How to get middle string characters?
NSString tokenize in Objective-C
Enqueuing Google Web Fonts the usual way, i.e., using the wp_enqueue_style function like so...  function wpse_google_webfonts() {     wp_enqueue_style( 'google-webfonts', 'http://fonts.googleapis.com/css?family=Ubuntu+Condensed|Open+Sans:400italic,700italic,400,700' ); } add_action( 'wp_enqueue_scripts', 'wpse_google_webfonts' );   ...results in a link tag placed in the header like so:  &lt;link rel='stylesheet' id='google-webfonts-css'  href='http://fonts.googleapis.com/css?family=Ubuntu+Condensed%7COpen+Sans%3A400italic%2C700italic%2C400%2C700&amp;#038;ver=3.5' type='text/css' media='all' /&gt;   As you can see, the resultant URL is encoded.  I am pretty sure it poses no problems, but to keep things clean and clear, I would like to go ahead and ask -- Is there a way to enqueue Google Web Fonts (via functions.php and not a plugin) in a way that the URL output is not encoded?  That's like so:  &lt;link rel='stylesheet' id='google-webfonts-css'  href='http://fonts.googleapis.com/css?family=Ubuntu+Condensed|Open+Sans:400italic,700italic,400,700?ver=3.5' type='text/css' media='all' /&gt;   Reason For Bounty  @webaware's answer is near perfect, especially because it's similar to the method employed in  theme.  The only problem in the output is that it's like this:  &lt;link rel='stylesheet' id='twentytwelve-fonts-css'  href='http://fonts.googleapis.com/css?family=Ubuntu+Condensed|Open+Sans:400italic,700italic,400,700&amp;#038;subset=latin,latin-ext' type='text/css' media='all' /&gt;   Notice the &amp;#038;? It should be &amp;, otherwise the font-files served only have the latin glyphs (i.e. the subset parameter in the URL is neglected unless you use &amp; and NOT its HTML entity).  Anyone who can help modify @webaware's answer so that the output's looks like this...  &lt;link rel='stylesheet' id='twentytwelve-fonts-css'  href='http://fonts.googleapis.com/css?family=Ubuntu+Condensed|Open+Sans:400italic,700italic,400,700&amp;subset=latin,latin-ext' type='text/css' media='all' /&gt;   ...wins the bounty. As the title say, I want to prove that  $C_c^{\infty}(\mathbb R^n)$ is dense in $W^{k,p}(\mathbb R^n)$  i.e.  $\displaystyle{ W^{k,p} (\mathbb R^n) = W_0^{k,p}(\mathbb R^n)  \quad (\star)}$. In a book I found that in order to prove it, we need the following claim:  Claim: Let $\displaystyle{\zeta \in C^{\infty} ([0, \infty)) }$ such that $\zeta (t)  =1 $ for $ t \leq 1 $ and $\displaystyle{ \zeta (t) =0 }$ for $ t \geq 2$. For $R&gt;0$ and  $x \in \mathbb R^n$ define $\displaystyle{ \eta_R (x) = \zeta \left( \frac{|x|}{R} \right)}$. If $ \displaystyle{ u \in W^{k,p} ( \mathbb R^n) }$ with $1 \leq p &lt; \infty $ then, $\displaystyle{ \eta_R u \to u }$ in $W^{k,p}(\mathbb R^n) $ as $ R \to \infty$.  If I prove the claim then the $(\star)$ follows using mollifiers. But unfortuently I have stuck, with the proof of the claim.  Any ideas? What's the best way to protect your house from Endermen stealing your walls? raw data stationary but still can see trend and seaonality is stl When the site is in read-only mode, I get a message like this:     This site is currently in read-only mode.   Would it be possible to update that message to provide links to these resources on SE's status:   : Official SE tweets on SE's status. : Official blog posts on SE's status. Bread and butter is/are my breakfast? Bread and butter (is or are) my breakfast?  And what's the difference between the above sentence and saying "My breakfast is bread and butter"?  Thanks. What exactly does Perl's "bless" do? I understand one uses the "bless" keyword in Perl inside a class's "new" method:  sub new {     my $self = bless { };     return $self; }       But what exactly is "bless" doing to that hash reference ? Python: Find a substring in a string and returning the index of the substring Is there a quick proof as to why the vector space of $\mathbb{R}$ over $\mathbb{Q}$ is infinite-dimensional? It would seem that one way of proving this would be to show the existence of non-algebraic numbers. Is there a simpler way to show this? Is it safe to check floating point values for equality to 0? I know you can't rely on equality between double or decimal type values normally, but I'm wondering if 0 is a special case.  While I can understand imprecisions between 0.00000000000001 and 0.00000000000002, 0 itself seems pretty hard to mess up since it's just nothing.  If you're imprecise on nothing, it's not nothing anymore.  But I don't know much about this topic so it's not for me to say.  double x = 0.0; return (x == 0.0) ? true : false;   Will that always return true? Does the sign of scores or of loadings in PCA or FA have a meaning? May I reverse the sign? I performed principal component analysis (PCA) with R using two different functions (prcomp and princomp) and observed that the PCA scores differed in sign. How can it be?  Consider this:  set.seed(999) prcomp(data.frame(1:10,rnorm(10)))$x              PC1        PC2  [1,] -4.508620 -0.2567655  [2,] -3.373772 -1.1369417  [3,] -2.679669  1.0903445  [4,] -1.615837  0.7108631  [5,] -0.548879  0.3093389  [6,]  0.481756  0.1639112  [7,]  1.656178 -0.9952875  [8,]  2.560345 -0.2490548  [9,]  3.508442  0.1874520 [10,]  4.520055  0.1761397  set.seed(999) princomp(data.frame(1:10,rnorm(10)))$scores          Comp.1     Comp.2  [1,]  4.508620  0.2567655  [2,]  3.373772  1.1369417  [3,]  2.679669 -1.0903445  [4,]  1.615837 -0.7108631  [5,]  0.548879 -0.3093389  [6,] -0.481756 -0.1639112  [7,] -1.656178  0.9952875  [8,] -2.560345  0.2490548  [9,] -3.508442 -0.1874520 [10,] -4.520055 -0.1761397   Why do the signs (+/-) differ for the two analyses? If I was then using principal components PC1 and PC2 as predictors in a regression, i.e. lm(y ~ PC1 + PC2), this would completely change my understanding of the effect of the two variables on y depending on which method I used! How could I then say that PC1 has e.g. a positive effect on y and PC2 has e.g. a negative effect on y?    In addition: If the sign of PCA components is meaningless, is this true for factor analysis (FA) as well? Is it acceptable to flip (reverse) the sign of individual PCA/FA component scores (or of loadings, as a column of loading matrix)? Grub rescue prompt, repair grub Negative pressure How is negative pressure created in a fluid system?Isn't it counter intuitive that we are reducing the pressure of a system containing no molecules(zero pressure) to a lower value? I get the following error when I try to typeset a beamer document.  kpathsea: Running mktexpk --mfmode / --bdpi 600 --mag 0+525/600 --dpi 525 mathkerncmssi8 gsftopk: fatal: map file `cid-base.map' not found. mktexpk: don't know how to create bitmap font for mathkerncmssi8. mktexpk: perhaps mathkerncmssi8 is missing from the map file. kpathsea: Appending font creation commands to missfont.log.  ) !pdfTeX error: pdflatex (file mathkerncmssi8): Font mathkerncmssi8 at 525 not found  ==&gt; Fatal error occurred, no output PDF file produced!   But if I remove sansmathaccent.sty from the TeX Live tree, the document typesets fine. Here is a minimal working example.  \documentclass[10pt]{beamer}  \begin{document}  \begin{frame}{A very short beamer document}  $e^{i\pi}+1=0$  \end{frame}  \end{document} Using `\input` to insert a section of a document into another What functionality do 'marks' offer in the El Capitan Terminal? Since upgrading to OS X El Capitan, I've noticed a change in the Terminal: Executed lines show an opening bracket on the left, and a closing bracket on the right, as shown in this screenshot:    Similar questions have been asked here:          Some of the questions are referring to these brackets as marks, and the Terminal's Edit menu has a couple of entries related to marks, for example:   Edit > Marks > Mark as Prompt and Send Return Edit > Clear to Previous Mark Edit > Navigate > Jump to Previous Mark     Is there a summary of what these marks can be used for? I have not seen any reference to this new feature in any of the El Capitan feature overviews. According to the original paper of , there is no key validation needed when using Curve25519 for Diffie-Hellman Key Exchange. However, where does this property come from? Is there any proof or argumentation available in order to understand this really practical property of Curve25519? Does this mean that each $x$ coordinate could belong to a point $P=(x,y)$ from Curve25519? Is that even possible? Html Textarea elements only wrap when they reach a space or tab character. This is fine, until the user types a looooooooooooooooooooooong enough word. I'm looking for a way to strictly enforce line breaks (eg.: even if it results in "loooooooooooo \n ooooooooooong").    The best I've found is to add a zero-width unicode space after every letter, but this breaks copy and paste operations. Anyone know of a better way?  Note: I'm referring to the "textarea" element here (i.e.: the one that behaves similarly to a text input) - not just a plain old block of text. A great Python IDE for Ubuntu Possible Duplicate:          I want to develop Python apps in Ubuntu, and I'm tired of working with gedit one time and another.  So I'm trying to find a great Python IDE (a true IDE, not just a syntax-highlighting editor) on the Ubuntu repositories. Which one do you recommend me? Definite Integral $\int_{-\infty}^{\infty}\frac{x\sin x}{(x^2+a^2)(x^2+b^2)}\,\mathrm{d}x$ $$\int_{-\infty}^{\infty}\frac{x\sin x}{(x^2+a^2)(x^2+b^2)}\,\mathrm{d}x$$  This is easy to evaluate with complex analysis but is there an elementary way (substitution, partial fractions, integration by parts)?