How can I check if a string has characters and numbers Java
Learning Regular Expressions
Code snippets for methods in Visual Studio How can I make realistic looking potions as handouts How can I Remove .DS_Store files from a Git repository? Is there any way to prevent mc from taking 10-30 seconds to open? Formula for expected value of continuous random variable without using density How to add right-click (on desktop) to create text file functionality 16.04.2 Ubuntu GNOME How can I identify what application is using a given file? How do I get rid of the Start Menu "zombie" icon? Windows 7 has a large icon above the username on the right-hand pane of the Start menu. By default it is a faceless torso in a blue collarless shirt that I call the "zombie icon". (I don't know the icon's real name: . (Although "Molly Clark" has a zinnia icon instead of a zombie icon.)  The zombie icon fades from one pointless icon to another as you move your mouse over "Documents", "Computer", "Devices and Printers" etc. This icon is a waste of space and the fades are distracting.  How do I make it go away? How to overload __init__ method based on argument type? Gradient borders Obtaining a formula for prediction limits in a linear model (i.e.: prediction intervals) Let's take the following example:  set.seed(342) x1 &lt;- runif(100) x2 &lt;- runif(100) y &lt;- x1+x2 + 2*x1*x2 + rnorm(100) fit &lt;- lm(y~x1*x2)   This creates a model of y based on x1 and x2, using a OLS regression.  If we wish to predict y for a given x_vec we could simply use the formula we get from the summary(fit).  However, what if we want to predict the lower and upper predictions of y? (for a given confidence level).  How then would we build the formula? Can a werewolf turn a muggle into another werewolf? I got a UK visa for one month (restricted validity). It expires on November 4. Pakistani citizens are eligible to apply for a Turkish e visa if they have a valid UK visa. I want to visit Istanbul for a couple of days - from October 31 to November 2. Would I be eligible to still apply for an e visa?   My visa is for single entry. It's valid from October 4 to November 4. I quite often add a question as a favourite when there is something of interest to me in it or its answers. Looking back through my favourites, I cannot remember why I added some of them as a favourite.  What I'd like to be able to do is to add a note/comment when I add a favourite as a reminder as to why I've added it. This will show on my favourites page, but nowhere else - and possibly to no one else.  In addition, it would be good to be able to favourite an answer to a question, thereby adding a favourite to both the question and a particular answer with something of note in it. This would only show as a single favourite, but when clicking its link would go to the favourited answer.  Possible? Or is there another way of doing this? I've already got too many favourites to remember why I added a lot of them. Find the number of solutions of $x^2=x\mod m$ for any integer $m$.  I was thinking about bringing the $x$ over to the other side and somehow apply chinese remainder thm. Get client IP address via third party web service Is tipping mandatory at Restaurants and Bars in Germany? access controller variable in javascript Is there any way to access controller variable set in a Method in Javascript. In the example above the value is set in constructor. But when I set it in a method it is showing as NULL in Javascript  In controller:  public class abc {     public string varA { get;set; }     public void fn(){         varA='hello';     } }   In VFPage:  function hello(){     var bool = '{!varA}';     alert(bool); }   The alert statement in the VF Page(i.e bool) is displayed as null. Can you please help how to access a variable set from a method instead of constructor? Show that the operator norm is submultiplicative We had in our lecture on numerical analysis the following: Let $\mathrm{Lin}(X,Y)$ be the set of all linear maps $X\rightarrow Y$. Let $A\in\mathrm{Lin}(\mathbb R^l,\mathbb R^n)$ and $B\in\mathrm{Lin}(\mathbb R^n,\mathbb R^m)$ and $\|C\|_{op}:=\max_{\|x\|\leq1}\|C(x)\|$. Then our lecturer followed $\|A\circ B\|_{op}\leq\|A\|_{op}\cdot\|B\|_{op}$. So he didn't prove it and so I've tried it by my own. My attempt: $$\begin{aligned} \|A\circ B\|_{\mathrm{op}} &amp;= \max_{\|x\| &lt; 1}\|(A \circ B)(x)\| \\ &amp; \leq \max_{\|x\| &lt; 1} \|A\|_{\mathrm{op}} \|B(x)\| \\ &amp;= \|A\|_{\mathrm{op}} \max_{\|x\|\leq1}\|B(x)\|\\ &amp;= \|A\|_{\mathrm{op}}\|B\|_{\mathrm{op}} \end{aligned}$$ But this seems too easy. I am really interested in a nice proof so anybody could help? Thanks a lot! Why is everything in minecraft opaque red and blue?