Subtract Unless Negative Then Return 0
One way… >>> max(0, x)
math
Is `scipy.misc.comb` faster than an ad-hoc binomial computation?
Referring to the source code of scipy.misc.comb, the update routine of the result is: val = 1 for j in xrange(min(k, N-k)): val = (val*(N-j))//(j+1) return val whereas the update routine you suggested is: ntok = 1 ktok = 1 for t in xrange(1, min(k, n – k) + 1): ntok *= n ktok *= … Read more
How to distribute points evenly on the surface of hyperspheres in higher dimensions?
Very interesting question. I wanted to implement this into mine 4D rendering engine as I was curious how would it look like but I was too lazy and incompetent to handle ND transcendent problems from the math side. Instead I come up with different solution to this problem. Its not a Fibonaci Latice !!! Instead … Read more
Getting angle back from a sin/cos conversion
atan2(s_y, s_x) should give you the correct angle. Maybe you have reversed the order of s_x and s_y. Also, you can use the acos and asin functions directly on s_x and s_y respectively.
Integer division in Java [duplicate]
They are being divided in integer arithmetics. So dividing integer a by integer b you get how many times b fits into a. Also a % b will give you a remainder of a division. So (a / b ) * b + a % b = a
How do I find the orthogonal projection of a point onto a plane
The projection of a point q = (x, y, z) onto a plane given by a point p = (a, b, c) and a normal n = (d, e, f) is q_proj = q – dot(q – p, n) * n This calculation assumes that n is a unit vector.
How do you normalize a zero vector
Mathematically speaking, the zero vector cannot be normalized. Its length will always remain 0. For given vector v = (v1, v2, …, vn) we have: ||v|| = sqrt(v1^2 + v2^2 + … + vn^2). Let us remember that a normalized vector is one that has ||v||=1. So for v = 0 we have: ||0|| = … Read more
Does Swift has built-in logarithm function?
You can use the log2(:Double) or log2f(:Float) methods from the documentation, available by e.g. importing UIKit or Foundation: func log2(x: Double) -> Double func log2f(x: Float) -> Float E.g., in a Playground print(log2(8.0)) // 3.0 (Edit addition w.r.t. your comment below) If you want to compute your custom-base log function, you can make use of … Read more
Is F# really better than C# for math?
I think most of the important points were already mentioned by someone else: F# lets you solve problems in a way mathematicians think about them Thanks to higher-order functions, you can use simpler concepts to solve difficult problems Everything is immutable by default, which makes the program easier to understand (and also easier to parallelize) … Read more
Using M_PI with C89 standard
A conforming standard library file math.h is not only not required to, but actually must not define M_PI by default. In this context ‘by default’ means that M_PI must only get defined through compiler-specific tricks, most often undefined behavior through the use of reserved identifiers. Just define the constant yourself (you can use the name … Read more