How to clean up the files left by deleted VirtualBox VMs? I am running OS X Sierra on a 2016 Macbook Air.  I installed VirtualBox recently, and had 48 GB of free space after installation. I then set up an Ubuntu VM with a 10 GB hard drive. After 20 minutes of playing around, I deleted the VM.  Upon checking my free space, I saw that I now have only 46 GB left. Undoubtedly, VirtualBox left some files undeleted because I did not install/download/transfer anything else in that time. I even went to the path where the VMs are stored on my real hard drive and deleted that directory, but it still didn't help.  I can't afford to lose 2 GB every time I delete a VM. I am on a lightweight Macbook Air and memory space is very valuable to me. Any help would be appreciated, thanks.  EDIT: This eating up of space is most definitely due to VirtualBox. I created and deleted another Ubuntu VM instance and sure enough, lost out on another 2 GB.
How can I figure out what's slowly eating my HD space? Every few days I get notices on my MacBook that it's running or run out of hard drive space. Curiously, restarting the computer will enable me to recover gigabytes of space (this past time, it was able to recover about 2.2GB). However, I can't identify anything in my personal activity that consumed that space.  It's possible that it's a rogue iTunes podcast or a huge software update that my Mac is automatically downloading - would either of these reclaim the space upon a restart?  One possibility that I can think of is that FileVault has some sort of disk leak, allocating but not freeing files. Does this make sense? Is there a tool that I can run to determine where this space is going? Assuming it is FileVault, should I try to disable it? What's the best way to turn of FileVault on a nearly full computer?
I'm taking an intro course in Probability theory, and we have just defined expectation for a random variable as $E(X) = E(X^+) - E(X^-)$ if either of them is finite (extending the definition first from simple positive rv to positive rv, and then to all rvs, positive or not).  Then I came across this result for the expectation of a positive random variable. Let $(\Omega, \mathcal{F}, P)$ be a probability space and $X \ge 0$ be a positive rv:  $$ E(X) = \int_{\Omega} X dP = \int_\Omega \int_0^\infty \mathbf{1}_{\{X &gt; t\}} dt  \, d P = \int_{0}^\infty P(X &gt; t) dt. $$ Actually, I'm familiar with this result, and the proof I've seen before involves converting $\int^\infty_0 P(X &gt; t) \, dt$ to a double integral. What I'm struggling with is the step $ \int_{\Omega} X dP = \int_\Omega \int_0^\infty \mathbf{1}_{\{X &gt; t\}} dt  \, d P $, and also the formal definition of an expectation itself.   I have no previous with integration or a "hard analysis" background, and the material covered so far in the course I'm taking has only used $\int_\Omega X dP$ as a notational device for $E(X)$. In general, any pointers to literature or "intuitive" explanations are more than welcome.  Thanks in advance! Can Ubuntu really run all Windows programs? Apply a modifier as a shapekey into existing shapekey or merge shapekeys? I am making a shapekey of a model shrinkwrapped to another model. The shrinkmap modifier is too inaccurate to wrap to the model alone. So, my first step was to roughly hand position the geometry around of the first model around the second, then use shrinkwrap. The rough positioning was done as a shape key. I can then apply shrinkwrap, but its as a separate shapekey. The two do not work well together. I need them to be the same shapekey. How do I apply a modifier to an existing shapekey, or merge/combine/join the two shapekeys? How should I implement hook_menu()? Gaussian/Normal plots from a data distribution in scientific notation I am new to Tex and trying to plot a gaussian distribution from a set of values. I have the following set of values and would like to plot a normal distribution for them.  2.9954E-09  3.1314E-09  3.1155E-09  3.0940E-09  2.8861E-09  3.0875E-09  2.9685E-09  3.0532E-09  2.9003E-09  3.0931E-09  I have tried using the sample code but can't figue out where to input my values.   \begin{tikzpicture} \begin{axis}[   no markers,    domain=0:6,    samples=10,   ymin=0,   axis lines*=left,    xlabel=$x$,   every axis y label/.style={at=(current axis.above origin),anchor=south},   every axis x label/.style={at=(current axis.right of origin),anchor=west},   height=5cm,    width=11cm,   xtick=\empty,    ytick=\empty,   enlargelimits=false,    clip=false,    axis on top,   grid = major,   hide y axis   ]   \addplot [very thick,cyan!50!black] {gauss(x, 3, 1)};  \pgfmathsetmacro\valueA{gauss(1,3,1)} \pgfmathsetmacro\valueB{gauss(2,3,1)} \draw [gray] (axis cs:1,0) -- (axis cs:1,\valueA)     (axis cs:5,0) -- (axis cs:5,\valueA); \draw [gray] (axis cs:2,0) -- (axis cs:2,\valueB)     (axis cs:4,0) -- (axis cs:4,\valueB); \draw [yshift=1.4cm, latex-latex](axis cs:2, 0) -- node [fill=white] {$0.683$} (axis cs:4, 0); \draw [yshift=0.3cm, latex-latex](axis cs:1, 0) -- node [fill=white] {$0.954$} (axis cs:5, 0);  \node[below] at (axis cs:1, 0)  {$\mu - 2\sigma$};  \node[below] at (axis cs:2, 0)  {$\mu - \sigma$};  \node[below] at (axis cs:3, 0)  {$\mu$};  \end{axis}  \end{tikzpicture}   Your assistance will be highly appreciated. Thanks! "In the case of medical diagnostics, there is a cost associated with each medical procedure that provides additional information (blood test, x-ray, etc.)."   Should that end with "etc.).", "etc)." or "etc.)"? Is there always an equilibrium point in space for gravity? For instance, for a two-body system, there will always be a point in-between the two in which the forces of gravity completely cancel, and if I were there then I would experience no net force. I believe there is also a point, or a region, for three body systems as well. Assuming we treat the stars or planets as simply point-masses, will there always be, for any number of objects, a point, or a region, of equilibrium? Or no? I get that some spells are "especially swift" to cast and thus have a casting time of "Bonus Action". But is there any reason I couldn't cast such a spell as my Action?   Does it make a difference if the idea is for the one spell to be cast all by itself on a turn or if the desire is to use another Bonus Action (possibly a spell) on the same turn? Why does nothing show up in the Compositing tab? I am trying to follow Blender Guru's beginner tutorial. He went to the Compositor tab and was using it to Denoise an image but when I got there, no nodes show up. Can you guys help? Getting a better understanding of callback functions in JavaScript I understand passing in a function to another function as a callback and having it execute, but I'm not understanding the best implementation to do that. I'm looking for a very basic example, like this:  var myCallBackExample = {     myFirstFunction : function( param1, param2, callback ) {         // Do something with param1 and param2.         if ( arguments.length == 3 ) {             // Execute callback function.             // What is the "best" way to do this?         }     },     mySecondFunction : function() {         myFirstFunction( false, true, function() {             // When this anonymous function is called, execute it.         });     } };   In myFirstFunction, if I do return new callback(), then it works and executes the anonymous function, but that doesn't seem like the correct approach to me. Hi I'm traveling to Uzbekistan and have 12 hours layover in Seoul via Korean Airlines. Do I need a visa to go out of the airport for sightseeing? I'm a Philippine passport holder. How do I get back some deleted records? I mistakenly deleted around 2,000,000 records from a remote SQL Server 2008 table.  The server is not granting me access to the backup files on the server side.   Is there any way to get back these records? How can I remove duplicate values from an array in PHP? Pagination returns 404 after page 20 I got a paged loop that pulls in 4 posts per page from custom post type. It works great, with the only downside that the pagination wont go over the page/20 everything after that is 404, and the posts_nav_link won't show the next arrow at all. Like the pages just aren't there.  In total there are 119 published posts in the custom post type. If I change posts_per_page to, say 6, then I get access to more of the posts from the end, but it also stops at the page/20.  On the production site the pagination stops at 21, I guess because the live database has more entries.  I got the "Blog pages show at most" setting set to 6.  Here's the loop I'm using:  &lt;?php $paged = get_query_var('paged') ? get_query_var('paged') : 1; $args  = array(     'posts_per_page' =&gt; 4,     'orderby'        =&gt; 'modified',     'post_type'      =&gt; "projekte",     'paged'          =&gt; $paged ); $custom_query = new WP_Query($args); $c = 0; while($custom_query-&gt;have_posts()) :     $custom_query-&gt;the_post();     ?&gt;     &lt;article&gt;...&lt;/article&gt;     &lt;?php endwhile; wp_reset_postdata(); // reset the query ?&gt;   I've gone through the functions.php a million times looking for a some limiting get_pre_posts filter but there's nothing I can see.  I also got an error log setup and nothing is returned there, I've tested it that it works.  Any suggestions? How to change boot priority? I tried and got this   $$e=\sum_{k=0}^\infty\frac{1}{k!}=\lim_{n\to\infty}\sum_{k=0}^n\frac{1}{k!}$$ $$n!\sum_{k=0}^n\frac{1}{k!}=\frac{n!}{0!}+\frac{n!}{1!}+\cdots+\frac{n!}{n!}=m$$ where $m$ is an integer. $$\lim_{n\to\infty}n\sin(2\pi en!)=\lim_{n\to\infty}n\sin\left(2\pi n!\sum_{k=0}^n\frac{1}{k!}\right)=\lim_{n\to\infty}n\sin(2\pi m)=\lim_{n\to\infty}n\cdot0=0$$  Is it correct? How to apply a modifier in V2.9+ Why I can't apply mirror modifier? Here's screen How do I change the plymouth bootscreen? How to compare the output of \ref to a number? I want to compare the output of \ref to a number in LaTeX. I thought it would be easy but after spending lots of hours surfing the net I still don't know the answer. I found similar questions on this site but I would prefer a solution that does not require another package to be included, so that I can see clearly how the \ref command (and some others) works. I tried a lot of things, some of which I share below, therefore my question is rather long, I'm sorry about that. First, I tried the following codes (the resulting error messages are shown after a % sign):  \begin{equation} \label{eq:myeq}   a=b   \end{equation}  \ifnum\ref{eq:myeq}=1 true\else false\fi % error: "Missing number, treated as zero."  \expandafter\ifnum\ref{eq:myeq}=1 true\else false\fi % error: "Missing number, treated as zero."  \edef\blabla{\ref{eq:myeq}} % error: Incomplete \iffalse; all text was ignored after line 42. \ifnum\blabla=1 true\else false\fi \expandafter\ifnum\blabla=1 true\else false\fi   Of course, \ref{eq:myeq} gave the expected result, namely 1.  Then, I found the definition of \ref using the latexdef ref command:       \ref:   macro:#1->\expandafter \@setref \csname r@#1\endcsname \@firstoftwo {#1}   Further examining \@setref and \firstoftwo, I concluded that the equation number (together with the page number) is stored in a control sequence called \r@eq:myeq. More precisely, the content of \r@eq:myeq is {1}{1} where the first number is the equation number and the second number is the page number. (The output of \expandafter{\csname r@eq:myeq\endcsname} is 11.) If I understand well, in order to obtain the equation number we have to expand \csname r@eq:myeq\endcsname by only two levels to get {1}{1} (the first level of expansion yields \r@eq:myeq), and then we choose the first argument by \@firstoftwo. Since there is no simple way to expand a control sequence by only one level, it is done in a rather circuitous (say tricky) way by \ref. This I could also reproduce by the following code:  \def\sth#1#2{\expandafter #2#1} \makeatletter \expandafter\sth\csname r@eq:myeq\endcsname\@firstoftwo \quad \ifnum1=\expandafter\sth\csname r@eq:myeq\endcsname\@firstoftwo true\else false\fi \makeatother   which resulted in 1   true. So far so good but there are still a few questions. First of all, if the above code works then why does the code with \ifnum1=\ref{eq:myeq}... fail (see above)? Seemingly, the two "algorithms" are doing the same. Second, the above code works only if the auxiliary file (with aux extension) contains the label definition. If it doesn't (the reference is undefined) then LaTeX gives the following error message: Missing number, treated as zero. How can I write a code that works even if the reference is undefined? Thank everybody who read all my above struggle and I would appreciate if someone shed light on the points that were not clear to me and who corrected me where I was wrong and confirmed where I was correct. Unfortunately the whole command syntax of (La)TeX is still very strange to me. How are connections differentiated from behind NAT routers?