code: public static void extractHouseholderColumn( ZMatrixRMaj A ,
                                                   int row0 , int row1 ,
                                                   int col , double u[], int offsetU )
      {
          int indexU = (row0+offsetU)*2;
          u[indexU++] = 1;
          u[indexU++] = 0;
  
          for (int row = row0+1; row < row1; row++) {
              int indexA = A.getIndex(row,col);
              u[indexU++] = A.data[indexA];
              u[indexU++] = A.data[indexA+1];
          }
      }
docs: Extracts a house holder vector from the column of A and stores it in u
  @param A Complex matrix with householder vectors stored in the lower left triangle
  @param row0 first row in A (implicitly assumed to be r + i0)
  @param row1 last row + 1 in A
  @param col Column in A
  @param u Output array storage
  @param offsetU first index in U