From: Vlad Cojocaru (
Date: Thu Apr 01 2004 - 09:30:13 CST

Dear vmd users
   I am trying to draw a triangle between 3 atoms with the script shown
below. I get the following message all the time:
"need three numbers for a vector"
   I am wondering what is this because all the $coord1 2 and 3 are
defined properly. If I use the numbers instead of the variables $coord1
2 and 3 everything works fine.
Thanks a lot in advance
Best wishes

set sel1 [atomselect 0 "name P and resid 16" frame 0]
set sel2 [atomselect 0 "name P and resid 5" frame 0]
set sel3 [atomselect 0 "name P and resid 9" frame 0]

set coord1 [$sel1 get {x y z}]
set coord2 [$sel2 get {x y z}]
set coord3 [$sel3 get {x y z}]

draw triangle $coord1 $coord2 $coord3

Vlad Cojocaru 
Max Planck Institute for Biophysical Chemistry 
Department: 060 
Am Fassberg 11, 37077 Goettingen, Germany 
tel: ++49-551-201.1327 
home tel: ++49-551-9963204