Hi Jinghua, I made a couple corrections to the code I sent in the previous email so that if the command arguments are incorrect an error message is properly reported. Tom --- zoom/ChimeraExtension.py follows: # --------------------------------------------------------------------------- # The status line and command entry box at the bottom of the main Chimera # window prevent the window from being resized by this code to a width # smaller than about 450 pixels. The status line can be turned off using # Favorites / Preferences / Messages / Show status line, and the command-line # can be hidden with Tools / Command-line / hide. Commands can still be # typed with the command-line hidden. # def set_window_size(cmd_name, args): try: width, height = map(int, args.split()) except: from Midas import MidasError raise MidasError, 'Syntax error: %s <width-in-pixels> <height-in-pixels>' % cmd_name import chimera v = chimera.viewer v.windowSize = (width, height) # # If user resizes the main window by hand the above size will not take # effect unless we reset top level geometry. # from chimera import tkgui app = tkgui.app top = app.winfo_toplevel() top.wm_geometry('') # --------------------------------------------------------------------------- # def set_camera_zoom(cmd_name, args): try: pixels_per_angstrom = float(args) except: from Midas import MidasError raise MidasError, 'Syntax error: %s <pixels-per-angstrom>' % cmd_name import chimera have_bbox, bbox = chimera.openModels.bbox() if not have_bbox: return v = chimera.viewer width, height = v.windowSize # window size in pixels min_size = min(width,height) r = .5 * min_size / pixels_per_angstrom v.viewSize = r v.scaleFactor = 1 v.camera.focal = bbox.center().z # --------------------------------------------------------------------------- # import Midas.midas_text Midas.midas_text.addCommand('windowsize', set_window_size) Midas.midas_text.addCommand('setzoom', set_camera_zoom)