How To Find All Intersection Points Of Graphs In A Loop In Python?

I plot a certain set of circles as follows: import numpy as np import matplotlib.pyplot as plt fig = plt.figure(1, figsize=(10,10)) numbers = [2,4,6] for i in range(1,len(numbers

Solution 1:

Here is some SymPy code to find all the intersections. Note that your code generates a lot of circles multiple times, so I put them in a set. (The circle-circle intersection of a circle with itself is of course itself, in which case intersect doesn't return a list, but just the circle.)

from sympy import *
from sympy.geometry import *
import itertools

numbers = [2,4,6]
circles = set()

for i inrange(1,len(numbers)+1):
    for n in numbers:
        for j inrange(1,4):
            circles.add(Circle(Point(i, 0), numbers[i-1]*j))

all_intersections = []
for c1, c2 in itertools.combinations(circles, 2):
    all_intersections += c1.intersection(c2)

print(all_intersections)
all_intersections_as_tuple = [tuple(p.evalf()) for p in all_intersections]

Which outputs:

[Point2D(5/2, -5*sqrt(23)/2), Point2D(5/2, 5*sqrt(23)/2), Point2D(-3, 0), Point2D(3/2, -3*sqrt(7)/2), Point2D(3/2, 3*sqrt(7)/2), Point2D(2, sqrt(35)), Point2D(2, -sqrt(35))]

Adding them to your plot:

plt.plot([x for x, y in all_intersections_as_tuple], [y for x, y in all_intersections_as_tuple], 'or', color='red')