electrostatics.py 文件源码

def is_left(x0, x1, x2):
    """Returns True if x0 is left of the line between x1 and x2,
    False otherwise.  Ref: https://stackoverflow.com/questions/1560492"""
    assert x1.shape == x2.shape == (2,)
    matrix = array([x1-x0, x2-x0])
    if len(x0.shape) == 2:
        matrix = matrix.transpose((1, 2, 0))
    return det(matrix) > 0