I just ran into the same problem as Wei Xie did last year: An existing
histogram has to be overwritten. I do not want to delete it and copy
constuct a new one, since it is attached to lists. I have only a TH1
pointer, while the histogram is of type TH1F or TH2F (or maybe something
else).
Fons Rademakers wrote on 25 Jun 1998:
> use either the histogram TH1::operator=() or the TH1::Copy()
> or the TObject::Clone() methods.
>
> Cheers, Fons.
>
> Wei Xie wrote:
> >
> > Dear ROOTers'
> >
> > Is there a way to copy one histogram directly to another
> > histogram ?
[...]
As far as I understand it,
* TH1::operator does not copy the entire object (no polymorphism
possible),
* TH1::Copy() is protected,
* TObject::Clone() creates a new object in a different memory location.
Do I miss the point here? Do I have to use memcpy (*shudder*)?
Thank you for your answer
Christoph
--
Christoph Borgmeier Mail: DESY F15/HERA-B, Geb. 61/117
Notkestr. 85, 22607 Hamburg
Humboldt Univ Berlin Phone: +49 40 8998 4850
Email: Christoph.Borgmeier@desy.de