From: John Stone (johns_at_ks.uiuc.edu)
Date: Sat Jan 14 2017 - 00:20:59 CST

You might look at existing libraries that do things of this sort if
you're not familiar with the techniques I described, such as:
and:
  http://stackoverflow.com/questions/25991553/interpolation-resampling-large-irregular-matrix-or-surface-data-points-to-regula

and:
  https://www.mathworks.com/help/matlab/ref/griddata.html?requestedDomain=www.mathworks.com

and:
  https://docs.scipy.org/doc/scipy-0.14.0/reference/generated/scipy.interpolate.griddata.html
  http://stackoverflow.com/questions/3864899/resampling-irregularly-spaced-data-to-a-regular-grid-in-python
 
A paper that covers some of the ideas for doing these things, albeit for
a totally different field:
  https://ai2-s2-pdfs.s3.amazonaws.com/de95/ea52e8a18b261729f67a6cb0b0a614cd9804.pdf

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Sat, Jan 14, 2017 at 11:35:10AM +0530, hirak chatterjee wrote:
> Thank you for the sharp reply, however, I could not understand properly
> the technique you have described to me. Would you please elaborate it to
> me ? thanks again.
> Thanks and regards,
> [1]Hirak Chatterjee
> Research Scholar
> C/O Dr. Sujit Kumar Ghosh
> Department of Chemistry
> Assam University
> Silchar-788011
> Assam,A INDIA
> Contact No: +918486882543 (ASSAM)
> A A A A A A A A A A A A +919475265107 A (WEST BENGAL)
> On Sat, Jan 14, 2017 at 11:28 AM, John Stone <[2]johns_at_ks.uiuc.edu> wrote:
>
> Hi,
> A At present this isn't (directly) possible without writing additional
> code.
> All of the existing interfaces in VMD assume grids with uniform sample
> spacing.
> To achieve your goal at present, one would need to resample the
> potential field
> in your unstructured mesh onto a regular grid, and then you would be
> able
> to load and display it in VMD.A You could resample the unstructured
> mesh
> by working through it one tetrahedra at a time, essentially by
> rasterizing
> the tetrahedra in the unstructured mesh onto the voxels in a regular
> grid,
> interpolating values between the four vertices of the tetrahedra as you
> go.
> I'm sure you can do this sort of resampling/conversion using some
> existing
> software somewhere, but it's not built into VMD at present since most of
> the existing tools use uniform grids for density maps, potential fields,
> etc.
>
> Cheers,
> A John Stone
> A [3]vmd_at_ks.uiuc.edu
>
> On Sat, Jan 14, 2017 at 11:22:28AM +0530, hirak chatterjee wrote:
> >A A Dear Colleagues,
> >A A AA AA AA AA Is there any possibility in VMD through which an
> unevenly
> >A A spaced data could be read in the form of a potential file and be
> shown
> >A A through an isosurface?
> >A A Thanks and regards,
> >A A [1]Hirak Chatterjee
> >A A Research Scholar
> >A A C/O Dr. Sujit Kumar Ghosh
> >A A Department of Chemistry
> >A A Assam University
> >A A Silchar-788011
> >A A Assam,A INDIA
> >A A Contact No: +918486882543 (ASSAM)
> >A A AA AA AA AA AA AA AA AA AA AA AA AA +919475265107 A
> (WEST BENGAL)
> >
> > References
> >
> >A A Visible links
> >A A 1. [4]https://www.researchgate.net/profile/Hirak_Chatterjee3
> --
> NIH Center for Macromolecular Modeling and Bioinformatics
> Beckman Institute for Advanced Science and Technology
> University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> [5]http://www.ks.uiuc.edu/~johns/A A A A A A Phone: 217-244-3349
> [6]http://www.ks.uiuc.edu/Research/vmd/
>
> References
>
> Visible links
> 1. https://www.researchgate.net/profile/Hirak_Chatterjee3
> 2. mailto:johns_at_ks.uiuc.edu
> 3. mailto:vmd_at_ks.uiuc.edu
> 4. https://www.researchgate.net/profile/Hirak_Chatterjee3
> 5. http://www.ks.uiuc.edu/~johns/
> 6. http://www.ks.uiuc.edu/Research/vmd/

-- 
NIH Center for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
http://www.ks.uiuc.edu/~johns/           Phone: 217-244-3349
http://www.ks.uiuc.edu/Research/vmd/