application gets crashed while using shared preferences
My application got crashed because of not initializing the view
How do I delete a board when the admin is no longer part of the group? One of our programmers decided to leave us. We took him off the group, but his board that he is the only admin of is still hanging around. How do I remove it? "Least Astonishment" and the Mutable Default Argument How can I acknowledge, thank, or otherwise approve of an edit? Possible Duplicate:    Sometimes I get an edit that greatly improves a question or answer I have submitted.  I'd like to acknowledge an edit like this, so that readers can know that the revision was approved of by the OP (me!). I was thinking of comments on edit, or a checkbox noting that OP vouches for the edit.  Sometimes I would like to add a comment to the question or answer, but those don't make a lot of sense in that context. Any suggestions about the best way to do this?  Consider this a feature request, as it seems useful to know that a particular edit was endorsed/vetted by the OP. How does entropy depend on location and scale? The entropy of a continuous distribution with density function $f$ is defined to be the negative of the expectation of $\log(f),$ and therefore equals  $$H_f = -\int_{-\infty}^{\infty} \log(f(x)) f(x)\mathrm{d}x.$$  We also say that any random variable $X$ whose distribution has density $f$ has entropy $H_f.$  (This integral is well-defined even when $f$ has zeros, because $\log(f(x))f(x)$ can be taken to equal zero at such values.)  When $X$ and $Y$ are random variables for which $Y = X+\mu$ ($\mu$ is a constant), $Y$ is said to be a version of $X$ shifted by $\mu.$  Similarly, when $Y = X\sigma$ ($\sigma$ is a positive constant), $Y$ is said to be a version of $X$ scaled by $\sigma.$ Combining a scale with a shift gives $Y=X\sigma + \mu.$  These relations occur frequently.  For instance, changing the units of measurement of $X$ shifts and scales it.  How is the entropy of $Y = X\sigma + \mu$ related to that of $X?$ Does a creature with Lifelink provide lifegain equal to its power, or the defender's toughness? Where are packages stored installed with APT in Ubuntu 16.04? How to make a safe in vanilla Minecraft that locks and unlocks with a key? How can I make a safe/vault or something to lock my door that is very easy (as I am not that advanced with redstone) to keep people out of my house? Without mods? What is the reason that the value "47" is so popular in electrical engineering? $K \subset \mathbb{R}^n$ is compact iff it is closed and bounded I want to prove $\Leftarrow$.  I just need one more step, now. If I find a compact set that contains K, then it will finish the proof. Rudin take a k-cell to do that, but before it he proves that every k-cell is compact, and I think I can take a more simple compact to do this step. I has thinked in the closed ball, but don't know how to prove that it is compact. Can anyone help me to find this set, if it really exists? Thanks. If a two vectors $\bf u$ and $\bf v$ in linearly independent, can their images be linearly dependent given they were transformed by a linear transformation $T$? I think not. My reasoning If the images are linearly dependent, then $c_1T({\bf u})+c_2T({\bf v})={\bf 0}$ for scalars $c_1$ and $c_2$, not both $0$. Then $c_1T({\bf u})+c_2T({\bf v})={\bf 0}$ $T(c_1{\bf u}+c_2{\bf v})=T({\bf 0})$ $c_1{\bf u}+c_2{\bf v}={\bf 0}$ Therefore, ${\bf u}$ and $\bf v$ are linearly dependent. My reservation A homework problem seems to contradict the above. Here's the problem: Let $\mathbb R^n\rightarrow\mathbb R^m$ be a linear transformation. Suppose $\{{\bf u},{\bf v}\}$ is a linearly independent set, but $\{T({\bf u}),T({\bf v}\})$ is a linearly dependent set. Show that $T({\bf x})={\bf 0}$ has a nontrivial solution. Batch script to resize height of all layers to same height but keeping their original aspect ratio I have hundreds of product image layers and I am trying to resize them all to the same height (ignoring the width) and retaining their individual aspect ratio's.  Is there a script available that does this? Or a feature I am unaware of?  Thanks! Android How to use MediaScannerConnection scanFile A large number of variants of this question were already asked here, including these - , , which are close, but none seem to answer my question. Assume that $n$ balls are thrown randomly and independently into $k$ bins.  What is the probability of finding $x$ empty bins? What is the expectation of the number of empty bins? Determining the Actual Server Create Date I am interested in determining the ages of all 70+ my servers. I would like to create a growth graph showing when servers and databases were added to the environment either/both monthly or annually. I executed the following query using the SSMS multi-query feature with only partial success.  SELECT [name], create_date FROM sys.databases   It's partial success because the master and model databases return with a date of 'April 8, 2003' when I know that I created some of these servers during the past couple years.  I refresh databases from one server to another several times a week, which appears to be causing issues with the database create date.   Is there a simple method to determine the actual create date for both servers and databases? Stern-Brocot tree where each node has two fathers After logging in on terminal with user name and password, how do I start the GUI? I am new to Ubuntu, and I am working on a Mac. The Ubuntu installation was done by someone else. I logged in with the user name and password, but I'm not sure what next to do in the terminal to get to the graphical interface. Could someone assist or point me in a direction where I can get useful guidelines? I have done research, but nothing I found helped me.   When I tried to start the lightdm greeter, I got the following message:  lightdm.service not found     Update: My understanding is that Ubuntu Server is installed. Extracting text from HTML file using Python What is the analytic continuation of the Riemann Zeta Function Why can not upgrade texlive2016 to texlive2017 on windows I have texlive 2016 installed on my windows OS, to use texlive 2017 you need to download it (over then 2.5GO), I think this is a tedious operation every time you  want to pass from an old texlive to a recent one.  My question is is there a posibility just to upgrade texlive 2016 to texlive 2017without removing, downloading, and installinig  the entire texlive? What torque for caliper brakes onto carbon-alloy forks? I've recently got a new bike with a . This comes with deep-drop calliper brakes (Shimano R451 Dual Pivot). The first time out I bumped one of the brakes and it twisted around the single attachment bolt and rubbed on the rim.  I managed to easily twist it back by hand and carry on, however I thought the bolt probably needs tightening. The question is: How tight can it be?  As the fork is part carbon I've so far only dared to take it up to 4Nm, but it still seems possible to twist the whole calliper around with a bump of the hand. Maybe that's normal? Perhaps it's easier to bump around because of the longer deep-drop lever. Should I be aiming to get it really secure?    I'm not sure whether the brake mount in the fork is all carbon, or some of it is alloy underneath, but either way I'd like to know what a sensible torque is. As far as I can see from the  there is no such specification. How can I find this out?