question: @ Override public String graph ( ) throws Exception { if ( m_Tree == null ) { throw new Exception ( "REPTree: No model built yet." ) ; } StringBuffer resultBuff = new StringBuffer ( ) ; m_Tree . toGraph ( resultBuff , 0 , null ) ; String result = "digraph Tree {\n" + "edge [style=bold]\n" + resultBuff . toString ( ) + "\n}\n" ; return result ; }
target:  Outputs the decision tree as a graph