Hi list,

I'm very new to PyMOL, so please be gentle. I use macPyMOL 0.98

I ran into a problem when trying to run what may seem like a very simple script in order to create a movie that zooms into a ligand binding site of a protein:

    set ray_trace_frames, 1
    set cache_frames, 0
    set hash_max, 400
    cmd.mset("1 x5")
    for a in range (1, 5):
        cmd.mdo(a, "move z, 10")
    cmd.mpng("/frames/frame")

When I run this script, I do get 5 rendered png files, but they're all the same. The move command does not get executed. The log reveals the following:

PyMOL>set ray_trace_frames, 1
 Setting: ray_trace_frames set to on.
PyMOL>set cache_frames, 0
 Setting: cache_frames set to off.
PyMOL>set hash_max, 400
 Setting: hash_max set to 400.
PyMOL>cmd.mset("1 x5")
PyMOL>for a in range (1, 5):
Traceback (most recent call last):
  File "/users/warren/pymol/products/MacPyMOL.app/pymol/modules/pymol/parser.py", line 194, in parse
    exec(com2[nest]+"\n",pymol_names,pymol_names)
  File "<string>", line 1
     for a in range (1, 5):
                           ^
 SyntaxError: unexpected EOF while parsing
PyMOL>cmd.mdo(a, "move z, 20")
Traceback (most recent call last):
  File "/users/warren/pymol/products/MacPyMOL.app/pymol/modules/pymol/parser.py", line 356, in parse
    exec(com2[nest]+"\n",pymol_names,pymol_names)
  File "<string>", line 1, in ?
NameError: name 'a' is not defined
PyMOL>cmd.mpng("/frames/frame")
 Ray: total time: 8.47 sec. = 425.2 frames/hour. (8.47 sec. accum.)
 Ray: total time: 8.55 sec. = 421.0 frames/hour. (17.02 sec. accum.)
 Ray: total time: 8.51 sec. = 423.2 frames/hour. (25.52 sec. accum.)
 Ray: total time: 8.49 sec. = 424.1 frames/hour. (34.01 sec. accum.)
 Ray: total time: 8.49 sec. = 424.1 frames/hour. (42.50 sec. accum.)

The file path in the Traceback obviously does not exist on my Mac. Does anyone know what's going on here? 

TIA for any advice. I really would like to get this zoom thing accomplished.

-Reinhold