code: private void fillOsubMatrix( Coordinate[] controlPoints, GeneralMatrix L ) {
          int controlPointsNum = controlPoints.length;
          for( int i = controlPointsNum; i < (controlPointsNum + 3); i++ ) {
              for( int j = controlPointsNum; j < (controlPointsNum + 3); j++ ) {
                  L.setElement(i, j, 0);
              }
          }
      }
docs: Fill O submatrix (<a href="http://elonen.iki.fi/code/tpsdemo/index.html"> see more here</a>)