving at the Quantum Mechanial Potential From The Energy Eigenvalues

In Quantum Mechanics, we know that given a potential we can solve the eigen value problem to find out the energy eigen values and eigen functions. Now suppose in an experiment we have information only about the energy levels of a system and not the potential. Can we do the reverse and find out the nature of the Potential of the System uniquely?


Why do some commands require su instead of just sudo to do?

I thought that running a command with sudo was identical to logging in as the root user and executing the command.  However I have found a few commands that do not work with sudo but do work for su.  For instance,  sudo > mail.log bash: mail.log: Permission denied   but actually typing su and executing the same command works.  Why is this?


Launch application on a specific monitor

I have Ubuntu 14.04 and two monitors. When I open applications I need some of them to be on the primary monitor and others On the secondary. At the moment, apps always open in the primary monitor.   I have dash icons only on one (left) display, so I can't launch apps using the cursor or active window setting from Compiz.


How to schedule a task to run when shutting down windows

How do you schedule a task in Windows XP to run when you shutdown windows. Such that I want to run a simple command line program I wrote in c# everytime I shut down windows. There doesn't seem to be an option in scheduled tasks to perform this task when my computer shuts down.


Does "Delete Local Content" retain save files?

If you remove a single player game installation with the Delete Local Content option from the Steam Libary, in general will save files be deleted or retained?


Move objects , code etc from sandbox to Dev org

Is there a way we can move Objects, profiles, Apex, LWC etc from a company provided partial sand box to Dev Org? When I googled I am seeing lots of Answers also but what I feel is if there is any option like this any person in a organization can upload the code to their personal Dev org right? So just wondering really we can Move details from a sand box to Dev org?


Can the signs of charge of electron and proton be reversed?

I was thinking that the electron, proton, neutron etc. are human given names to some particles. So, are the signs, positive of proton and negative of electron, given just to show their opposite behaviour? If yes, then can we assume electron to be positive and proton to be negative? And can the direction of electric fields (emerging from positive and converging to negative charge) be reversed if we assume that the sign is reversed? In short,what I want to ask whether the electric fields really emerge from a positive charge and move inwards to a negative charge or are they just assumed to do so to show opposite behaviour of the two charges(and if proton can be taken as negative)?  Also, I'm not talking about change in current but electric field due to reversed sign of charges.


Induction to prove Fibonacci's sequence grows exponentially fast

How to solve this using induction? Use induction to prove that $F_n\ge2^{\frac n2}\;,\;$ for $n\ge6\;.$ $F_0=0\;,\;F_1=1\;,\;F_n=F_{n-1}+F_{n-2}\;.$


HTTPS certificate error for meta redirect pages (meta..stackexchange.com)

Visiting  displays an HTTPS certificate error in Google Chrome and Internet Explorer 10.  For reference, meta.<sitename>.stackexchange.com is the old URL for per-site metas. Child metas were migrated to <sitename>.meta.stackexchange.com during the implementation of . The old URLs were configured to silently redirect users to the correct page.  This issue has technically been reported a few times before, (, , , , ). However, these reports were made before HTTPS support for child metas was officially completed in .


Determine Windows version via application

I wanted to ask, is there any possibility to determine the Windows version via the application, I have made some research, but haven't found,  Thank you in advance ^^


Does the caster of Dispel Magic know if they are successful?

Upon reading the text of Dispel Magic it isn't clear to me whether or not the caster of Dispel Magic knows whether or not they have been successful at dispelling a higher level effect. Or even if there is a higher level effect.   In particular the caster needs to     For each spell of 4th level or higher on the target, make an ability check using your spellcasting ability. The DC equals 10 + the spell''s level. On a successful check, the spell ends.   So because of this ability check, the caster seems like they might know about whether they have succeeded at the spell or not (just like a rogue knows they succeeded at their ability check to pick a lock for example).  So does the caster know if they have successfully dispelled a spell/magical effect (for these or any other reasons)?    This is related to, but distinct from,  because my question is unconcerned about saves or immunity specifically.


Stimulus 2021 double payed for dependent that's no longer dependent

I haven't filed 2020 taxes yet. On my last return (2019) my adult daughter was on my return as a dependent. When I file 2020, I will not put her on my return as a dependent, because she finished college in 2019. I had her file her 2020 return early this year so she would be sure to get a stimulus check in case they did another one (I assumed they would exclude adult dependents as they had with previous stimulus payments). Today, she got the $1,400 deposited to her account by the Treasury. However, I was surprised to see $4,200 deposited to my account, when I expected only $2,800 (for me and my wife). They paid for my daughter twice, $1,400 to her (based on her 2020 return) and $1,400 to me (based on my 2019 return that showed her as a dependent). They have the social security numbers, so I assumed the IRS and Treasury would have figured this out. I have searched and searched, but am unsure whether this overpayment will be clawed back or not. I can't even find a mechanism for returning it (and getting credit for doing that if they later do say I owe it to them). I've read if your 2019 income made you eligible, but your 2020 income (if you file after the stimulus) would have made you ineligible, they won't claw back the stimulus they sent. Stimulus money for people that died between the tax return and the stimulus disbursement does have to be returned to the treasury. I can't find guidance for our situation. There must be a fair number of people with college kids that have the same scenario. This question  seems at first to ask the same thing, but it doesn't include the key point of overpayment by the Treasury.


What is the best-looking way to produce enlarged mathematical symbols in equation mode using lmodern?

I noticed that there is no way to produce a larger version of the summation symbol when writing equations. This  \usepackage{lmodern}  \begin{equation} \sum \end{equation}   cannot be magnified using any commands. In looking for answers, I read that perhaps this is a bug, and the lmodern font does not contain any large versions of mathematical symbols. I am not sure if that is true. I have attempted to use some packages such as exscale to change this, but I have not been able to produce enlarged symbols, even if I remove lmodern. I do not want to make the entire equation larger -- JUST the summation symbol, for example.  I would like to keep the lmodern font, but simply scale up the symbols. Is there a way to do this that looks natural?


Integral with differential is purely imaginary

Prove that if $f(z)$ is analytic and $f'(z)$ is continuous on a closed curve $\gamma$, then $\int_\gamma\overline{f(z)}f'(z)dz$ is purely imaginary.  I'm not so sure where to start. Maybe parametrize $z$ by $z(t)$, so that the integral becomes $\int_a^b\overline{f(z(t))}f'(z(t))z'(t)dt$. Why will this be purely imaginary?


I used the following code to test the performance between Array/ArrayList/LinkedList  import java.util.ArrayList; import java.util.LinkedList;  public class Main3 {     public static void main(String[] args) throws Exception{          int n = 20000000;         long bt = 0, et = 0;          int[] a0 = new int[n];         ArrayList<Integer> a1 = new ArrayList<>(n);         LinkedList<Integer> a2 = new LinkedList<>();         Integer[] a3 = new Integer[n];          bt = System.currentTimeMillis();         for(int i=0; i<n; i++){             a0[i] = i;         }         et = System.currentTimeMillis();         System.out.println("===== loop0 time =======" + (et - bt));          bt = System.currentTimeMillis();         for(int i=0; i<n; i++){             a1.add(i);         }         et = System.currentTimeMillis();         System.out.println("===== loop1 time =======" + (et - bt));          bt = System.currentTimeMillis();         for(int i=0; i<n; i++){             a2.add(i);         }         et = System.currentTimeMillis();         System.out.println("===== loop2 time =======" + (et - bt));           bt = System.currentTimeMillis();         for(int i=0; i<n; i++){             a3[i] = i;         }         et = System.currentTimeMillis();         System.out.println("===== loop3 time =======" + (et - bt));     } }   The result is  ===== loop0 time =======11 ===== loop1 time =======6776 ===== loop2 time =======17305 ===== loop3 time =======56   Why the ArralyList/LinkedList is so slower than array ?  How could I improve the performance.  env: Java: jdk1.8.0_231  Thanks


Does this process happen when a user has a single account in three different sites initially and all three are below 200 and say after a year one of them crosses 200, so does the user get +100 for each of the three sites?


I want to test a new kernel for my ubuntu. I want the most recent stable kernel available. How can I do it securely? That is, no http downloads.


The placeholder text is masked from the right end and the bracket is missing too:    Zoomed in:


Are cantrips gained from Pact of the Tome considered warlock spells?

The warlock's Pact of the Tome option for the Pact Boon feature says:     When you gain this feature, choose three cantrips from any class's spell list. While the book is on your person, you can cast those cantrips at will.   Are these cantrips considered warlock spells for the purposes of determining attack bonuses and save DCs?  I think that might be the intent, but unless I'm missing something, I don't think the rules as written support that. Similar features seem to specify when a spell becomes a class spell, such as a cleric's domain spells:     If you have a domain spell that doesn't appear on the cleric spell list, the spell is nonetheless a cleric spell for you.   Is my interpretation correct that while the warlock can cast those cantrips, they need to use the spellcasting ability of the class whose list the cantrip comes from when casting them?


"Error: Forbidden" when I try to apt-get update

Hit:1 http://deb.debian.org/debian experimental InRelease                                                           Err:2 http://repo.kali.org/kali kali-rolling InRelease                                                                    403  Forbidden [IP: 144.217.77.182 80] Hit:3 http://ftp.debian.org/debian unstable InRelease                                                                   Hit:4 http://ftp.yzu.edu.tw/Linux/kali kali-rolling InRelease            Hit:5 http://ftp.yzu.edu.tw/Linux/kali kali-bleeding-edge InRelease Reading package lists... Done E: Failed to fetch http://repo.kali.org/kali/dists/kali-rolling/InRelease  403  Forbidden [IP: 144.217.77.182 80] E: The repository 'http://repo.kali.org/kali kali-rolling InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.


Python is not showing floating decimals correctly

I have python2.7 installed on ubuntu 16.04. It's showing strange behavior. If I check for (5/4), it will just display 1 as output.  for (6/7) it is showing 0  Can anyone help me to fix this?


Assume $k|n$, show $D_{2n}/\langle r_n^k \rangle \cong D_{2k}$

Definition of Dihedral Group: $D_{2n}=\langle r,s|r^n=s^2=1, sr=r^{-1}s \rangle $  I need to show that $D_{2n}/\langle r_n^k \rangle \cong D_{2k}$, assuming $k|n$.  I have already proven that $\langle r_n^k \rangle \trianglelefteq D_{2n}$ so we know that $D_{2n}/\langle r_n^k \rangle$ is a quotient group. Also I know that $|\langle r_n^k \rangle| = \frac{n}{k}$, so by Lagrange's Thm  $$|D_{2n}/\langle r_n^k \rangle| = \frac{|D_{2n}|}{|\langle r_n^k \rangle|}=  \frac{2n}{\frac{n}{k}}=2k=|D_{2k}|$$  So everything looks good, but I am just not quite understanding how I show that these two groups are isomorphic. I feel there is one step missing, or I need to use one of the isomorphism Theorems maybe?


Did the Council of Elrond know that destroying the Ring would destroy Sauron?

Did they decide to destroy it simply because they were Wise and knew it was dangerous to wield? Did they create the Fellowship simply because they were heroic; and decided to face Sauron after the Ring was destroyed?  Or did they know that destroying the ring would defeat Sauron, and they wouldn't actually have to do anything once that is taken care of?


I want to put Ubuntu on my middle-aged laptop

Ive never put an OS on anything before. My brother in law wiped my entire OS off laptop, when he was certain he was just doing a factory reset! It HAD windows 10. Now, it has a black screen and a blinking cursor... please help


could someone help me with calling the first constructor and putting it in the second and third? I may have some problems with the syntax, it seems...


I was reading a tutorial on debouncing the outputs of a rotary-encoder which are read by a micro-controller. Below is the circuit given:    The writer of the tutorial claims the following:  "In the above circuit we use a 1uF capacitor with an SN7414 Schmitt-trigger input NAND gates that clean up the switch-contact noise."  I have couple of questions regarding this claim and the circuit.  1-) I can understand the reason for the use of capacitors, they act as RC low pass filters and can filter bounces. But how does the SN7414 Schmitt-trigger help debouncing here? Is that really needed or does it improve debouncing?  2-) In the above circuit the resistor and the capacitor forms a low-pass filter with a cut-off freq. fc. What is the motivation/idea when it comes to sizing the capacitor here. Why 1uF? I mean let's say we have a rotary-encoder and it is recommended to be used with 10k resistors. Which parameter of the encoder from its data-sheet should be taken into account when sizing the capacitor. Is there a method or reasoning between choosing the capacitance and a parameter in the data-sheet?


Rational number arbitrarily close to a square root of 2

I am trying to prove the proposition by contradiction     For all rational $c > 0$, there exists a rational number $x$ such that $x^2 < 2 < (x + c)^2$.   with the negation $x^2 \ge 2 \lor 2 \ge (x+c)^2$. But I can not prove it.


File systems vs partitions vs directories

I am new to Linux so pardon me for the possible confusion you may encounter in this question. From what I understand, filesystem specifies how a partition stores/manages file, with standards such as ext2, ext3, reiserfs, xfs, etc. Occasionally I see people seem to refer to each "directory" as     /boot filesystem     /usr/bin filesystem     /root filesystem     /bin filesystem  Why would we refer to these as filesystems? If each of them is a partition, that confuses me because as far as I know, /usr and /usr/bin tend to be in the same partition, but I saw people refers to both "/usr filesystem" and "/usr/bin filesystem". If filesystem here is equivalent to Window's directory, it's not clear to me as apparently filesystem is something more than just directories. Also, as far as I know, Linux does not have "directory" concept; all are files.


Prove that the sum $$\sum_{k=1}^{n-1} (n-k)\cdot\cos\left(\frac{2k\pi}{n}\right) $$ Is an integer for any $n\geq 3$.  I found this in my textbook but am unable to evaluate this sum. Any help would be appreciated.


Let $A$ be a ring, and let $a \in A$. Can the prime ideals of $A_a$ be identified with those prime ideals of $A$ which do not contain $a$?


I need to integrate this function:  $$\int \frac {x^3}{\sqrt{4-x^2}} \;dx$$  I don't know how i should integrate,  should i divide because the numerator has an higher grade? There is any strategy i should know for choosing the best way?


Show a subset is subspace of a vectorspace and find the dimension

Let $n>1$ be a natural number and let $\alpha\in\mathbb{R}$ be a real scalar.  Let $V$ be a subset of the vector space $P_n(\mathbb{R})$. Define $V$ as  $$V=\{p\in P_n(\mathbb{R}):p(\alpha)=0\}$$  Task: show that V is a sub space of $P_n(\mathbb{R})$ and find the dimension of V.  I believe I have the correct definitions but I'm not sure if I've done this correctly.    I know V is a subspace if the following holds  1) Vector 0 is in the subset.  2) V is closed under addition.  3) V is closed under scalar multiplication.  For (1): I have a hard time showing but from the definition of V it only contains the zero vector. Meaning it satisfies (1).  For (2): Any real scalar multiplied with the zero vector gives the zero vector, which is in $V$. Therefore it satisfies (2).  For (3): If you add two zero vectors you will always get a the zero vector. Therefore it satisfies (3).  I'm uncertain how to find the dimension but I know how to define it using the dimension formula for V.   $L:P_n(\mathbb{R}) \mapsto (\mathbb{R})$ defined by $L(p)=p(\alpha)$.  We can use the formula: $Dim(V)=Dim(Ker(L))+Dim(L(v))$


I am new here and the following code is what I am testing. Is it possible to change the typeface of the words from a .txt file? Thank you for any kind help!  \documentclass[a4paper]{article} \usepackage{titling} \newcommand{\subtitle}[1]{%   \posttitle{%     \par\end{center}     \vskip5em     \begin{center}\LARGE#1\end{center}     \vskip5em}% }  \usepackage{palatino} \usepackage[utf8x]{inputenc} \usepackage[top=1in,bottom=1in,left=1in,right=1in]{geometry} \usepackage{indentfirst} \usepackage{lipsum} \usepackage{verbatim} \usepackage{graphicx} \usepackage{booktabs,multirow}  \usepackage{amsmath,amssymb} \usepackage{xcolor} \usepackage{cite}  \begin{document}  \section{Test section} \subsection{Test section} \subsubsection{Test section} \paragraph{Test section} \setlength{\parindent}{0pt}This document is for testing. \Large \verbatiminput{verb.txt}  \end{document}


Old kids show from the 80's about two kids with a magical compass that took them to another world

I remember watching this one show when I was a kid in the 80's/early 90's in Canada. It was a live-action show about these two kids and had some puppet/muppet-like characters, but it kind of had a dark/mysterious element to it. I can't remember too much about it except portions of some episodes, but the main characters were kids, and they had some mysterious artifact (kind of like a compass?) that took them to this other world where there were giants and other mysterious beings that we rarely saw. The two kids weren't the only one's going to this place either, they find out kids from all around the world that also had this same artifact (and they all fit together like a round puzzle?). I seem to recall that the giants in this other world were the ones who made the artifacts, and were dying/or in desperate need of the help of the kids.  A couple episodes I remember:   There was one where the leaves were falling, and the world was doomed to end as soon as the last leaf touched the ground, so they're trying to figure out how to prevent all the leaves from falling, but after a long and suspenseful episode (for a kid) the last leaf dramatically falls, but out of no where the main girl catches the leaf and saves the world (it was very exciting for my young self, and I remember being very impressed with the pretty girl for thinking to catch the leaf).     There was another episode where the kids meet these two old guys with long white hair (muppets) sullenly working in a mine/tunnel, they're in tattered old clothes working away with their pick axes or hammers and they are connected to each other at the beard. This long old white beard grows out of one of their faces right into the other's. The kids save the day by cutting the old guy's beard in the middle, freeing them from each other. They celebrate being free from their bonds and excitedly thank the kids, but after the kids leave they continue to work away, this time in much brighter spirits. Seemingly unbeknownst to them though, as they work, their beards slowly and subtly grow back together.   Anyone else remember this show?


I want to remove brackets [] and quotes around each value and add quotes at start and end. X= ['8922','9292','3220'] I want output as below. Y = '8922,9292,3220' How can I do this. Please suggest.


What is the difference between AOSP and AOKP? Are they related to Stock ROM?


How would one show that the  $\sum_{k=1}^{n} c^k = \frac{c(c^n-1)}{c-1}$ is true?


What is the significance of the output of cat /etc/group?

When I run cat /etc/group on Ubuntu 18.04, I get this output:    root:x:0: daemon:x:1: bin:x:2: sys:x:3: adm:x:4:syslog,singrium tty:x:5: disk:x:6: lp:x:7: mail:x:8: news:x:9: uucp:x:10: man:x:12: proxy:x:13: kmem:x:15: dialout:x:20: fax:x:21: voice:x:22: cdrom:x:24:singrium floppy:x:25: tape:x:26: sudo:x:27:singrium audio:x:29:pulse dip:x:30:singrium www-data:x:33: backup:x:34: operator:x:37: list:x:38: irc:x:39: src:x:40: gnats:x:41: shadow:x:42: utmp:x:43: video:x:44: sasl:x:45: plugdev:x:46:singrium staff:x:50: games:x:60: users:x:100: nogroup:x:65534: systemd-journal:x:101: systemd-network:x:102: systemd-resolve:x:103: input:x:104: crontab:x:105: syslog:x:106: messagebus:x:107: netdev:x:108: mlocate:x:109: ssl-cert:x:110: uuidd:x:111: avahi-autoipd:x:112: bluetooth:x:113: rtkit:x:114: ssh:x:115: lpadmin:x:116:singrium whoopsie:x:117: scanner:x:118:saned saned:x:119: pulse:x:120: pulse-access:x:121: avahi:x:122: colord:x:123: geoclue:x:124: gdm:x:125: hani:x:1000: sambashare:x:126:singrium nvidia-persistenced:x:127: rdma:x:128: docker:x:999:   I know that 'root', 'daemon', etc. .. are groups or user names, but what does the rest of that mean (:x:0:, :x:125:, :x:126:, ...)?


Creating new users using PHP not recognized by Apache 2.4

I have a server setup where new linux users are created using (PHP)  shell_exec ( '/usr/sbin/useradd ' . $username ); exec ('usermod -a -G ' . $username . ' '. $username); #add user into the usergroup exec ('usermod -a -G ' . $username . ' www-data'); #add usergroup with the www-data   And then the user script changes the owner and group of the files to this owner. The server is setup with suPHP which then allows these files to be run as the owner.  This setup worked fine with Apache 2.2 but is breaking in Apache 2.4. Everything works fine except when I try to oepn the files, it gives a 403 forbidden error. Restarting apache after the user is added fixes the issue but that is not a viable solution for me. The users are added using a web server and hence I need to be able to do this without having to reload/restart apache everytime.  I have searched for serveral hours and tried to fix the issue but haven't been able to do so! I am running ubuntu 14.04 and I am not able to downgrade to apache 2.2 as well.


I have a WordPress site which is 90% based on images.  I've installed Wp-Super-Cache, now it seems to load a little bit faster.   I've made a speed test on Pingdom Tools:   Page size 4.7MB Load time 5.09s Requests 153 Perf. grade 74/100   And also the Time Spent per Content Type:   Image    88.23%     So the problem is obviously the images.   My plan is to try as much as I can to optimize the images in terms of size, and then to add CDN support.  Is this enough in terms of improving the loading of images?


FFmpeg concatenate audio and offset parts between each other

I figured out how I can concatenate multiple audio files with complex filter, but struggling with offsetting audio in result file. Say, I want to add a gap of 1 seconds silence between each concatenate file. Is it possible to do with FFmpeg?


Strict warning: Only variables should be passed by reference

I am getting this error on this line in my code. I'm guessing I need to break this line down a bit. Any comments would be great.  $promobox_id = reset(array_keys($result['fieldable_panels_pane']));


Name for a conversation where two people are talking about two things, without their knowledge

The show Arrested Development uses a writing technique I haven't seen very often, but I find very interesting. The idea is that two people will have a conversation where they are both talking from two completely different contexts, the conversation works in either context, and they both end without ever realizing they didn't understand each other. Example: in this clip George Michael is shy about the fact that he has a crush on his teacher. His aunt thinks he doesn't want to admit that he sees his teacher as a mother-figure and confidant.


I have  \documentclass{article} \usepackage{pdfpages}  \begin{document}    Lorem. Read the answer for this from the document \ref{3rd_part} ....  \appendix \includepdf[pages={-}]{3rd_part.pdf} \label{3rd_part} % NOT working, problem here! \end{document}   This labelling does not work.  There is no need for   no figure environment no table environment no caption,   since the document is only a WYSIWYG made document.  How can you label an included pdfdocument and refer to it?


Morphisms from $\mathbb{P}^2$ to $\mathbb{P}^1$

Let $K$ be algebraically closed field. Can we show there are no non-constant morphisms from $\mathbb{P}^2 \to \mathbb{P}^1$? What is the most elementary way to show this (assuming its true)?


Let $n$ be an odd positive integer. Show that $24 \vert(n^3-n).$  So since $n^3-n=(n-1)n(n+1)$, we have that $3\vert(n^3-n).$ Also since we have that $n$ is odd we can say that $n=2k+1$, for some $k \in \mathbb{Z^+}.$ This implies that $(n+1) = 2k +2 = 2(k+1)$, hence $2\vert(n+1).$ Similar argument can be made for $(n-1)$. Now $24 = 2 \cdot 3 \cdot 4$ so essentially I'm only missing the part where I would have to show that $4$ divides some of the terms. How can I find that?


git: error: you need to resolve your current index first

I was trying to merge a branch with my branch, but had merge conflicts.  After seeing the conflicts, I've decided to revert my branch, but am unsure how to do so, as my usual approach of running the following doesnt seem to work to reset my branch  git fetch origin git reset --hard origin/BRANCH   How can I do this?


How to copy text to clipboard using javascript from variable?

I have a string:  var mystr = "Hello".  I want to fire an event when clicking on the button that puts the text in the mystr into the clipboard as if they highlighted some text and hit Ctrl+C.  Note that I do not want to involve a text input box.


Is there a program to mine bitcoins in ubuntu 13.10?

I do not understand much about mine bitcoins, but I downloaded a program that is like a wallet, but I want to know how I do to mine. Has a calling GUIminder but is for windows, someone knows one that is for ubuntu?


Let $G$  be a semigroup and for each $x \in G$ there exists a unique element $y \in G$ such that $xyx = x$. Prove that $G$ is a group.  Since G is a semigroup the properties of a closure and associativity hold, so all we need to prove is the existence of a unique identity and inverse for each element. For identity, since $xyx = x$ can we say that $yx = e$ and $xy = e$ and since $x \in G$  and $y \in G$ therefore $yx \in G$ and $xy \in G$ and hence $e \in G$. This proves that identity exists.  Again, for inverse, $yx = e$ and $xy = e$ proves that $y = x^{-1}$.  Therefore $G$ is a group. Can someone please tell me if my approach is correct.  Thanks in advance!


Please stop adding chat notifications when I'm actually just using mobile

Regardless of the actual functionality of , one thing that really bugs me is that if I do chat on mobile, somehow the supernoticollider thinks that I need to have every single message I have received while using mobile chat as a notification, as if I'd been away.  Please stop doing this.  Okay so apparently I should click the 'mention' button. This is terrible.


I couldn't upadate and upgrade software.it showing some errors

aditya@aditya-pc:~$ sudo apt-get update Reading package lists... Done E: Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) E: Unable to lock directory /var/lib/apt/lists/ W: Target Packages (partner/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4 W: Target Packages (partner/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4 W: Target Packages (partner/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4 W: Target Translations (partner/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4 W: Target Translations (partner/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4 W: Target Translations (partner/i18n/Translation-en_GB) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4 W: Target DEP-11 (partner/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4 W: Target DEP-11-icons (partner/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4


Do I need a Schengen Visa to transit in both Amsterdam and Paris on the way flighting from Canada to Vietnam?

I am Vietnamese. I am studying in Canada. In this December I will fly from Canada to Vietnam. In my fight schedule, I must transit in Amsterdam for 1.5 hours and then in Paris for 3 hours. I wonder if I need a Schengen Visa to flight from Amsterdam to Paris in my schedule?


I have a very slow internet connection (200kbps), and don't want to wait for it to install all packages from the web. Is it possible to upgrade to 14.04 from 12.04 using the Live DVD?


Why did Voldemort choose to kill half-bloods first over Muggles?

If half-bloods were filthy scum, according to Voldemort, I don't have words to describe Muggles. Why didn't Voldemort choose to eliminate Muggles first which would have been very easy? Also, destruction of entire Muggle gene pool would have removed the possibility of birth of half-bloods.


How to install Kubuntu on other hard disk

I would like to install Kubuntu 12.10 on my computer. I have 2 hard drives, 500 GB each. I have Windows 7 Home Premium installed on one disk, and I want to install Kubuntu 12.10 on the other. How do I do this?


Do pullbacks commute with filtered limits in this sense?

Let $A_n, B_n, C_n$ be directed systems in some abelian category. Denote by $A \times_C B$ the fibre product of $A$ and $B$ over $C$.  Is it true that $(\varprojlim A_n) \times_{\varprojlim C_n} (\varprojlim B_n) = \varprojlim (A_n \times_{C_n} B_n)$, if $\varprojlim (A_n \rightarrow C_n)= (A \rightarrow C)$ and similarly for $B$?  I know that "morally" limits preserve limits, but I don't know the exact statement I need here (i.e. limits in which categories?)  Edit: Analogously, what can we say after replacing filtered limits with filtered colimits? Edit2: I think in the case of filtered colimits, I just checked the universal property of a colimit. In case I didn't make a mistake, the statement holds. The other case (filtered limits), and arbitrary colimits/limits are not as important for my purposes, but if you have a nice statement, please feel free to post it.


I build a microserver to access my personal data and web services from my client machines. Since this is all the stuff I collected in the past 15-20 years, I'd like to keep it safe, so I'd like to use RAID this time. I have already checked that only 3.5" HDD-s have rational prices, so using 2.5" hdd or ssd is not an option. The motherboard supports RAID 0/1/5/10. I am currently selecting a case, but I am not sure whether it should have 3 or 4 drive bays for 3.5" hdd-s. The case I really like (Tt Core V21) has only 3 x 3.5" drive bays. The other case which is not that good if we are talking about cooling and air flow (BitFenix Phenom Micro-ATX) has 4 x 3.5" drive bays. What are the pros and cons using 3 or 4 disks if we are talking about RAID? (I guess it is something general, but if not, then I'd like to know it by each RAID version.)  Conclusions:   I think 3 drives with RAID-5 is sufficient for my needs. I need a self-healing filesystem like ZFS or BTRFS (I chose the latter one), which can fix data degradation using RAID parity data. These filesytems can make incremental snapshots too, so they are great if you want a fast backup without halting the system. Using an event storage can do the same on application level, so that part does not really matter in my case. People here never heard that backup does not protect against , but a self-healing filesystem with RAID most of the time does. Probably they are too focused on their RAID is not a backup mantra to learn new things...


How do I find the key that looks like ^ with _ on top of it?

The keyboard shortcut for sending an email in Thunderbird looks like this:    I know that the first symbol is the Command key, but I can't figure out the second symbol.  I have looked at the  about menu symbols, but it doesn't have this symbol!


How to get rid of blank pages in PDF exported from SSRS

I have a two-page SSRS report. When I exported it to PDF it was taking 4 pages due to its width, where the 2nd and 4th pages were displaying one of my fields from the table. I tried to set the layout size in report properties as width=18in and height =8.5in.  It gave me the whole table in a single page of PDF, but I am still getting the 2nd and 4th pages blank.   Is the way I am doing it incorrect?  How else can I get rid of those blank pages?


Minecraft program frame rate is very slow

I have recently downloaded Minecraft to Ubuntu 12.04. It launches and plays successfully, however- the frame rates for the game are extremely slow. They never go past 9 fps and usually drop below 3 fps.   I have been a Windows XP user for years and have just recently switched to Ubuntu, so I'm not an expert with this OS. My video card is a Diamond Stealth s60 with Radeon 7000.  I don't know what other information you guys need but if you ask for it, and would please tell me how to get to it, I will tell you as soon as I can. Thanks for your help.


What is the best format to deliever an illustrator logo design to a client?

Which file format is best to export from illustrator for prints & enlargements and web?


Vertical connector between left (west) aligned boxes

If I have two connected nodes of different widths, which are aligned on the left (west) side, the connector between them is diagonal (or -| which I don't want for this application).  Here's what it looks like:  \begin{tikzpicture}[>=latex, thick]     \tikzstyle{all nodes}=[shape=rectangle]     \tikzstyle{box}=[draw]     % % Nodes     \node[box, label=above:{Short box}](init)     {This box is short};     \node[box, below=of init.west,            align=left, anchor=west, label=below:Long box]     (country)     {         this box is really really really long. Much longer.     };      % % Connectors     \draw [->] (init) -- (country); \end{tikzpicture}     I'd really like that diagonal arrow to lead from the bottom centre of Short box to wherever is required on the top of Long box to make the arrow vertical.  Is that possible?


How can I capture images from two cameras simultaneously, directly to my Mac?

I am looking to use this feature for two purposes: scanning books (one camera pointed at each of a pair of pages), and for stereo 3D photography.  I would like to be able to preview and capture photos from two cameras simultaneously, and download them to my Mac (recent laptop, Mac OS X 10.8.x). Being able to keep track of which photos were from which camera is also a must.  I see a couple of packages that will do this via USB tethering on Windows, namely  (which other than being on Windows, looks perfect for my needs) and . I certainly could run Windows on my Mac somehow, but I'd rather avoid that, if possible.  I haven't bought the cameras yet, and I do not have any requirements as to which cameras are supported (it seems the packages above only support Canons), other than that they be relatively inexpensive. This is a hobby-type project, not a $3000 dSLR-type project.  However, even if all you have is a dSLR solution for this problem, I'd still like to hear about it. Perhaps it will lead to related solution.  Inventive hacky solutions welcome!


I have applied all transformations but still not working


Is it feasible to compile Python to machine code?

How feasible would it be to compile Python (possibly via an intermediate C representation) into machine code?  Presumably it would need to link to a Python runtime library, and any parts of the Python standard library which were Python themselves would need to be compiled (and linked in) too.  Also, you would need to bundle the Python interpreter if you wanted to do dynamic evaluation of expressions, but perhaps a subset of Python that didn't allow this would still be useful.  Would it provide any speed and/or memory usage advantages?  Presumably the startup time of the Python interpreter would be eliminated (although shared libraries would still need loading at startup).


iMac with 8GB RAM -- memory always almost full

I have a 27'' iMac (Late 2012, OS X 10.9.2) with 8GB RAM. The usage of memory is always above 7GB, even though I don't think I am running that much stuff. This leads to the occasional hanging of a program and occasional feeling of the computer being lagged.  The heaviest thing I am running is a Parallels virtualization of a defunct Windows laptop (for my Windows-only programs; work-related). Then I mostly surf with Chrome (10-20 tabs, some with youtube videos). Of course I have other things opened, like Mail, Evernote and a few more. But I don't think a 8GB RAM computer should be overwhelmed by that. I could be wrong.  I am willing to provide an export of processes from the Activity Monitor. I tried looking into it, of course, and I am running A LOT of small processes (unknown to me) -- system stuff I presume. I am a long-time PC user and I know my way around process management in PCs, but not on Mac.  What do you think? Do I just need more RAM or it doesn't feel like it?  Regards,