c++ - OpenCV SVM HOG detector svm.predict() exception -

i using visual studio 2013 opencv 2.4.11 trained svm with xml file of positiv , negative samples. here code want compare image. build ok, when run debug it's break on svm.predict().

unhandled exception @ 0x00007fff43148a5c in consoleapplication2.exe: microsoft c++ exception: cv::exception @ memory location 0x000000af2d16eca0.

and there in local variables near svm

information not available, no symbols loaded opencv_ml2411d.dll

any idea or clue what's wrong?

void compare() {      //variables       char fullfilename[100];     char firstfilename[100] = "e:\dropbox/dip/images/train/";       int filenum = 5; //262;        //load trained svm xml data        cvsvm svm;     svm.load("e:/dropbox/dip/images/train/trainedsvm.xml");      //count variable       int nnn = 0, ppp = 0;      (int = 1; i< filenum; ++i)     {         sprintf_s(fullfilename, "%s%d.jpg", firstfilename, + 1);         //printf("%s\n", fullfilename);            //read image file           mat img, img_gray;         img = imread(fullfilename);          //resizing           resize(img, img, size(64, 48)); //size(32*2,16*2)); //size(80,72) );            //gray           cvtcolor(img, img_gray, cv_rgb2gray);          //extract hogfeature           hogdescriptor d(size(32, 16), size(8, 8), size(4, 4), size(4, 4), 9);         vector< float> descriptorsvalues;         vector< point> locations;         d.compute(img_gray, descriptorsvalues, size(0, 0), size(0, 0), locations);         //vector mat           mat fm = mat(descriptorsvalues);          //classification whether data positive or negative   here come problem         int result = svm.predict(fm); //svm.predict(fm);         printf("%s - > %d\n", fullfilename, result);          //count data           if (result == 1)             ppp++;         else             nnn++;          //show image           imshow("origin", img);          waitkey(5);     }      printf(" positive/negative = (%d/%d) \n", ppp, nnn); }