/**
* Converts a libsvm sparse matrix to a svdlibj sparse one
*
* @param mx the libsvm sparse matrix
* @return the svdlibj matrix
*/
private static SMat convertLibsvmToSvdlibj(VectorNode[][] mx) {
SMat S;
int i, j, n;
int maxColIndex = 0;
// n = number of non-zero elements
for (i = 0, n = 0; i < mx.length; i++) {
for (j = 0; j < mx[i].length; j++) {
n++;
if (mx[i][j].index > maxColIndex) {
maxColIndex = mx[i][j].index;
}
}
}
S = new SMat(mx.length, maxColIndex, n);
for (j = 0, n = 0; j < maxColIndex + 1; j++) {
VectorNode[] column = SparseVector.columnVector(mx, j);
S.pointr[j] = n;
for (i = 0; i < column.length; i++) {
S.rowind[n] = column[i].index;
S.value[n] = column[i].value;
n++;
}
}
S.pointr[S.cols] = S.vals;
return S;
}
