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Why does the order of the loops affect performance when iterating over a 2D array?
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You have a 2-dimensional array, but memory in the computer is inherently 1-dimensional. So while you imagine your array like this:
0,0 | 0,1 | 0,2 | 0,3
----+-----+-----+----
1,0 | 1,1 | 1,2 | 1,3
----+-----+-----+----
2,0 | 2,1 | 2,2 | 2,3
Your computer stores it in memory as a single line:
0...
Comparing two NumPy arrays for equality, element-wise
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edited Nov 7 '19 at 8:57
answered May 14 '12 at 9:37
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Why does (1 in [1,0] == True) evaluate to False?
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1 Answer
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Why does Math.round(0.49999999999999994) return 1?
...n Java 6 (and presumably earlier), round(x) is implemented as floor(x+0.5).1 This is a specification bug, for precisely this one pathological case.2 Java 7 no longer mandates this broken implementation.3
The problem
0.5+0.49999999999999994 is exactly 1 in double precision:
static void print(do...
What is the difference between map and flatMap and a good use case for each?
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16 Answers
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Why is GHC so large/big?
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188
It's a bit silly really. Every library that comes with GHC is provided in no less than 4 flav...
Efficient Algorithm for Bit Reversal (from MSB->LSB to LSB->MSB) in C
...reverse(register unsigned int x)
{
x = (((x & 0xaaaaaaaa) >> 1) | ((x & 0x55555555) << 1));
x = (((x & 0xcccccccc) >> 2) | ((x & 0x33333333) << 2));
x = (((x & 0xf0f0f0f0) >> 4) | ((x & 0x0f0f0f0f) << 4));
x = (((x & 0xf...
How do I get both STDOUT and STDERR to go to the terminal and a log file?
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171
Use "tee" to redirect to a file and the screen. Depending on the shell you use, you first hav...
Is R's apply family more than syntactic sugar?
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The apply functions in R don't provide improved performance over other looping functions (e.g....