I have been looking around on Google and StackOverFlow and I have not been able to find a good SIMPLE definition for:  @Override when it is used.  Can someone help me find a very simple definition for this?  Thanks.
What are the best practices for using Java's @Override annotation and why?     It seems like it would be overkill to mark every single overridden method with the @Override annotation.   Are there certain programming situations that call for using the @Override and others that should never use the @Override?
How do I install transition molding between my new hardwood and existing tile floors? I have ripped out some old carpet and am preparing to install a new solid hardwood floor myself.  In several places, the floor transitions to an existing tile floor.  The hardwood floor guys told me the best transition between the two is a T molding.  You simply leave a gap between the two floors, and then place down the T molding between the two floors, so it sits on both surfaces.  Sounds simple enough.  However, the height difference of the two floors is considerable, and the T molding does not sit flush.  What are my options?  Here is a diagram showing the dimensions.      NOTE:  Using the T molding is not a requirement, I could go some other route if there is a better option. Why is "glide symmetry" its own type? Artin's Algebra pages 155 &amp; 156 list the types of symmetry of a plane figure as:   Reflective Rotational Translational Glide   He then goes on to say "Figures such as wallpaper patterns may have two talk about other figures having combinations of independent" symmetries. EDIT: He says "... having combinations of independent translational symmetries". See Joriki's answer.  Why doesn't glide symmetry count as having two independent (reflection + translation) symmetries? If we're going to count combinations, why not have rotation + translation etc. as their own types too? I am currently working on an update of tkz-euclide and new documentation but I just met the following problem. If I compile this code with pdflatex or lualatex and pgf 2.1 (The library babel does not exist with pgf 2.1) then the code compiles fine but with 3.0 pgf I must comment on the call \usetikzlibrary{babel} (pgf doc gives so I recommend to always load this library by saying \usetikzlibrary{babel}).  I'd like to know where the error occurred. Especially I would like to work around this problem.   With \usetikzlibrary{babel} I get the error Latex Error: ./untitled 2.tex:46 Undefined control sequence. l.1 \tkz@line@start  Bug in babel, bug in tikzlibrary{babel} bug in my code. I would like to keep  \usetikzlibrary{babel} but to avoid the error.  %!TEX TS-program = pdflatex \documentclass[a4paper]{article} \usepackage[french]{babel} \usepackage{tikz}  \usetikzlibrary{calc} %\usetikzlibrary{babel}  \makeatletter \pgfkeys{%     tkzdrawline/.cd,     start/.code         =  {\gdef\tkz@line@start{#1}},%     end/.code           =  {\gdef\tkz@line@end{#1}},%     start style/.code   =  {\tikzset{tkzstartstyle/.style={#1}}},%     end style/.code     =  {\tikzset{tkzendstyle/.style={#1}}},%    /tkzdrawline/.unknown/.code ={\let\searchname=\pgfkeyscurrentname\pgfkeysalso{%                          \searchname/.try=#1,/tikz/\searchname/.retry=#1}}}  %&lt;--------------------------------------------------------------–&gt; %                              Draw line %&lt;--------------------------------------------------------------–&gt; \pgfkeys{tkzdrawline/.cd, start/.code       =  {\def\tkz@line@start{#1}},% end/.code         =  {\def\tkz@line@end{#1}}, start style/.code =  {\tikzset{tkzstartstyle/.style={#1}}}, end style/.code   =  {\tikzset{tkzendstyle/.style={#1}}},   /tkzdrawline/.unknown/.code   = {\let\searchname=\pgfkeyscurrentname                                  \pgfkeysalso{\searchname/.try=#1,                                 /tikz/\searchname/.retry=#1}}}%         %&lt;--------------------------------------------------------------–&gt;  \def\tkzDrawLine{\pgfutil@ifnextchar[{\tkz@DrawLine}{%                                   \tkz@DrawLine[]}}%   \def\tkz@DrawLine[#1](#2,#3){%  \begingroup   \pgfkeys{tkzdrawline/.cd,start = {}, end = {}, start style={}, end style={},}   \pgfqkeys{/tkzdrawline}{#1}   \draw[ /tkzdrawline/.cd,#1] (#2) to%     node [at start,left,/tkzdrawline/.cd,tkzstartstyle] {\tkz@line@start}%     node [at end,right,/tkzdrawline/.cd,tkzendstyle] {\tkz@line@end} (#3);  \endgroup  }%   \makeatother   \begin{document}    \begin{tikzpicture}      \node (A) at (0,1) {};       \node (B) at (5,2) {};       \tkzDrawLine[end = {$\alpha$}](A,B)       \end{tikzpicture}  \end{document} How do I trim leading/trailing whitespace in a standard way? Is there a clean, preferably standard method of trimming leading and trailing whitespace from a string in C? I'd roll my own, but I would think this is a common problem with an equally common solution. How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version So far I've been using public void run() {} methods to execute my code in Java. When/why might one want to use main() or init() instead of run()? Why does the following code sometimes causes an Exception with the contents "CLIPBRD_E_CANT_OPEN":  Clipboard.SetText(str);   This usually occurs the first time the Clipboard is used in the application and not after that. Beamer and pseudocode How can I change the icon of an application in the Unity launcher? I'm trying to change the icon of a specific application (Pidgin) in my Ubuntu 11.10 Unity launcher. I have tried searching in the options and in the Compiz settings but could locate no option for changing individual icons.  I can change the theme but that's not what I want.   I am willing to edit configuration files to get this change. It doesn't have to be a UI solution. Ping a site in Python? I installed blender for the first time, so I have the latest version, 2.78c.  I played with it for a bit.  Then I discovered I couldn't save my work.  I uninstalled it and reinstalled it.  Rebooted.  Same problem.  After a little testing, I realized I CAN save to my NAS storage drive.  I cannot save on my C: drive.  Any project.  Any folder.  C: always fails.  If I run blender as Administrator, it will save to the C: drive.  But not as my normal userid.  So it sounds like a bug of some kind.  I am running Windows 10.  Bitdefender A/V.  I use OneDrive.  I have a 2TB drive installed.  All clean and purring nicely.  Is there a better way to install it?  Or some change I can make (other than always running as administrator)?    Sounds like a bug - but hopefully there's a proper solution.  Thanks,  Jerry How to measure supply currents ranging from 1μA to 10mA? addtocontents not working with certain other packages This is a follow up question on   How do I change the toc dept mid document while using packages (in this case only mathtools).  An example:  \documentclass[a4paper,10pt,oneside]{book}  \usepackage{mathtools}  \begin{document}   \frontmatter             \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \setcounter{tocdepth}{3}  \tableofcontents   \mainmatter   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \appendix   \addtocontents{toc}{\setcounter{tocdepth}{0}}   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}  \end{document}   This example generates an error and very strangely puts an exclamation mark in the ToC as you can see here   however when I comment out the \usepackage{mathtools} it suddenly works again or replacing it with a different package such as \usepackage[T1]{fontenc} also generates no errors.  But this is not limited to just this specific package, certain other packages also introduce the same behavior (I just took this package to keep the example small). Generate four random words from a list for XKCD-like passwords For start, we know how can we output random lines from a txt file:   perl -MList::Util -e 'print List::Util::shuffle &lt;&gt;' words.txt   But we need a general solution (perl is usually installed on every unix-like OS) to output 4 random words from a txt file, how can we do it?    $ cat words.txt ... alpha beta gamma delta epsilon ... $   The "..." represents many other words.   Example output (without newline between them, but one unix newline is needed at the end, spaces should separate them):  $ perl SOMEMAGIC words.txt gamma alpha delta beta $   Using only perl, the shortest possible solution (oneliner).   It will be used as human memorable password generator:    Since afaik perl is enough good to be named "random generator".   Example common english wordlist with 32768 unique lines: What is the best way to increase my reputation and privileges? Biblatex handling of Dutch "van" prefix This question has been posed in many different variants, but not exactly as I ask here, so please do not consider this as a duplicate.  I use biblatex with the option useprefix. I would like to have the following automatic behavior:   Name prefixes are rendered before the last name in the bibliography, but always in lower case. The name prefixes are ignored for the sake of sorting of the bibliography. In running text, the name prefix is rendered with a capital letter at the beginning of a sentence, and lower case elsewhere (possible using \Textcite vs. \textcite).   To achieve this, I can have three author fields for each concerned entry, with the following scheme:  author = { {v}an Dijk, A.} shortauthor = { van Dijk, A.} sortname = {Dijk, A. van}   Is there a simple way to automate this? Ideally, such a way could also allow for easy changing of the system. "Mornings came and cast a blinding sunlight over everything, and he felt like nothing worthwhile could be accomplished."  For some reason, I feel like "a blinding light" is ok, but if its sunlight, then I should drop the "a" and write "cast blinding sunlight", but I'm not sure why I feel this way.   Can anyone offer some enlightenment?  edit - alternate phrasing, closer to being a literal translation: "Mornings came without warning, flooding the day with a strong sun, and he felt like nothing worthwhile could be accomplished."   I would still like an answer to the technical question of whether I should drop the "a", but would also appreciate knowing if anyone thinks option #2 is a better choice. Strange issue with the right side margin Irreducible polynomial in field extension I have this problem      Let $L/K$ be a finite field extension and $|L:K|=m$. Let $f(x)$ be an irreducible polynomial of degree $n$ in $K[x]$ and $\gcd(m,n)=1$. Prove that $f$ is irreducible over $L$.   I'm just a beginner so I'm really confused with the $\gcd(m,n)=1$, I don't know how to use it. So help me with this problem. Thank you Can anyone make me understand in simple language why the second condition for being an Euclidean domain is superfluous ?  Why $v(a)  \leq v(ab)$ is not needed?  How we can deduce from the first one?