python画出三角形外接圆和内切圆的方法

import matplotlib.pyplot as pltfrom scipy.linalg import solveimport numpy as npfrom matplotlib.patches import Circle'''求三角形外接圆和内切圆'''# 画个三角形def plot_triangle(A, B, C):  x = [A[0], B[0], C[0], A[0]]  y = [A[1], B[1], C[1], A[1]]  ax = plt.gca()  ax.plot(x, y, linewidth=2)# 画个圆def draw_circle(x, y, r):  ax = plt.gca()  cir = Circle(xy=(x, y), radius=r, alpha=0.5)  ax.add_patch(cir)  ax.plot()# 外接圆def get_outer_circle(A, B, C):  xa, ya = A[0], A[1]  xb, yb = B[0], B[1]  xc, yc = C[0], C[1]  # 两条边的中点  x1, y1 = (xa + xb) / 2.0, (ya + yb) / 2.0  x2, y2 = (xb + xc) / 2.0, (yb + yc) / 2.0  # 两条线的斜率  ka = (yb - ya) / (xb - xa) if xb != xa else None  kb = (yc - yb) / (xc - xb) if xc != xb else None  alpha = np.arctan(ka) if ka != None else np.pi / 2  beta = np.arctan(kb) if kb != None else np.pi / 2  # 两条垂直平分线的斜率  k1 = np.tan(alpha + np.pi / 2)  k2 = np.tan(beta + np.pi / 2)  # 圆心  y, x = solve([[1.0, -k1], [1.0, -k2]], [y1 - k1 * x1, y2 - k2 * x2])  # 半径  r1 = np.sqrt((x - xa)**2 + (y - ya)**2)  return(x, y, r1)# 内切圆def get_inner_circle(A, B, C):  xa, ya = A[0], A[1]  xb, yb = B[0], B[1]  xc, yc = C[0], C[1]  ka = (yb - ya) / (xb - xa) if xb != xa else None  kb = (yc - yb) / (xc - xb) if xc != xb else None  alpha = np.arctan(ka) if ka != None else np.pi / 2  beta = np.arctan(kb) if kb != None else np.pi / 2  a = np.sqrt((xb - xc)**2 + (yb - yc)**2)  b = np.sqrt((xa - xc)**2 + (ya - yc)**2)  c = np.sqrt((xa - xb)**2 + (ya - yb)**2)  ang_a = np.arccos((b**2 + c**2 - a**2) / (2 * b * c))  ang_b = np.arccos((a**2 + c**2 - b**2) / (2 * a * c))  # 两条角平分线的斜率  k1 = np.tan(alpha + ang_a / 2)  k2 = np.tan(beta + ang_b / 2)  kv = np.tan(alpha + np.pi / 2)  # 求圆心  y, x = solve([[1.0, -k1], [1.0, -k2]], [ya - k1 * xa, yb - k2 * xb])  ym, xm = solve([[1.0, -ka], [1.0, -kv]], [ya - ka * xa, y - kv * x])  r1 = np.sqrt((x - xm)**2 + (y - ym)**2)  return(x, y, r1)if __name__ == '__main__':  A = (1., 1.)  B = (5., 2.)  C = (5., 5.)  plt.axis('equal')  plt.axis('off')  plot_triangle(A, B, C)  x, y, r1 = get_outer_circle(A, B, C)  plt.plot(x, y, 'ro')  draw_circle(x, y, r1)  x_inner, y_inner, r_inner = get_inner_circle(A, B, C)  plt.plot(x_inner, y_inner, 'ro')  draw_circle(x_inner, y_inner, r_inner)  plt.show()