On 04 Nov 2013, at 20:59, Marios Papadopoulos <[email protected]> wrote:
> Hello Martin, > > I've checked the option you mentioned and nothing happened when I select > "vertex" and not "barycenter" for the Glyph Location. You can check it out in > a simple example with one quad element. Attached you will find scalar field > plotted in gmsh and the same contour plot taken from wikipedia lemma > (bilinear interpolation). (see > http://en.wikipedia.org/wiki/Bilinear_interpolation) > > The question is, how I can use gmsh's $InterpolationScheme feature to get the > same contour plot inside the quad element? > Hi Marios, You actually don't need to define a specific $InterpolationScheme for this, as your function space is the classical, built-in one. The issue is that by default we draw the colormap on quads by splitting them into 2 triangles. You can get better visual accuracy by using our adaptive visualization scheme: select "Adapt visualization grid" in the View's Option panel. Set the "Target visuzalisation error" to the minimum (slide your mouse to the left). Set the recursion level to 1 to match the display of your other code. Note that this is still not exact. Increase the recursion level more to get closer to the exact visu. Christophe > Regards! > > > On Mon, Nov 4, 2013 at 2:14 PM, Martin Vymazal <[email protected]> > wrote: > Hello Marios, > > could you check that gmsh plots the values in vertices and not in > barycenters? > You can verify this by clicking on Tools->Options, then select your > postprocessing view, go to tab 'Aspect' and look at 'Glyph location'. > > Best regards, > > Martin Vymazal > > On Sunday 03 November 2013 19:03:56 Marios Papadopoulos wrote: > > Dear gmshers, > > > > attached you will find two contour plots from a scalar field. The first one > > (contour1.png) was made with gmsh using $NodeData feature, without using > > any extra $InterpolationScheme rule info. The second one (contour2.png) was > > made using another post-processing software with the same nodal values. > > This second image is the right represantion of the contour for the scalar > > field. > > > > As you notice, gmsh interpolate the nodal values with a "wrong" way. > > Ignoring the color mapping, how i can use the $InterpolationScheme feature > > in .msh format in order to get the right distribution inside the elements > > from the corresponding nodal values? > > > > i.e. > > $InterpolationScheme > > "name" > > number-of-element-topologies > > elm-topology > > number-of-interpolation-matrices > > num-rows num-columns value > > ... ... > > $EndInterpolationScheme > > > > Thank you in advance! > > > _______________________________________________ > gmsh mailing list > [email protected] > http://www.geuz.org/mailman/listinfo/gmsh > > <interpolation.msh><interpolation_gmsh.png><interpolation_wiki.png>_______________________________________________ > gmsh mailing list > [email protected] > http://www.geuz.org/mailman/listinfo/gmsh -- Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://www.montefiore.ulg.ac.be/~geuzaine _______________________________________________ gmsh mailing list [email protected] http://www.geuz.org/mailman/listinfo/gmsh
