code: private static void transposeBlock(DMatrixRBlock A , DMatrixRBlock A_tran,
                                         int indexA , int indexC ,
                                         int width , int height )
      {
          for( int i = 0; i < height; i++ ) {
              int rowIndexC = indexC + i;
              int rowIndexA = indexA + width*i;
              int end = rowIndexA + width;
              for( ; rowIndexA < end; rowIndexC += height, rowIndexA++ ) {
                  A_tran.data[ rowIndexC ] = A.data[ rowIndexA ];
              }
          }
      }
docs: Transposes an individual block inside a block matrix.