
hello, I remember seeing a pdb-to-density-map discussion at some point on this mail list, maybe using something from the EMAN package (pdb2mrc or something like that)? At any rate, a colleague recently asked me if I knew a way to generate a density map from point-cloud data that he has. This sounds a lot like the same question, except his data is anisotropic in z, so instead of assuming an isotropic/spherical gaussian around point centers, he has different sigmas for x/y and z. Does anyone have an algorithm he might be able to use to generate an MRC map from this kind of data? He is wanting to do some volume visualization, but to use Chimera he would need some sort of volume map (such as MRC). thanks for any advice on this, -Jeff -- ------------------------------------------------------------- Jeff Triffo Auer Group, Donner Lab, Lawrence Berkeley National Laboratory Raphael Group, Bioengineering Department, Rice University Medical Scientist Training Program (MSTP), Baylor College of Medicine phone (Berkeley): 510-486-7940 fax (Berkeley): 510-486-6488

Hi Jeff, The Chimera molmap command will make a map by placing Gaussians at a set of points (atoms or markers). Its intended to simulate an EM map. http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/molmap.html All the points use the same standard deviation which is the same along all 3 axes. But you could then change the voxel size of the resulting map (to say stretch z) using the Coordinates panel of the volume dialog or the volume command to get anisotropic Gaussians. Tom William Jeffrey Triffo wrote:
hello,
I remember seeing a pdb-to-density-map discussion at some point on this mail list, maybe using something from the EMAN package (pdb2mrc or something like that)?
At any rate, a colleague recently asked me if I knew a way to generate a density map from point-cloud data that he has. This sounds a lot like the same question, except his data is anisotropic in z, so instead of assuming an isotropic/spherical gaussian around point centers, he has different sigmas for x/y and z.
Does anyone have an algorithm he might be able to use to generate an MRC map from this kind of data? He is wanting to do some volume visualization, but to use Chimera he would need some sort of volume map (such as MRC).
thanks for any advice on this,
-Jeff
participants (2)
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Tom Goddard
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William Jeffrey Triffo