# coding:utf-8

"""

@Function:

使用坐标轴变换绘制一个带有阴影效果的曲线

@author:Minux

@date:2017-12-19

"""

import numpy as np

import matplotlib.pyplot as plt

import matplotlib.transforms as transforms

# 设置解决负号问题

plt.rcParams['axes.unicode_minus'] = False

def shadow_curve():

x = np.arange(0., 2., 0.01)

y = np.sin(2 * np.pi * x)

# 设置阴影的条数

N = 7

for i in xrange(N, 0 , -1):

# 向X轴偏移i单位，向Y轴偏移i单位

offset = transforms.ScaledTranslation(i, -i, transforms.IdentityTransform())

shadow_trans = plt.gca().transData + offset

# shadow_trans = plt.gca().transAxes + offset

# 将shadow_trans参数传给transform

plt.plot(x, y, lw = 4, color = "black", transform = shadow_trans, alpha = (N-i)/2.0/N)

plt.plot(x, y, lw = 4, color = "black")

plt.ylim((-1.5, 1.5))

plt.show()

if __name__ == "__main__":

shadow_curve()