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What is tail call optimization?
... space as (fact 3). This is not the case with the non-tail-recursive fact, and as such large values may cause a stack overflow.
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Fastest way to replace NAs in a large data.table
... data.table , with many missing values scattered throughout its ~200k rows and 200 columns. I would like to re code those NA values to zeros as efficiently as possible.
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how to draw smooth curve through N points using javascript HTML5 canvas?
...nts), but for my purposes (a drawing application), it's good enough for me and visually you can't tell the difference. There is a solution to go through all the sample points, but it is much more complicated (see http://www.cartogrammar.com/blog/actionscript-curves-update/)
Here is the the drawing...
bool operator ++ and --
... supports ++ (increment) for bool, but not -- (decrement). It this just a random decision, or there is some reason behind this?
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Select mySQL based only on month and year
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SELECT * FROM projects WHERE YEAR(Date) = 2011 AND MONTH(Date) = 5
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Better way to shuffle two numpy arrays in unison
...o sequences of the same length results in the same number of calls to the random number generator, and these are the only "random" elements in the shuffle algorithm. By resetting the state, you ensure that the calls to the random number generator will give the same results in the second call to shu...
how to use “AND”, “OR” for RewriteCond on Apache?
Is this how to use AND, OR for RewriteCond on Apache?
3 Answers
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How to delete duplicates on a MySQL table?
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Notice: this would keep the oldest duplicate record and would erase the newer ones. If you want to keep the newest you cannot do this with ALTER IGNORE.
– Haralan Dobrev
Oct 1 '12 at 10:26
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How does the bitwise complement operator (~ tilde) work?
...representation of a number, taking its complement (inverting all the bits) and adding one. Two starts as 0000 0010, and by inverting the bits we get 1111 1101. Adding one gets us the result above. The first bit is the sign bit, implying a negative.
So let's take a look at how we get ~2 = -3:
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What is the difference between a port and a socket?
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Summary
A TCP socket is an endpoint instance defined by an IP address and a port in the context of either a particular TCP connection or the listening state.
A port is a virtualisation identifier defining a service endpoint (as distinct from a service instance endpoint aka session identifier)...