Star Trek: First Contact was released while the television series Star Trek: Deep Space Nine was still running. When does the film take place in conjunction with the series. I know that it should take place in the fifth season, but is it during any specific episode? Are the events ever mentioned in the series, since Worf was in both?

In Memory Alpha, the page on the  states that two Defiant-class ships had that name: the prototype Defiant, and a successor, the U.S.S. Sao Paulo, which was assigned to DS9 and renamed Defiant after the loss of the original. All of this happened during the DS9 series.  In the Star Trek: First Contact movie, the Defiant participates in the opening battle, where a Borg Cube penetrates the Sol system's defenses and besieges Earth. Worf is in command, and is transported out of the crippled Defiant along with whatever's left of his crew by the Enterprise; out-of-universe, this is a rather transparent method to get Worf back into the TNG side of things after the events of ST: Generations, when he moved to DS9 as tactical officer and unofficial envoy to the Klingon Empire.  The question is, was Worf's Defiant in the movie the original, or the Sao Paulo? This would primarily depend on where the movie falls in the overall canon timeline. According to in-movie dialog, whichever one it was was salvageable and therefore would have survived the movie, so the movie would have had little impact on the canon of any running TV series at the time.


I am having an issue with rendering fire on a transparent background. I've gone into the world and changed the alpha from the sky to transparency. I've checked the transparent box under the render properties, under the film section. However, when I do this only my emitter renders, not my fire simulation. Unchecking the box under the film section causes renders to return to normal. Any help would be appreciated. Wondering if something is setup incorrectly with my nodes? Or If I am missing some setting.  Thanks!

When rendering volumes with Film > Transparent enabled, the alpha appears to be the wrong type (premultiplied/straight). In the 3D view it works as expected:    This is a known .  Is there any way to work around this?


working on a problem to evaluate  $\int_0^\infty \frac {e^{-x} -  e^{-ax}} {x} dx$   the instructions say to first evaluate  $\int_1^a e^{-xy} dy$   which comes out to the integrand of the original improper integral.  using this it seems we can rewrite the improper integral as the double integral as follows  $\int{_0^\infty}\int{_1^a} e^{-xy}dydx$   However where I am stuck is changing the order of integration on this double integral in order to evaluate it.

Today I had an exam and I mixed up the integration by parts formula.  The question was to integrate $$ \int\nolimits_0^\infty \frac{e^{-at} - e^{-bt}}{t} \text{d}t $$  I will try solve this again with the right formula when I arrive home. I would appreciate if somebody could tell me the solution so I can double check and maybe give a hint to another way of solving this instead of integration by parts (if possible).


Not sure where else to ask. There is no help or support forum? Anyways, is it possible to upload an audio file, or how can I create a link to my machine, or is there a website to upload it to and then link it?

Should Stack Exchange introduce the ability to upload embedded sounds (maybe via HTML5/Flash, whichever the user has) as part of questions and answers to Stack Exchange?  It could require a certain amount of rep to stop new users from doing it frivolously.  My rationale behind this is the new language & usage sites.  I often find myself thinking that it might be helpful, when discussing a regional dialect or something, for the person answering to just pronounce what they're trying to describe in words.


This is hard to describe by words but the following code and the picture is worth more than a thousand words I can use to describe my question. Thanks in advance \documentclass[12pt, xcolor=dvipsnames]{beamer} \beamertemplatenavigationsymbolsempty  %no navigation pane \usetheme{CambridgeUS} \usecolortheme{seahorse} %\setbeamertemplate{page number in head/foot}{\makebox[-1em][r]{}}  \title[A Large Topic Name for the Presentation]{A Large Topic Name for the Presentation That Cannot Be Shortened} \author[John Doe]{John Doe} %\subtitle{} %\setbeamercovered{transparent}  %\setbeamertemplate{navigation symbols}{}  %\log_2o \institute[]{\includegraphics[height=1.5cm]{image-placeholder.jpg}} \date[{\includegraphics[height=2mm]{image-placeholder.jpg}}]{Some Day in 2021}  %\subject{}   \begin{document}  \begin{frame}[noframenumbering, plain] \titlepage \end{frame}    \section{some section} \subsection{some subsection} \begin{frame}{\centerline{A Slide}}  \vspace{12em}  I need the middle section of the bottom line to be larger sacrificing equally from the "name" and the "frame number" stips.  $$\downarrow $$  \end{frame}  \end{document}

I work in Beamer extensively (specifically the Madrid theme). Sometimes, my "title" is quite long. Beamer puts this title at the bottom, but when it's too long it cuts it off. I'd really like to know how to increase the size of the bottom middle rectangular footer.    Here's the code (sorry for all of the packages and commands):  \documentclass[t]{beamer} %Add "mathserif" to script math lettering. "t" places all text to start at the top of each slide \usetheme{Madrid}  %Packages  \usepackage{amsmath} %Math mode \usepackage{amssymb} %Math mode \usepackage{commath} \usepackage{graphicx} %Including pictures \usepackage{color} %Define colours \usepackage{setspace} %Enables double-spacing/variable spacing \usepackage{pgfplots} %Draw graphs \usepackage{upgreek} %Insert theta symbol as unitalicized  \usepackage[version=3]{mhchem} %Chemistry equation mode \ce{} \usepackage[export]{adjustbox} %Place black borders around images \usepackage{scrextend} %Used to change font size \usepackage{caption} %Used to utilize * in caption function \usepackage{subfig} %Used to place figures side-by-side with sub-captions \usepackage{siunitx} %SI Units (+ scientific notation) \usepackage{cancel} \usepackage{fancybox} %\usepackage{enumitem} %Making lists %\usepackage[english]{babel} %Lists with letters  %Erases Beamer Navigation Symbols on the bottom left \setbeamertemplate{navigation symbols}{}  %\setbeamertemplate{footline}{} \captionsetup[subfigure]{labelformat=empty}  %Defined Colours \definecolor{orangered}{RGB}{255,69,0} \definecolor{darkgreen}{RGB}{0,100,0}  \definecolor{firebrick}{RGB}{178, 34, 34} \definecolor{navy}{RGB}{0,0,128} \definecolor{lightsteelblue}{RGB}{176,196,222} \definecolor{steelblue}{RGB}{70,130,180} \definecolor{darkslateblue}{RGB}{72, 61, 139} \definecolor{forestgreen}{RGB}{34, 139, 34} \definecolor{Gold}{RGB}{218,165,32}  %Defined Colour Theme and List Sizing \setbeamercolor{structure}{fg = Gold} \setbeamertemplate{navigation symbols}{}  \setbeamerfont*{itemize/enumerate body}{size=\normalsize} \setbeamerfont*{itemize/enumerate subbody}{parent=itemize/enumerate body} \setbeamerfont*{itemize/enumerate subsubbody}{parent=itemize/enumerate body}  %Opening Title Page \title{Chapter 7 - Absolute Value and Reciprocal Functions} \subtitle{Section 7.3 - Absolute Value Equations} \date{}  \begin{document}     %Slide 1     \maketitle \end{document}


I saw  (link at bottom), with a supposed "proof" that $3=0$. It goes as follows:  Let $x$ be a solution of $$x^2+x+1=0 \tag1$$  Since $x\neq0$, we can divide both sides by $x$: $$\frac{x^2+x+1}{x}=\frac0x\implies x+1+\frac1x=0 \tag2$$  From $(1)$, $$x^2+x+1=0\implies x+1=-x^2$$  Substitute $x+1=-x^2$ into $(2)$ $$\begin{align*} -x^2+\frac1x&=0 \tag3\\ \frac1x&=x^2\\ 1&=x^3\implies x=1 \tag4 \end{align*}$$ Substitute $x=1$ into $(1)$ $$\begin{align*} 1^2+1+1&=0\\ 3&=0 \end{align*}$$  The explanation given in the video is  Substituting $x+1=-x^2$ into $(2)$ creates the extraneous solution $x=1$ which is not a solution to the original equation $(1)$, $x^2+x+1=0$.  Equations $(1)$ and $(2)$ have solutions $\frac{-1\pm i\sqrt3}{2}$, but after the substitution, equation $(3)$ has these two solutions and $1$.  Basically, it is saying that the issue is substituting $x+1=-x^2$, but I'm not sure if this is actually the problem. How can a substitution cause an issue if everything before the substitution is correct? After reading the comments, I realised many of them say that the real issue is $(4)$, because $1=x^3$ could also mean that $x=\frac{-1\pm i\sqrt3}{2}$. Not considering these solutions is the issue with the "proof". One also needs to check these solutions before making conclusions, and "pick" whichever one is correct. So, my question is, what is the issue with the above "proof" that $3=0$?  Video: "Prove" 3 = 0. Can You Spot The Mistake? .

I came across this example of how you could end up with an extraneous solution but I was wondering how it arose. We have the equation: $$x^2+x+1=0 $$ Since x=0 does not satisfy the equation, you can divide by x on both sides which yields: $$x+1+\frac{1}{x}=0$$ which is equivalent to our first equation. From our first eqution we can conclude that: $$-x^2=x+1$$ We now substitute that into the second equation to get:$$x^2=\frac{1}{x}$$ which results in $$x^3=1$$ which is equivalent to our previous equation since x cannot be 0. However, one solution from our last equation is x=1, which is not a solution to our original equation. I have a vague idea that it may have to do with the fact that you get a cubic equation and you began with a quadratic, and that steps imply the following and not vice versa, but can you provide a very detailed answer as to why it arises? Can you please provide more examples?


I am currently writing my master's thesis with LaTeX and most things really go super good and a lot better than in Word, but I can't seem to get this one working. What I want:  60 yE/m2s (I hope you know what I mean...)   This is what I tried so far:   \SI{60}{\micro\einstein\per\meter\squared\second}   I installed the package correctly as it's working fine with other units like:  \SI{20}{\degreeCelsius}

I'm having a hard time figuring out the LaTeX commands to define new units of year and century in siunitx.  I'd like to write \SI{3}{\cm\per\year} and have it show: 3 cm yr-1, or \SI{42}{\micro\meter\per\century} become 4.2E-5 m/century


I've some problems concerning Point Distance in ArcGIS 10.5.   Whenever I try it to open, this tool appeared "require licensed tools".

I am using ArcView (ArcGIS Desktop Basic) 10.1 and I need to perform a point distance analysis.   What are the steps to determine the distance from A to B-Z, B to A-Z, C to A-Z, etc?


im getting  uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. error when adding array to linkedlist  Here is my work  LinkedList main_list = new LinkedList(); int arr = new int[2] arr[0] = 0; arr[1] = 1;  main_list.add(arr);

For example:  javac Foo.java Note: Foo.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details.


It seems like electronic transfers can take 2 - 3 days to complete. For example, when I ask my online broker to transfer money from my checking account, the money won't actually be available to trade with until the third business day.  Why is this? Don't banks just use some kind of EDI? Is there some kind of tangible benefit to them of having the additional time (other than the banks hanging on to the money a little longer)?

Based on , I figured that there might be multiple questions for distinct locales. Why do the most common transactions to or from bank accounts in the US require waiting one or more days before they are completed? In the information age, it seems like we should be able to transfer money instantly (or nearly so).


I was trying out some stuff in CSS on Codepen (jst to get more familiar with CSS), and ran into a problem where I could not vertically center the divs. This confused me, as I was able to move all of the child divs into the center.Thanks for any help!      .bg{   display: block;   margin-left: auto;   margin-right: auto;   background-color: black;   width: 800px;   height: 800px;   left: 50%; } .red {   display: block;   margin-left: auto;   margin-right: auto;   border-radius: 20px;   width: 100px;   height: 75px;   background-image: linear-gradient(to right, #f78ca0 0%, #f9748f 19%, #fd868c 60%, #fe9a8b 100%); }  .blue{   position: relative;   display: block;   margin-left: auto;   margin-right: auto;   width: 100px;   height: 50px;   background-image: linear-gradient(to top, #fbc2eb 0%, #a6c1ee 100%);;   top: 50px; }  .green{   position: relative;   display: block;   margin-left: auto;   margin-right: auto;   width: 100px;   height: 50px;   background-image: linear-gradient(to top, #0ba360 0%, #3cba92 100%);   top: 50px;  }  .stick{   position: relative;   display: block;   margin-left: auto;   margin-right: auto;   width: 30px;   height: 80px;   background-image: linear-gradient(60deg, #29323c 0%, #485563 100%);   top: 50px; }

I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
Div to be aligned vertically
   How can I center a div vertically in all major browsers, including Internet Explorer 6?


I'm used to hearing expressions like 'I got no money' or 'I got a lot of work to do', in which 'got' is used with the same meaning as 'have'. My British friends, however, always put strange faces when I say them. Is it correct to use 'got' instead of 'have' in these sentences? (I guess it's not proper English, but anyway, do people use it in casual speech?)

I have looked through several questions and answers on EL&U, and often there is an indication that American English prefers "have" while British English prefers "have got". In addition, there are several references to "have got" being more informal than "have" (e.g.: , ). But where is it considered more informal? In American English alone or both American and British English?   This point may seem obvious to those who made the above mentioned references, but the fact is that even the most fluent users of English in my country will say without a doubt that 'have got' is the preferred usage in the UK and, therefore, it must also be more formal. Why? Because in an academic environment, the more informal structures are generally frowned upon, outside some specific spoken exercises. And if the teachers insist on using "have got", it follows it isn't informal.  So, is the teaching of (British) English in our schools transmitting the wrong idea?  EDIT: I'm adding some information in answer to the comments.  I'm mainly concerned with the idea of possession:      I have got a cat vs. I have a cat and She has got a dog vs. She has a dog   As mentioned in the comments, every (Portuguese) student will be told that "have" and "have got", when it comes to the idea of possession, are absolute synonyms, the only two differences being:    "have got" is preferred by British English, "have" is preferred by American English   the negative and interrogative structures differ    I have never heard of any distinction in formality. In fact, I was rather surprised when I went through the EL&U archives and read about it.  So, would "I have got a cat" be as formal/informal as "I have a cat"?   And how do British and American English look at its formality/informality? Is it the same?


// The below is the main class i'm using.  import javax.swing.JFrame;  public class Workspace {      public static void main(String[] args){      dummyClass var1 = new dummyClass();      var1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     var1.setSize(100,100);     var1.setVisible(true);     } }   // The below is the subclass i'm using.  import java.awt.FlowLayout; import javax.swing.JFrame; import javax.swing.JLabel;  public class dummyClass extends JFrame {     private JLabel item1;      public dummyClass() {         super("I'm the title;");         setLayout(new FlowLayout());          item1.setToolTipText("I'm the ToolTipText");         add(item1);     } }

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


I have a class that has std::vector<std::unique_ptr<T>> and I want to crate an iterator over the reference of pointers that std::unique_ptr holds.  #include <iostream> #include <vector> #include <memory> #include <algorithm>  class Pointer { public:     Pointer() {}     ~Pointer() {}      void printSomething()     {         std::cout << "Hi" << std::endl;     } };  class Keeper { public:     typedef std::vector<std::unique_ptr<Pointer>> vector_type;      Keeper() {}     virtual ~Keeper() {}      void push_back(vector_type::value_type pointer)     {         data.push_back(pointer);     }      vector_type::const_iterator begin() const     {         return data.begin();     }      vector_type::const_iterator end() const     {         return data.end();     } private:     vector_type data; };  int main() {     Keeper keeper;     keeper.push_back(std::make_unique<Pointer>());      std::for_each(keeper.begin(), keeper.end(), [] (auto pointer) {         pointer.printSomething();     }); }   I got a cascade of errors that I cannot put here...  How to provide an interface to interact over the references of std::unique_ptr?

I was wondering if there is an iterator in the STL that dereferences the object pointed before returning it. This could be very useful when manipulating containers aggregating pointers. Here's an example of what I would like to be able to do:  #include <vector> #include <iterator> #include <algorithm>  using namespace std;  int main() {   vector<int*> vec;    int i = 1;   int j = 2;   int k = 3;    vec.push_back(&i);   vec.push_back(&j);   vec.push_back(&k);    copy(deref_iterator(vec.begin()),         deref_iterator(vec.end()),         ostream_iterator<int>(cout, " ")); // prints "1 2 3"    return 0; }


Find the non negative continuous function defined over $[0,1]$ such that $$\int_0^1 x^kf(x){\rm d}x=a^k,$$ where $k=0,1,2$ and $a\in[0,1]$  solution i try  from $$\int^{1}_{0}f(x)dx=1\cdots (1)\times a^2$$  and $$\int^{1}_{0}x\cdot f(x)dx=a\cdots (2)\times 2a$$  and $$\int^{1}_{0}x^2\cdot f(x)dx=a^2\cdots (3)$$  getting $$\int^{1}_{0}(x-a)^2f(x)dx=0$$  how i get functions which satisfy given equation, help required

Find the continuous function defined over $[0,1]$ such that $$\int_0^1 x^kf(x){\rm d}x=a^k,$$ where $k=0,1,2.$ My Thought Indeed, the conditions imply that $$\int_0^1f(x)=1,~~~\int_0^1 xf(x){\rm d}x=a,~~~\int_0^1 x^2f(x){\rm d}x=a^2.$$ Thus, it's easy to obtain that $$\begin{align*}\int_0^1(1-x)^2f(x){\rm d}x&=\int_0^1(1-2x+x^2)f(x){\rm d}x\\&=\int_0^1f(x){\rm d}x-2\int_0^1xf(x){\rm d}x+\int_0^1 x^2f(x){\rm d}x\\&=1-2a+a^2\\&=(1-a)^2\end{align*}.$$ But how to go on with this? I'm stuck here. Please offer some help. Thanks.


If I have a column CHAR(100) and is allowed to have NULL values, when the value is NULL, how much space will this take?  Also, will there be a performance hit, considering the column will be written only one, never updated and selected a lot of times?

What exactly does null do performance and storage (space) wise in MySQL?  For example:  TINYINT: 1 Byte TINYINT w/NULL 1 byte + somehow stores NULL?


I'm having trouble proving the following inequality:  $\frac{x^2}{y+z}+\frac{y^2}{x+z}+\frac{z^2}{y+x}\geq\frac{1}{2}(x+y+z)$, for $x,y,z>0$  There is an equality case, which is where $x=y=z$. Then assume without loss of generality that $x>y>z$. By combining the fractions, we get $\frac{x^2(x+z)+y^2(y+z)(x+y)+z^2(y+z)(x+z)}{(y+z)(x+z)(x+y)}>\frac{x^3+y^3+z^3}{(2z)^2(2x)}$.  I have no idea if this is at all useful and I would be very grateful for some hints.

let $x,y,z$ be positive real numbers  $$\frac{x^2}{y+z}+\frac{y^2}{x+z}+\frac{z^2}{x+y} \ge \frac{1}{2}(x+y+z)$$  then how to prove above by Cauchy Schwarz  -Inquality


I am studying differential algebraic equations. Given the following equation:  $1 = x^2+y^2$  Differentiate this equation with respect to time. The correct solution is:  $0=2x \dot x + 2y \dot y $  But why?  My wrong idea was:  $0=2x+2y$  Thank you very much!

I was just wondering where the y'/(dy/dx) in implicit differentiation comes from. $$ x^2 + y^2 = 25 $$ $$ (d/dx) x^2 + (d/dy) y^2 **(dy/dx)** = 25 (d/dx) $$ $$ 2x + 2y (dy/dx) = 0 $$ $$ (dy/dx) = -x/y $$ Where does the bold part come from? Wikipedia says it's a byproduct of the chain rule, but it's just not clicking for me.


While reviewing grammar, I came upon this sentence: "I was able to inspect the apartment without his noticing the movement of my eyes." However, this phrasing seems awkward, especially the "his". I feel like one of the following two changes would be more grammatical:  I was able to inspect the apartment without him noticing the movement of my eyes. I was able to inspect the apartment without his noticing of the movement of my eyes.  Are either of these two more "correct"? Or are there any other better changes?

I assume that the following sentences are grammatically correct:   He resents your being more popular than he is. Most of the members paid their dues without my asking them. They objected to the youngest girl's being given the command position. What do you think about his buying such an expensive car? We were all sorry about Jane's losing her parents like that.   I'm still getting used to this possessive gerund structure. It sounded so weird to me at first. Is the structure used in both formal and informal contexts? Are there any alternative structures that result in the same meaning and are more frequently used? (Examples taken from )


I have HP Pavilion 15-AB031tx Laptop, which has Intel I5 5200U 5th Generation Processor, Is it possible to upgrade 5th Generation to 6th Generation?

I have Lenovo Ideapad Y510 with dual core 1.6 Ghz processor, 1GB ram, 160GB HDD. I want to upgrade my current cpu with any latest one like i3, i5 or i7 to get more speed but don't know if it is possible. I don't know how to get all technical details of the pc so I have have attached a screenshot of boot screen, hope you will find all required info about my pc to answer this question.  I am a java developer so my basic need is to run eclipse and java application and application server with db like MySql very smoothly on my machine. Earlier I was using Win7 but machine was running slow so I switched to Ubuntu 12.04 but not much improvement so I thought to upgrade the cpu and memory. I need your suggestion that to which cpu I can upgrade and should I also upgrade ram.


This bug was found on the wall of my closet in Seattle, Washington. It has been around 40-50°F lately, and it is winter. It looks like a tiny, brown, fuzzy stick/twig, but there is a hole through the middle of it. A tongue kind of thing comes out of the hole. The tongue thing is clear/tan and has a brown tip. The tongue is how it moves around and it looks like the tip sticks to the ground, and then it pulls the rest of its body/the stick part forward from there. It doesn’t seem to like it when light is shined on it (like from a phone flashlight) and goes back into the twig part when light gets shined on it. The twig part doesn’t seem to move on its own. The twig when the tongue is inside is about 0.5 cm.

This creature was found on a bed. At first, I thought it was a piece of lint, but then it suddenly moved. I picked it up in a paper towel and put it in an eye cream containers, which it is currently in. I believe this means that it is pretty strong, since it appeared to have pulled itself all the way up from the floor, to the top of the bed, then across to the other side of a King-sized mattress.   It appears to be a worm wrapped in a cocoon. It is pretty short, being small enough to fit inside an eye cream container.  The creature is a pale yellow-white/cream, with brownish-red tips on each end (unless it can somehow turn around without exiting its casing). It looks from the side as if it has a rather flat face, one that comes to a slight bump at the bottom, but is pretty much flat. The casing is light grey, with some small portions that appear to be almost the same color as the organism, just slightly darker. There is an opening at each end of the casing, which the organism uses to slide slightly out. It has never fully come out of the casing. The edges of the openings at each end are white. The casing seems to either be made out of or covered in dust.  It can create a substance that is sticky and strong enough to support its weight. I cannot tell if the substance is created by the 'worm', or the 'cocoon'. A thread at each end of the casing is connected to the side of the container by the substance. When I accidentally detached one end of the casing, the entire thing began to shake violently when held so that one end was hanging. It wouldn't stop until I had turned it so that both ends were touching the side of the container. Within minutes, though, it had reattached the broken end. Minutes. Not hours, but one minute.  The holes at each end of the cocoon can either grow or shrink closed. I believe this allows us to tell which opening is in use. If it is nearly shut, it will come out the other end.  It appears to be nocturnal, since it doesn't move during the day, but it is very active at night. It also appears to react to light. If some is put on it, it will poke out to look around.    It has survived for four days straight without food, as far as we know. We put a small piece of lettuce in with it. However, there are two small, brownish things on the bottom of the container. This may be its excrement.  The creature moves by reaching out with its 'tentacle/worm', grabbing onto something (including the ground), and pulling itself forward.  I cannot tell if the creature is attaching to the container's side to climb, or because it is morphing. If that is the case, then the outer shell may be a cocoon. It did detach itself from the side of the container, and first hid under a ledge of lettuce, but now has wrapped itself in lettuce.  To summarize: can someone please help me identify this creature?


I'm not really tech savvy so simple explanations please!   So at the moment I'm having 240GB SSD, I'm running Ubuntu 16.04 and Windows 7. I have 2 partitions. 100GB for Ubuntu and 140GB for Windows. But I would like to change it so Ubuntu would have 25GB, Windows 100GB and remaining 115GB would be it's own partition so both OS can access it easily. Can I make this change while these two OS installed or do I have to reinstall them and while doing it, make three different partitions? And I tried search before but I didn't really find similiar situation.   Edit: and if I have to install these OS again, can I make a backup of current setups and restore them in new partitions? And I should make the partitions during Windows install?

Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers.  Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions).  Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space.  How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions?


RewriteBase is set in httpd.conf for an alias:  Alias /test /home/user/test <Directory "/home/user/test">     AllowOverride All     Allow from All      RewriteEngine On     RewriteBase /test     RewriteRule ^foo$ foo.html [QSA,L] </Directory>   This works fine:  is foo.html.  Now, I'd like to move the RewriteRule to .htaccess, because that's where it makes more sense. It's a configuration for the test project after all. However, if I do that, then RewriteBase is not interpreted any longer, and loading  fails.  Is there any way to set RewriteBase in httpd.conf plus RewriteRule in .htaccess?

This is a  about Apache's mod_rewrite.   Changing a request URL or redirecting users to a different URL than the one they originally requested is done using mod_rewrite. This includes such things as:   Changing HTTP to HTTPS (or the other way around) Changing a request to a page which no longer exist to a new replacement. Modifying a URL format (such as ?id=3433 to /id/3433 ) Presenting a different page based on the browser, based on the referrer, based on anything possible under the moon and sun. Anything you want to mess around with URL   Everything You Ever Wanted to Know about Mod_Rewrite Rules but Were Afraid to Ask!  How can I become an expert at writing mod_rewrite rules?   What is the fundamental format and structure of mod_rewrite rules? What form/flavor of regular expressions do I need to have a solid grasp of? What are the most common mistakes/pitfalls when writing rewrite rules? What is a good method for testing and verifying mod_rewrite rules? Are there SEO or performance implications of mod_rewrite rules I should be aware of? Are there common situations where mod_rewrite might seem like the right tool for the job but isn't? What are some common examples?   A place to test your rules  The  web site is a great place to play around with your rules and test them. It even shows the debug output so you can see what matched and what did not.


I need to extract the last two characters of a phrase, but I don't know how as there isn't a minus 0.

I need a good explanation (references are a plus) on Python's slice notation.   To me, this notation needs a bit of picking up.   It looks extremely powerful, but I haven't quite got my head around it.


In some [closed] questions, an edit may not be enough to the community consider it to reopening, so it is voted to Leave Closed three times. Therefore, the question will no longer be on the Reopen Votes review queue.    If the question is edited after three Leave Closed votes, does it return to the Reopen Votes review queue?

I'd like to have this   by animuson confirmed or refuted:      This is unverified, but I remember reading somewhere that an edit can only bump a question into the Reopen Votes queue once. Further edits would not continue bumping it into review. I could not find a source for that, though.   I could not find a source, either. There is an  of how edits send questions into Reopen queue, but it does not address this point.    My reason for asking: I often see  questions with minor formatting edits (made by someone other than OP) in the Reopen queue. The reviewers decide to Leave Closed, since the reason for closure still applies. Suppose that  OP edits the question later; will the edit send it to be reviewed again? If not, this means that minor  edits to an on-hold question reduce the chance of the question being reopened.


Recent events have made it clear to me that after giving up attempts to create a friendly environment years ago, Stack Exchange now prioritises  over everything else. This is not an environment to which I wish to contribute.  Unfortunately, the instructions for deleting accounts appear to be out of date. They say there is a link "Edit Profile & Settings" on the "profile page" or on the "user page". Presumably that would be the page that I can reach by clicking on 'my' icon when logged in. There is no such link there, nor anything similar, and I can't find anything better.  So how can one delete one's profile nowadays?

How can I delete my Stack Exchange account(s)? Also,  What happens to my content? Can I request it be deleted as well? What if I'm suspended, rate-limited, or banned from posting questions or answers? What will happen to my votes? Will other users be impacted? Why wasn't my account deleted immediately after the timer expiring? What will happen to my pending bounties and close, reopen, delete, or undelete votes? I want my account deleted on all Stack Exchange sites. How do I do this? Will my profile on chat be removed once I delete my site account?   For more information, see "" in the .


If, for example, I want to view the bytecode for the function x:  def f(x):     print(x * 10)   I would use the dis module, which would generate this:  >>> def f(x): ...     print(x * 10) ... >>> dis.dis(f)   2           0 LOAD_GLOBAL              0 (print)               2 LOAD_GLOBAL              1 (x)               4 LOAD_CONST               1 (10)               6 BINARY_MULTIPLY               8 CALL_FUNCTION            1              10 POP_TOP              12 LOAD_CONST               0 (None)              14 RETURN_VALUE >>>   Yet, is there a way to view the actual code of the function? For example, the output would be:  def func1(var1):     const1 = 10     print(var1 * const1)

Suppose I have a Python function as defined below:  def foo(arg1,arg2):     #do something with args     a = arg1 + arg2     return a   I can get the name of the function using foo.func_name. How can I programmatically get its source code, as I typed above?


Let's consider a set of data points of some observable in several bins, and a theoretical model. The agreement between the two is using the $\chi^2/ndf$ formula (where we divide $\chi^2$ by the number of freedom). Let's concentrate on the $\chi^2$ part :  The $\chi^2$ formula itself is $\chi^2=\sum_i (d_i-t_i)^2/\sigma_i^2$  where :  $i$ is the bin of a given observable  $d_i$ is data in the bin $i$  $t_i$ is the prediction from theory in the bin $i$  Is there a needed minimum number of entries from data in a given bin $i$ in order not bias completely the $\chi^2$, by making it exploding ?  Is there a connection with gaussian behaviour from Poisson distribution ?

I applied a survey consisting of 12 questions to 120 people and each questions include 4 nominal categories; I want to make comparison of people's answers according to their socio-demographic characteristics such as their educational level or socioeconomic status. All of my comparison criteria consist of nominal categories and number of categories change between 3 to 6. I cannot drop or combine comparisons; categories in other words number of categories are fixed.    My question is when I compare the frequency distribution of people's answers based on their education levels (for example) through chi-squared test, I got a warning that says (for instance) 7 cells have less than count five; minimum expected count is; 43.  I got this warning for almost my all questions - demographic characteristics comparisons.    Shall I underestimate this warning and use my test results or is there a different test I should use? If I should use a different test, which one?


I need to build a simple voltage regulator that can drop voltage from 24V(from a DC power supply) to 3.7V and supply at least 2A or more(up to 5A if possibile).  Can I just use a 2 resistor voltage devider? Or should I use a voltage regulator?

It is well-know that switching regulators are more efficient then linear regulators.  I also know that linear regulator have to dissipate the difference between the input voltage and output voltage times the current as heat.  But why does this not apply to switching regulators with the same conditions: same input voltage and output voltage and current?  I know switchers can get hot; I have one on a board that gets so hot you can barely touch it, but then again it's only 2 1/2 millimeters on each side and looks like an ant compared to a through-hole 7805 with its heat sink.


I was wondering, why is it that OpenOffice is not available in Ubuntu.Even if Ubuntu choose LibreOffice over OpenOffice, that does not mean that OpenOffice should be removed or not available as an option. Isn't having options is one of the great things about Linux.   Beside having problems coexisting with LibreOffice, a warning or a statement should be issued when installing OpenOffice from the Software Center, such as 'You can't install OpenOffice and LibreOffice at the same time, please remove LibreOffice'.

What is the difference between OpenOffice and LibreOffice? I understand that LibreOffice is another fork that is going to be developed. I have used OpenOffice since v1 and am wondering if there is a definite advantage to uninstalling and trying LibreOffice.


I have a List Stack like this:  private ProjectHistoryModel ProjectHistoryModel = new ProjectHistoryModel(); private Stack<ProjectHistoryModel> myStack = new Stack<ProjectHistoryModel>(10);   That I want to do is to remove last item of my stack if my stack is full, so I try:  if (myStack.Count == 10) {     myStack.Pop(); }   But Pop method remove first item of stack instead last. How can I remove last one?

Is there a built in way to limit the depth of a System.Collection.Generics.Stack? So that if you are at max capacity, pushing a new element would remove the bottom of the stack?  I know I can do it by converting to an array and rebuilding the stack, but I figured there's probably a method on it already.  EDIT: I wrote an extension method:      public static void Trim<T> (this Stack<T> stack, int trimCount)      {         if (stack.Count <= trimCount)             return;         stack = new              Stack<T>             (                 stack                     .ToArray()                     .Take(trimCount)             );                }   So, it returns a new stack upon trimming, but isn't immutability the functional way =)  The reason for this is that I'm storing undo steps for an app in a stack, and I only want to store a finite amount of steps.


I have been having a problem with my LibreOffice, all the icons have vanished.    I have tried resetting everything but I did not make changes from the start so that did nothing. Then I tried to purge libreoffice through terminal but ran into another problem there with (13: Permission denied).

I open an excel file containing a macro in LibreOffice cal, then my LibreOffice was hanged for while. So, I decide to force end its process by issued command ps aux | grep libreoffice, kill 3401 -f to force close application.  However, on next open, my LibreOffice toolbar icons were all blank like this:    As I use office document often, it makes me have a hard time formatting my document.  Really much appreciate for any help please. Thanks.


Prove: Use the triangle inequality to prove that for all $x, y, z, |x-z|≤|x−y|+|y−z|$ Is my proof correct?  Proof: Let $a = x-y$, and $b=y-z$. We can say that $|a+b| = |(x-y) + (y-z)| = |x - z|$. Further more we can say: $$|a| + |b -a| \ge |a + b -a| = |b|$$ $$|b| + |a -b| \ge |b + a -b| = |a|$$ Move |a| to the right side in the first inequality and |b| to the second inequality. We get: $$|b +a| \ge |b| + |a|$$ $$|a +b| \ge |a| +|b|$$ From absolute value properties we know that $|b+a|=|a+b|$ Combining these two facts together we get: $$|a+b| \le |a|+|b|$$ Which implies $$|x − z | ≤ | x − y | + | y − z |$$  Or applying the triangle inequality directly we can also prove it this way:  Proof: Let $a = x-y$, and $b=y-z$. We can say that $|a+b| = |(x-y) + (y-z)| = |x - z|$. Substituting $a$ and $b$ into given inequality we get $$|a+b| \le |a|+|b|$$ which by claim is equivalent to the triangle inequality. QED.

Let $a,b,c$ real numbers. Prove the inequality $|a-b| \leq |a-c| + |c-b|$. Prove that equality holds if and only if $a \leq c \leq b$ or $b \leq c \leq a$.   I've tried starting with just $a \leq c$ and using field properties to reconstruct the inequality, however I haven't been able to make it work. I also tried making the negatives positive and stripping the inequalities and making something happen but again I don't know if that's a proper rule and it didn't seem to get me anywhere.


I'm working on a NodeJS project (using @babel/preset-env) and need to figure something out: If I have two objects, one of them identical to the other but possibly minus some fields (depends on input object), how do I edit the "larger" one such that its fields are changed to the values of the matching ones from the smaller object? That's probably worded badly, so here's an example...say I have these two objects: const obj1 = {     a: 1,     b: 2,     c: 3,     d: 4 }  const obj2 {     b: 'hello',     d: 'world' }  What I'm wanting to do is modify obj1 in this instance such that the values of obj1.b and obj1.d get updated with the values from obj2. Is there a way to edit the values directly, or should I just create a copy of obj1 and set values depending on whether or not they exist in obj2?

I need to be able to merge two (very simple) JavaScript objects at runtime.  For example I'd like to:  var obj1 = { food: 'pizza', car: 'ford' } var obj2 = { animal: 'dog' }  obj1.merge(obj2);  //obj1 now has three properties: food, car, and animal   Does anyone have a script for this or know of a built in way to do this?  I do not need recursion, and I do not need to merge functions, just methods on flat objects.


I uninstalled Windows 8 completely and then installed only "Ubuntu". Now I want to uninstall ubuntu and reinstall Windows, I dont have a live cd of ubuntu. I have my genuine windows in a flash drive (USB). Does the installation work if I format the drive from Disks option in Ubuntu?, what would be the consequence of formatting from there. Assist me with best possible solution. Thanks in advance.

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


Knowing that for $n \geq 2$, $\mathrm{GL}(n, \mathbb{Z}) = \big\{ A \in \mathrm{M}_{n,n}(\mathbb{Z}) \mid \det(A) \in \{ 1, −1 \} \big\}$ is a group with respect to matrix multiplication, prove that for every integer $n \geq 2$ the group $\mathrm{GL}(n, \mathbb{Z})$ is finitely generated.  If I prove that  $\mathrm{GL}(n, \mathbb{Z})$ has finite subgroups does that mean it has a finite set of generators so that it is finitely generated?

I'm searching for a way to generate the group $\mathrm{GL}(n,\mathbb Z)$. Does anyone have an idea?  The intention of my question is that I am searching for an easy proof of the existence of the epimorphism:  $\Phi:\mathrm{Aut}(F_n )\to \mathrm{Aut}(F_n/[F_n,F_n])=\mathrm{Aut}(\mathbb {Z}^n)=\mathrm{GL}(n,\mathbb {Z})$  I know that $\Phi$ is an canonical homomorphism since the commutator subgroup is characteristic in $F_n$. So I need some nice generators of $\mathrm{GL}(n,\mathbb {Z})$ to find their preimages in $\mathrm {Aut}(F_n)$ to prove the surjectivity of $\Phi$.  Thanks for help!


In a terminal,i wrote this command:  apt-get install gimp   And it returns with this output:  E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?   I'm new to ubuntu and been using ubuntu 1 week.

I get this error whenever I try to install programs using the terminal:  home@ubuntu:~$ apt-get install myunity E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?   Also I'm unable to install updates using the terminal.


I'm often helping new users with problems they have while getting started with a particular software. After having solved one problem, it is not unlikely that they run into another problem. The follow-up problems obviously deal with the same software, but they usually have completely different causes, and therefore should be asked as separate questions.  Nevertheless, users often ask these follow-up questions in comments.  I am inclined to not answer these questions (in particular if no-one else will ever be able to find my answer and benefit from it). On the other hand, I still want to be helpful, so I at least try to convince the user to ask a separate questions. However, I find it hard to explain in a short and friendly way why I (and potentially also others) don't want to answer follow-up question in comments.  So I was wondering if there is a good explanation somewhere that I could reference to educate the users? (And if not, could someone write one as answer to this question? ;-)

I'm not sure if there's already an existing term for this, so I'm inventing my own. (tl;dr: I call them "chameleon questions" because they change every time you submit or edit an answer.  If you're already intimately familiar with the phenomenon, please skip past the first set of bullet points to where I ask for recommendations.)  I think many of us have experienced this on occasion:  You open up a narrow-looking question, usually dealing with some specific error message.  The question probably contains a snippet of sloppy but not quite awful code; code indicating that the author, typically a new/low-rep user, possibly a , doesn't really know what they're doing.  I'm not trying to be condescending here, they're probably very intelligent and hardworking, but in this specific case, they're clearly in way over their head.  However, as a question, it's not really too bad.  The goal and problem are both clearly stated.  The code is formatted (sort of).  Mort was polite and checked their spelling.  The question looks answerable, although from a rep perspective* it's an obvious dead-end, it's had maybe 3 views in the past 30 minutes.  So you decide, you know what, this person took the time to write up the question properly, they deserve an answer, put on your good citizen hat and throw them a bone.  You slog through the ugly code, find the offending line, direct their attention to it and explain why it's wrong and how it needs to be fixed.  Later, they leave a comment saying that yes, that was indeed the problem and your answer helped them fix it (great!).  Oh, but, now there's another problem (uh-oh...). Something else is broken.  After letting out a long sigh, you read the comment and/or edited question, roll up your sleeves, and write up Take 2, hoping that's the end of it.  And of course it's not the end.  Now maybe the error is gone, but it's not doing what it's supposed to.  If you're anything like me, your patience is now starting to wear thin. It's lousy code and you didn't volunteer to help them rewrite their whole app.  And of course, the question still only has 12 views, and nobody has upvoted either the question or your answer, including the person you're helping, so this is turning out to be a genuinely thankless task in all respects.  Welcome to "Family Tech Support", Web 2.0 Edition.   * Which is of course just an arbitrary number that none of us care about. Not really, anyway. Not very much, at least.  So, here's where I get to my question.  At this point, do you:  Leave a comment, stating as politely as possible that you've done your best to help them answer the original question they asked, and if they have a new problem then they should start a new question?  (I did this once, and actually ended up with an accept, but I felt kind of guilty afterwards, I don't think anybody answered their 2nd question).  Bite the bullet and edit your answer a 3rd, 4th, 5th time, however many times it takes to resolve their issue, knowing full well that they may not even remember to accept the answer once you're done? (I may work for free on SO, but that doesn't mean my time is worthless.)  Just abandon the question, hoping that it will force Mort to start thinking for himself?  Something else?   I've tried all three of the above and none of them ever quite feel right. I do want to help, but at the same time there are a lot more "lucrative" questions I could be answering. And I don't mind spending a lot of time on an answer either, if the question is interesting or important to me, but debugging is dull work. I'd prefer not to reference specific questions here; I'm pretty sure that this is a shared experience, and my objective isn't to point fingers at "misbehaving" members.  I'm more looking for some practical advice on how to dig myself out of these pits of despair. Anybody have any other ideas?


I'm trying to include the titles of TED talks that I'm translated into my resume, but since the talks are in Spanish there are some characters that don't show up correctly.  When I write:  \item (Spanish into English){De que el futuro de la educación está a tan sólo un clic}   the text shows up as   De que el futuro de la educacin est a tan slo un clic   and simply doesn't show the special characters.  How do I get Latex to display special characters in Spanish or Portuguese?

How to type these special letters from European languages in latex? ä, é, and L'?


In "Hell Bent," when he was talking to Clara in the diner, he said he remembers her name is Clara, and he knows they traveled together; he remembers ice warriors in a submarine and the mummy on the express and remembers being in the cloisters, but he doesn't remember the message she said or how she talked or looks like.  It made me think the neural block wiped the Doctor's memories of Clara, but does he still remember his adventures with her as the 11th and 12th doctor from Asylum of the Daleks to Hell Bent and does he still remember the adventures as his past regenerations (Hartnell - Smith)?

In the last episode of season 9, the Doctor said he needed to erase Clara's memory. And after Clara said that she reversed the Doctor's device, he used it anyway. Why did someone (the Doctor or Clara) have to lose their memory? And how much of the Doctor's memory was erased?


I'm trying to use the ST_Point_Inside_Circle function from PostGIS but I'm not sure about the unit the radius is stored.  Let's say I have a table with the following points:     Id | Point     1 | POINT(-60.64855 -32.96482)      2 | POINT (-60.65871 -32.93411)   and I want to query them by doing    st_point_inside_circle(Point,  -32.93690, -60.64343, radius)   Now, I know that distance from (-32.93690, -60.64343) to P1 is of about 1460 m and from (-32.93690, -60.64343) to P2 is of 3117.5 m.  Using a trial-and-error approach I was able to determine that if   radius < 0.02839 and radius > 0.02838 I was able to get the 2 points in my query. However, the value for radius doesn't make much sense. Which units is it expressed in? Since the distance between points is too short, I don't think that not using a spheroid would affect the results. Maybe I am doing something wrong. Should I use ST_Buffer instead?

I'd like to begin by saying that I have very little knowledge and understanding when it comes to GIS (despite extensive experience with Google Maps API). PostGIS appears to be a whole new ball game on its own.  I've recently installed PostGIS (v2.1.5) with my PostgreSQL (v9.4) instance in order to begin storing and working with GIS data. I'm currently using Google Maps API v3's DrawingManager to draw polygons, circles, rectangles and markers which need to be stored in the database, and later retrieved to display the polygons again on Google Maps; These shapes will also be used for various aggregate queries.  I currently have two tables. The one is called "locations" which will store the polygons, circles and rectangles created with Google Maps' DrawingManager. The second, called "rawdata" will contain a set of records with a POINT (lat, long) inside of it.  First and foremost, I do not entirely understand the concept of projections and how they work, but, based on what I've read online is that calculations and accuracy may vary, significantly. I understand that Google Maps works with the Web Mercator projection which I believe is officially known as the EPSG:3857 projection (or CRS), while the preferred method for storing and working with geometry() shapes in PostGIS is in the EPSG:4326. As such and in reference to my create table statements below, I have chosen to store my geometry data in EPSG:4326 in the tables.  An easier method would to be store my geometry in the newer geographic format, but I do not wish to impose those performance and lack of functionality drawbacks as I will be working with a significant amount of data (hundreds of thousands, if not millions of records).  I am trying to test the ST_Point_Inside_Circle() function but this appears to be inaccurate and I can only assume so because the function expects degrees as the radius parameter, yet Google Maps supplies me with a radius in meters. In reference to , I have tried converting meters to degrees by multiplying meters by 0.00001. However, the greater the radius in meters, the more inaccurate it appears to be. What can I do to achieve an accurate result?  SELECT ST_Point_Inside_Circle(ST_SetSRID(ST_MakePoint(28.239418677985668, -25.75443387513752), 4326), 28.241967111825943, -25.759674774140656, (583 * 0.00001));  Google Maps reports the distance in meters between the two points (center of circle and point) as 637 meters, yet ST_Point_Inside_Circle returns true when trying to convert 583 to degrees. This leads me to the assumption that one cannot convert meters to degrees using 0.00001.  What is the correct way to determine the radius with meters?


Can the substitution method of integration be used for $\int_0^x\sqrt{t^2+1}dt$?

I need to calculate the following indefinite integral:  $$I=\int \frac{1}{\cos^3(x)}dx$$  I know what the result is (from Mathematica):  $$I=\tanh^{-1}(\tan(x/2))+(1/2)\sec(x)\tan(x)$$  but I don't know how to integrate it myself. I have been trying some substitutions to no avail.   Equivalently, I need to know how to compute:  $$I=\int \sqrt{1+z^2}dz$$  which follows after making the change of variables $z=\tan x$.


I've  been trying to put a vector in the title of a section but no matter what I've tried, I keep getting the same error message (see below). I am using pdfLaTeX. \section{Das Drehmoment $\overrightarrow{M}$}  The error message I receive is the following : ! Illegal parameter number in definition of \@themark.   to be read again  \crcr   l.71 \section{Das Drehmoment $\overrightarrow{M}$}  Edit:  \vec  works just fine, but because I've used \overrightarrow for all my other vectors, I don't want to break the tradition.

I want to use the symbol \angle at a section title but I get an error message:      ! Illegal parameter number in definition of \reserved@a. to be read   again $ l.9   \section{Second section: $\angle$ }   See the MWE:  \documentclass{article}  \begin{document}     This is my document.      \section{First section: $S=\sin(\alpha)$}     Use $\angle$ at normal text.      \section{Second section: $\angle$ } %Here the error occurs     Text at second section.  \end{document}   So the question is, how may I use the \angle symbol in a section title?  Thanks!


Open to any and all suggestions / alternative layouts. Need to be able to cleanly circle a number inside of a table. Currently I have this (stolen from elsewhere) and it produces output as attached.    \usepackage{tikz}  \newcommand*\circled[1]{\tikz[baseline=(char.base)]{             \node[shape=circle,draw,inner sep=2pt] (char) {#1};}}  % A completed self assessment sheet (see end of this document). \section{Self Assessment}  \begin{table}[h] \begin{tabular}{llllllllllllll} Level 1 & A & 18 & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & \circled{10} \\ Level 2 & V & 12 & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & \circled{10} \\ Level 3 & AA & 10 & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & \circled{9} & 10 \\ Level 4 & S & 12 & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 & \circled{8} & 9 & 10 \\ Level 5 & I & 10 & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 & \circled{8} & 9 & 10 \\ Level 6 & S & 10 & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 & \circled{8} & 9 & 10 \\ Level 7 & C & 6  & 0 & 1 & 2 & 3 & 4 & 5 & 6 & \circled{7} & 8 & 9 & 10 \\ Level 8 & R & 16 & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 & \circled{8} & 9 &    \end{tabular} \end{table}


For example if I have a web server with 512 MB of RAM and my server is for downloads, will many downloads make my server unresponsive? By unresponsive I mean server error 508(Resource limits has reached). Please help, I am going to choose best hosting.

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


I have a 15A breaker that trips whenever the small space heater and the iron are used at the same time (not in the same outlet, just the same circuit). Is the solution as easy as upgrading to a 20A breaker? Thanks for any info.

When I plug-in a conventional heating pad or a hair dryer into any bedroom duplex, the lights dim; and/or trips the circuit breaker. The home is of new construction-- placed in service 31 Dec 2013. My question is: Can I safely replace the existing 15 AMP Breaker with that of a 20 AMP? . . . the service cable is of 14 Gauge Copper Conductor.


I recently acquired an HP Mini 1000 that had been purged of the operating system.  There is no CD, only USB ports.  I downloaded ubuntu 12.04 onto a flash drive, stuck it in the notebook, told it to boot from the USB and got a black screen "No bootable partiton in table".  How do I use ubuntu to boot my conputer.  Thanks.

I have a bootable CD image that I would like to transfer to a USB stick, so that I can boot from it. The Startup-Disk creator doesn't support it. How can I make a bootable USB disk from it? The ISO is quite old so that might be a problem.


Why are we interested in asymptotics if the real-world data is almost always finite?

I hope that this question does not get marked "as too general" and hope a discussion gets started that benefits all.  In statistics, we spend a lot of time learning large sample theories. We are deeply interested in assessing asymptotic properties of our estimators including whether they are asymptotically unbiased, asymptotically efficient, their asymptotic distribution and so on. The word asymptotic is strongly tied with the assumption that $n \rightarrow \infty$.   In reality, however, we always deal with finite $n$. My questions are:  1) what do we mean by large sample? How can we distinguish between small and large samples?  2) When we say $n \rightarrow \infty$, do we literally mean that $n$ should go to $\infty$?  e.x. for binomial distribution, $\bar{X}$ needs about n = 30 to converge to normal distribution under CLT. Should we have $n \rightarrow \infty$ or in this case by $\infty$ we mean 30 or more?!  3) Suppose we have a finite sample and suppose that We know everything about asymptotic behavior of our estimators. So what? suppose that our estimators are asymptotically unbiased, then do we have an unbiased estimate for our parameter of interest in our finite sample or it means that if we had $n \rightarrow \infty$, then we would have an unbiased one?  As you can see from the questions above, I'm trying to understand the philosophy behind "Large Sample Asymptotics" and to learn why we care? I need to get some intuitions for the theorems I'm learning.


$$\lim_{x \to 0}x^x$$   I know the answer is one but I have no idea how to get there.  I tried taking a natural log and I think I need lhopitals rule but I keep going In circles.

I know when evaluated it gives one but I can't figure out how to prove it.  Can anyone help? I believe it requires L'Hopitals rule and taking a natural log but i cannot figure out the exact math.


Consider the following Git graph  master:   A - B - C - D - E*                \         / feature:        X - Y - Z   I want to make a new commit in master, E, such that E precisely matches Z. In other words, any changes that may have been made in commits C and D are completely discarded. However, I would still like to retain the property that doing git checkout HEAD~1 in master would checkout D.   Doing git checkout master; git reset --hard feature gets the working directory in the proper state (i.e., all tracked content precisely matches that of Z). However, is does not leave the history in the way that I intend.  Doing something like git checkout feature -- . almost works, but retains any files created in B or C, so it won't always precisely match the state of Z.  Doing something suggested in other responses to similar questions seems quite inefficient, as it involves several different checkouts and merges and is something I need to specifically avoid, as this operation will be done frequently and on rather large repositories.  It seems like years ago someone asked a similar question and got this response:   Part two of this question is: Seriously? Unless I'm missing something major, why is this not obvious to do?  Thanks!

When merging topic branch "B" into "A" using git merge, I get some conflicts. I know all the conflicts can be solved using the version in "B".  I am aware of git merge -s ours. But what I want is something like git merge -s theirs.   Why doesn't it exist? How can I achieve the same result after the conflicting merge with existing git commands? (git checkout every unmerged file from B)  UPDATE: The "solution" of just discarding anything from branch A (the merge commit point to B version of the tree) is not what I am looking for.


Does there exist a finite non-abelian $2$-group $G$ such that $G^{\prime}\cong D_8$ or $G^{\prime}\cong Q_8$? By an easy inspection with GAP, I could not find any example!  Any answer or comment will be greatly appreciated!

Every undergraduate student knows that there are (exactly) two non-abelian groups of order 8: Dihedral ($D_8$) and Quaternion ($Q_8$). The group $Q_8$ has many interesting properties; simple of them are: it has unique element of order $2$, all subgroups are normal, etc. A property, which is strange and not obvious, the group $Q_8$ has, is that there is no group $G$ such that $G/Z(G)$ is isomorphic to $Q_8$. On the other hand, $D_8$ has no such property; there are (infinitely many) groups $G$ such that $G/Z(G)$ is isomorphic to $D_8$; example - $D_{16}$.   The question, I would like to ask, is related to a property of $D_8$, which is not shared by $Q_8$. There are (infinitely many) groups whose derived subgroup is $Q_8$; example- $SL_2(3)$. For groups $G$ of order <100, one can check on GAP that $D_8$ is not a derived subgroup of any group. The natural question is then:  Question 1: Does there exist a finite/infinite group whose derived subgroup is equal to $D_8$?  Question 2: Does there exist a finite/infinite group whose derived subgroup is equal to (general) dihedral group $D_{2n}$ of order $2n$ ($n>2$)?


Background: I am building a laser that is running off of an M140 M-Type 2+ W 445 nm laser diode and an adjustable constant current driver.  Here are the specifications for both the driver and the diode as stated by the seller.  DRIVER 8 - 12V Operation Adjustable Constant Current Output up to 5A (preset to 500mA) Suitable for Laser Diodes up to 7W+ 0 - 5V TTL/PWM Input Control 0 - 150kHz Frequency 2x 12V Fan Driver Delayed Startup - <10 Seconds Includes 2-pin JST-XH Crimp Connectors Driver is ON by default when powered.   DIODE This listing is for ONE Brand New Nichia M140 M-Type Japan 445nm 2+  Watt 5.6mm Laser Diode mounted in 12mm x 30mm Metal Housing Module  w/ G-2 Glass Lens, ~6" 22AWG Silicone Leads. The diodes are   meticulously extracted from a new laser diode array. Recommended    current is 1 to 1.6 Amps. A constant current driver must be used to  power the diode. Do not connect directly to battery or unregulated  power supply!    As of now, I have the diode in module with a lens and leads, the driver, and a heat sink which is currently on its way.  Problem:  What I need to do now is supply power to the driver. Since the driver is operational up to 12V, I am considering running 3 18650 batteries rated at 3.7V in series. This will give me a total voltage of 11.1 volts. My concern, however, is that I am unsure if the current of these batteries running in series matters. I know that the current remains the same, however, does the input current need to match the preset current on the driver (500mA)? Does the input current need to be more? If so, how much more? What is a safe amount of current that can be driven to the driver so that it does not break down. I am having trouble understanding how a constant current driver steps down the incoming current without messing up the driver. I apologize if these questions seem silly, but I am genuinely interested in this project, and I would like to power it properly and safely.  Also, how can I calculate the output power of the laser diode? If Watts is equal to voltage * amps, and the driver is sending 500mA to the diode with 11.1 volts, the output power SHOULD be 5.55 Watts. However, this doesn't sound right since the diode is rated at 2 Watts AND since the seller recommends a current between 1.0 to 1.6A. Is my calculation wrong?  Note: My major is in chemical engineering. I am very unfamiliar with electronics. I have tried my hardest to learn everything there is to know in order to successfully build a high-powered laser. If there is anything wrongly stated, please correct me.

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


Does anyone have idea why "word-wrap" not working in below html code?   <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\" /><meta name=\"viewport\" content=\"width=341.0px, minimum-scale=1, word-wrap=break-all, maximum-scale=1, user-scalable=no, shrink-to-fit=no\" />HelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHelloHello

I have a long string (a DNA sequence). It does not contain any whitespace character.  For example:  ACTGATCGAGCTGAAGCGCAGTGCGATGCTTCGATGATGCTGACGATGCTACGATGCGAGCATCTACGATCAGTCGATGTAGCTAGTAGCATGTAGTGA   What would be the CSS selector to force this text to be wrapped in a html:textarea or in a xul:textbox?


i would convert the following byte content as str using python to an bytearray  '0B C0 C0 C0 C8 FF 43 ED 44 C0 \r\n'  like below  bytearray(b'\x0b\xc0\xc0\xc0\xc8\xffC\xedD\xc0')  how it can be done?

I have a long sequence of hex digits in a string, such as      000000000000484240FA063DE5D0B744ADBED63A81FAEA390000C8428640A43D5005BD44   only much longer, several kilobytes.  Is there a builtin way to convert this to a bytes object in python 2.6/3?


I have the following code. It simply makes the python script formatted, with the colors using .   hljs.highlightAll();   function clicked(){       if(document.getElementById("code").style.display === "block"){           document.getElementById("code").style.display = "none"         }else{           document.getElementById("code").style.display = "block"        }   } html{     text-align: center; }  #code{     display: none;     text-align: left;     width: 150px; /* removing this line will center */ } <!DOCTYPE html>       <link       rel="stylesheet"       href="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@10.7.2/build/styles/atom-one-dark.min.css"     />              <button onclick="clicked()">Show Code</button>
print('hello world')
      After clicking the button, it will not center the code. But if you uncomment the line which changes the width in the CSS file, it centers. Why does it not center when I change the width?

How can I horizontally center a
 within another
 using CSS?

Foo foo


In particle data group's (PDG) The Review of Particle Physics (2016) page number 29, the mass of the photon is given to be $<1\times10^{-18}eV$ and that of graviton as $<6\times10^{-32}eV$.   In case those limits are experimental upper bounds, what makes them give theoretical value for gluons and experimental limits for photon and graviton? Why aren't we sure that photon's mass is zero, even though we are sure that gluons mass is zero (as given in it)?  In case they have mass, why do we think graviton may have lesser mass that of the photon even though they both are carriers of forces of similar range?

I was under the impression that gluons had no mass. Then Wikipedia throws this curveball:  Mass: 0 (theoretical value) < 0.0002 eV/c2 (experimental limit)  Which one should a poor soul go by? If the theoretical value just the one that people "thought" was right, until they found out the truth, or is the experimental limit(?) an impossibility that still has not been explained? Or something third?


The function Celsius2Fahrenheit will convert Celsius to Fahrenheit to be used later, and the range is supposed to go up each time by .5, and stop at 101, but you cant use a float value in range, (I am a beginner at python), can someone please help.   def Celsius2Fahrenheit(c): """ This will Convert c Celsius to its Fahrenheit equivalent""" return c * 9 / 5 + 32   for x in range(0,101,.5): # This will print the values using new style formatting     e = Celsius2Fahrenheit(x)     if (e > 0):         print(" {:3.1f} (C) | {:6.2f} (F) ".format(x,e))     else:         print(" {:3.1f} (C) | {:6.2f} (F) ".format(x,e))

Is there a way to step between 0 and 1 by 0.1?   I thought I could do it like the following, but it failed:  for i in range(0, 1, 0.1):     print i   Instead, it says that the step argument cannot be zero, which I did not expect.


Could you tell if this is correct? Why sometimes the names of schools, museums and churches have the definite article while the others have not?     Kazimierz Wielki Primary School in Przedbórz       John Paul II Junior High School in Przedbórz      Folk Museum in Przedbórz      Church of Saint Alex in Przedbórz   Should I use "the" before the names? There is no "official name" in these cases (I mean whether is with "the" or not). What would you use? I know that with "of" phrases the article "the" is used but I also found a confusing case: In wikipedia there is the name:      the Johns Hopkins University   but on their website there is:      Johns Hopkins University   Could you explain this?

I'm editing a children's book about wonders of the World. In this book, the authors are not native speakers(they are XACT BOOK(India)), and they wrote these specific places without article "the":     -It is Taj Mahal.      -It is Tower of Pisa.   At first, I thought it's okay, but there are some pages has article "the":     -It is the Great Pyramid of Giza.      -It is the Temple of Artemis.   These sentences really make me confused. After researching, this website- - gives me some advice:     Do use the before:           names of rivers, oceans, and seas: the Nile, the Pacific          points on the globe: the Equator, the North Pole          geographical areas: the Middle East, the West     deserts, forests, gulfs, and peninsulas: the Sahara, the Persian Gulf, the Black Forest, the Iberian Peninsula      Unfortunately, I'm still not sure that adding "the" before each wonder's name is a right choice. Should I add article "the" or not? I already posted this problem in , but I'm still in vain.


Say I have four files. Two are completely unencrypted, while the other two are the exact same files other than that they have been encrypted with (apparently) the same public key (via a ransomware virus). Is it possible to deduce the key from these files, so I can apply it to other files also encrypted with the same key?  Edit  Sorry, after searching through the questions related to my tags, I see the simple answer is no, because although the public key is easily discovered, it's probably a private key I'm looking for, which would be hosted elsewhere.   But to modify the question:   Does the length of the public key imply the length of the private key, or can they be unrelated?  Also, wouldn't more plaintext information provide a brute-force program a starting point to speed the process?    I don't understand why, given that all the files would be decrypted using the same key, we can't deduce said key by comparing encrypted files to unencrypted ones.

One of our users seems to have been hit by . As a result, he has a hard drive full of encrypted files. The ransom-ware claims to have used public key encryption on  the files.  If we know exact contents of some of the files prior to them being encrypted, would it be feasible to use those files to discover the private key?


Im trying to make an 9x9 array using nested lists and when I set am trying to set a single value for some reason it is setting that value in every row of that array. It starts with a list like this [[0,0,0,0,0],  [0,0,0,0,0],  [0,0,0,0,0],  [0,0,0,0,0],  [0,0,0,0,0]]  I did something like list[2][3]=1 and the list changed to [[0,0,0,1,0],  [0,0,0,1,0],  [0,0,0,1,0],  [0,0,0,1,0],  [0,0,0,1,0]]  I can't figure out what I did wrong. My code is def resetGrids():     gridHidden=[]     gridShown=[]     gridpart=[]     for i in range(9):         gridpart.append(0)     for i in range(9):         gridHidden.append(gridpart)         gridShown.append(gridpart)     for i in range(10):         searching=True         while searching:             checkX=random.randint(0,8)             checkY=random.randint(0,8)             print(checkX, checkY)             if gridHidden[checkY][checkX]!=10:                 print(gridHidden[checkY][checkX])                 gridHidden[checkY][checkX]=10                 print("a")                 #for a in range(-1,2):                 #    if checkY+a>=0 and checkY+a<=8:                 #        for b in range(-1,2):                 #            if checkX+b>=0 and checkX+b<=8:                 #                if gridHidden[checkY+a][checkX+b]!=10:                 #                    gridHidden[checkY+a][checkX+b]+=1                 searching=False                 print("B")             print(gridHidden)         print("c")     print("d")

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


This code is not working, although it seems correct to me. Can you please tell me what's the issue?
hii

What characters/symbols are allowed within the CSS class selectors? I know that the following characters are invalid, but what characters are valid?  ~ ! @ $ % ^ & * ( ) + = , . / ' ; : " ? > < [ ] \ { } | ` #


So, basically I clean installed windows 10, the third time in a week. Then appeared the windows.old folder in the C: after the very third time. I tried deleting the folder from settings, disk cleanup etc. But it just wouldn't. So, I tried changing the ownership through cmd and tried deleting it & 'voila' it worked. But, the very moment I restarted my PC, it reappeared not only in my C: but my other two hard disk partitions ( D: and E:) as well. I followed the same old step for the C: and quick-formatted the other two drives(as they were almost empty). Well, it was fine, but at the next reboot, they appeared again, the folder size increase from mere 3-4 GB to about 30GB in each folder, consuming about 100 GB total. I am utterly devastated and the folder size is just increasing.  Programs I used are piriform defraggler, ccleaner and avast. I haven;t downloaded any software from any suspicious websites or so.

When I try to delete the file, using the GUI it says      The action cannot be completed because the file is open in another   program   And using the del /f /q command line it says     Access is denied   I have tried unlocking the file with Unlocker, as well as trying to locate which process is using the file with the Resource Monitor or the Process Explorer, but no locking handle was found in either case.  I am able to rename or move the file, but not to delete it or change its content.


I had created this small dent in my door and I am wondering how to fix it.

My son sometimes has a temper, and has been known to hit his door when sent to his room. He has actually done so enough to punch a bit of a hole in it. I'm trying to figure out what might be doable to fix the door. Here is a photo of it:    As can be seen, there is a crack on the left that is visible and slightly dented in, and the center/right hole is actually pressed in pretty good. The punched hole is approximately 6 inches in diameter.   I'm going to make my son pay for the repairs from his allowance, and as that is limited, I am hoping for a fairly quick/inexpensive solution.  Any ideas as to what can be done?


I install mate environment with that command   sudo apt-get install ubuntu-mate-desktop   And now i want to get original back but i try so many different things all over the internet without any result still when i reboot my pc start with mate theme (i have too many fails and programs i dont want to lose its about 2TB of information) and i dot want to reinstall my ubuntu just i want to make him like original (sorry about my terrible english) please help me to get rid of that mate environment i already try this   sudo apt-get remove mate-desktop sudo apt-get remove --auto-remove mate-desktop sudo apt-get purge mate-desktop sudo apt-get purge --auto-remove mate-desktop   but still ubuntu ends and start with that green mate icon ...... Many THANKS!

With regards to Plymouth --  Are there alternative boot screens available?  What's the easiest way to change the boot screen?


I have a class  class A{     A(/*constructor arguments*/);     double MethA(double); };   And I want to pass the method MethA in a function that takes a pointer to a function :  double function(double (*f)(double), double x){     return f(x); }   So  what I'm doing is to call  A a(/*constructor arguments*/); function(a.MethA,1.0);   but it doesn't compile.  I'm pretty sure that this question is answered somewhere else, but I couldn't find where because I'm not sure that the terminology I use is correct. Am I trying to pass a pointer on a class method as a function argument ? Or, to pass a function pointer as a member of a class... I'm confused :-(

I am trying to pass a member function within a class to a function that takes a member function class pointer.  The problem I am having is that I am not sure how to properly do this within the class using the this pointer.  Does anyone have suggestions?  Here is a copy of the class that is passing the member function:  class testMenu : public MenuScreen{ public:  bool draw;  MenuButton<testMenu> x;  testMenu():MenuScreen("testMenu"){     x.SetButton(100,100,TEXT("buttonNormal.png"),TEXT("buttonHover.png"),TEXT("buttonPressed.png"),100,40,&this->test2);      draw = false; }  void test2(){     draw = true; } };   The function x.SetButton(...) is contained in another class, where "object" is a template.  void SetButton(int xPos, int yPos, LPCWSTR normalFilePath, LPCWSTR hoverFilePath, LPCWSTR pressedFilePath, int Width, int Height, void (object::*ButtonFunc)()) {      BUTTON::SetButton(xPos, yPos, normalFilePath, hoverFilePath, pressedFilePath, Width, Height);      this->ButtonFunc = &ButtonFunc; }   If anyone has any advice on how I can properly send this function so that I can use it later.


I am doing my project. and it's about a DC-DC converter. I am using HCPL 3021 as a driver for the MOSFET IPPR045C7. in open loop cicuit, I am using Vin=60V, with duty cycly = 60% of PWM signal (F=20KHz). The output voltage should be Vout=36V. But it's not. I got Vout=16V. even with a load connected the voltage remains wrong. the circuit is shown in the joined picture. Can you please help me and tell me what's wrong with circuit? Is the ground connection wrong?

my circuit is shown on the picture. the problem is the output of the mosfet does't work as desired. For example, If I use Vin=100V and the duty cycle is 50%, the output is Vout=19V.  Anyway, the output is not even near to the desired value. can you help, please?


Recently I have finished the Chronicles trilogy by Margaret Wise and Tracy Hickman. I tried to find the Trilogy that comes after Chronicles, but the library didn't know.  What is the correct reading order of the Dragonlance trilogies?

I wanted to try out more of Weis and Hickman's works(I liked the Deathgate Cycle very much), and I decided to do it with Dragonlance. Since there are a lot of books in the series, can somebody clarify whether I should be reading in the chronological order or not?


Suppose $a_n>0$,$\sum a_n$ converges, $\{na_n\}_{\Bbb N}$ is monotonic, prove   $$\lim na_n\ln n=0$$   My attempt so far has shown that $\{na_n\}$ is decresing: otherwise, $na_n\ge a_1\implies a_n\ge\frac{a_1}{n}\implies \sum a_n=+\infty$ which contradicts the convergence of $\sum a_n$.  My friend has got a bit further: $(n+1)a_{n+1}< na_n\implies \frac{a_{n+1}}{a_n}<\frac{n}{n+1}$. He then let $$b_n:=\frac{a_n}{\frac{1}{n\ln n}}$$ and therefore $$\frac{b_{n+1}}{b_n}=\frac{a_{n+1}}{a_n}\cdot\frac{(n+1)\ln(n+1)}{n\ln n}<\frac{\ln(n+1)}{\ln n}$$ However he can't prove the monotony of $b_n$ because the RHS of the inequality is too weak. In fact it only shows $\limsup \frac{b_{n+1}}{b_n}\le 1$, which is not effective here. And I can't come up with a stronger version, either.  Can you help me? Any direct help or hint will be appreciated. Thanks!

Let $a_n>0$,$\sum a_n$ is convergent,$na_n$ is monotone, Prove: $$\lim\limits_{n\to\infty}na_n\ln(n)=0.$$  I try to prove $a_n=o(n\ln(n))$, but it doesn't work.


i have   const char* hour = "Wed Mar 23 18:10:57 2016";   I would like to cut "18:10:57" in another new const char*

I'm trying to iterate over the words of a string.  The string can be assumed to be composed of words separated by whitespace.  Note that I'm not interested in C string functions or that kind of character manipulation/access. Also, please give precedence to elegance over efficiency in your answer.  The best solution I have right now is:  #include <iostream> #include <sstream> #include <string>  using namespace std;  int main() {     string s = "Somewhere down the road";     istringstream iss(s);      do     {         string subs;         iss >> subs;         cout << "Substring: " << subs << endl;     } while (iss); }   Is there a more elegant way to do this?


I use notifications in the "recent achivements" toolbar dropdown more to see whether people are upvoting/downvoting me than to see how much rep I'm going to get out of it.   Consequently, it's frustrating that voting activity on my Meta.SO answers, which of course imbue no rep, is not represented in this dropdown.  In fact, looking through my profile, I'm not sure whether it's possible at all to find out when people are disagreeing/agreeing with me.  Could we have some way to see this activity, please?  (Since all per-site metas have this repless feature, this is a global SE feature request.)

Child metas don't have rep, so there's no point in tracking a rep stat or reporting changes.  But one of the things rep updates do on main sites is to alert me when there's activity on older posts.  On metas, unless I revisit a question I'll never notice that there's been a bunch of voting (which might be accompanied by new comments that didn't ping me).  I'd like to know about that activity, not because of any ego reasons but because meta is where site policies get discussed and set and it's useful to know about changes in the community will.  A couple days ago I visited a meta post where, a few weeks ago, my answer had been voted down, and this time it was at the top.  Could we have something like the reputation-changes tab on meta?  I suspect that the data already exists, because I once  (and I see I'm not the only one).  If something akin to reputation is already being tracked internally on per-site metas, can we get it exposed?


Why do some people pronounce "idea" like "idier"? Sometimes they do the same thing with some other words too.

This may sound absolutely crazy but I really need an answer to that.   How do natives pronounce "idea of"  I am not sure if I hear it correctly, but to me, it seems like when natives pronounce 'idea of' they add an extra 'r' to the pronunciation. So I hear something like 'idear of'. If that is true, why do they do that?


I am new to ML and recently came across the L1 and L2 norm. The tutorials that I read  and  show some circle and diamond plots to explain these topics but I don't really understand the below things  a) Why are we trying to find an intersection point? b) Does it always have to intersect? c) I believe, the size of circle and diamond can be larger as well. Right now it's 1 (C = 1) but guess it can be C=2,3 and 4 etc as well d) I know with linear regression gradient descent, we get the estimate Beta (without any constraints). So, when we use a constraint like Lasso or Ridge, why are we trying to make sure it intersects? e) I read that this circle or diamond region is called a feasible area. Not sure what that means? Can help, please? f) I read an explanation Heuristically, for each method, we are looking for the intersection of the red ellipses and the blue region as the objective is to minimize the error function while maintaining the feasibility. May I check what does feasibility mean and why does it have to intersect? In addition, may I also know in the below graph, why does it have to intersect at the green contour line and not the red contour line  If the contour plot had been placed a little above, we could have got intersection at green instead of red? what does L1 Norm Isosurface mean? Can you guys help me?

Whenever someone writes about Lasso and Ridge Regression thy draw this diagram with the circle or with the diamond.    In the case of the diamond (Lasso regression) it is then always stated that Lasso forces one of the coefficients to 0. Therefor it introduces sparsity. I understand it somehow, but whenever I see the diagram my doubts return. Why couldn't one just draw it like this:    Obviously none of the coefficients is forced to zero in this case. Both can take number between -1 and 1. What am I missing? My drawing has to be wrong, but I don't get it why they always draw so that it hits $\beta_1=0$  Edit:  Just found this quote:     However, the lasso constraint has corners at each of the axes and so the ellipse will often intersect the constraint region at an axis   Is that it? It will intersect often with the constraint region, but it doesn't have to? Can't wrap my head around it. I can only imagine that in higher dimensional cases hitting a corner becomes more likely or even inevitable.


Let $(M,d)$ be a metric space and $x\in M$, $x_n\to x$  So $|d(x_n,a)-d(a,x)|\leq d(x_n,x)$ is a concluse form the triangle inequallty?

Here there is my proof (quite short and easy) of a rather straightforward result. The text of this question comes from a previous question of mine, where I ended up working on a wrong inequality. Here things are fixed. Still, I would like to know:  if it is sound, because absolute value always creates me some problem, and if there is a shorter (neater) way to get the result (maybe without using contradiction).    Proposition: $|d(x,y)-d(y,z)| \leq d(x,z)$. Proof: We proceed by cases.  Case 1: $d(x,y)-d(y,z) \geq 0$. Assume by contradiction that $d(x,y)-d(y,z) > d(x,z)$. Hence, $d(x,y)> d(y,z) + d(x,z)$, contradicting the triangle inequality.  Case 2: $d(x,y)-d(y,z) < 0$. Assume by contradiction that $ - d(x,y) + d(y,z) > d(x,z)$. Hence, $d(x,y) < d(y,z) - d(x,z)$. By applying the triangle inequality, we have that $d(y,x) \geq d(y,z) + d(x,z)$, which is by symmetry equivalent to  $d(x,y) \geq d(y,z) + d(x,z)$, obtaining the desired contradiction. $\square$     As always, any feedback is welcome. Thank you for your time.


Why are Basilisks so rare if they are born from such common conditions? (A Chicken egg and a Toad sitting on top whilst hatching) A simple charm should keep the Toad stationary you'd have thought? A chicken and a toad are all that are mentioned from what I can find. I understand the mythology is borrowed from the Cockatrice, but if this is genuinely the way these serpents are born then surely these creatures would litter the Wizarding world? I imagine these would also be quite common naturally if a toad happened to hop on an egg in a farmhouse. Also Hermione finds this in the library, I assume not from the restricted section since only the older students studying Defence against the dark arts can use this without a note from a Teacher. So technically any student in the school could walk into the library and create one of the most feared creatures known to Wizard-kind. This doesn't seem right? Some extracts below for context.  "This snake, which may reach gigantic size, and live many hundreds of years, is born from a chicken's egg, hatched beneath a toad." "It is a creature bred by Dark Wizards. Herpo the Foul was the first to breed a Basilisk; he accomplished this by hatching a chicken egg beneath a toad which resulted in the creature known as a Basilisk. Basilisk breeding was banned in Medieval times. The practise can be hidden when the Department for Regulation and Control of Magical Creatures comes to check by simply removing the egg from the toad."

I mean to say that anybody can hatch a chicken's egg under a toad, (even Neville can do that with his own toad ), so why are they so rare that there is only one in all of Hogwarts?


I've just written a quick algorithm that tests if a random number (decimal or whole) between -million and +million is divisible by 2. It iterated a million numbers. The sum of even numbers was ~50% every time.  I've read mixed opinions about if 'half of all numbers are even/odd'. My test shows it is true. But I feel I maybe missing something. Is there a mathematical explanation behind why this seems to be true?

Plato puts the following words in Socrates' mouth in the Phaedo dialogue:     I mean, for instance, the number three, and there are many other examples. Take the case of three; do you not think it may always be called by its own name and also be called odd, which is not the same as three? Yet the number three and the number five and half of numbers in general are so constituted, that each of them is odd though not identified with the idea of odd. And in the same way two and four and all the other series of numbers are even, each of them, though not identical with evenness. ()   The  is that there exists an Idea (or Form) called Odd and odd numbers are merely specific instances of Odd.  The are not, themselves, identical to the concept of Oddness.  But I bolded a throwaway phrase that prompts my question: Are half of all integers odd?    Plato likely did not consider  nor did he likely consider either zero or negative integers among his set of "numbers in general".  I don't see his proof (if he had or was aware of one), but I would imagine it be something along the lines that for every even number N there is an odd number N+1.  Therefore half of all numbers greater than 1 are odd.  I'm aware that , which makes me think there is one extra even number than odd numbers.  My thinking is that if half of all positive numbers are odd and half of all negative numbers are odd, than leaving out zero, half of all integers are odd.  But when you add in the only non-positive, non-negative number, which is even, you have an extra even number.  (The programmer in me wants to add the concepts of -0 and +0 for symmetry.  The rest of me thinks that's nuts!)  However, I think my imagined platonic proof still works as long as zero is definitely even and won't work if it's either odd or neither parity.  Are either of these proofs valid?


Hope everyone is doing OK. Since I upgraded my laptop to Ubuntu 20.04, I cannot access my HD partition to send files via Telegram. Every time I want to attach a file/pic, I need to copy it to the "Documents" in Home. As you can imagine, it's not practical at all, so I'd be great if someone knew how to solve it. TIA and keep safe!

I have Ubuntu 18.04 LTS installed. I inserted USB-flash to my laptop. It was automounted to /media/username/DISKLABEL and opened in Nautilus. I can read and write objects to it. How can I access it from the application, which is installed as Snap? I tried snaps of the following applications such as gedit, arduino-mhall119, organize-my-files. All them show me errors if I navigate to /media folder:    Could not read the contents of Media Error opening the directory of '/media': permission denied  Output of active Snap  is below: $ snap interfaces  | grep -v ".*-$" Slot                             Plug :browser-support                 organize-my-files :core-support                    core:core-support-plug :cups-control                    gedit :desktop                         gedit,organize-my-files :desktop-legacy                  gedit,organize-my-files :gsettings                       gedit,organize-my-files :home                            arduino-mhall119,gedit,organize-my-files :network                         arduino-mhall119,gedit,organize-my-files,pulsemixer :opengl                          organize-my-files :pulseaudio                      organize-my-files,pulsemixer :unity7                          arduino-mhall119,gedit,organize-my-files :wayland                         gedit :x11                             arduino-mhall119,organize-my-files,pulsemixer gnome-3-26-1604:gnome-3-26-1604  gedit gtk-common-themes:gtk3-themes    gedit gtk-common-themes:icon-themes    gedit gtk-common-themes:sound-themes   gedit -                                arduino-mhall119:serial-port -                                gedit:avahi-observe -                                gedit:mount-observe  Updates:  connecting mount-observe to Gedit with snap connect gedit:mount-observe does not help. it seems that we need special Snap with support of  interface.


I know from ${\bf F}=q({\bf v}\times {\bf B})$ the force is perpendicular to displacement and so work by magnetic field is always zero. But then how is that a magnet is able to displace any magnetic or metallic object and still cause no work because the motion of the object should be in the direction of force. So what is causing this object to move and which force is doing this work?

I learned that the force from a magnetic field does no work. However I was wondering how magnets can be used to pick up pieces of metal like small paperclips and stuff. I also was wondering how magnets can stick to pieces of metal like a refrigerator?


Edit: I don't think this is a duplicate. That question is generally about efficient algorithms for calculating the determinant. While my question is about practical tips and tricks which can be used when doing this sort of thing by hand.    During one of the questions I was solving I came across the following determinant:  $\left|\matrix{t-1&3&0&-3\\2&t+6&0&-13\\0&3&t-1&-3\\1&4&0&t-8}\right|$  I solved it directly by expanding from the third column and got the result $(t-1)^4$.  However, along the way I made a couple of calculation errors and finding them took me a while. This got me thinking that maybe there are some tips and tricks I could use to calculate this in a faster less error prone method. Or maybe, at least know that I got the right answer in some way?  Any tips that could interest me?

Are there efficient algorithms for calculating determinants of matrices?


I have a program for school to make and i thought i'd use vectors, everything went smoothly but at the end I saw that function in my program that pushes elements to vector of classes do it only inside function, out of function the vector has the same size.  I wrote a small test code to show it.  #include <iostream> #include <fstream> #include <string> #include <vector> #include <cassert>  using namespace std;  class Player { public:     int i = 1;      Player() {} };  void pb(vector<Player> v) {     v.push_back(Player());     cout << v.size() << endl; }  int main() {     vector<Player> v;     v.push_back(Player());      cout << "1st element i = " << v[0].i << endl;     cout << "vector size: " << v.size() << endl;      pb(v);      cout << "Second element i = " << v[1].i << endl;     cout << "vector size: " << v.size() << endl; }   The code send error "Vector subscript out of range" because I try to enter the non-existent v[1] that should exist because in function I did use push_back().  Can someone explain to me why does it happen, and how would I do it with the usage of pointers if I can do so?

What is the difference between    a parameter passed by reference a parameter passed by value?   Could you give me some examples, please?