SMO实现

#include "stdio.h"
#include <vector>
using namespace std;

float function(float alfa[5],float H[5][5],float sign[5])
{

        float ret = alfa[0]+alfa[1]+alfa[2]+alfa[3]+alfa[4];
        for(int j=0;j<5;++j)
        {
                float t=0.0;
                for(int i=0;i<5;++i)
                {
                        t+=sign[i]*alfa[i]*H[j][i];
                }
                ret += -1*(t*alfa[j]*sign[j])/2;
        }
        return ret;
}
int main(void)
{
        float matrix[5][4]={
                {1,5,1},
                {1,2,1},
                {2,2,-1},
                {2,1,-1},
                {1,1,-1}};
        float H[5][5];
        vector<float> c1;
        vector<float> c2;
        for(int i=0;i<5;++i)
        {
                c1.push_back(matrix[i][0]);
                c2.push_back(matrix[i][1]);
        }
        for(int i=0;i<5;++i)
        {
                for(int j=0;j<5;++j)
                {
                        H[i][j]=c1[i]*c1[j]+c2[i]*c2[j];
                        printf("%f ",H[i][j]);
                }
                printf(" ");
        }
        float alfa[5]={3,3,2,2,2};
        float sign[5];
        for(int i=0;i<5;++i)
                sign[i]=matrix[i][2];
        float last_r = function(alfa,H,sign);
        float new_r;
        float con_r;
        for(int i=0;i<5;++i)
        {
                for(int j=0;j<5;j++)
                {
                        printf("%f,alfa={%f,%f,%f,%f,%f} ",last_r,alfa[0],alfa[1],alfa[2],alfa[3],alfa[4]);
                        if(i==j) continue;
                        else if((alfa[i]<0.01&&alfa[i]>-0.01)&&(alfa[j]<0.01&&alfa[j]>-0.01)) continue;
                        else if((alfa[j]>0.01)&&(alfa[i]<0.01&&alfa[i]>-0.01))
                        {
                                while(alfa[j]>0.01){
                                        alfa[i]+=0.1;
                                        new_r = function(alfa,H,sign);
                                        if( new_r > last_r )
                                        {
                                                alfa[j] -= 0.1*sign[i]*sign[j];
                                                last_r = function(alfa,H,sign);
                                        }
                                        else
                                        {
                                                alfa[i]-=0.1;
                                                break;
                                        }
                                };
                        }
                        else if((alfa[i]>0.01)&&(alfa[j]<0.01&&alfa[j]>-0.01))
                        {
                                while(alfa[i]>0.01){
                                        alfa[j]+=0.1;
                                        new_r = function(alfa,H,sign);
                                        if( new_r > last_r )
                                        {
                                                alfa[i] -= 0.1*sign[i]*sign[j];
                                                last_r = function(alfa,H,sign);
                                        }
                                        else
                                        {
                                                alfa[j]-=0.1;
                                                break;
                                        }
                                };
                        }
                        else
                        {

                                alfa[j]+=0.1;
                                new_r = function(alfa,H,sign);
                                alfa[j]-=0.2;
                                con_r = function(alfa,H,sign);
                                alfa[j]+=0.1;

                                if(new_r>con_r&&new_r>last_r)
                                {
                                        while(alfa[i]>0.01&&alfa[j]>0.01)
                                        {
                                                alfa[j] += 0.1;
                                                alfa[i] -= 0.1*sign[i]*sign[j];
                                                new_r = function(alfa,H,sign);
                                                if(new_r > last_r)
                                                {
                                                        last_r = new_r;
                                                }
                                                else
                                                {
                                                alfa[j] -= 0.1;
                                                alfa[i] += 0.1*sign[i]*sign[j];
                                                break;
                                                }
                                        };

                                }
                                else if(con_r>new_r&&con_r>last_r)
                                {
                                        while(alfa[i]>0.01&&alfa[j]>0.01)
                                        {
                                                alfa[j] -= 0.1;
                                                alfa[i] += 0.1*sign[i]*sign[j];
                                                con_r = function(alfa,H,sign);
                                                if(con_r > last_r)
                                                {
                                                        last_r = con_r;
                                                }
                                                else
                                                {
                                                alfa[j] += 0.1;
                                                alfa[i] -= 0.1*sign[i]*sign[j];
                                                break;
                                                }
                                        }
                                }
                                else
                                {}
                        }

                }
        }
        printf("%f,alfa={%f,%f,%f,%f,%f} ",last_r,alfa[0],alfa[1],alfa[2],alfa[3],alfa[4]);
        return 0;
}
原文地址:https://www.cnblogs.com/cl1024cl/p/6205282.html