[3dem] Remove negative density from a map

[m.maletta at nki.nl]

Dear all
Does anybody know how to remove negative density (set to zero) from a mrc map?
I subtracted two structures to highlight a factor and the negative peaks are making my life miserable.
Best
Max

__________________________________
Massimiliano Maletta
post-doc in
NKI Netherlands Cancer Institute -Antoni van Leeuwenhoek Hospital Plesmanlaan 121 B6 1066CX Amsterdam
group of Peter Peters
www.nki.nl/research/peters/<http://www.nki.nl/research/peters/>   | www.necen.nl<http://www.necen.nl/>
m.maletta at nki.nl<mailto:m.maletta at nki.nl>
Tel : +31 20 512 2022
Fax : +31 20 512 2029