public static IMatrix regularizedLaplacianMatrix(IMatrix m) {
IMatrix tmp = MatrixOp.prod(m, MatrixOp.transpose(m));
int size = tmp.nCols();
IMatrix i = diagonal(1, size);
IMatrix d = diagonal(rowSums(tmp));
IMatrix laplacian = new GuavaMatrix();
for (int ii = 0; ii < size; ii++)
for (int ji = 0; ji < size; ji++)
laplacian.set(
ii, ji, (d.get(ii, ji) - tmp.get(ii, ji)) / Math.sqrt(d.get(ii, ii) * d.get(ji, ji)));
return laplacian;
}
public static double[] stationaryDistribution(IMatrix m) {
int times = 6;
IMatrix tmp = m;
for (int i = 0; i < times; i++) tmp = MatrixOp.prod(tmp, m);
return rowSums(tmp);
/* Matrix tmp = MatrixFactory.toMatrix(m);
int N = tmp.getColumnDimension();
Matrix B = tmp.minus(Matrix.identity(N, N));
for (int j = 0; j < N; j++)
B.set(0, j, 1.0);
Matrix b = new Matrix(N, 1);
b.set(0, 0, 1.0);
return MatrixFactory.toGMatrix(B.solve(b));
*/
}