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Is False == 0 and True == 1 an implementation detail or is it guaranteed by the language?
...ill always produce the same results, whatever the version of Python (both existing and, likely, future ones)?
6 Answers
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Fastest way to replace NAs in a large data.table
...alue=0) { v[is.na(v)] = value; v }
for (i in names(dt))
eval(parse(text=paste("dt[,",i,":=na.replace(",i,")]")))
}
system.time(a_gdata = f_gdata(dt1))
user system elapsed
18.805 12.301 134.985
system.time(a_andrie = f_andrie(dt1))
Error: cannot allocate vector of size 305.2 Mb
Timin...
Is there any particular difference between intval and casting to int - `(int) X`?
...) can be passed a base from which to convert. (int) cannot.
int intval( mixed $var [, int $base = 10 ] )
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Ruby: How to iterate over a range, but in set increments?
...html#M000695 for the full API.
Basically you use the step() method. For example:
(10..100).step(10) do |n|
# n = 10
# n = 20
# n = 30
# ...
end
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Remove trailing newline from the elements of a string list
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Be aware of the following: If you are using Python 3.x and you want to return a list, you have to list, so that it's list(map(str.strip, my_list)). Also check that out: link.
– So S
Dec 1 '15 at 21:31
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Is MATLAB OOP slow or am I doing something wrong?
I'm experimenting with MATLAB OOP , as a start I mimicked my C++'s Logger classes and I'm putting all my string helper functions in a String class, thinking it would be great to be able to do things like a + b , a == b , a.find( b ) instead
of strcat( a b ) , strcmp( a, b ) , retrieve first...
What does “./bin/www” do in Express 4.x?
I just started to learn about Express 4.0 in my Node.js app, and I found that it generated ./bin/www file, on which only the application server and port settings are written and everything others like middleware and routing is defined in ./app.js file.
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JavaScript, elegant way to check nested object properties for null/undefined [duplicate]
...urse of using the app this gets populated. Let's say somwhere, after an AJAX call or something i do this:
4 Answers
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Finding quaternion representing the rotation from one vector to another
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Quaternion q;
vector a = crossproduct(v1, v2);
q.xyz = a;
q.w = sqrt((v1.Length ^ 2) * (v2.Length ^ 2)) + dotproduct(v1, v2);
Don't forget to normalize q.
Richard is right about there not being a unique rotation, but the above should give the "shortest arc," which is pro...
HTML5 Pre-resize images before uploading
...function(e) {img.src = e.target.result}
reader.readAsDataURL(file);
var ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0);
var MAX_WIDTH = 800;
var MAX_HEIGHT = 600;
var width = img.width;
var height = img.height;
if (width > height) {
if (width > MAX_WIDTH) {
height *= MAX_WIDT...