Dear Axel, it is true, but with a*(x-const)**(0.5) or a*pow(x-const,0.5) or a*TMath::Power(x-const,0.5) I have got the same problem. At the end I figured out that negative arguments for roots cause the problem even in positive subrange fit. I defined a user defined function where I check negative arguments. This solved the problem. Thanks, Falk On Tue, 16 Mar 2004, Axel Naumann wrote: > Hi Falk, > > >(2) a*(x-const)^(1/2) > >what DOES NOT give a fit. > > > > > No wonder, it's latex and fortran, but not c(++) :-] There are two > problems with this expression: 1/2 evaluates to 0, and the operator ^ is > not defined the way you want it. Grab a c(++) manual and have a look. > Axel. > > ++++++++++++++++++++++++++++++++++++++++++++++++++++ + Falk Karstens + + Abt. Prof. A. Bamberger/ Universit"at Freiburg + + Zimmer 1d/148 + + Tel. ++49 (0) 40 - 8998 3346 + + Fax ++49 (0) 40 - 8998 3092 + ++++++++++++++++++++++++++++++++++++++++++++++++++++ + Deutsches Elektronensynchrotron, DESY + + Notkestr. 85 + + D-22603 Hamburg, Germany + ++++++++++++++++++++++++++++++++++++++++++++++++++++
This archive was generated by hypermail 2b29 : Sun Jan 02 2005 - 05:50:06 MET