python plot non linear equation

Question

What is the easiest way to plot a non linear equation in python.

For example:

0 = sqrt((-6 - x) ** 2 + (4 - y) ** 2) - sqrt((1 - x) ** 2 + y ** 2) - 5

I would like to plot that equation for x in [0, 10] and look like a continuous curve.

Thanks!

Answer 1

Here's a simple way to plot implicit equations by using numpy+matplotlib:

import matplotlib.pyplot
from numpy import arange, meshgrid, sqrt

delta = 0.025
x, y = meshgrid(
    arange(0, 10, delta),
    arange(0, 10, delta)
)

matplotlib.pyplot.contour(
    x, y,
    sqrt((-6 - x) ** 2 + (4 - y) ** 2) - sqrt((1 - x) ** 2 + y ** 2) - 5,
    [0]
)
matplotlib.pyplot.show()

Output:

This method is really handy to analize closed forms, for instance, a circle of radius 3 would look like:

matplotlib.pyplot.contour(
    x, y,
    x**2+y**2-9,
    [0]
)