Converting spatialPointsDataFrame into ppp

Hi!

Is it possible (and if yes, how) to convert from an spatialPointsDataFrame
to a ppp object (selecting the appropriate variable in the
dataframe) so that I can run Kest ?
I've tried with as.ppp with no success.

(I always have a bad time converting among the different spatial
objects in R, I promise contributing a flow chart soon, or is ti
included in the new book?).

Thanks!

Agus

Dr. Agustin Lobo
Institut de Ciencies de la Terra "Jaume Almera" (CSIC)
LLuis Sole Sabaris s/n
08028 Barcelona
Spain
Tel. 34 934095410
Fax. 34 934110012
email: Agustin.Lobo at ija.csic.es
http://www.ija.csic.es/gt/obster