code: public DenseMatrix range() {
          if (!full) {
              throw new IllegalStateException("This is not a FULL singular value decomposition.");
          }
  
          int nr = 0;
          DenseMatrix rnge = Matrix.zeros(m, rank());
          for (int j = 0; j < n; j++) {
              if (s[j] > tol) {
                  for (int i = 0; i < m; i++) {
                      rnge.set(i, nr, U.get(i, j));
                  }
                  nr++;
              }
          }
          return rnge;
      }
docs: Returns a matrix of which columns give an orthonormal basis for the range space.