测试bp神经网络时遇到了这个问题,
上网搜索了这个代码示例,发现大家都是这么写的,但是这种报错该怎么修改呢?望赐教,不胜感激。
# -*- coding: utf-8 -*-
# -*- coding: utf-8 -*-
#%%
from __future__ import division
import math
import random
import string
import pickle
flowerLables = {0: 'Iris-setosa',
1: 'Iris-versicolor',
2: 'Iris-virginica'}
random.seed(0)
# 生成区间[a, b)内的随机数
def rand(a, b):
return (b-a)*random.random() + a
# 生成大小 I*J 的矩阵,默认零矩阵 (当然,亦可用 NumPy 提速)
def makeMatrix(I, J, fill=0.0):
m = []
for i in range(I):
m.append([fill]*J)
return m
# 函数 sigmoid,这里采用 tanh,因为看起来要比标准的 1/(1+e^-x) 漂亮些
def sigmoid(x):
return math.tanh(x)
# 函数 sigmoid 的派生函数, 为了得到输出 (即:y)
def dsigmoid(y):
return 1.0 - y**2
class NN:
''' 三层反向传播神经网络 '''
# __init__()可以方便地自己对类的属性进行定义,又被称为构造器(constructor)
def __init__(self, ni, nh, no):
print("运行__init__")
# 输入层、隐藏层、输出层的节点(数)
self.ni = ni + 1 # 增加一个偏差节点
self.nh = nh
self.no = no
# 激活神经网络的所有节点(向量)
self.ai = [1.0]*self.ni
self.ah = [1.0]*self.nh
self.ao = [1.0]*self.no
# 建立权重(矩阵)
self.wi = makeMatrix(self.ni, self.nh)
self.wo = makeMatrix(self.nh, self.no)
# 设为随机值
for i in range(self.ni):
for j in range(self.nh):
self.wi[i][j] = rand(-0.2, 0.2)
for j in range(self.nh):
for k in range(self.no):
self.wo[j][k] = rand(-2.0, 2.0)
# 最后建立动量因子(矩阵)
self.ci = makeMatrix(self.ni, self.nh)
self.co = makeMatrix(self.nh, self.no)
print("self.ci:",self.ci)
print("self.co:",self.co)
def update(self, inputs):
# print("运行update")
if len(inputs) != self.ni-1:
raise ValueError('与输入层节点数不符!')
# 激活输入层
for i in range(self.ni-1):
#self.ai[i] = sigmoid(inputs[i])
self.ai[i] = inputs[i]
# 激活隐藏层
for j in range(self.nh):
sum = 0.0
for i in range(self.ni):
sum = sum + self.ai[i] * self.wi[i][j]
self.ah[j] = sigmoid(sum)
# 激活输出层
for k in range(self.no):
sum = 0.0
for j in range(self.nh):
sum = sum + self.ah[j] * self.wo[j][k]
self.ao[k] = sigmoid(sum)
# print("self.ao:",self.ao)
return self.ao[:]
def backPropagate(self, targets, N, M):
# print("运行backPropagate")
''' 反向传播 '''
# if len(targets) != self.no:
# raise ValueError('与输出层节点数不符!')
# 计算输出层的误差
output_deltas = [0.0] * self.no
for k in range(self.no):
error = targets[k]-self.ao[k]
output_deltas[k] = dsigmoid(self.ao[k]) * error
# 计算隐藏层的误差
hidden_deltas = [0.0] * self.nh
for j in range(self.nh):
error = 0.0
for k in range(self.no):
error = error + output_deltas[k]*self.wo[j][k]
hidden_deltas[j] = dsigmoid(self.ah[j]) * error
# 更新输出层权重
for j in range(self.nh):
for k in range(self.no):
change = output_deltas[k]*self.ah[j]
self.wo[j][k] = self.wo[j][k] + N*change + M*self.co[j][k]
self.co[j][k] = change
#print(N*change, M*self.co[j][k])
# 更新输入层权重
for i in range(self.ni):
for j in range(self.nh):
change = hidden_deltas[j]*self.ai[i]
self.wi[i][j] = self.wi[i][j] + N*change + M*self.ci[i][j]
self.ci[i][j] = change
# 计算误差
error = 0.0
# for k in range(len(targets)):
# error = error + 0.5*(targets[k]-self.ao[k])**2
error += 0.5*(targets[k]-self.ao[k])**2
return error
def test(self, patterns):
print("运行test")
count = 0
for p in patterns:
target = flowerLables[(p[1].index(1))]
result = self.update(p[0])
index = result.index(max(result))
print(p[0], ':', target, '->', flowerLables[index])
count += (target == flowerLables[index])
accuracy = float(count / len(patterns))
print('accuracy: %-.9f' % accuracy)
# for p in patterns:
# print(p[0], '->', self.update(p[0]))
def weights(self):
print("运行weights")
print('输入层权重:')
for i in range(self.ni):
print(self.wi[i])
print()
print('输出层权重:')
for j in range(self.nh):
print(self.wo[j])
def train(self, patterns, iterations=1000, N=0.1, M=0.01):
print("运行train")
# N: 学习速率(learning rate)
# M: 动量因子(momentum factor)
for i in range(iterations):
error = 0.0
for p in patterns:
inputs = p[0]
targets = p[1]
self.update(inputs)
error = error + self.backPropagate(targets, N, M)
if i % 100 == 0:
print('误差 %-.9f' % error)
#%%
def demo():
print("运行demo")
# 一个演示:教神经网络学习逻辑异或(XOR)------------可以换成你自己的数据试试
pat = [
[[0,0], [0]],
[[0,1], [1]],
[[1,0], [1]],
[[1,1], [0]]
]
# 创建一个神经网络:输入层有两个节点、隐藏层有两个节点、输出层有一个节点
n = NN(2, 2, 1)
# 用一些模式训练它
n.train(pat)
# 测试训练的成果(不要吃惊哦)
n.test(pat)
# 看看训练好的权重(当然可以考虑把训练好的权重持久化)
#n.weights()
#%%
demo()
#%%
import numpy as np
import pandas as pd
import os
# features 0-3
# labels 4
def iris():
print("运行iris")
data = []
# read dataset
raw = pd.read_csv('./iris.csv')
raw_data = raw.values
raw_feature = raw_data[0:,0:4]
for i in range(len(raw_feature)):
ele = []
ele.append(list(raw_feature[i]))
if raw_data[i][4] == 'Iris-setosa':
ele.append([1,0,0])
elif raw_data[i][4] == 'Iris-versicolor':
ele.append([0,1,0])
else:
ele.append([0,0,1])
data.append(ele)
# 随机排列data
random.shuffle(data)
# print data
training = data[0:100]
test = data[101:]
nn = NN(4,7,3)
nn.train(training,iterations=10000)
# save weights
with open('./wi.txt', 'wb') as wif:
pickle.dump(nn.wi, wif, 0)
with open('./wo.txt', 'wb') as wof:
pickle.dump(nn.wo, wof, 0)
nn.test(test)
#鸢尾花的分类
iris()