docs: protected void updateA( int w )
      {
          final double u[] = dataQR[w];
  
          for( int j = w+1; j < numCols; j++ ) {
  
              final double colQ[] = dataQR[j];
              double val = colQ[w];
  
              for( int k = w+1; k < numRows; k++ ) {
                  val += u[k]*colQ[k];
              }
              val *= gamma;
  
              colQ[w] -= val;
              for( int i = w+1; i < numRows; i++ ) {
                  colQ[i] -= u[i]*val;
              }
          }
      }