Hi!
I'd like to use TFormula's parsing capabilities in a ROOT application.
The problem is, that parameters with real names (like "sigma") cannot
be readily used since they trigger an error 30 (bad numerical
expression). Going through the formula in a pre-parsing step and
replacing the names with [0], [1], and so on kind of defeats the
purpose of this excercise, as I would need to write a parser myself,
which would have to know about all the special names ("sin", ...).
Unless someone can suggest a better solution, I would insert some code
into TFormula::Analyze so that the "error 30" case (after everything
else has been tried) is replaced by looking through the list of
parameter names, replacing this token with the appropriate [n] action,
adding it to the list first if it didn't yet exist. This should
probably be configurable as it changes the user interface considerably.
It's the first time I dig so deeply into ROOT, so if you have any help
to offer, I would kindly accept any suggestions you wanted to make.
Ciao,
Roland
--
TU Muenchen, Physik-Department E18, James-Franck-Str. 85747 Garching
Telefon 089/289-12592; Telefax 089/289-12570
--
A mouse is a device used to point at
the xterm you want to type in.
Kim Alm on a.s.r.
This archive was generated by hypermail 2b29 : Sun Jan 02 2005 - 05:50:09 MET