将水流箭头添加到Matplotlib Contour Plot

Question

我用Matplotlib生成地下水高程轮廓.见下文

这就是我现在拥有的; 如何添加水流箭头,如下图所示？

我想添加箭头使它看起来像这样:

如果有人有一些想法和/或代码样本将非常感激.

Answer 1

你需要一个最新的(> = 1.2)版本的matplotlib,但streamplot这样做.你只需要采取负头梯度(也就是表面含水层的"水位")网格.

作为从头部的随机点观察产生的快速示例:

import numpy as np
from scipy.interpolate import Rbf
import matplotlib.pyplot as plt
# Make data repeatable
np.random.seed(1981)

# Generate some random wells with random head (water table) observations
x, y, z = np.random.random((3, 10))

# Interpolate these onto a regular grid
xi, yi = np.mgrid[0:1:100j, 0:1:100j]
func = Rbf(x, y, z, function='linear')
zi = func(xi, yi)

# -- Plot --------------------------
fig, ax = plt.subplots()

# Plot flowlines
dy, dx = np.gradient(-zi.T) # Flow goes down gradient (thus -zi)
ax.streamplot(xi[:,0], yi[0,:], dx, dy, color='0.8', density=2)

# Contour gridded head observations
contours = ax.contour(xi, yi, zi, linewidths=2)
ax.clabel(contours)

# Plot well locations
ax.plot(x, y, 'ko')

plt.show()