2023-02-24 23:10:33 +08:00
|
|
|
# https://www.bilibili.com/video/BV1ar4y137GD/?spm_id_from=333.337.search-card.all.click&vd_source=311a862c74a77082f872d2e1ab5d1523
|
2021-01-19 13:16:03 +08:00
|
|
|
import numpy as np
|
|
|
|
|
import matplotlib.pyplot as plt
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
def f(x):
|
|
|
|
|
return x**2-3
|
|
|
|
|
|
|
|
|
|
def df(x):
|
|
|
|
|
return 2*x
|
|
|
|
|
def plotf(loss):
|
|
|
|
|
x = range(len(loss))
|
|
|
|
|
plt.plot(x,loss)
|
|
|
|
|
plt.xlabel('Iteration')
|
|
|
|
|
plt.ylabel('Loss')
|
|
|
|
|
plt.show()
|
|
|
|
|
|
|
|
|
|
def main():
|
2024-02-27 11:40:20 +08:00
|
|
|
x = 1000
|
|
|
|
|
lr = 0.9
|
2021-12-28 22:52:03 +08:00
|
|
|
steps = 400
|
2021-01-19 13:16:03 +08:00
|
|
|
loss = []
|
|
|
|
|
for i in range(steps):
|
|
|
|
|
x = x-lr*df(x)
|
2021-10-02 22:11:06 +08:00
|
|
|
loss.append(f(x))
|
2023-02-24 23:10:33 +08:00
|
|
|
# print(loss[i])
|
|
|
|
|
y = f(x)
|
|
|
|
|
print(y)
|
2021-01-19 13:16:03 +08:00
|
|
|
plotf(loss)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if __name__ == '__main__':
|
|
|
|
|
main()
|
|
|
|
|
|
