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Is R's apply family more than syntactic sugar?
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The apply functions in R don't provide improved performance over other looping functions (e.g. for). One exception to this is lapply which can be a little faster because it does more work in C code than in R (see this question for an example of this).
But ...
Avoid synchronized(this) in Java?
... two different variables:
public class Test {
private Object lockA = new Object();
private Object lockB = new Object();
public void method1() {
// do something ...
synchronized(lockA) {
a ++;
}
// ................
}
public vo...
Simple Pivot Table to Count Unique Values
... You can do this now automatically with Excel 2013. I've created this as a new answer because my previous answer actually solves a slightly different problem.
If you have that version, then select your data to create a pivot table, and when you create your table, make sure the option 'Add this data...
What is mod_php?
...server, which makes the CGI version preferable if you are testing a lot of new settings and want to see instant responses.
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Why use JUnit for testing?
Maybe my question is a newbie one, but I can not really understand the circumstances under which I would use junit ?
11 An...
Add only non-whitespace changes
..."I edited my answer to specifically address Git..." - why didn't you ask a new question in the context of mercurial, and then add your own answer to the new question???
– jww
Jul 24 '15 at 23:59
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Convert python datetime to epoch with strftime
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@Michael That function is new in Python 2.7, you must be using an older version. For versions before 2.7 you can do td.seconds + td.days*24*3600. This discards the microseconds part.
– jleahy
Apr 21 '14 at 12:31
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How to create multidimensional array
... a multidimensional array of inputs? Hope you could help because I'm still new to the JavaScript.
13 Answers
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In Visual Studio C++, what are the memory allocation representations?
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iPhone - Grand Central Dispatch main thread
...ndividual block in the queue takes too long the server stays responsive to new requests.
If your program does nothing but spend its whole life responding to events then this can be quite natural. You just set up your event handlers to run on the main queue and then call dispatch_main(), and you may...