/**
* 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;
}
/**
* The main method.
*
* @param args[0] the libsvm-formatted term-document matrix file name
* @param args[1] the co-occurrence file name
* @param args[2] the left singular vectors file name
* @param args[3] the right singular vector file name
* @param args[4] the singular values file name
* @throws IOException Signals that an I/O exception has occurred.
*/
public static void main(String[] args) throws IOException {
if (args.length != 5) {
throw (new IllegalArgumentException(
"There were " + args.length + " arguments, instead of the expected 5."));
}
String tdMatrixFilename = args[0];
String cooccurFilename = args[1];
String leftSingularVectorsFilename = args[2];
String rightSingularVectorsFilename = args[3];
String singularValuesFilename = args[4];
VectorNode[][] mx = SparseVector.transpose(SparseVector.readSparseMatrix(tdMatrixFilename));
logger.info("Calculating co-occurrence matrix");
mx = SparseVector.matrixMultiplyWithTranspose(mx, mx);
DenseVector.writeDenseMatrix(DenseVector.convertFromSparseMatrix(mx), cooccurFilename);
SVDRec svdResult = decompose(mx);
DenseVector.writeDenseMatrix(svdResult.Ut.value, leftSingularVectorsFilename);
DenseVector.writeDenseMatrix(svdResult.Vt.value, rightSingularVectorsFilename);
DenseVector.writeDenseMatrix(new double[][] {svdResult.S}, singularValuesFilename);
}