[R] constraining the shape of a PDF

[tibi.codilean at ges.gla.ac.uk]

Dear all,

This is probably off topic, but I did not know where to turn and since
most of you have an excellent knowledge of statistics, I thought of
sending my question to this list.

I was wondering whether there is some literature on (or a way to
calculate) how many data points one would need to constrain the shape of a
PDF to such an extent that this can be statistically differentiated from
another given PDF.

I am aware that this depends on many things and the answer is not
straightforward, however my problem is very simple and would need a very
simple answer.

I would really appreciate your help
Thanks

Tibi