c++~实现感应器学习算法~1

利用Eigen实现感应器学习算法，用学and运算和or运算。

//Perceptron learn and operator
#include<iostream>
#include<Eigen/Dense>

using namespace std;
using namespace Eigen;

#define COL 2
#define NUM 4

class Perceptron{
    private:
        Matrix<double,1,COL> weigths;  //权重矩阵
        double bias;                   //偏移
        int step_func(int x);          //激活函数
    public:
        int trianum;                   //训练数据数量
        Perceptron();
        void show();
        int predict(const Matrix<double,COL,1>& input);
        void train(Matrix<double,COL,1>* input,int* label,
            int iteration,double rate);
        void one_iteration(Matrix<double,COL,1>* input,int* labels,
             float rate);
        void update_weights(const Matrix<double,COL,1>& input,int 
            output,int label,float rate);
};

int Perceptron::step_func(int x){
    int a=x>0 ? 1:0;
    return a;
}

Perceptron::Perceptron(){
    weigths.setZero();
    bias=0;
}

void Perceptron::show(){
    cout<<"The weigths "<<weigths<<" and the bias "
        <<bias<<endl;
}

int Perceptron::predict(const Matrix<double,COL,1>& input){
    double temp=weigths*input;
    temp+=bias;
    return step_func(temp);
}

void Perceptron::train(Matrix<double,COL,1>* input,int* label
    ,int iteration,double rate){
    for(int i=0; i<iteration;i++){
        one_iteration(input,label,rate);
    }
}

void Perceptron::one_iteration(Matrix<double,COL,1>* input,
    int* labels,float rate){
    for(int i=0; i<trianum;i++){
        int output=predict(input[i]);
        update_weights(input[i],output,labels[i],rate);
    }
}

void Perceptron::update_weights(const Matrix<double,COL,1>& 
    input,int output,int label,float rate){
    int delta=label-output;
    weigths+=rate*delta*input.transpose();
    bias+=rate*delta;
}

int main(){
    Perceptron percetron;
    Matrix<double,COL,1> _triandata[NUM]; 
    int temptrian[]={1,1,0,0,1,0,0,1};
    int label[]={1,0,1,1};
    percetron.trianum=sizeof(label)/sizeof(int);
    for(int i=0,j=0 ;i<NUM;i++,j+=COL){
        _triandata[i](0,0)=temptrian[j];
        _triandata[i](1,0)=temptrian[j+1];
    }
    cout<<"Start trianing "<<endl;
    percetron.show();
    percetron.train(_triandata,label,10,0.1);
    percetron.show();
    cout<<"Testing trian result"<<endl;
    for(int i=0, j=0; i<NUM;i++,j+=2){
        cout<<temptrian[j]<<" or "<<temptrian[j+1]<<"=  ";
        cout<<percetron.predict(_triandata[i])<<endl;
    }
}