Get named Vector values with non-unique names
Indexing redundantly named vector in R
Problem with PDO MySQL For the last couple of days I've been getting the following error:     Fatal error: Undefined class constant 'MYSQL_ATTR_USE_BUFFERED_QUERY' in /home/mydomain/public_html/drupal/includes/database/mysql/database.inc on line 46   This comes after my Hosting did an upgrade and PHP is now version 5.2.17.  From what they have told me, I think I have to enable a PDO MySQL extension in php.ini.  The problem is I'm on a shared hosting and I don't have access to the file; also, my Hosting said they can't change it either.  My info.php shows:     PDO      PDO support enabled      PDO drivers sqlite, sqlite2        pdo_sqlite      PDO Driver for SQLite 3.x enabled      PECL Module version (bundled) 1.0.1 $Id: pdo_sqlite.c 293036 2010-01-03 09:23:27Z   sebastian $      SQLite Library 3.3.7     I tried modifying the .htaccess file and/or adding my own php.ini file to the root directory per some suggestions I found, but nothing I've tried has worked yet.  Can anyone please suggest what else I could do?  EDIT:  Once again I asked the Hosting to enable PDO_MySQL extension and their answer was that they could not, that cPanel (to which they migrated from Plesk, causing this whole problem) had this extension disabled by default and changing it would affect their servers.  Their solution?  That I would change my programming to adjust to these new features, which I wouldn't even know how to go about.  Are they right requesting that I do this? Is there any other way? Difference between "@id/" and "@+id/" in Android I have a set of measurements which is partitioned into M partitions. However, I only have the partition sizes $N_i$ and the means $\bar{x}_i$ from each partition. Because all measurements are assumed to be from the same distribution, I believe I can estimate the mean of the population, $\bar{y}$, and standard deviation of the mean, $\sigma_{mean}$: $$ N=\sum_{i=1}^M N_i $$ $$ \bar{y} = \frac{1}{N}\sum_{i=1}^MN_i\bar{x}_i $$  $$ \sigma_{mean}=\sqrt{\frac{1}{N}\sum_i N_i(\bar{x}_i-\bar{y})^2} $$  My questions:   Am I right in my assumptions, that the mean $\bar{y}$ can be computed as above?  How can I find the standard deviation for the population, given only the means?  I read that the standard deviation of the population and standard deviation of the mean is related with $$ \sigma_{mean}=\frac{\sigma}{\sqrt{n}} \mbox{[1]} $$ where $n$ is the number of samples used in the computation of $\bar{x}_i$. So is it actually as simple as just multiplying $\sigma_{mean}$ with $\sqrt{n}$ if $n$ for all means are the same?   If it's that simple, what do I do if each $\bar{x}_i$ is computed using a different number of samples?    [1] What can I do to lift a 10 year ban for making a mistake in my UK visa application? I am a Nigerian citizen.  In 2007 I was twice denied a visa to the UK.  Recently I was filling out an application for another UK visitor visa and by mistake I answered no to the question whether I had ever been denied a UK visa, instead of yes.  When reviewing my application, the visa officer found out about the previous visa rejections and as a result I got a 10 year ban on travel to the UK.  What can I do to lift my 10 year ban?   Will this ban affect my chances of obtaining a visitor visa to the USA? Bibliography style elsarticle-num-names with DOI and hyperlinks but no explicit url I prepared my article with elsarticle, using \citep &amp; \citet throughout. I originally used apalike bibliographystyle but now need to change it to elsarticle-num-names for citation formatting requirements (see point #2 below).  Now, I am attempting to make 2 changes:     add DOIs to the bibliography change reference style to [1] for \citep and Author et al. [1] for \citet.   I want to keep hyperref and do not want explicit URLs (only DOIs) but cannot make this work!  Thank you for any help you might have!  MWE:  \documentclass[preprint,12pt]{elsarticle} %\usepackage{hyperref}  \journal{Test Journal} \begin{document} \begin{frontmatter} \title{The Title} \author{Prof. Big Ol' Wanker} \address{123 Happy Lane} \begin{abstract} TEXT \end{abstract} \begin{keyword} keyword 1 \sep keyword 2 \sep keyword 3 \end{keyword} \end{frontmatter}  \section{SECTION1TEST} \noindent cite: \cite{Richards1931} \\ citep: \citep{Richards1931} \\ citet: \citet{Richards1931} \\  \bibliography{library} \bibliographystyle{elsarticle-num-names}  \end{document}   Here is the reference for Richards1931 from my library.bib file:    @article{Richards1931, author = {Richards, LA}, doi = {10.1063/1.1745010}, file = {:D$\backslash$:/Papers/Richards - 1931 - Capillary Conduction of Liquids Through Porous Mediums - Journal of Applied Physics.pdf:pdf}, issn = {01486349}, journal = {Journal of Applied Physics}, pages = {318}, title = {{Capillary Conduction of Liquids Through Porous Mediums}}, url = {http://scitation.aip.org/content/aip/journal/jap/1/5/10.1063/1.1745010}, volume = {1}, year = {1931} }   without hyperref (wanted hyperlinks present, DOI displays correctly, but unwanted URL is present):    with hyperref (hyperlinks not present, DOI displays incorrectly, and unwanted URL is present): Show that $\forall (x,y)$ in the first quadrant: $\frac {x^2+y^2}{4}\leq e^{x+y-2}$ How to close aberrant tooltips in Windows So, here I am, trying to watch The Cleveland Show (TM).      And, as happens from time to time, some program or another has left a modal tooltip.  I don't know which program; how can I lose the tooltip, short of logoff/reboot?  Currently happening on Windows 10, but I have seen it on other versions. When should I use "didn't" instead of "haven't"? Is haven't supposed to mean something I may still do and didn't not?  Can I use didn't for something I might still do? How does entropy depend on location and scale? How to search only unanswered questions with an open bounty ? php SimpleXML check if a child exists Python Argument Binders How can I bind arguments to a Python method to store a nullary functor for later invocation?  Similar to C++'s boost::bind.  For example:  def add(x, y):     return x + y  add_5 = magic_function(add, 5) assert add_5(3) == 8 Odds made simple Do you ever need to specify 'javascript:' in an onclick? Find the expected value of $\frac{1}{X+1}$ where $X$ is binomial The problem:  X is a binomial random variable, find $E[\frac{1}{X+1}]$ n and p are not given  PDF for a binomial distribution is $\binom{n}{k}p^k(1-p)^{n-k}$  Expected value is $\sum{x_ip(x_i)}$  But this is where I get stuck, I'm really rusty on my statistics and I'm not sure exactly how to structure it in the next step? I think I want to get the form of the following out of the summation  $\sum _{k=0}^{n} \binom{n}{k}p^k(1-p)^{n-k} = (p + 1 - p)^n = 1$  But I'm not sure if it should look like  $\sum \frac{1}{xp(x)+1} $  and if it should where to go from here? Lebesgue density theorem in the line Find the center of the symmetry group $S_n$.   Attempt:  By definition, the center is $Z(S_n) = \{ a \in S_n : ag = ga \forall\  g \in S_n\}$. Then we know the identity $e$ is in $S_n$ since there is always the trivial permutation. Suppose $a$ is in $S_n$, but not equal to identity. Now we can imagine the permutation as bijective function that maps from $\{1,2,\dotsc,n\}$ to $\{1,2,\dotsc,n\}$.  So suppose $p$ is a permutation map. Then $p$ maps from a location $i$ to a location $j$. Take $p(i) = j$ where $i\neq j$. Let $k$ be in $\{1,2,\dotsc,n\}$, where $k$, $i$ and $j$ are all different elements. The cycle $r = (jk)$, then we will see if this commutes.  $rp(i) = rj$    Can someone please help me, I am stuck?  Thank you. I remember reading a time travel book when I was young, which means it would have been written no later than the '80s, but probably much before that.  It featured an adult and some kids back in time and them trying to get back to the present.  I recall that the time travel effect was a ring, as at one point the ring opened up and a "brontosaurus" hit it and burned it's leg sending chunks of it back through the ring.  I recall a section where they were with "cave people" who had just hunted and killed some animal, and they used their pocket knife to extract more meat from the carcass, and actually cooking the meat unlike their paleolithic 'friends'.  (I seem to recall that one of the paleolithic girls seemed to fancy the boy time traveler, much to his discomfort.)  I am pretty sure that at one point they were watching the time ring appear over water, knowing they could not reach it, and waiting for it to be reachable.  I think the close of the book was them freezing to death in the ice age, commenting on how in the future when their bodies are found how it would be hard to explain how they got there, and then finally being rescued before it was too late.  I hope that's enough to go on?  Any ideas? Show that the range of $p(z)e^{q(z)}$ for nonconstant polynomials $p$ and $q$ is all of $\mathbb{C}$. Can you make an unwilling creature willing? In other words, what defines “willing”? Going through the spells, I see the phrase "Willing creature" used to determine who you can cast some spells on. I don't ever see a proper definition of what a willing creature is, but I would assume that it would go something like if you asked them "Can I perform this spell on you" they would answer yes. Is there a more formal definition of what makes a target willing in 5e?  What are the ways I could make an otherwise unwilling creature willing? Suggestion spells, for instance, should probably work but what other options do I have?