plotNonconservative.py

#!/usr/bin/env python3
 

 
# Authors: Caleb Voss, Wilson Beebe
 
import matplotlib.pyplot as plt
from pylab import meshgrid, arange, quiver, quiverkey, sqrt
import numpy as np
 
 
def makeVectorField(f, xmin, xmax, ymin, ymax, step):
    X, Y = meshgrid(arange(xmin, xmax, step), arange(ymin, ymax, step))
    U, V = zip(*map(lambda xx: f(*xx), zip(X, Y)))
    Q = quiver(X, Y, U, V, units="width")
    quiverkey(Q, 0, 0, 4, "", coordinates="figure", labelpos="W")
 
 
fig = plt.figure()
ax = fig.gca(aspect="equal")
x = np.loadtxt("vfrrt-nonconservative.path")
makeVectorField(
    lambda x, y: (y / sqrt(x * x + y * y + 1e-6), -x / sqrt(x * x + y * y + 1e-6)),
    -6,
    6,
    -6,
    6,
    0.5,
)
ax.plot(x[:, 0], x[:, 1])
plt.show()