In normal linear regression, defining $Y_i = X_i\beta+\epsilon_i,$ with $\epsilon_i$ c.i.i.d. $\mathcal{N}(0,\sigma^2)$, is equivalent to say $Y|X \sim \mathcal{N}_n(X\beta,\sigma^2I_n)$. The second seems a better choice for generalization, for instance in GLM's, where the distribution of $Y|X$ usually belongs to the exponential family. In practice, if there are no &quot;physical constraints&quot; in choosing the statistical model, how does one model the stochastic part of a GLM? I used to think that you could do it by looking at the histogram of $Y$, but this question  made me realize I was completely wrong!
I have fish density data that I am trying to compare between several different collection techniques, the data has lots of zeros, and the histogram looks vaugley appropriate for a poisson distribution except that, as densities, it is not integer data. I am relatively new to GLMs and have spent the last several days looking online for how to tell which distribution to use but have failed utterly in finding any resources that help make this decision. A sample histogram of the data looks like the following:   I have no idea how to go about deciding on the appropriate family to use for the GLM. If anyone has any advice or could give me a resource I should check out, that would be fantastic.
Which of the following are correct and which are wrong?   The 2000-year-old computer The 2000 year-old computer The 2000 year old computer The 2000-years-old computer The 2000 years-old computer The 2000 years old computer   In a documentary, BBC4 used the title The 2000 year-old computer, which I believe to be wrong. Am I right? Elysia cron module does not execute cron job automatically I have installed the elysia cron module and setup the cron job. My module has a cron function test_cron() which inserts some data into a table.  This function lists in the elysia cron status page. I have setup the the default scheduled rule to */1 * * * * to run the cron after every minute.  When I click on the run infront of the test_cron() the cron runs and some data inserts into the database.  But this the manual method, I want to execute the cron after every minute therefore I defined the scheduled time for the test_cron(),  but it does not executed automatically after every minute.  What should I do? Is there any other configuration which I should do to run the cron automatically? I try to create a common extent for rasters in QGIS 2.99. Here is my script:  import processing  processing.runalg("script:unifyextentandresolution",                   "/qgis_data/rasters/Image2.tif;                   /qgis_data/rasters/Image1.tif",                  -9999,"/qgis_data/rasters",True)   However, processing.runalg is being used for QGIS 2.99. I need it for QGIS 2.99 What is the equivalent of gksudo in Kubuntu/KDE? In regular Ubuntu (Unity/Gnome), I use gksudo to run GUI programs with root privileges. I'm trying out Kubuntu (or KDE) now -- what do I use? Using a foreign driver's license in California when staying with a J-1 visa Getting the class name of an instance? For context, see .  In essence:     "This question is protected to prevent "thanks!", "me too!", or spam answers by new users. To answer it, you must have earned at least 10 reputation (not including the ) on this site."   Suggested addition to existing message is in bold. Usually \label does not create any white spaces. However, It creates an white space when \label is used after \phantomsubcaption from subcaption package.   Why? How can I get rid of this white space?   Here is a MWE:  \documentclass{article} \usepackage{subcaption}  \begin{document}  \section{a} a\label{sec:a}b% no white space between `a' and `b'  \begin{figure}   \centering   {a\phantomsubcaption\label{fig:a}}%   {b\phantomsubcaption\label{fig:b}}   \caption{With label}% undesired white space between `a' and `b' \end{figure}  \begin{figure}   \centering   {a\phantomsubcaption}%   {b\phantomsubcaption}   \caption{Without label}% no white space between `a' and `b' \end{figure}  \end{document} Software to read a QR code? I saw a  reading a book, but I don't have a smart phone to check it.    So I just took a picture of it and saved my PC. And I downloaded libdecoderqr0, libdecodeqr-dev, libdecodeqr-examples for reading it. But I don't know how to use it.    What do I do next, or is there a nicer way to read QR codes? How does $cos(x) = \frac{\vec{v} \cdot \vec{w}}{|\vec{v}| \cdot |\vec{w}|}$ make sense? In Multivariable Calculus, the professor said that in order to compute the angle $x$ between two vectors $v$ and $w$, we use the formula: $\cos(x) = \frac{\vec{v} \cdot \vec{w}}{|\vec{v}| \cdot |\vec{w}|}$  He also mentioned "Projection" but I didn't understand much of it. The only thing I got was that we can create a right triangle by drawing a perpendicular line from one vector to the head of the other and compute the angle like that using $\cos$, but I don't understand why we're multiplying vectors, or dividing by their magnitudes…how do those operations make sense?  Also, in the specific example, the result of $\cos(x) = \frac{\vec{v} \cdot \vec{w}}{|\vec{v}| \cdot |\vec{w}|}$ ended up being $1/2 = \pi/2$. Where does $\pi/2$ come from here? I can't understand how we go from $1/2$ to $\pi/2$. Why is cd not a program? I've got a stylesheet that will not, for whatever reason, apply list-style-type to a UL element. I'm using YUI's Grid CSS with their reset-fonts-grid.css file, which I know strips that out as part of the CSS reset.  After calling YUI, I call the stylesheet for the website and in there have a block for UL:  ul {list-style-type: disc;}   I've also tried setting it via list-style but get the same result. I know that the above CSS block is getting read as if I add things like padding or margins those do get applied. The style-type isn't showing up in either Firefox or IE.  The only other CSS I've applied to UL's are in a #nav div but that CSS doesn't touch the list-style-type, it uses the reset that YUI provided, and YUI and the site style sheet are the only two CSS sheets that are called.  I've also got FCKEditor on the admin side of the site and that editor does show the bullet styles so I know it has to be something with the CSS that isn't being filtered by FCKEditor. In unix/linux, any number of consecutive forwardslashes in a path is generally equivalent to a single forwardslash. eg.  $ cd /home/shum $ pwd /home/shum $ cd /home//shum $ pwd /home/shum $ cd /home///shum $ pwd /home/shum   Yet for some reason two forwardslashes at the beginning of an absolute path is treated specially. eg.  $ cd ////home $ pwd /home $ cd /// $ pwd / $ cd // $ pwd // $ cd home//shum $ pwd //home/shum   Any other number of consecutive forwardslashes anywhere else in a patch gets truncated, but two at the beginning will remain, even if you then navigate around the filesystem relative to it.  Why is this? Is there any difference between /... and //... ? A slick proof that a field which is finitely generated as a ring is finite It is a known fact that if $k$ is a field that is finitely generated as a ring, which is the same as having a surjective ring homomorphism $f:\mathbb{Z}[x_1,\dots,x_n]\to k$ for some $n\in \mathbb{N}$, then $k$ must be finite. Since finite generation as a ring implies finite generation over the prime field ($\mathbb Q$ or $\mathbb F_p$), by Noether normalization it follows that $k$ must be a finite extension of its prime field. In positive characteristic this finishes the job and in zero characteristic, should lead quickly to a contradiction, though I don't see immediately how. Is there an elementary/slick proof of this fact? Referring to unidimensional motion, it is obvious that it doesn't always make sense to write the speed as a function of position. Seems to me that this is a necessary condition to derive formulas like:  $$v^2=v_0 ^2 +2\int_{x_0}^{x}a\cdot dx$$  In fact, in the first step of the demonstration (the one I saw, but I think that this step is crucial) it's required to write $a=dv/dt=(dv/dx)(dx/dt)$, that doesn't make sense if $v$ isn't a function of $x$.   When can one rigorously write $v=v(x)$? Where has the trailing newline char gone from my command substitution? In my opinion the accepted answer should permanently stick as only the original question submitter has the ability to accept. This is a question that arose in the comments here:   I normally hide footnotes from the TOC by doing this:  \section[title]{title\footnote{This is a footnote.}}.   This works in a lot of document classes (memoir, article, ...), but not in all of them. amsbook, for example, uses the optional argument only for the running heads so the footnote mark still ends up in the TOC. So what is the 'universal solution'? How to remove feeds from WordPress totally? I want to completely remove feeds from WordPress. I am using this little function from    /** * disable feed */ function fb_disable_feed() { wp_die( __('No feed available,please visit our &lt;a href="'. get_bloginfo('url') .'"&gt;homepage&lt;/a&gt;!') ); } add_action('do_feed', 'fb_disable_feed', 1); add_action('do_feed_rdf', 'fb_disable_feed', 1); add_action('do_feed_rss', 'fb_disable_feed', 1); add_action('do_feed_rss2', 'fb_disable_feed', 1); add_action('do_feed_atom', 'fb_disable_feed', 1);   Still there is tons of transient options.. like _transient_feed_mod or _transient_timeout_feed_mod  How can i completely remove feeds from WordPress? If parsing the output of ls is dangerous because it can break on some funky characters (spaces, \n, ... ), what's the best way to know the number of files in a directory?  I usualy rely on find to avoid this parsing, but similarly, find mydir | wc -l will break for the same reasons.  I'm working on Solaris right now, but I'm looking for a answer as portable across different unices and different shells as possible.