code: public void writeScriptExportingDataFrame(Engine engine, Writer writer,
              InputVariable a, InputVariable b, Reader reader,
              List<OutputVariable> outputVariables) throws IOException {
          writeScriptHeader(writer, engine);
  
          writer.append("engine.fldFile = \"");
          new FldExporter().write(engine, writer, reader);
          writer.append("\"\n\n");
  
          writer.append("engine.df = read.delim(textConnection(engine.fld), header=TRUE, "
                  + "sep=\" \", strip.white=TRUE)\n\n");
  
          writeScriptPlots(writer, a, b, outputVariables);
      }
docs: Writes an R script plotting multiple surfaces based on a data frame
  generated with the given number of values and scope for the two input
  variables on the output variables.
  
  @param engine is the engine to export
  @param writer is the output where the engine will be written to
  @param a is the first input variable
  @param b is the second input variable
  @param reader is an input stream of data whose lines contain
  space-separated input values
  @param outputVariables are the output variables to create the surface for
  @throws IOException if any error occurs upon writing on the writer