Source code for pyleecan.Functions.Geometry.inter_line_circle

# -*- coding: utf-8 -*-
from numpy import sqrt, abs as np_abs

[docs]def inter_line_circle(Z1, Z2, R, Zc=0):
"""INTER_LINE_CIRCLE find the intersection between a circle of center Zc
and radius r with a line defined by two points

Parameters
----------
Z1 : complex
Complex coordinate of a point on the line

Z2 : complex
Complex coordinate of another point on the line
R : float
Zc : complex
Complex coordinate of the center

Returns
-------
Zlist: list
List of the complex coordinates of the intersection
"""
# Set the coordinate system on the circle center
if np_abs(Zc) > 1e-6:
Z1 = Z1 - Zc
Z2 = Z2 - Zc
else:
Zc = 0

x1 = Z1.real
y1 = Z1.imag
x2 = Z2.real
y2 = Z2.imag

dx = x2 - x1
dy = y2 - y1
dr = sqrt(dx ** 2 + dy ** 2)
D = x1 * y2 - x2 * y1

delta = R ** 2 * dr ** 2 - D ** 2
if delta < 0:  # 0 point
return list()
elif delta == 0:  # 1 point(tangent)
return [(D * dy - 1j * D * dx) / dr ** 2 + Zc]

else:  # 2 points
if dy < 0:
xs1 = (D * dy - dx * sqrt(delta)) / dr ** 2
xs2 = (D * dy + dx * sqrt(delta)) / dr ** 2
else:
xs1 = (D * dy + dx * sqrt(delta)) / dr ** 2
xs2 = (D * dy - dx * sqrt(delta)) / dr ** 2
ys1 = (-D * dx + abs(dy) * sqrt(delta)) / dr ** 2
ys2 = (-D * dx - abs(dy) * sqrt(delta)) / dr ** 2

return [xs1 + 1j * ys1 + Zc, xs2 + 1j * ys2 + Zc]