rotate.py

ax = plt.gca()
ax.set_xlabel('Principal component 1')
ax.set_ylabel('Principal component 2')
plt.scatter(T[:, 0], T[:, 1], c='#663399', alpha=0.5)
plt.scatter(T_mean[0], T_mean[1], c='red', s=50)

for length, vector in zip(w_12_T, v_12_T):
    dir_ = vector * 3  * np.sqrt(length)
    arrowprops = dict(arrowstyle='->', linewidth=2, shrinkA=0,
                      shrinkB=0, color='red', alpha=0.5)
    dir_[0] = -dir_[0]
    start = X_mean; end = start + dir_
    ax.annotate('', xy = end, xytext = start, arrowprops=arrowprops)
    
#plt.axis('equal') <-- '''Let the plot scale by axes'''