问题
This question/answer pair shows how to extract vertices from contour plot:
p = cs.collections[0].get_paths()[0]
v = p.vertices
x = v[:,0]
y = v[:,1]
But how to get the value (i.e z
for an elevation model) for each path?
回答1:
There's no direct way, but cs.collections
is in the exact same order as cs.levels
(which is the "z" values you're after).
Therefore, it's easiest to do something like:
lookup = dict(zip(cs.collections, cs.levels))
z = lookup[line_collection_artist]
As a quick interactive example:
import numpy as np
import matplotlib.pyplot as plt
def main():
fig, ax = plt.subplots()
cs = ax.contour(np.random.random((10,10)))
callback = ContourCallback(cs)
plt.setp(cs.collections, picker=5)
fig.canvas.mpl_connect('pick_event', callback)
plt.show()
class ContourCallback(object):
def __init__(self, cs):
self.lookup = dict(zip(cs.collections, cs.levels))
def __call__(self, event):
print self.lookup[event.artist]
main()
来源:https://stackoverflow.com/questions/17051131/matplotlib-extracting-values-from-contour-lines