# [Gmsh] errors.....

Ramesh Balakrishnan bramesh at ncsa.uiuc.edu
Mon Nov 17 04:52:54 CET 2003

```Christophe,
Perhaps I am not following you. But the instructions you have given me
for transfinite (structured) grids do not work. I am appending the
untitled.geo file for this simple geometry.

The unstructured mesh works in a rather simple way by partitioning the
square into two triangles by drawing a diagonal. Is it possible to
increase the number of points inside the figure to get more triangles?

I would appreciate of you could give me a few more hints to generate
structured and unstructured grids.

Also, does each edge require a characteristic length. For instance, when
I go to mesh -> define -> transfinite, there are three options line,
surface , volume. Clicking on line brings up a window entitled
"Contextual mesh definitions". Under the tab transfinite line, I entered
100 (number of points) and 1 for progression. Then under volume it asks
me for the volume number. What do I enter here?

Sincerely,
Ramesh Balakrishnan

On Fri, 2003-11-14 at 19:01, Christophe Geuzaine wrote:
> Ramesh Balakrishnan wrote:
> >
> > I did try out a simple example. I defined a square,
> > (0,0),(1,0),(1,1),(0,1), and then connected these points with lines and
> > then defined the surface. Now I am stuck. Let us say I would like to
> > generate unstructured and structured (transfinite) grids for this simple
> > geometry. Could you give me pointers as to how I could proceed in the
> > interactive mode?
> >
>
> To generate an unstructured mesh, go to the Mesh menu, click on 2D, et
> voila... ;-)
>
> To generate a transfinite mesh, go to the Mesh menu, click on
> 'Define->Transfinite' and select the appropriate entities.
>
> Christophe
--
-------------- next part --------------
Point(1) = {0.0,0.0,0.0,1.0};
Point(2) = {1.0,0.0,0.0,1.0};
Point(3) = {1.0,1.0,0.0,1.0};
Point(4) = {0.0,1.0,0.0,1.0};
Line(1) = {1,2};
Line(2) = {2,3};
Line(3) = {3,4};
Line(4) = {4,1};
Line Loop(5) = {2,3,4,1};
Plane Surface(6) = {5};
Point(10) = {0.5,0.5,0,};
Ruled Surface(7) = {5};
Ruled Surface(8) = {5,5,5,5};
Ruled Surface(9) = {5};
```