Here is some code to scale a molecule size by a given factor. That is all atoms have their coordinates multiplied by a factor. Tom ------- Start of forwarded message ------- Date: Wed, 27 Apr 2005 11:05:55 -0700 (PDT) From: Thomas Goddard <goddard@cgl.ucsf.edu> Hi Jinghua, By "virus cage pdb file" I guess you mean you placed atoms at icosahedral positions, and want to show them connected up to show some icosahedral pattern. I think the easiest approach is to open your old session, run a command to change the diameter of the cage, then save a new session. Below is some Python code that provides a "scalemol" Chimera command. Make a directory chimera/share/scalemol in your Chimera distribution and put the code below in file chimera/share/scalemol/ChimeraExtension.py. Then start Chimera, open the cage PDB model, use menu entry Favorites/Command line, and type a command: scalemol 0 1.5 to make model number 0 bigger by a factor of 1.5. If you have more than one model open you can see the model numbers using Favorites / Model Panel, the model number is shown in the left hand column. Tom - ---- scalemol/ChimeraExtension.py code follows: # ----------------------------------------------------------------------------- # def scale_molecule(cmdname, args): from Midas.midas_text import error fields = args.split() try: model_num = int(fields[0]) factor = float(fields[1]) except: error('Syntax error: scalemol <model-number> <factor>') return import chimera mlist = chimera.openModels.list(id = model_num) if len(mlist) == 0: error('scalemol: No model number %d' % model_num) return for model in mlist: for a in model.atoms: x, y, z = a.coord().xyz.data() c = chimera.Coord() c.x, c.y, c.z = (factor*x, factor*y, factor*z) a.setCoord(c) # ----------------------------------------------------------------------------- # import Midas.midas_text Midas.midas_text.addCommand('scalemol', scale_molecule) ------- End of forwarded message -------