getting error in multiclass SVM classification??

edit

Hello all, I'm getting error in my code. here i'm doing multiclass classification using svm with 20 classes. here the training data of each class is feature vector .yml file named as Dictionay1 , Dictionay2, ......Dictionay20 such as

vocabulary: !!opencv-matrix
   rows: 100
   cols: 1
   dt: f
   data: [ 4.48574181e+01, 3.61391605e-04, 1.06644783e+02,
       1.75997910e+02, 8.53040619e+01, 2.40742096e+02, 1.35315109e+02,
              9.74207458e+01, 7.31249542e+01, 5.95427322e+01, 3.08762417e+01............
%YAML:1.0
---
vocabulary: !!opencv-matrix
   rows: 100
   cols: 1
   dt: f
   data: [ 6.63631945e-04, 1.00589867e+02, 1.60471497e+02,
       4.06750679e+01, 1.32695053e+02, 2.54314590e+02, 8.82780228e+01... etc

My code is

char filename[80];

int main(int argc, char* argv[])
{
    Mat trainData, trainLabels;

        for (int i = 0; i < 22; i++ )
        {
        sprintf_s(filename, "VocabularyHOG/Dictionary%d.yml", i);
        Mat feature;
        FileStorage fs(filename, FileStorage::READ);
        fs["vocabulary"] >> feature;
        feature.convertTo(feature, CV_32F); // make sure we got float data
        trainData.push_back(feature.reshape(1, 1)); // as a flat column
        trainLabels.push_back(i); // the classlabel
        }

    // Train the SVM
    Ptr<SVM> svm = SVM::create();
    svm->setType(SVM::C_SVC);
    svm->setKernel(SVM::LINEAR);
    svm->setTermCriteria(TermCriteria(TermCriteria::MAX_ITER, 100, 1e-6));
    svm->train(trainData, ROW_SAMPLE, trainLabels);

    Mat testData;
    FileStorage fs("DictionaryrunningHOG.yml", FileStorage::READ);
    fs["vocabulary"] >> testData;
    int response = svm->predict(testData);
    if (response == 1)
        cout << "boxing";
    else
        cout << "negative result";

    waitKey(27);
    return 0;
}

I'm getting error

please help where i'm doing wrong. Thanks