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How to iterate for loop in reverse order in swift?
...
With Swift 2.0 it is now: 5.stride(to: 1, by: -1) or 5.stride(through: 1, by: -1)
– Binarian
Sep 21 '15 at 9:23
6
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How do I create an empty array/matrix in NumPy?
...rt numpy
>>> a = numpy.zeros(shape=(5,2))
>>> a
array([[ 0., 0.],
[ 0., 0.],
[ 0., 0.],
[ 0., 0.],
[ 0., 0.]])
>>> a[0] = [1,2]
>>> a[1] = [2,3]
>>> a
array([[ 1., 2.],
[ 2., 3.],
[ 0., 0.],
[ 0., 0.],
[ 0., 0.]])
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What's the fastest way to merge/join data.frames in R?
...he first example sqldf is 3x slower than data.table and in the second its 200x faster than plyr and 100 times faster than data.table. Below we show the input code, the output timings for the merge and the output timings for the aggregate. Its also worthwhile noting that sqldf is based on a databa...
Tricky Google interview question
... implementation of Dijkstra’s solution.
int main()
{
const int n = 20; // Generate the first n numbers
std::vector<int> v(n);
v[0] = 1;
int i2 = 0; // Index for 2
int i5 = 0; // Index for 5
int x2 = 2 * v[i2]; // Next two candidat...
How to form tuple column from two columns in Pandas
...
208
Get comfortable with zip. It comes in handy when dealing with column data.
df['new_col'] = li...
Remove insignificant trailing zeros from a number?
... first place since it was created as a Number, not a String.
var n = 1.245000
var noZeroes = n.toString() // "1.245"
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Obfuscated C Code Contest 2006. Please explain sykes2.c
...>> ";;;====~$::199"[_*2&8|_/64]/(_&2?1:8)%8&1
: 10);
}
Introducing variables to untangle this mess:
main(int i) {
if(i^448)
main(-~i);
if(--i % 64) {
char a = -~7[__TIME__-i/8%8][">'txiZ^(~z?"-48];
char b = a >> ";;;====~$::199"[i...
Fast Bitmap Blur For Android SDK
... I'm looping through the pixels of an image to blur it. This takes about 30 seconds on a 640x480 image.
19 Answers
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Truncate number to two decimal places without rounding
...eform.rounded
var with2Decimals = num.toString().match(/^-?\d+(?:\.\d{0,2})?/)[0]
rounded.value = with2Decimals
}
<form onsubmit="return calc(this)">
Original number: <input name="original" type="text" onkeyup="calc(form)" onchange="calc(form)" />
<br />"Rounded" numb...
How to plot two histograms together in R?
...gle numeric column which lists the length of all measured carrots (total: 100k carrots) and cucumbers (total: 50k cucumbers).
...