Distance from Point to Line 2D

Problem

Compute the distance from point p to the line through points a and b in 2D:

d = |cross(b - a, p - a)| / ||b - a||_2

If a == b, return the point distance ||p - a||_2.

Hint

The cross product gives twice the triangle area; divide by the base length.

case 1

in: [[2,3],[0,0],[4,0]]

expected: 3

case 2

in: [[1,0],[0,0],[1,1]]

expected: 0.7071067811865475

case 3

in: [[4,5],[1,1],[1,1]]

expected: 5

case 4

in: [[0,0],[0,0],[3,4]]

expected: 0

Starter codePython

def point_line_distance(p, a, b):
    # Your code here
    pass

4 test cases · run your code against them in the editor