- Chimera-users - RBVI Mailing Lists

Little help to write a python script
by Eduardo Sanz Garcia 05 Jun '07

05 Jun '07

I have previously written command scripts for chimera. Now, I need to do something more complicated that, I believe, is not possible to do from the command line. This is the task: I have a list of 100 electron density maps. 1- I want to display each map, one by one. 2- Change the default threshold. 3- Save an image of the current volume. 4- Close the current volume and open the next model. Has anyone done this before? An example of a python script that can do this or something similar could help me a lot. Thanks in advance.

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Volume segmentation question
by Toby Starborg 05 Jun '07

05 Jun '07

Dear Chimera users. I am new to using chimera, so this question may seem a bit simplistic. I'm trying to use Chimera to examine EM tomographs of fairly busy data sets. I'd like to be able to divide the data into separate features so that I can better understand which parts are noise and which are structural (segmentation). So far I have found the "Pick Surface Pieces" tool is very useful for colouring the surface of features of interest. I have also found it useful to colour some surfaces with 0 opacity to remove items that are in the way, but I would prefer to do this in a more permanent fashion sot that I can return to a data set and quickly compare structures. I have also tried using "Volume Path Tracker" with "Color Zone" and "Split Map by Color" (after adjusting the voxel size to angstroms rather than nm to give a reasonable volume segmentation). My question is would it be possible to alter "Pick Surface Pieces" so that it colours (or tags in some way) all of the voxels within the chosen mesh, so that it would then be possible to split the map into separate compartments that could be saved and examined separately? This would also offer the ability to use different threshold levels to examine different features. I realise that this is more of a wish list than a trouble shooting question, but I'd also appreciate any input from more experienced Chimera/tomography users. Thank you for your help. Toby S -- Dr T Starborg FLS, University of Manchester Michael Smith Building, Rumford Street, Manchester,M13 9PL. UK tel:+44(0)161 275 1557 fax +44(0)161 275 1505

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(no subject)
by Газизов А.С. 04 Jun '07

04 Jun '07

Hello everybody. Is there Fe2+ ion in Chimera? I'm trying to add charges to hem molecule and it always appears to be Fe3+ (and Add Charge tool reports "There is odd number of electrons..." and fails).Assigning odd overall charge helps (i.e. +1, +3, etc), but I need +2...

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problem with chimera-->followup
by Vinay Kumar 04 Jun '07

04 Jun '07

Hello all, Firstly. Greg, Thank you. Though, i have been using the linux OS for quite sometime, i still have a few doubts about upgrading and these sort of things. I have actually gone to mesa3d, OpenGL, and DRI websites. but they contain terms which i am not acquainted with. I have downloaded, MesaLib 6.4.2 and tried installing it as per their instructions, only to find the installation stopping with some error. ( i shall post the error in the next email.) I would like to know, if the installation went well, would i have upgraded X11?? With regards, Vinay. ps- MesaLib 6.5.3 was available, but 6.4.2 was stated to be a stable release hence opted that.

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problem with chimera
by Vinay Kumar 01 Jun '07

01 Jun '07

Hello all, I have been using chimera and dock6.0 on a RHL9.0 system. More recently if i perform simple processes like coloring a molecule in chimera, the display goes blank and also logs me out of the session. meaning, i come back to the graphical login for my system. I am unable to proceed any further as repeated attempts to do simple tasks simply logs me out. Kindly help with suggestions. With regards, Vinay.

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Volume thresholds in Chimera
by Tom Goddard 01 Jun '07

01 Jun '07

Huang, Ren-Huai wrote: > Hi, > > Thanks for your help before. > > Chimera runs smoothly in my Linux computer. It generates very nice images for > EM reconstruction map. > Could you explain the concepts of thresholds of contour used in Volume > histogram? What is the value mean? > Thanks very much in advance, > > Ren-Huai > Thomas Goddard wrote: > Hi Ren-Huai, > > The map values shown in the Chimera volume viewer dialog are the > values that come from the file. Typically the map files do not have > any meaningful normalization. There is currently no facility for > instead showing values in standard deviation units. Chimera also does > not report the mean. These capabilities are on our requested features > list (entry #88). http://www.cgl.ucsf.edu/chimera/plans.html > > The histogram shows the distribution of map data values. The height > is the logarithm of the number of grid points with values in a small > value range. > > Tom >

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Software tools wiki pages
by Bridget Carragher 01 Jun '07

01 Jun '07

Hi there, In preparation for an announcement to go out about the JSB Software Tools Special Issue I am asking people who have entries on the 3DEM Software Tools wiki pages to update these if possible - eg. can you update the ref from the current "in press" to the right reference and also just check that the entry is otherwise up to date. Thanks, Bridget P.S. The url for these pages is: http://en.wikipedia.org/wiki/ Software_tools_for_molecular_microscopy in case you don't have it handy. ------------------------------------------------------------------------ ---------------------------------------------------------- Bridget Carragher, Associate Professor Automated Molecular Imaging Group, Department of Cell Biology The Scripps Research Institute, MC CB129,10550 North Torrey Pines Road, La Jolla, CA 92037 tel: (858) 784-9070; fax: (858) 784-9090; bcarr(a)scripps.edu; http:// ami.scripps.edu National Resource for Automated Molecular Microscopy: http:// nramm.scripps.edu ------------------------------------------------------------------------ ----------------------------------------------------------

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ESP grid is offset from original PDB coordinates??
by Kenward Vaughan 30 May '07

30 May '07

I was playing with esp results yesterday from Delphi on several structures, and ran a quick calculation on 2ace. To my surprise, the results as visualized as a solid under volume viewer were very obviously offset from the structure itself. They stand alone to one side of the original. I've attached a small jpg of this. I'm using the latest Linux production version (beta version 1 build 2415) on an amd64 box (Debian Sid, kernel 2.6.20). I hope there is a simple explanation... ;-) I am no expert with Delphi, so something may be odd there. I used a couple of the siz/crg files, with the same results in each case, so I suspect something in the original pdb file is messing things up? Cheers! Kenward -- .'^~;,_ Dr. Kenward Vaughan `:,'~~~~~ Professor of Chemistry \;:/ Bakersfield College |,;| 1801 Panorama Drive / ', \ Bakersfield, CA 93305 / o O \ http://www2.bc.cc.ca.us/kvaughan (oOoOOoOo) ---========--- ???$$MM$$???

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Python script for reading volume values at atom positions
by Tom Goddard 30 May '07

30 May '07

Hi Terry, Here is a Python script to read a volume map and a PDB file and print the values of the map interpolated at the atom positions. It will work without the Chimera graphical user interface. I tested it in Chimera 1.2415. Tom # ----------------------------------------------------------------------------- # Script that opens PDB and map files and prints the map values interpolated # at each atom position. Can be run without graphical user interface: # # chimera --nogui avalnogui.py # def map_values_at_atoms(pdb_path, map_path): # Open map file. # File name has to have file suffix indicating volume format. from VolumeData import open_file data = open_file(map_path) from VolumeViewer import Data_Region, full_region, Rendering_Options ro = Rendering_Options() map = Data_Region(data, full_region(data.size), '', ro) attribute_name = data.name.split('.')[0] # Open PDB model(s). from chimera import openModels molecules = openModels.open(pdb_path, 'PDB') # Interpolate map values at atom positions. from AtomDensity import set_atom_volume_values for mol in molecules: set_atom_volume_values(mol, map, attribute_name) # Print values. for mol in molecules: for a in mol.atoms: v = getattr(a, attribute_name) print '%-15s %12.4g' % (a.oslIdent(), v) # ----------------------------------------------------------------------------- # map_path = '/usr/local/src/chimera-demos/volume/examples/1a0m.omap' pdb_path = '/usr/local/src/chimera-demos/volume/examples/1a0m.pdb' map_values_at_atoms(pdb_path, map_path)

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Color in Chimera
by Albion Baucom 25 May '07

25 May '07

How do I determine the exact color value of a model from a previous session? I want to open a session, determine the color of a selected chain, and then color another chain that exact color. I can't seem to find an "eye-dropper" or other comparable tool to determine the color value (RGB, hex, etc). Thanks. Albion

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