I\'m using Python+Numpy (can maybe also use Scipy) and have three 2D points
(P1, P2, P3);
I am trying to get the distance from P3 perpend
Try using the norm function from numpy.linalg
d = norm(np.cross(p2-p1, p1-p3))/norm(p2-p1)
For the above-mentioned answers to work, the points need to be numpy arrays, here's a working example:
import numpy as np
p1=np.array([0,0])
p2=np.array([10,10])
p3=np.array([5,7])
d=np.cross(p2-p1,p3-p1)/np.linalg.norm(p2-p1)