python sdm0718由HiKat1创建 - https://repl.it/JaLD/7

Posted 2021-05-09

#!/usr/bin/env python
# coding:utf-8
#
# use Python3 !!!
#
import math
# import numpy as np

LEAERNING_RATE = 0.1

b1 = 8
b2 = 2
b3 = 0

w11 = (b2 + 1.0) / 10.0
w12 = -1.0 * (b3 + 1.0) / 10.0
w13 = (b1 + 1.0) / 10.0
w14 = (b3 + 1.0) / 10.0
w21 = -1.0 * (b1 + 1.0) / 10.0
w22 = -1.0 * (b2 + 1.0) / 10.0


# 順伝搬計算
def forward_backward_update(x1, x2, y):
	global w11
	global w12
	global w13
	global w14
	global w21
	global w22
	
	# 順伝搬計算
	a2 = x1 * w11 + x2 * w13
	a3 = x1 * w12 + x2 * w14
	a1 = math.tanh(a2) * w21 + math.tanh(a3) * w22
	y_dash = math.tanh(a1)
	
	# 逆伝搬計算
	delta1 = -1.0 * (y - math.tanh(a1)) * (1.0 - pow(math.tanh(a1), 2))
	delta2 = delta1 * w21 * (1.0 - pow(math.tanh(a2), 2))
	delta3 = delta1 * w22 * (1.0 - pow(math.tanh(a3), 2))

	# 勾配計算
	grad_w11 = delta2 * x1
	grad_w12 = delta3 * x1
	grad_w13 = delta2 * x2
	grad_w14 = delta3 * x2
	grad_w21 = delta1 * math.tanh(a2)
	grad_w22 = delta1 * math.tanh(a3)

	# 勾配更新       
	w11 = w11 + LEAERNING_RATE * -1.0 * grad_w11
	w12 = w12 + LEAERNING_RATE * -1.0 * grad_w12
	w13 = w13 + LEAERNING_RATE * -1.0 * grad_w13
	w14 = w14 + LEAERNING_RATE * -1.0 * grad_w14
	w21 = w21 + LEAERNING_RATE * -1.0 * grad_w21
	w22 = w22 + LEAERNING_RATE * -1.0 * grad_w22

	return [y_dash, w11, w12, w13, w14, w21, w22]

print("Answer Q1 ================================")
print('w11 = {0} ,w13 = {1}, w21 = {2}'.format(w11, w13, w21))
print('w12 = {0} ,w14 = {1}, w22 = {2}'.format(w12, w14, w22))

print("Answer Q2 ================================")
temp = []
temp = forward_backward_update(1.0, 1.0, 1.0)
print("y' = " + str(temp[0]))
print('w11 = {0} ,w13 = {1}, w21 = {2}'.format(temp[1], temp[3], temp[5]))
print('w12 = {0} ,w14 = {1}, w22 = {2}'.format(temp[2], temp[4], temp[6]))

print("Answer Q3 ================================")
temp = []
temp = forward_backward_update(0, 1.0, -1.0)
print("y' = " + str(temp[0]))
print('w11 = {0} ,w13 = {1}, w21 = {2}'.format(temp[1], temp[3], temp[5]))
print('w12 = {0} ,w14 = {1}, w22 = {2}'.format(temp[2], temp[4], temp[6]))

print("Answer Q4 ================================")
temp = []
temp = forward_backward_update(0, 0, 1.0)
print("y' = " + str(temp[0]))
print('w11 = {0} ,w13 = {1}, w21 = {2}'.format(temp[1], temp[3], temp[5]))
print('w12 = {0} ,w14 = {1}, w22 = {2}'.format(temp[2], temp[4], temp[6]))

print("Answer Q5 ================================")
temp = []
temp = forward_backward_update(1.0, 0, -1.0)
print("y' = " + str(temp[0]))
print('w11 = {0} ,w13 = {1}, w21 = {2}'.format(temp[1], temp[3], temp[5]))
print('w12 = {0} ,w14 = {1}, w22 = {2}'.format(temp[2], temp[4], temp[6]))