opencv求cov_matrix

#include<cv.h>
#include<highgui.h>

Mat_<double> covMat;
Mat_<double> meanMat;
calcCovarMatrix(samples, 3, covMat, meanMat, CV_COVAR_NORM);

string fileName = "test.txt";
FileStorage fs(fileName, FileStorage::WRITE);
fs << "meanMat" << meanMat;
fs << "covMat" << covMat;
fs.release();