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How to use R's ellipsis feature when writing your own function?
...nts. For example, the function data.frame takes any number of arguments, and each argument becomes the data for a column in the resulting data table. Example usage:
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Regular expression that matches valid IPv6 addresses
...ular expressions, so I wrote one that works with POSIX regular expressions and PERL regular expressions.
It should match:
IPv6 addresses
zero compressed IPv6 addresses (section 2.2 of rfc5952)
link-local IPv6 addresses with zone index (section 11 of rfc4007)
IPv4-Embedded IPv6 Address (section 2 ...
StringIO in Python3
I am using Python 3.2.1 and I can't import the StringIO module. I use
io.StringIO and it works, but I can't use it with numpy 's genfromtxt like this:
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What is the difference between Gemfile and Gemfile.lock in Ruby on Rails
I am a beginner to Ruby on Rails and I am using Rails 3.0.9.
3 Answers
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What does the git index contain EXACTLY?
What does the Git index exactly contain, and what command can I use to view the content of the index?
5 Answers
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When to use LinkedList over ArrayList in Java?
...nkedList. If you're not sure — just start with ArrayList.
LinkedList and ArrayList are two different implementations of the List interface. LinkedList implements it with a doubly-linked list. ArrayList implements it with a dynamically re-sizing array.
As with standard linked list and array op...
How to sort in-place using the merge sort algorithm?
...s the array xs, the two sorted sub-arrays are represented as ranges [i, m) and [j, n) respectively. The working area starts from w. Compare with the standard merge algorithm given in most textbooks, this one exchanges the contents between the sorted sub-array and the working area. As the result, the...
How does C compute sin() and other math functions?
I've been poring through .NET disassemblies and the GCC source code, but can't seem to find anywhere the actual implementation of sin() and other math functions... they always seem to be referencing something else.
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Sorting multiple keys with Unix sort
...s that need to be sorted by 1-n keys. Some of these keys might be numeric and some of them might not be. This is a fixed-width columnar file so there are no delimiters.
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What is the difference between an expression and a statement in Python?
In Python, what is the difference between expressions and statements?
14 Answers
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