[ROOT] Project3D with variable binning

[Chris Roat]

Hi.

I notice that the Project3D of TH3, which projects a 3D histogram onto 1
or 2 dimensions, uses the following type of constructor for it's lower
dimensional histogram (here I present the 1d case of projecting onto the
x axis):

TH1D(name,title,nx,fXaxis.GetBinLowEdge(ixmin),fXaxis.GetBinUpEdge(ixmax));

Unfortunately, this does not allow for the original histogram to have
variable width binning along the direction(s) being projected onto. In my
application I was able to write some code to get around this, but I was
wondering if there is some subtlety that does not allow this to be
implemented in general. If there is no such problem, would it be possible
to allow this feature in the future?

Chris Roat

[Rene Brun]

Hi Chris,
I suppose you mean the case of a 2-d histogram with variable bin size.
Variable bin size 2-d histograms are not yet supported
in the current implementation of Project3D. This should be added.

Rene Brun