python实现并绘制 sigmoid函数，tanh函数，cjdbq，Pcjdbq
# -*- coding:utf-8 -*-
from matplotlib import pyplot as plt
import numpy as np
import mpl_toolkits.axisartist as axisartist
def sigmoid(x):
return 1. / (1 + np.exp(-x))
def tanh(x):
return (np.exp(x) - np.exp(-x)) / (np.exp(x) + np.exp(-x))
def relu(x):
return np.where(x<0,0,x)
def prelu(x):
return np.where(x<0,0.5*x,x)
def plot_sigmoid():
x = np.arange(-10, 10, 0.1)
fig = plt.figure()
# ax = fig.add_subplot(111)
# ax.spines[‘bottom‘].set_color(‘none‘)
# ax.spines[‘left‘].set_color(‘none‘)
plt.xlim([-10.05, 10.05])
plt.ylim([-0.02, 1.02])
plt.tight_layout()
plt.savefig("sigmoid.png")
plt.show()
def plot_tanh():
x = np.arange(-10, 10, 0.1)
fig = plt.figure()
# ax.spines[‘bottom‘].set_color(‘none‘)
# ax.spines[‘left‘].set_color(‘none‘)
plt.xlim([-10.05, 10.05])
plt.ylim([-1.02, 1.02])
plt.tight_layout()
plt.savefig("tanh.png")
plt.show()
def plot_relu():
x = np.arange(-10, 10, 0.1)
fig = plt.figure()
# ax.spines[‘bottom‘].set_color(‘none‘)
# ax.spines[‘left‘].set_color(‘none‘)
plt.xlim([-10.05, 10.05])
plt.ylim([0, 10.02])
plt.tight_layout()
plt.savefig("relu.png")
plt.show()
def plot_prelu():
x = np.arange(-10, 10, 0.1)
fig = plt.figure()
# ax.spines[‘bottom‘].set_color(‘none‘)
# ax.spines[‘left‘].set_color(‘none‘)
plt.xticks([])
plt.yticks([])
plt.tight_layout()
plt.savefig("prelu.png")
plt.show()
if __name__ == "__main__":
plot_sigmoid()
plot_tanh()
plot_relu()
plot_prelu()