在 Python 中实现感知器算法时遇到问题答案

【问题标题】：Having Problems With Implementing the Perceptron Algorithm in Python在 Python 中实现感知器算法时遇到问题
【发布时间】：2019-01-20 17:54:28
【问题描述】：

我在调试以下代码时遇到问题，由于某种原因感知器在使用随机值作为权重的几个步骤后停止自我更新。我尝试过不使用课程来完成工作，并将所有内容都编辑到最低限度，但仍然遇到同样的问题。我还检查了 Perceptron.train()，它工作得很好。所以，我猜主要问题是火车功能本身。我是python编程的新手，所以任何帮助都会受到赞赏。随机导入将绘图导入为 plt 将 numpy 导入为 np

#-----Function Of the line that seperates the two different Data Types-----$
def f(x):
    return x

#-----Activation Function-----#
def act(x):
    if x >= 0:
        return 1.0
    return 0.0

class Point:

    def __init__(self, x, y):
        self.X = x
        self.Y = y
        if y > f(x):
            self.Target = 1.0
        else:
            self.Target = 0.0


class Perceptron:

    def __init__(self, n, actFunc = act, lr = 0.2):
        self.Weights = [0 for i in range(n)]
        self.ActFunc = actFunc
        self.LR = lr

    def guess(self, inputs):
        valSum = 0
        for i in range(len(inputs)):
            valSum += self.Weights[i] * inputs[i]
        return self.ActFunc(valSum)

    def train(self, inputs, target):
        cal = self.guess(inputs)
        err = target - cal
        for i in range(0, len(self.Weights)):
            self.Weights[i] += self.LR * err * inputs[i]

    def printWeights(self):
        for i in range(len(self.Weights)):
            print("WEIGHT[" + str(i) + "] = " + str(self.Weights[i]))
        print("")

    def lineFunc(self):
        # y = w0 + w1x + w2y
        # (1 - w2)y = w0 + w1x
        # y = w0/(1-w2) + w1/(1 - w2)x
        w0 = self.Weights[0]
        w1 = self.Weights[1]
        w2 = self.Weights[2]
        return (str(w0/(1 - w2)) + " + " + str(w1/(1 - w2)) + " * x")

#-----INITIALISING DATA------#
brain = Perceptron(3)

n = 20
points = [Point(random.uniform(-10, 10), random.uniform(-10, 10)) for x in range(n)]

t = 1000

#-----Training-----#
for i in range(t):
    point = points[random.randrange(0, n)]
    brain.train([1, point.X, point.Y], point.Target)
    brain.printWeights()
    print(brain.lineFunc())

【问题讨论】：

标签： python-3.x machine-learning neural-network perceptron

【解决方案1】：

我自己确实发现了问题。 LineFunc() 方法中存在错误。返回值错误，应该是：

    return (str(-w0/w2) + " + " + str(-w1/w2) + " * x")

【讨论】：