[Gmsh] ellipse strange behavior

jean pierre aubry jeanpierre at lamachine.fr
Sun Apr 17 16:23:20 CEST 2011


hello

i have discovered a strange behavior of gmsh regarding creating an
ellipse,
the following code 

Point(1) = {0, 0, 0, 100};
Point(2) = {-500, 0, 0, 100};
Point(3) = {500, 0, 0, 100};
Point(4) = {0, -500, 0, 100};
Point(5) = {0, 500, 0, 100};
Ellipse(1) = {3, 1, 1, 2};

produces the following log file

Info    : Reading '/dedalus/arbeit/2011/jpa/tutorial/gmshcircle.geo'...
Error   : Ellipse 1 is wrong
Error   : Ellipse -1 is wrong
Info    : Done reading
'/dedalus/arbeit/2011/jpa/tutorial/gmshcircle.geo'
Info    : Meshing 1D...
Info    : Meshing curve 1 (Ellipse)
Info    : Done meshing 1D (0 s)
Info    : 35 vertices 36 elements

with 2 warnings
however all seems to be ok

i thought i had discovered a trick to create a full 360° circle 
which cannot be done with gmsh except by using 3 arcs, that is 3 units

of course nodes are not automatically created at the geometry points
used to describe the ellipse/circle

is there anything wrong with this way of procceding?

jean pierre aubry