python绘制有箭头的直线_python-Polar Matplotlib图中的箭头

箭头尺寸太大,这是：

import matplotlib

import numpy as np

import matplotlib.pyplot as plt

print "matplotlib.__version__ = ", matplotlib.__version__

print "matplotlib.get_backend() = ", matplotlib.get_backend()

# radar green, solid grid lines

plt.rc('grid', color='#316931', linewidth=1, linestyle='-')

plt.rc('xtick', labelsize=15)

plt.rc('ytick', labelsize=15)

# force square figure and square axes looks better for polar, IMO

width, height = matplotlib.rcParams['figure.figsize']

size = min(width, height)

# make a square figure

fig = plt.figure(figsize=(size, size))

ax = fig.add_axes([0.1, 0.1, 0.8, 0.8], polar=True, axisbg='#d5de9c')

r = np.arange(0, 3.0, 0.01)

theta = 2*n