The easiest one is to just multiply with a factor, add a number or use an exponent to all node results of a certain dataset with the ''ds'' command.
The next level is using variables which can be used to do calculations based on results and can be written back to an existion dataset or a new one. This requires a good knowledge of the way cgx works and of the necessary commands (''if'', ''while'', ''stack'', ''valu'', ''enq'', ''prnt'', ''ds'', ''sys'' etc.). In this way data can be written to a file with the ``sys'' command (using echo) were an external program might be invoked by the ``sys'' command which in turn could provide data for cgx.
Finally, complex operations can be coded in C in the file userFunction.c. The user function is activated by the ''call'' command. A new compilation of cgx is required unless a dynamically linked library is used.