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Is R's apply family more than syntactic sugar?
... n < 2 ) n
+ else fibo(n-1) + fibo(n-2)
+ }
> system.time(for(i in 0:26) fibo(i))
user system elapsed
7.48 0.00 7.52
> system.time(sapply(0:26, fibo))
user system elapsed
7.50 0.00 7.54
> system.time(lapply(0:26, fibo))
user system elapsed
7.48 ...
Normalizing mousewheel speed across browsers
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10 Answers
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Extract elements of list at odd positions
...l. The result will contain the elements placed on the following positions (0-based, so first element is at position 0, second at 1 etc.):
1, 3, 5
so the result (actual numbers) will be:
2, 4, 6
Explanation
The [1::2] at the end is just a notation for list slicing. Usually it is in the followi...
How to remove the first Item from a list?
I have the list [0, 1, 2, 3, 4] I'd like to make it into [1, 2, 3, 4] . How do I go about this?
10 Answers
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Ruby, remove last N characters from a string?
..._suffix!('123') # => "abc"
It's even significantly faster (almost 40% with the bang method) than the top answer. Here's the result of the same benchmark:
user system total real
chomp 0.949823 0.001025 0.950848 ( 0.951941)
range ...
How to compare versions in Ruby?
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Gem::Version.new('0.4.1') > Gem::Version.new('0.10.1')
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How do I convert a TimeSpan to a formatted string? [duplicate]
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edited Aug 16 '09 at 17:51
answered May 8 '09 at 22:22
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Two-dimensional array in Swift
...Int]] = []
OR if you need an array of predefined size (as mentioned by @0x7fffffff in comments):
// 2 dimensional array of arrays of Ints set to 0. Arrays size is 10x5
var arr = Array(count: 3, repeatedValue: Array(count: 2, repeatedValue: 0))
// ...and for Swift 3+:
var arr = Array(repeating: ...
计算统计特征（正态分布）函数及实例 - C/C++ - 清泛网 - 专注C/C++及内核技术
...ain(int argc, _TCHAR* argv[])
{
std::map<int, int> map_test;
map_test[0] = 100;
map_test[5] = 80;
map_test[2] = 10;
map_test[8] = 99;
map_test[4] = 102;
StdevInfo stdev_info;
stdev_info.init();
stdev_info.caculate_stdev_info(map_test.begin(), map_test.end(),
[](const std::p...
Why is it slower to iterate over a small string than a small list?
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TL;DR
The actual speed difference is closer to 70% (or more) once a lot of the overhead is removed, for Python 2.
Object creation is not at fault. Neither method creates a new object, as one-character strings are cached.
The difference is unobvious, but is likely created f...