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data.table vs dplyr: can one do something well the other can't or does poorly?
...j and by together is by design. By keeping related operations together, it allows to easily optimise operations for speed and more importantly memory usage, and also provide some powerful features, all while maintaining the consistency in syntax.
1. Speed
Quite a few benchmarks (though mostly on g...
How to get Vim to highlight non-ascii characters?
...aracter range, therefore highlighting (assuming you have hlsearch enabled) all other characters lying outside the ASCII range:
/[^\x00-\x7F]
This will do a negative match (via [^]) for characters between ASCII 0x00 and ASCII 0x7F (0-127), and appears to work in my simple test. For extended ASCII,...
Null vs. False vs. 0 in PHP
...ers can spot/utilize the difference between Null and False and 0 and all the other good "nothing" entities.
What is the difference, specifically in PHP? Does it have something to do with === ?
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IE7 Z-Index Layering Issues
...ex bug, but don't know how to fix it.
I have been playing with z-index all day long.
11 Answers
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When and why JPA entities should implement Serializable interface?
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This usually happens if you mix HQL and native SQL queries. In HQL, Hibernate maps the types you pass in to whatever the DB understands. When you run native SQL, then you must do the mapping yourself. If you don't, then the default m...
Is a successor for TeX/LaTeX in sight? [closed]
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There is a LaTeX3 project that has been going on for basically forever. In that sense, it is a successor to the current LaTeX2e.
You forget/ignore the primary goal for TeX when it was created -- "TeX is a new typesetting system intended for the creation of beautiful books". The goa...
HTML5 Canvas vs. SVG vs. div
...rs.
Canvas has the best performance hands-down, but you have to implement all concepts of managed state (object selection, etc) yourself, or use a library.
The long answer:
HTML5 Canvas is simply a drawing surface for a bit-map. You set up to draw (Say with a color and line thickness), draw tha...
Overwriting my local branch with remote branch [duplicate]
...n
update your list of remote branches and sync new commits:
git fetch --all
then, reset your branch to the point where origin/branch points to:
git reset --hard origin/branch
be careful, this will remove any changes from your working tree!
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Which is more efficient, a for-each loop, or an iterator?
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If you are just wandering over the collection to read all of the values, then there is no difference between using an iterator or the new for loop syntax, as the new syntax just uses the iterator underwater.
If however, you mean by loop the old "c-style" loop:
for(int i=0; i&l...
How to start new activity on button click
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Yeah, easy lol. There is more codemissing than code actually typed. Where is all xml interface and .java code missing? Downvote
– Liquid Core
Jun 21 '15 at 12:50
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