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Sort hash by key, return hash in Ruby
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229
In Ruby 2.1 it is simple:
h.sort.to_h
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HSL to RGB color conversion
...m, but is archived here and the original author has a gist - thanks to user2441511).
The code is re-posted below:
HSL to RGB:
/**
* Converts an HSL color value to RGB. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes h, s, and l are contained in the se...
Printing the correct number of decimal points with cout
I have a list of float values and I want to print them with cout with 2 decimal places.
12 Answers
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How to iterate a loop with index and element in Swift
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print("Item \(index): \(element)")
}
Before Swift 3.0 and after Swift 2.0, the function was called enumerate():
for (index, element) in list.enumerate() {
print("Item \(index): \(element)")
}
Prior to Swift 2.0, enumerate was a global function.
for (index, element) in enumerate(list) {
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How to find the sum of an array of numbers
Given an array [1, 2, 3, 4] , how can I find the sum of its elements? (In this case, the sum would be 10 .)
43 Answers
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Understanding how recursive functions work
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2
I'm not too happy with thinking of it as a copy. I find that a more intuitive explanation is to differentiate the function itself (the code,...
How to add an extra column to a NumPy array
...np.random.rand(N,N)
b = np.zeros((N,N+1))
b[:,:-1] = a
And timings:
In [23]: N = 10
In [24]: a = np.random.rand(N,N)
In [25]: %timeit b = np.hstack((a,np.zeros((a.shape[0],1))))
10000 loops, best of 3: 19.6 us per loop
In [27]: %timeit b = np.zeros((a.shape[0],a.shape[1]+1)); b[:,:-1] = a
1000...
Get column index from column name in python pandas
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Sure, you can use .get_loc():
In [45]: df = DataFrame({"pear": [1,2,3], "apple": [2,3,4], "orange": [3,4,5]})
In [46]: df.columns
Out[46]: Index([apple, orange, pear], dtype=object)
In [47]: df.columns.get_loc("pear")
Out[47]: 2
although to be honest I don't often need this myself. Usu...
How do I use floating-point division in bash?
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248
You can't. bash only does integers; you must delegate to a tool such as bc.
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How to find the size of localStorage
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226
Execute this snippet in JavaScript console (one line version):
var _lsTotal=0,_xLen,_x;for(_x ...