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How to count the number of true elements in a NumPy bool array
...xample:
>>> import numpy as np
>>> boolarr = np.array([[0, 0, 1], [1, 0, 1], [1, 0, 1]], dtype=np.bool)
>>> boolarr
array([[False, False, True],
[ True, False, True],
[ True, False, True]], dtype=bool)
>>> np.sum(boolarr)
5
Of course, that is ...
How to catch integer(0)?
Let's say we have a statement that produces integer(0) , e.g.
6 Answers
6
...
Optional Parameters with C++ Macros
...rd trick to count the number of arguments to a macro.
enum
{
plain = 0,
bold = 1,
italic = 2
};
void PrintString(const char* message, int size, int style)
{
}
#define PRINT_STRING_1_ARGS(message) PrintString(message, 0, 0)
#define PRINT_STRING_2_ARGS(message, size) ...
How to map atan2() to degrees 0-360
atan2(y, x) has that discontinuity at 180° where it switches to -180°..0° going clockwise.
15 Answers
...
Why does parseInt(1/0, 19) return 18?
...
The result of 1/0 is Infinity.
parseInt treats its first argument as a string which means first of all Infinity.toString() is called, producing the string "Infinity". So it works the same as if you asked it to convert "Infinity" in base 19 ...
How can I scale the content of an iframe?
...ra and Safari if you change the CSS to:
<style>
#wrap { width: 600px; height: 390px; padding: 0; overflow: hidden; }
#frame { width: 800px; height: 520px; border: 1px solid black; }
#frame {
-ms-zoom: 0.75;
-moz-transform: scale(0.75);
-moz-transform-origin...
All falsey values in JavaScript
...
Falsey values in JavaScript
false
Zero of Number type: 0 and also -0, 0.0, and hex form 0x0 (thanks RBT)
Zero of BigInt type: 0n and -0n (new in 2020, thanks GetMeARemoteJob)
"", '' and `` - strings of length 0
null
undefined
NaN
document.all (in HTML browsers only)
This is a ...
Regular expressions in C: examples?
...):
#include <regex.h>
regex_t regex;
int reti;
char msgbuf[100];
/* Compile regular expression */
reti = regcomp(&regex, "^a[[:alnum:]]", 0);
if (reti) {
fprintf(stderr, "Could not compile regex\n");
exit(1);
}
/* Execute regular expression */
reti = regexec(&regex, ...
iOS UIImagePickerController result image orientation after upload
...
20 Answers
20
Active
...
Does .NET provide an easy way convert bytes to KB, MB, GB, etc.?
...izeSuffix(Int64 value, int decimalPlaces = 1)
{
if (decimalPlaces < 0) { throw new ArgumentOutOfRangeException("decimalPlaces"); }
if (value < 0) { return "-" + SizeSuffix(-value); }
if (value == 0) { return string.Format("{0:n" + decimalPlaces + "} bytes", 0); }
// mag is 0 ...