readme.md

sanity check for convex optimization book (https://web.stanford.edu/~boyd/cvxbook/) section 2.5.1 on separaing hyperplane theorem

mid_hyperplane_line.py

import numpy as np
import matplotlib.pyplot as plt
n_steps = 50
c, d= np.array([3,3]),np.array([1,2])
a = c-d
b = (np.linalg.norm(c)**2-np.linalg.norm(d)**2)/2

x = np.linspace(0, 4, n_steps) 
y = np.linspace(0, 4, n_steps) 
X, Y = np.meshgrid(x, y)
Z = np.c_[X.flatten(),Y.flatten()]@a-b
Z = Z.reshape(n_steps,n_steps)
fig = plt.figure(0)
ax = plt.subplot(111)
cs = ax.contour(X,Y,Z,levels=20, colors="#666666")
plt.clabel(cs, inline=1, fontsize=10)
plt.plot(c[0],c[1],"o", label="c")
plt.plot(d[0],d[1],"o", label="d")
plt.legend()

plt.show()