code: public static void divideElementsCol(final int blockLength ,
                                           final DSubmatrixD1 Y , final int col , final double val ) {
          final int width = Math.min(blockLength,Y.col1-Y.col0);
  
          final double dataY[] = Y.original.data;
  
          for( int i = Y.row0; i < Y.row1; i += blockLength ) {
              int height = Math.min( blockLength , Y.row1 - i );
  
              int index = i*Y.original.numCols + height*Y.col0 + col;
  
              if( i == Y.row0 ) {
                  index += width*(col+1);
  
                  for( int k = col+1; k < height; k++ , index += width ) {
                      dataY[index] /= val;
                  }
              } else {
                  int endIndex = index + width*height;
                  //for( int k = 0; k < height; k++
                  for( ; index != endIndex; index += width ) {
                      dataY[index] /= val;
                  }
              }
          }
      }
docs: Divides the elements at the specified column by 'val'.  Takes in account
  leading zeros and one.