void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) {
/* Check number of input arguments */
if (nrhs > 4) {
ERROR("Four or fewer input arguments are required.");
} else if (nrhs < 3) {
ERROR("At least three input arguments are required.");
}
/* Check number of output arguments */
if (nlhs > 1) {
ERROR("Too many output arguments.");
}
DOUBLE *X1 = (DOUBLE*) mxGetData(prhs[0]);
DOUBLE *X2 = (DOUBLE*) mxGetData(prhs[1]);
DOUBLE *S = (DOUBLE*) mxGetData(prhs[2]);
INT sqrtFlag;
if (nrhs >= 4) {
sqrtFlag = (INT)*(DOUBLE*) mxGetData(prhs[3]);
if (sqrtFlag > 0) {
sqrtFlag = 1;
}
} else {
sqrtFlag = 0;
}
INT N = (INT) mxGetM(prhs[0]);
INT numSamples1 = (INT) mxGetN(prhs[0]);
INT numSamples2 = (INT) mxGetN(prhs[1]);
if ((numSamples2 != 0) && ((INT) mxGetM(prhs[1]) != N)) {
ERROR("The signal dimension (first dimension) of the second sample matrix does not match the signal dimension (first dimension) of the first sample matrix.");
} else if (mxGetM(prhs[2]) != N) {
ERROR("The first dimension of the Mahalanobis matrix does not match the signal dimension (first dimension) of the first sample matrix.");
} else if (mxGetN(prhs[2]) != N) {
ERROR("The second dimension of the Mahalanobis matrix does not match the signal dimension (first dimension) of the first sample matrix.");
}
if (numSamples2 == 0) {
X2 = NULL;
plhs[0] = mxCreateNumericMatrix(numSamples1, numSamples1, MXPRECISION_CLASS, mxREAL);
} else {
plhs[0] = mxCreateNumericMatrix(numSamples1, numSamples2, MXPRECISION_CLASS, mxREAL);
}
DOUBLE *distanceMat = (DOUBLE *) mxGetData(plhs[0]);
DOUBLE *tempX1 = (DOUBLE *) MALLOC(N * numSamples1 * sizeof(DOUBLE));
DOUBLE *tempX2 = (DOUBLE *) MALLOC(N * numSamples2 * sizeof(DOUBLE));
DOUBLE *normMat1 = (DOUBLE *) MALLOC(numSamples1 * 1 * sizeof(DOUBLE));
DOUBLE *oneVec = (DOUBLE *) MALLOC(numSamples1 * 1 * sizeof(DOUBLE));
mahalanobis_distance(distanceMat, X1, X2, S, N, numSamples1, numSamples2, \
sqrtFlag, tempX1, tempX2, normMat1, oneVec);
FREE(tempX1);
FREE(tempX2);
FREE(normMat1);
FREE(oneVec);
}
void pdist_mahalanobis(const double *X, const double *covinv,
double *dm, int m, int n) {
int i, j;
const double *u, *v;
double *it = dm;
double *dimbuf1, *dimbuf2;
dimbuf1 = (double*)malloc(sizeof(double) * 2 * n);
dimbuf2 = dimbuf1 + n;
for (i = 0; i < m; i++) {
for (j = i + 1; j < m; j++, it++) {
u = X + (n * i);
v = X + (n * j);
*it = mahalanobis_distance(u, v, covinv, dimbuf1, dimbuf2, n);
}
}
dimbuf2 = 0;
free(dimbuf1);
}
