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 , , 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