api example code: bbox_intersect.py

(Source code, png, pdf)

"""
===========================================
Changing colors of lines intersecting a box
===========================================

The lines intersecting the rectangle are colored in red, while the others
are left as blue lines. This example showcases the `intersect_bbox` function.

"""

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.transforms import Bbox
from matplotlib.path import Path

left, bottom, width, height = (-1, -1, 2, 2)
rect = plt.Rectangle((left, bottom), width, height, facecolor="#aaaaaa")

fig, ax = plt.subplots()
ax.add_patch(rect)

bbox = Bbox.from_bounds(left, bottom, width, height)

for i in range(12):
    vertices = (np.random.random((2, 2)) - 0.5) * 6.0
    path = Path(vertices)
    if path.intersects_bbox(bbox):
        color = 'r'
    else:
        color = 'b'
    ax.plot(vertices[:, 0], vertices[:, 1], color=color)

plt.show()

Keywords: python, matplotlib, pylab, example, codex (see Search examples)