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How can I profile C++ code running on Linux?
... stack. If there is some code that is wasting some percentage of the time, 20% or 50% or whatever, that is the probability that you will catch it in the act on each sample. So, that is roughly the percentage of samples on which you will see it. There is no educated guesswork required. If you do have...
How to iterate a loop with index and element in Swift
...
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) {
...
Numpy first occurrence of value greater than existing value
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207
This is a little faster (and looks nicer)
np.argmax(aa>5)
Since argmax will stop at the ...
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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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...
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 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...
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 ...
How do I create a list of random numbers without duplicates?
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edited Apr 2 '18 at 12:59
nbro
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