pytorch 画loss曲线_Python练习绘制损失曲线,Pytorch,Loss

绘制Loss曲线

import绘制曲线的库和numpy库

import numpy as np

import matplotlib.pyplot as plt # 画图库

设置数据

x_data = [1.0, 2.0, 3.0]

y_data = [2.0, 4.0, 6.0]

定义模型

def forward(x):

return x * w

定义Loss函数

def loss(x, y):

y_pred = forward(x)

return (y_pred - y) * (y_pred - y)

定义权重和MSE(均方误差)的list

w_list = []

mse_list = []

计算MSE(均方误差)

for w in np.arange(0.0, 4.1, 0.1):

print('w=', w)

l_sum = 0

for x_val, y_val in zip(x_data, y_data):

y_pred_val = forward(x_val) # 预测结果

loss_val = loss(x_val, y_val) # 计算loss

l_sum += loss_val # loss的总和

print('\t', x_val, y_val, y_pred_val, loss_val) # x的真实值，y的真实值，y的预测值，loss值

print('MSE=', l_sum / 3)

w_list.append(w) # 权重w的list

mse_list.append(l_sum / 3) # 均方误差

输出

绘制Loss曲线

plt.plot(w_list, mse_list)

plt.ylabel('Loss')

plt.xlabel('w')

plt.show()

输出