计算马氏距离,datasample是基准总体，行为特征值，列为各样本值，如5x1000,testdata是要进行计算的特征向量,MD为计算出的马氏距离-Mahalanobis distance calculation, datasample benchmark overall behavior eigenvalues, as the value of each sample, such as 5x1000, testdata is necessary to calculate the feature vectors, MD for the calculated Mahalanobis distance