script fails to compile

From: Roger Mason <rmason_at_esd.mun.ca>
Date: Mon, 17 May 2010 16:59:06 -0230

hello,

I defined the following named script (hl.C):

#include <TMath.h>
#include <TF1.h>

Double_t myfunction(Double_t *x,Double_t *par) {   Double_t arg = 0;

  Double_t arg = x[0]/par[1];

  Double_t result = par[0]*TMath::Exp(-arg);   return result;
}

void hl() {
  TF1* decay = new TF1("decay","myfunction",0,10,2);

  decay->SetParameters(10,1);
  decay->Draw("AL");
}

The script won't compile:

root [0] .L hl.C+
Info in <TUnixSystem::ACLiC>: creating shared library
/home/rmason/Teaching/ES1002/Notes/Intersession_10/DatingEarth/scripts/./hl_C.so
In file included from
/home/rmason/Teaching/ES1002/Notes/Intersession_10/DatingEarth/scripts/./hl_C_ACLiC_dict.h:33,

                 from
                 /home/rmason/Teaching/ES1002/Notes/Intersession_10/DatingEarth/scripts/./hl_C_ACLiC_dict.cxx:16:

/home/rmason/Teaching/ES1002/Notes/Intersession_10/DatingEarth/scripts/./hl.C:
In function 'Double_t myfunction(Double_t*, Double_t*)':
/home/rmason/Teaching/ES1002/Notes/Intersession_10/DatingEarth/scripts/./hl.C:10:
warning: unused variable 'arg'
/usr/include/root/Math/ParamFunctor.h: In static member function 'static
double ROOT::Math::ParamFunctorHandler<ParentFunctor, Func>::FuncEvaluator<F*>::Eval(F*, double*, double*) [with F = const char, ParentFunctor = ROOT::Math::ParamFunctor, Func = const char*]':
/usr/include/root/Math/ParamFunctor.h:88: instantiated from 'double

ROOT::Math::ParamFunctorHandler<ParentFunctor,
Func>::operator()(double*, double*) [with ParentFunctor =
ROOT::Math::ParamFunctor, Func = const char*]'

/home/rmason/Teaching/ES1002/Notes/Intersession_10/DatingEarth/scripts/./hl_C_ACLiC_dict.cxx:301:
instantiated from here
/usr/include/root/Math/ParamFunctor.h:109: error: '* f' cannot be used
as a function
g++:
/home/rmason/Teaching/ES1002/Notes/Intersession_10/DatingEarth/scripts/./hl_C_ACLiC_dict.o:
No such file or directory
Error in <ACLiC>: Compilation failed!

I can't see what I did wrong.

Thanks for any help.

Roger

ROOT 5.26/00b (branches/v5-26-00-patches_at_32288, Apr 23 2010, 09:32:00 on linuxx8664gcc) Received on Mon May 17 2010 - 21:29:14 CEST