Dear Rooters,
I came across a slight problem in accessing the gPad-pointer in one of my
macros. The script below does not execute properly with my version of ROOT
(3.01/06 on RedHat Linux 6.?). ROOT is unable to find or access the
gPad-pointer:
Error: non class,struct,union object $gPad used with . or -> FILE:tc.C
LINE:15
Any ideas on what is causing this effect ?
Cheers,
Sven Schagen
// Failing Macro
void test1(void)
{
gROOT->Reset();
TCanvas c1("c1","test canvas",400,400);
c1.Divide(2,2);
TH1F* histo = new TH1F("histo","histo",1,1,2);
histo->SetBinContent(1,10);
for(Int_t i = 0; i < 4; i++){
c1.cd(i+1);
if(i == 1) // Remove this statement, and the script works
gPad->SetLogx();
histo->Draw();
}
}
The problem can be solved by doing the following:
// Successfull Macro
void test2(void)
{
gROOT->Reset();
TCanvas c1("c1","test canvas",400,400);
c1.Divide(2,2);
TH1F* histo = new TH1F("histo","histo",1,1,2);
histo->SetBinContent(1,10);
for(Int_t i = 0; i < 4; i++){
c1.cd(i+1);
TPad* paddy = gPad; // Store the gPad pointer in a temp var.
if(i==1)
paddy->SetLogx();
histo->Draw();
}
}
This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:50:59 MET