"On" is optional with time expressions, no?
Is it correct to omit preposition before date?
Previous question:    That was when my buttons died.  On other days, my text dies.    And some times it's just italics.    Now, I like blaming @skiwi for this, and he's often nearby when it happens.  But today, he's not here, and it happened again.    I'm running Windows 8 and using Chrome 40.0.2214.94 m.  Refreshing and such does not fix the issue.  Inspect element -> console -> error log:  http://chat.stackexchange.com/chats/8595/messages/new Failed to load resource: the server responded with a status of 409 (Conflict) http://i.stack.imgur.com/2ZJdJ.png?s=128&amp;g=1&amp;g&amp;s=16 Failed to load resource: the server responded with a status of 502 (Bad Gateway) http://i.stack.imgur.com/boUZp.jpg?g&amp;s=16 Failed to load resource: the server responded with a status of 502 (Bad Gateway) http://i.stack.imgur.com/U8P3C.jpg?s=128&amp;g=1&amp;g&amp;s=32 Failed to load resource: the server responded with a status of 502 (Bad Gateway) http://i.stack.imgur.com/boUZp.jpg?g&amp;s=16 Failed to load resource: the server responded with a status of 504 (Gateway Time-out) http://chat.stackexchange.com/messages/19891816 Failed to load resource: the server responded with a status of 409 (Conflict)   What's going on here?  I should note, I can view italics by selecting, then alt-tabbing:    So it reeks of a client-side issue. What's hiding the text from me?  EDIT:  30 april 2015 it happened again =/ Is there a technical reason to use > (<) instead of != when incrementing by 1 in a 'for' loop? Is it pythonic for a function to return multiple values? In python, you can have a function return multiple values.  Here's a contrived example:  def divide(x, y):     quotient = x/y     remainder = x % y     return quotient, remainder    (q, r) = divide(22, 7)   This seems very useful, but it looks like it can also be abused ("Well..function X already computes what we need as an intermediate value.  Let's have X return that value also").  When should you draw the line and define a different method? What's the difference between these two sentences? And which one's grammatically correct? How could it possible to factorise $x^8-1$ in product of irreducibles in the rings $(\mathbb{Z}/2\mathbb{Z})[x]$ and $(\mathbb{Z}/3\mathbb{Z})[x]$? How could it possible to factorize $x^8-1$ in product of irreducibles in the rings $(\mathbb{Z}/2\mathbb{Z})[x]$ and $(\mathbb{Z}/3\mathbb{Z})[x]$?  I'm having a hard time starting the problem. Could anyone help me at this point? How do I get a straight quote instead of curly quotes? I’m not inside verb or listing or any other special environments, and I’m not using XeLaTeX or anything—just normal LaTeX. I don’t want to change all quotes, just get the occasional straight quote. For example, I’d like a way to get something like this in the TeX:  ... some examples of these glyphs are curly quotes (``''), straight quotes ('"), and angled quotes ($'$$"$) ...   to look like this in the output:  ... some examples of these glyphs are curly quotes (“”), straight quotes ('"), and angled quotes (′″) ...   As I’m using an academic-publisher-provided template that does its own required font setup, I’m extremely wary of changing fonts or font encodings. I think the template uses the times package, and the formatting instructions say all fonts must be Type 1. Testing equality of coefficients from two different regressions This seems to be a basic issue, but I just realized that I actually don't know how to test equality of coefficients from two different regressions. Can anyone shed some light on this?   More formally, suppose I ran the following two regressions:  $$ y_1 = X_1\beta_1 + \epsilon_1 $$ and  $$ y_2 = X_2\beta_2 + \epsilon_2 $$ where $X_i$ refers to the design matrix of regression $i$, and $\beta_i$ to the vector of coefficients in regression $i$. Note that $X_1$ and $X_2$ are potentially very different, with different dimensions etc. I am interested in for instance whether or not $\hat\beta_{11} \neq \hat\beta_{21}$.   If these came from the same regression, this would be trivial. But since they come from different ones, I am not quite sure how to do it. Does anyone have an idea or can give me some pointers?   My problem in detail: My first intuition was to look at the confidence intervals, and if they overlap, then I would say they are essentially the same. This procedure does not come with the correct size of the test, though (i.e. each individual confidence interval has $\alpha=0.05$, say, but looking at them jointly will not have the same probability). My "second" intuition was to conduct a normal t-test. That is, take   $$ \frac{\beta_{11}-\beta_{21}}{sd(\beta_{11})} $$  where $\beta_{21}$ is taken as the value of my null hypothesis. This does not take into account the estimation uncertainty of $\beta_{21}$, though, and the answer may depend on the order of the regressions (which one I call 1 and 2).   My third idea was to do it as in a standard test for equality of two coefficients from the same regression, that is take  $$ \frac{\beta_{11}-\beta_{21}}{sd(\beta_{11}-\beta_{21})} $$   The complication arises due to the fact that both come from different regressions. Note that   $$ Var(\beta_{11}-\beta_{21}) = Var(\beta_{11}) + Var(\beta_{21}) -2 Cov(\beta_{11},\beta_{21}) $$ but since they are from different regressions, how would I get $Cov(\beta_{11},\beta_{21})$?  This led me to ask this question here. This must be a standard procedure / standard test, but I cound not find anything that was sufficiently similar to this problem. So, if anyone can point me to the correct procedure, I would be very grateful! Can Minecraft Pocket Edition play with a desktop Minecraft? As I understand it Q&amp;A style questions are  but a self answered question should be judged independently of the answer. Often after I've solved a problem I would like to share the question and answer on stack overflow (and have on a couple of occasions) but how to show &quot;minimal understanding of the problem&quot; is always challenging. For example I have been looking into the following question  How can I plot a straight line in the JMonkey Engine library I'm trying to plot straight lines between vertices that I specify using the JMonkey Engine 3D graphics library. So for example if I was to try to plot between: (2,0,0) (-1,0,1) (0,1,1) (1,1,1) (1,4,0) Then I would get:   This is something I do (and forget how to do) relatively often and the answer is harder to find than you'd imagine ( provides everything needed to figure it out but its spread out over several posts and isn't a complete solution on its own). Therefore I want to provide a Q&amp;A for it but at present this question feels like it would fail the minimal understanding test  Questions must demonstrate a minimal understanding of the problem being solved. Tell us what you've tried to do, why it didn't work, and how it should work  Should I make up some imaginary problem? (Probably the final source code messed up a bit) Or mention in the question that I’m self answering to assuage some of the normal &quot;This is not a do your work for you site&quot; comments. Complex towers: $i^{i^{i^{...}}}$ If $w = z^{z^{z^{...}}}$ converges, we can determine its value by solving $w = z^{w}$, which leads to $w = -W(-\log z))/\log z$.  To be specific here, let's use $u^v = \exp(v \log u)$ for complex $u$ and $v$.  Two questions:   How do we determine analytically if the tower converges?  (I have seen the interval of convergence for real towers.) Both the logarithm and Lambert W functions are multivalued.  How do we know which branch to use?   In particular $i^{i^{i^{...}}}$ numerically seems to converge to one value of $i2W(-i\pi/2)/\pi$.  How do we establish this convergence analytically?  (Yes, I have searched the 'net, including the tetration forum.  I haven't been able to locate the answer to this readily.) As things stand, will House Stark go extinct? According to the family tree in A World of Ice and Fire Ned Stark's children are in fact the only surviving Starks. And as of S06E09;      Bran is the only legitimate, male Stark.   In the Season Six Finale it is revealed that;      Jon is in fact the Son of Lyanna Stark and most likely, Rhaegar Targaryen.   This means that if Jon was legitimised and there was record of his birth in the Citadel;      He would become a Targaryen.   So I guess my big question is: Can Bran father children? I find it to be quite an important issue considering House Stark's long term survival depends on it.  In season 4 (I can't remember which episode) Locke Bolton gives Bran a cut on the leg to confirm his identity. Bran reacts only with fear and not pain, indicating that he has no feeling below his waist.  Does this mean that he wouldn't be able to...get it up? And if so, why hasn't the show addressed House Stark's impending doom? When is it OK to shrink a Database? I know shrink is the devil: It reverses page order and is responsible for skin cancer, data fragmentation, and global warming.  The list goes on... That being said, say I have a 100 GB database and I delete 50 GB of data -- not on one table, but a general pruning of old data on a database wide level, covering 90% of the tables -- does this constitute an appropriate use case for shrinking the database?  If not, what are the appropriate steps to take to clean house after removing such a high percentage of data from a database?  I can think of two: Rebuild Indexes and Update Stats. What else? What is meant by "Constant Amortized Time" when talking about time complexity of an algorithm? Currently, the number of "votes cast" excludes votes on deleted content. Once something gets deleted that you voted on, that vote vanishes from your stats. This of course happens frequently especially with down-votes - if you're a good voter, stuff you downvote often ends up getting deleted.  Seeing as the idea behind the public display of total votes you've cast is to encourage voting, is this really fair?   Also, doesn't it distort greatly all voting stats, especially when looking at candidates for moderator elections and such? Geomagnetic reversal? Let $A$ be a complex matrix such that $A^n = I$, show that $A$ is diagonalisable.  How do I do this?    I would hazard a guess that since $A^n = I$ that means that $A^n$ is obvious diagonal, and I suppose that a diagonal matrix can only be formed by the square of another diagonal matrix, but I am not sure if that is the case. Also I think this neglects the complex cases.  Is there a Jordan block argument that I should use? Problem on Extremal Graphs: three independent paths The problem states that:     A simple (or strict) graph with $n$ vertices and $m&gt;\dfrac{3(n-1)}{2}$ edges, has two vertex   joined by three independent paths.   Any hints, ideas or useful results, to attack this problem? Forward/Inverse Search Does Not work on certain tex files How do I compare binary files in Linux? I need to compare two binary files and get the output in the form:  &lt;fileoffset-hex> &lt;file1-byte-hex> &lt;file2-byte-hex>  for every different byte. So if file1.bin is    00 90 00 11   in binary form and file2.bin is    00 91 00 10   I want to get something like    00000001 90 91   00000003 11 10   Is there a way to do this in Linux? I know about cmp -l but it uses a decimal system for offsets and octal for bytes which I would like to avoid. By default after a new user signs up, a redirect to the home page happens.  But in such case I want to redirect such user to another page like node/35.  In this node/35 I then want to display some content.