[Gmsh] R: information on generated mesh

[Jose Paulo Moitinho de Almeida]

It is certainly spending time to find information that is (probably) already 
available "inside" gmsh when the mesh is generated. 

Nevertheless this pre-processing is "much" faster than checking "who is near 
who" by munching all the data (it does not grow exponentially with the 
dimension of the mesh). Should be similar to the time used to read a .msh file 
from gmsh.

May make a difference depending on what you are considering/using.

ZP

On Tuesday 11 October 2016 11:10:16 Alessandro Vicini wrote:
> In my case this mesh "pre-processing" may be a bit time consuming, when mesh
> size begins to grow, that's why I was wondering if the information could be
> obtained directly from gmsh...
 
> A.
> 
> 
> 
> -----Messaggio originale-----
> Da: Jose Paulo Moitinho de Almeida [mailto:moitinho at civil.ist.utl.pt] 
> Inviato: martedì 11 ottobre 2016 13.07
> A: gmsh at onelab.info
> Cc: jeremy theler; Alessandro Vicini; Luiz Fernando Martha
> Oggetto: Re: [Gmsh] information on generated mesh
> 
> 
> "Me too"
> 
> We created a matlab class that from a .msh file (2D or 3D) creates a
> topological data structure of the mesh (*). After that functions like 
 
> [ cell_edges, cell_verts ] = prob.mesh.get_ev_c(elem);
> 
> [ cell_faces, cell_edges, cell_verts ] = prob.mesh.get_fev_c(elem);
> 
> for a 2D or a 3D mesh respectively, are processed "efficiently". 
> 
> (Note that all the other topological queries are available.)
> 
> ZP
> 
> (*) described in "IBHM: index-based data structures for 2D and 3D hybrid
> meshes" http://link.springer.com/article/10.1007/s00366-015-0395-0
 
> 
> On Tuesday 11 October 2016 09:56:14 jeremy theler wrote:
> 
> > Hi Alessandro! Find below some historic questions similar to yours...
> > Long story short: I did the same you did.
> > 
> > http://onelab.info/pipermail/gmsh/2011/006878.html
> > http://onelab.info/pipermail/gmsh/2011/006881.html
> > http://onelab.info/pipermail/gmsh/2012/007480.html
> > http://onelab.info/pipermail/gmsh/2013/008183.html
> > http://onelab.info/pipermail/gmsh/2014/008833.html
> > http://onelab.info/pipermail/gmsh/2014/008914.html
> > http://onelab.info/pipermail/gmsh/2015/009739.html
> > http://onelab.info/pipermail/gmsh/2015/009920.html
> > 
> > --
> > Jeremy Theler
> > www.seamplex.com
> > 
> > 
> > On Tue, Oct 11, 2016 at 5:09 AM Alessandro Vicini <
> > 
> > alessandro.vicini at sitael.com> wrote:
> > 
> > > In my code I need to know the list of neighbor nodes of each grid node,
> > > and the list of neighbor cells of each grid cell, so I wrote a routine
> > > to get this information, but I was wondering whether it would be
> > > possible
> > > to obtain it directly from Gmsh….
> > > 
> > > 
> > > 
> > > Alessandro
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
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>