Why doesn't my string comparison with == work?
How do I compare strings in Java?
How can one change the timestamp of an old commit in Git? The answers to  describe a way to amend previous commit messages that haven't yet been pushed upstream.  The new messages inherit the timestamps of the original commits.  This seems logical, but is there a way to also re-set the times? Why does Maximum Likelihood estimation maximize probability density instead of probability I am trying to understand Maximum likelihood estimation but it looks like I am missing something rather elementary.          suppose we have an iid random sample $X_1, X_2,..., X_n$ for which the probability density function of each $X_i$ is $f(x_i; \theta)$ where $\theta$ is an unknown parameter. Then, the joint probability density function of $X_1, X_2,..., X_n$ is given by:          $f(X_1=x_1,X_2=x_2,\cdots,X_n=x_n)=\prod_{i=1}^{n} f(x_i, \theta)$      In Maximum Likelihood estimation, we try to maximize $f$ as a function of $\theta$.  Question: Why do we maximize probability density instead of probability? In what way does it make sense?  Edit: As explained in the answers, the probability of choosing a finite number of sample points from a continuous probability distribution is zero, so maximizing probability doesn't make sense, but how does maximizing probability density make sense? From this  by orlp:     If I strap a rocket booster to a rocket in space and fire it for one second, then the work provided is much higher when the rocket is flying fast compared to when the rocket was stationary. In both cases the rocket fires for the same duration but in the former case the rocket travels a much greater distance during this period. What gives? I've been writing in English for many years, but there are certain recurring issues that come up in my writing, which I can't seem to resolve permanently. Primarily I have a problem with punctuation. In my native language, commas are very commonly used. One would place a comma to separate any portion of the sentence that serves a specific grammatical role. At least, this is the case according to the rules I was taught in school. I can see when I write in English that there are extraneous commas, but I can't always figure out which ones, and why. When dependent clauses require commas, when do they allow them, and when are they definitely incorrect? How to find the last field using 'cut' How to set systemd for automatically force fsck disks after crash (hard poweroff)?  When I used sysvinit (in Arch Linux) as /sbin/init I used the hack: in the rc.local I create /forcefsck file; in the rc.local.shutdown I remove it. At boot-up rc.sysinit enable force fsck if /forcefsck exists.  How to do same in systemd? Maybe it has built-in facilities for automatic fsck after crush? I understand the reasoning behind the fairly narrow textwidth in a default LaTeX article. 60-80 characters per line and all that. However, I am preparing a document that features many lengthy equations, and it seems silly to me to restrict the equations to fit into the same margins as the text when there's all that whitespace going unused on either side.  I'd like to have equations which are wider than the textwidth do the obvious thing, that is, continue to be centered on the page just like all the other equations, and simply extend into both the left and right margin equally. My equations are unnumbered, so there's no concern about where to put equation numbers.  How might I go about implementing this? Overview of basic facts about Cauchy functional equation This question was , but I think that the only answer didn't quite understand the question so I thought I'd try again. I'm writing a paper in which I need to have references show up in two places:  a special list of &quot;key references&quot; in its own section, and a bibliography containing the rest of the references that were cited in the text. I thought that bibentry would do it, so the document looks something like: \documentclass[11pt]{article} \usepackage{natbib} \usepackage{bibentry} \nobibliography*  \begin{document}  \section{Amazing idea}  Chicken chicken chicken \citep{chicken:2010fj}.  Chicken chicken, chicken \citep{turkey:2010jk}.  \section{Key References}  \begin{enumerate} \item \bibentry{lemur:2009ii} \item \bibentry{gibbon:2011jk} \end{enumerate}  \bibliographystyle{apalike} \bibliography{amazing.bib} \end{document}  Unfortunately, this doesn't quite do it, as the resulting document presents the lemur and gibbon bibentry references correctly in the &quot;Key References&quot; section, but also prints them in the bibliography at the end of the document.  Ideally, the only entries in the bibliography would be the chicken and turkey \citep references.  I'd like it to look like:  Key references  Lemur, L. (2009). Lemur, 12(4):1-7. Gibbon, G. (2011). Gibbon, 135:1002-1009.  References Chicken, C. (2010). Chicken. Chicken Press, Coop. Turkey, T. (2010). Turkey, 7(4):E231.  What it actually looks like:  Key references  Lemur, L. (2009). Lemur, 12(4):1-7. Gibbon, G. (2011). Gibbon, 135:1002-1009.  References Chicken, C. (2010). Chicken. Chicken Press, Coop. Gibbon, G. (2011). Gibbon, 135:1002-1009. Lemur, L. (2009). Lemur, 12(4):1-7. Turkey, T. (2010). Turkey, 7(4):E231.  Is there any way to achieve this with the current method, or is there some other (possibly easier!?) way to do this? I don't have administrator account on my mac On my mac I have 2 accounts and the both are normal account. So in this moment I don't have a Administrator account, only one that was in the past a administrator, but now is not.  How I can have again a Administrator account? Connecting MySql with Android without using PHP Taking advantage of one-time pad key reuse? Suppose Alice wants to send encryptions (under a one-time pad) of $m_1$ and $m_2$ to Bob over a public channel.  Alice and Bob have a shared key $k$; however, both messages are the same length as the key $k$.  Since Alice is extraordinary lazy (and doesn't know about stream ciphers), she decides to just reuse the key.  Alice sends ciphertexts $c_1 = m_1 \oplus k$ and $c_2 = m_2 \oplus k$ to Bob through a public channel.  Unfortunately, Eve intercepts both of these ciphertexts and calculates $c_1 \oplus c_2 = m_1 \oplus m_2$.     What can Eve do with $m_1 \oplus m_2$?     Intuitively, it makes sense that Alice and Bob would not want $m_1 \oplus m_2$ to fall into Eve's hands, but how exactly should Eve continue with her attack? I just wrote an answer to , which was trying to find numeric strings with or without commas (e.g. 1,234,567.89). I wanted to be thorough because I've seen this problem a lot, both on SO and in real-world code.   When I finished, I found 7 other new answers waiting for me, mostly variations on each other. Which would be fine, except for one thing: They're garbage answers. Unless I'm severely mistaken, every answer but mine (so far) is deeply flawed, and I want to downvote all of them. Yeah, I'm a stickler on regex, but IMHO if your pattern lets stuff like  ...,.,,.,,..9 or even ... pass as "numeric input," then you've failed to meet even the bare minimum requirements.  Enough venting. The reason I'm whining to Meta about this is that I'm about to do something that'll REALLY look like tactical downvoting, and I'm mildly concerned about the consequences. If I answer a question and then rain downvotes on every competing answer, will I get flagged for abuse? That would certainly seem like suspicious behavior to me.  More of an opinion question: At what point does a semi-correct answer deserve a downvote? Obviously, if it were just a typo, I'd edit it myself. Where's the line between "close enough" and "this answer sucks?"  Basically, is it just me? You've seen the question; am I right that these answers deserve downvotes? Seven people thought that [0-9,.]+ was good enough to declare something a number, so why am I the only one who doesn't?    Note: I found some related questions, but nothing that seemed like a duplicate:    - More of an etiquette question, plus the voter hadn't posted his own answer.  - I guess this pretty much covers my second question.   Also, as some have noted, my answer ended up pretty long and thorough. I put in a lot of effort because, with all this talk about how the other answers sucked, I wanted to be extra sure mine didn't. I don't expect pages of detail in a normal SO answer. How fast is Earth moving through the universe? As the galaxy is moving and the solar system orbiting the galaxy and the Earth orbiting the sun. So how fast is each object moving and what is the fastest we move at?  Do we even know how fast the galaxy is moving that is not relative to another galaxy (although I guess velocity has to be measured relative to something). Why do I have to use \par if I change font size withing a group scope? What algorithm(s) are used by MoleculeModify's GenerateConformers? My friend had a  on the board with 10 counters on it.  If I destroy it and he sacs it in response to gain the life, is there anything that can be done about that?  Like, can I put another destroy artifact on the stack to resolve before his sac resolves? Is there console mode in Mac OS X? How do I rename a domain and preserve SEO? About an Hour ago, I faced a problem and tried different ways to solve it.  At last I was going to post my Question on Stack Overflow, but the last trick which came in my mind worked, and the problem got resolved.    Now, if I want to post that problem on Stack Overflow with the solution which worked for me, for the purpose to help other newbies to get their answer if they face the same problem, what is the proper way of posting such solution to a problem?