新手学习opencv七：svm

新手学习opencv七：svm

           新手学习opencv，svm。

       

1）opencv中svm参数和函数

svm参数：

CvSVMParams::CvSVMParams() :

    svm_type(CvSVM::C_SVC), kernel_type(CvSVM::RBF), degree(0),

    gamma(1), coef0(0), C(1), nu(0), p(0), class_weights(0)

{

    term_crit = cvTermCriteria( CV_TERMCRIT_ITER+CV_TERMCRIT_EPS, 1000, FLT_EPSILON );

}

 

svm_type表示SVM类型：

{C_SVC=100, NU_SVC=101, ONE_CLASS=102, EPS_SVR=103, NU_SVR=104 };//SVC是SVM分类器，SVR是SVM回归

kernel_type表示核函数的类型：

 { LINEAR=0, POLY=1, RBF=2, SIGMOID=3 }; //提供四种核函数，分别是线性，多项式，径向基，sigmoid型函数。

degree针对多项式核函数degree的设置，

gamma针对多项式/rbf/sigmoid核函数的设置

oef0针对多项式/sigmoid核函数的设置

默认值degree = 0，gamma = 1，coef0 = 0

svm训练函数

bool CvSVM::train( const CvMat* _train_data, const CvMat* _responses,

const CvMat* _var_idx, const CvMat* _sample_idx, CvSVMParams _params )

用的时候：svm.train(dataMat, labelMat, NULL, NULL, param);

svm预测函数

svm.predict(testMat);

支持向量机的个数

svm.get_support_vector_count();

支持向量机

svm.get_support_vector(i)

保存训练结果

svm.save("svmResult.txt");

2）用法流程：

1.设置svm参数

2.输入训练样本矩阵

3.训练样本

4.输入测试数据，根据训练结果分类

/////////svm/////////#include "cv.h"#include <highgui.h>#include "ml.h"#include "iostream"using namespace std;double inputArr[10][13] = {1,0.708333,1,1,-0.320755,-0.105023,-1,1,-0.419847,-1,-0.225806,0,1, -1,0.583333,-1,0.333333,-0.603774,1,-1,1,0.358779,-1,-0.483871,0,-1,1,0.166667,1,-0.333333,-0.433962,-0.383562,-1,-1,0.0687023,-1,-0.903226,-1,-1,-1,0.458333,1,1,-0.358491,-0.374429,-1,-1,-0.480916,1,-0.935484,0,-0.333333,-1,0.875,-1,-0.333333,-0.509434,-0.347032,-1,1,-0.236641,1,-0.935484,-1,-0.333333,-1,0.5,1,1,-0.509434,-0.767123,-1,-1,0.0534351,-1,-0.870968,-1,-1,1,0.125,1,0.333333,-0.320755,-0.406393,1,1,0.0839695,1,-0.806452,0,-0.333333,1,0.25,1,1,-0.698113,-0.484018,-1,1,0.0839695,1,-0.612903,0,-0.333333,1,0.291667,1,1,-0.132075,-0.237443,-1,1,0.51145,-1,-0.612903,0,0.333333,1,0.416667,-1,1,0.0566038,0.283105,-1,1,0.267176,-1,0.290323,0,1};double testArr[]={//0.25,1,1,-0.226415,-0.506849,-1,-1,0.374046,-1,-0.83871,0,-11.29,1,1,-0.132075,-0.237443,-1,1,0.51145,-1,-0.612903,0,0.333333};int main(){//1.svm参数设置CvSVM svm;CvSVMParams param;param.svm_type = 100;param.kernel_type = 1;param.degree = 2;param.gamma = 1;param.coef0 = 0;//2.输入样本矩阵CvMat *trainMat = cvCreateMat(10, 12, CV_32FC1);CvMat *labelMat = cvCreateMat(10, 1, CV_32SC1);//标签要有符号，代表正负for (int i=0; i<10; i++){for (int j=0; j<12; j++){cvSetReal2D(trainMat, i, j, inputArr[i][j+1]);}cvSetReal2D(labelMat, i, 0, inputArr[i][0]);}//3训练样本//计算时间double t = (double)cvGetTickCount();svm.train(trainMat, labelMat, NULL, NULL, param);t = (double)cvGetTickCount() - t;double timecost = t/(cvGetTickFrequency()*1000); cout<<"svm train耗时："<<timecost<<"ms"<<endl;//保存训练结果svm.save("svmResult.txt");CvMat *testMat = cvCreateMat(1, 12, CV_32FC1);for (int i=0; i<12; i++){cvSetReal2D(testMat, 0, i, testArr[i]);}//4预测分类float flag = 0;flag = svm.predict(testMat);int c = svm.get_support_vector_count();cout<<"svm个数"<<c<<endl;for (int i=0; i<c; i++){const float* v = svm.get_support_vector(i);for(int i=0;i<12;i++){cout<<*(v+i)<<",";}cout<<endl;}cout<<"testMat分类结果："<<flag<<endl;system("pause");cvReleaseMat(&trainMat);cvReleaseMat(&labelMat);cvReleaseMat(&testMat);return 0;}