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Why does changing 0.1f to 0 slow down performance by 10x?
...) {
double start = omp_get_wtime();
const float x[16]={1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2.0,2.1,2.2,2.3,2.4,2.5,2.6};
const float z[16]={1.123,1.234,1.345,156.467,1.578,1.689,1.790,1.812,1.923,2.034,2.145,2.256,2.367,2.478,2.589,2.690};
float y[16];
for(int i=0;i<16;i++)
...
Programmatically Lighten or Darken a hex color (or rgb, and blend colors)
...n or darken a hex color by a specific amount. Just pass in a string like "3F6D2A" for the color ( col ) and a base10 integer ( amt ) for the amount to lighten or darken. To darken, pass in a negative number (i.e. -20 ).
...
Get a random boolean in python?
...
349
Adam's answer is quite fast, but I found that random.getrandbits(1) to be quite a lot faster. ...
Apply multiple functions to multiple groupby columns
...
313
The second half of the currently accepted answer is outdated and has two deprecations. First a...
How to validate an Email in PHP?
... Manual should suffice.
Update 1: As pointed out by @binaryLV:
PHP 5.3.3 and 5.2.14 had a bug related to
FILTER_VALIDATE_EMAIL, which resulted in segfault when validating
large values. Simple and safe workaround for this is using strlen()
before filter_var(). I'm not sure about 5.3.4 fin...
How to access the ith column of a NumPy multidimensional array?
...
>>> test[:,0]
array([1, 3, 5])
Similarly,
>>> test[1,:]
array([3, 4])
lets you access rows. This is covered in Section 1.4 (Indexing) of the NumPy reference. This is quick, at least in my experience. It's certainly much quicker tha...
Javascript calculate the day of the year (1 - 366)
How do I use javascript to calculate the day of the year, from 1 - 366? For example:
22 Answers
...
Memoization in Haskell?
...
f mf 0 = 0
f mf n = max n $ mf (n `div` 2) +
mf (n `div` 3) +
mf (n `div` 4)
You can get an unmemoized f by using fix f
This will let you test that f does what you mean for small values of f by calling, for example: fix f 123 = 144
We could memoize this by def...
List comprehension on a nested list?
...
332
Here is how you would do this with a nested list comprehension:
[[float(y) for y in x] for x ...
Two-dimensional array in Swift
...ray 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: Array(repeating: 0, count: 2), count: 3)
Change element at position
arr[0][1] = 18
OR
let myVar = 18
arr[0][1] = m...