The speed of constructing a RooKeysPdf

Roofit and RooStats
1

I got a 50K entires of RooDataSet object to construct a RooKeysPdf object. Using the following construction method:

I spent about 3 mins to have it done. ( I used ACLiC complied library to run the code. )

Any expert knows how to speed this up?

Thanks in advance.
xiaorui

2

Hi,

The construction of a RooKeysPdf is intrinsically expensive as you
are essentially constructing the sum of 50K Gaussian distributions
with varying with (determined from the local event density).

If you have a recent ROOT version (5.26), you can however persist
the entire RooKeysPdf in a file and read it back for future use. In that
case you don’t incur this startup overhead. See tutorial macros
rf502 and rf503 concerning persistence and reading back of pdfs.

Wouter