[Gmsh] Domain defined by a function

Christophe Geuzaine cgeuzaine at ulg.ac.be
Thu Apr 11 18:50:14 CEST 2013


On 11 Apr 2013, at 17:42, mohamed mbehou <mbehoumoh at yahoo.fr> wrote:

> Dear,
> I am a Phd student and I started use GMSH for quiet few months.
> I want to generate a 3 nodes and 6-nodes triangles on a domain defined by 
> X=rsin(u)cos(v); Y=rsin(u)sin(v); Z=rcos(u) with r=3; u in [pi/10;pi/2] and v in [0, pi/2].
> I used Matlab to plot the domain and then got some points to use in GMSH (as below).
> But when I want to defined a plane surface, I got the wrong message (Error   : Plane surface 24 (0.487277x+-0.454202y+-0.74583z=-1.17328) is not plane!).
> I don't know what to do. Please your help will be very useful for me. 

A "Plane Surface" should be plane... You could do this:

Line(1) = {1, 2};
Spline(2) = {2:12};
Line(3) = {12, 13};
Spline(4) = {1,14:22, 13};
Line Loop(23) = {1, 2, 3, -4};
Ruled Surface(24) = {23};




> Thank you in advanced.
> 
> Here is the gmsh code:
>  // Gmsh project created on Wed Apr 10 10:37:50 2013
> l=1;
> Point(1) = {0.9271, 0, 2.8532, l};
> Point(2) = {3.0000, 0, 2.8532, l};
> //big quater cirlce
> Point(3) = {2.9631, 0.4693, 2.7145, l};
> Point(4) = {2.8532, 0.9271, 2.5330, l};
> Point(5) = {2.6730, 1.3620, 2.3115, l};
> Point(6) = {2.4271, 1.7634, 2.0536, l};
> Point(7) = {2.1213, 2.1213, 1.7634, l};
> Point(8) = {1.7634, 2.4271, 1.4453, l};
> Point(9) = {1.3620, 2.6730, 1.1044, l};
> Point(10) = {0.9271, 2.8532, 0.7461, l};
> Point(11) = {0.4693, 2.9631, 0.3760, l};
> Point(12) = {0.0000, 3.0000, 0.0000, l};
> Point(13) = {0.0000, 0.9271, 0.0000, l};
> //small quater cicle
> Point(14) = {0.9156, 0.1450, 2.7145, l};
> Point(15) = {0.8817, 0.2865, 2.5330, l};
> Point(16) = {0.8260, 0.4209, 2.3115, l};
> Point(17) = {0.7500, 0.5449, 2.0536, l};
> Point(18) = {0.6555, 0.6555, 1.7634, l};
> Point(19) = {0.5449, 0.7500, 1.4453, l};
> Point(20) = {0.4209, 0.8260, 1.1044, l};
> Point(21) = {0.2865, 0.8817, 0.7461, l};
> Point(22) = {0.1450, 0.9156, 0.3760, l};
> 
> Line(1) = {1, 2};
> Line(2) = {2, 3};
> Line(3) = {3, 4};
> Line(4) = {4, 5};
> Line(5) = {5, 6};
> Line(6) = {6, 7};
> Line(7) = {7, 8};
> Line(8) = {8, 9};
> Line(9) = {9, 10};
> Line(10) = {10, 11};
> Line(11) = {11, 12};
> Line(12) = {12, 13};
> Line(13) = {13, 22};
> Line(14) = {22, 21};
> Line(15) = {21, 20};
> Line(16) = {20, 19};
> Line(17) = {19, 18};
> Line(18) = {18, 17};
> Line(19) = {17, 16};
> Line(20) = {16, 15};
> Line(21) = {15, 14};
> Line(22) = {14, 1};
> Line Loop(23) = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22};
> Plane Surface(24) = {23};
> 
> 
> Best regard,
>  
> MBEHOU Mohamed
> 
> Dpt of Mathematics and Applied Mathematics,
> Faculty of Natural and Agriculture Sciences
> University of Pretoria, South Africa
> Phone (+27) (0) 7 36 55 04 87
> Botany Building 3-1
> mbehoumoh at gmail.com/mbehoumoh at uy1.uninet.cm
> 
>  
> 
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
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-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine