NullPointerException when filling a 2d array from Mat Object in OpenCV
What is a NullPointerException, and how do I fix it?
blink code(escape code) has been removed? I want to do something like String.Format("[{0}, {1}, {2}]", 1, 2, 3) which returns:  [1, 2, 3]   How do I do this in Python? Axiom of Choice: Family of non-empty sets mutually disjoint or not? How to open a folder in Finder by a single mouse click? (using Icon view) Is there a setting, key combination or similar to open a folder/subfolder in Finder with a single mouse click ?  I need a general solution which works on any folder in effort to minimize needless clicking ... that tiny triangle aside the folder icon will work yet its just too small and only appears using list view ... inspired by same behavior on osx inside a browser to hold down command key and single click a web link ... forcing users to double click is so 20th Century  Is there a way to enable this on macOS (High Sierra or higher)?  On ubuntu this single click preference is a simple setting ;-) Shell script- To fetch the content from the specific tag at all occurrence using shell scripting I have an XML file on my server. In that file, I have many tags in which there is a tag for example, "container" tag. I need to fetch the content of all the container tags content separately. Many thanks in advance. Pros & cons of buying gold directly vs. investing in a gold ETF like GLD, IAU, SGOL? Should I use the past tense with did? Should I use the past tense with did? For example, I was to say:     The important question is: Did they knew what it means or not?   Or should I say:     The important question is: Did they know what it means or not?   In other words: Should I use past tense with did?  I looked at this:    but it didn't really answer my question. I know that it is defined such that there is no more than one y-value output for any given x-value input, but I"m wondering WHY it is defined that way? Why can't we apply everything we know about functions to equations that have more than one y-value output for any given x-value input?   In short, what is the benefit or reason to define a function this way?  At the same time, a little historical context would also be appreciated (i.e., when the concept originated and why).  Thanks,  Moshe EDIT Like some comments below are remarking the table environment doesn't allow tables over more than one page. However the solution works fine  I need to make a table over more than one page. The standard approach seems to be to use the ltablex environment. However, it doesn't work; also I assume that the table environment may also be required for the thesis template I work on (e.g. suppose for the capture).   \documentclass[11pt]{article} \usepackage{booktabs} \usepackage{tabularx} \usepackage{ltablex}  \begin{document}  \begin{table} \caption{Example of an table} \label{tab:daypack}      \begin{tabularx}{\linewidth}{@{}cX@{}}   \toprule \textbf{Column 1} &amp; \textbf{Column 2} \\[6pt] \midrule \endhead $R$ &amp; 1This is an example sentence \\[6pt] $R$ &amp; 2As well as the line before \\[6pt] $A$ &amp; 3Also this is an example \\[6pt] $R$ &amp; 4This is an example sentence \\[6pt] $R$ &amp; 5As well as the line before \\[6pt] $A$ &amp; 6Also this is an example \\[6pt] $R$ &amp; 7This is an example sentence \\[6pt] $R$ &amp; 8As well as the line before \\[6pt] $A$ &amp; 9Also this is an example \\[6pt] $R$ &amp; 10This is an example sentence \\[6pt] $R$ &amp; 11As well as the line before \\[6pt] $A$ &amp; 12Also this is an example \\[6pt] $R$ &amp; 13This is an example sentence \\[6pt] $R$ &amp; 14As well as the line before \\[6pt] $A$ &amp; 15Also this is an example \\[6pt] $R$ &amp; 16This is an example sentence \\[6pt] $R$ &amp; 17As well as the line before \\[6pt] $A$ &amp; 18Also this is an example \\[6pt] $R$ &amp; 19This is an example sentence \\[6pt] $R$ &amp; 20As well as the line before \\[6pt] $A$ &amp; 21Also this is an example \\[6pt] $R$ &amp; 22This is an example sentence \\[6pt] $R$ &amp; 23As well as the line before \\[6pt] $A$ &amp; 24Also this is an example \\[6pt] $R$ &amp; 25This is an example sentence \\[6pt] $R$ &amp; 26As well as the line before \\[6pt] $A$ &amp; 27Also this is an example \\[6pt] $R$ &amp; 28This is an example sentence \\[6pt] $R$ &amp; 29As well as the line before \\[6pt] $A$ &amp; 30Also this is an example \\[6pt] $R$ &amp; 31This is an example sentence \\[6pt] $R$ &amp; 32As well as the line before \\[6pt] $A$ &amp; 33Also this is an example \\[6pt] $R$ &amp; 34This is an example sentence \\[6pt] $R$ &amp; 35As well as the line before \\[6pt] $A$ &amp; 36Also this is an example \\[6pt] $R$ &amp; 37This is an example sentence \\[6pt] \bottomrule \end{tabularx}    \end{table}      \end{document} Pluralization of names If I were to use the sentence "There are lots of John Smiths" in the world, would that be the correct use for saying that there are a lot of people named John Smith in the world?  I don't think there should be an apostrophe as that would imply ownership of something.  If my first example is correct, then what would you do if the name referenced already ended with an 's'? I installed ubuntu 16.04 LTS, but there is no ubuntu one software, not in ubuntu software center also..Though it is showing selected in unity tweak tool.How can I get it. Please reply. In "Settings" > "SD card &amp; phone storage settings" under "Internal Phone Storage" it lists "Available Space" as 13.78MB.  I'm trying to install an app that is 2.38MB.  Why do I get the "Insufficient storage available" error message?  I clearly have enough space.  If it's relevant, my phone is an LG Optimus V. Is there an easy way to add a hole into an object? Suppose $ \alpha, \beta&gt;0 $. Compute:   $$ \int_{0}^{\infty}\frac{\cos (\alpha x)-\cos (\beta x)}{x}dx $$   Here is what I do: $$\begin{align} \int_{0}^{\infty}\frac{\cos (\alpha x)-\cos (\beta x)}{x}dx &amp;= \int_{0}^{\infty}dx\int_{\alpha}^{\beta}\sin (yx)dy\\ &amp;=\int_{\alpha}^{\beta}dy\int_{0}^{\infty}\sin(yx)dx\\ &amp; \\ &amp;   \qquad\text{let $ yx=u $}\\ &amp; \\ &amp;=\int_{\alpha}^{\beta}\frac{1}{y}dy\int_0^{\infty}\sin u du\\ &amp;=\int_{\alpha}^{\beta}\frac{1}{y}dy\left( -\cos u|_{\infty}+\cos u|_0 \right)\\ &amp;=\log\frac{\beta}{\alpha}(-\cos(\infty)+1)\\ &amp;=\log\frac{\beta}{\alpha}-\cos(\infty)\log\frac{\beta}{\alpha} \end{align}$$  But $ \cos(\infty) $ does not exist right? Does it mean the integral actually diverse?  Edit: The question comes from   Who can point out my mistake in the above deduction? What is the best algorithm for overriding GetHashCode? In .NET, the  is used in a lot of places throughout the .NET base class libraries. Implementing it properly is especially important to find items quickly in a collection or when determining equality.  Is there a standard algorithm or best practice on how to implement GetHashCode for my custom classes so I don't degrade performance? What are "schlieren" in English? The German word for these patterns is "Schliere, pl. Schlieren", and apparently this word has entered the English language as a loanword (cf. article  in Wikipedia or entry  in OED). But the German loanword is probably not something most native speakers of English understand without the help of a dictionary, so what would you call, or how would you describe, the following patterns?  Concrete:    Air:    Oil on water:    Coffee and milk:    Paint:    Smoke:    Rock:    Marbled paper:    And so on.    "Waves" is not applicable, because waves are vertical undulations of the surface, while these are a pattern on, or inside, the surface level, with no amplitude.  "Striæ" does not really fit either, because those refer more to the parallel layers, than to the curly forms. I will have a 10 hour layover in Seoul (ICN) and I want to go out and do some shopping. Is it possible to check in a bag during my layover?  I will be traveling on Korean Air.  I will only have 1 checked bag, and international flights allow 2 bags free. Testing for linear dependence among the columns of a matrix I have a correlation matrix of security returns whose determinant is zero. (This is a bit surprising since the sample correlation matrix and the corresponding covariance matrix should theoretically be positive definite.)  My hypothesis is that at least one security is linearly dependent on other securities. Is there a function in R that sequentially tests each column a matrix for linear dependence?  For example, one approach would be to build up a correlation matrix one security at a time and calculate the determinant at each step. When the determinant = 0 then stop as you have identified the security who is a linear combination of other securities.  Any other techniques to identify linear dependence in such a matrix are appreciated. Has Marvel commented on the extra Infinity Gauntlet? Can spells with movable areas of effect be moved out of sight or behind obstacles? With spells like Moonbeam or Flaming Sphere, how should we treat the movement of their areas-of-effect when it comes to passing them behind a thick pillar or around a blind corner?  Should we treat any movement of them as if they are being 're-cast' (and so requiring a clear unobstructed view)? Or could a mage presumably will them somewhere out-of-sight?