hemisphere with hollow bottom

Dear all,
I am a beginner here. I hope you guys can help me with my problem.

I wanted to create a hemisphere geometry with a hollow bottom. And i write .geo file like this:

algebraic3d

solid main=sphere(0,0,0;1)
and plane(0,0,0;0,0,-1);
tlo main;

However i obtained a hemisphere with a closed bottom. Really appreciate it if you guys can help me this one. 
 

Hi suzarina3,

is this part of the documentation ( docu.ngsolve.org/latest/i-tutorials/unit...de/surface_pdes.html ) what you are after?

Best wishes,
Henry
 

Hi, it would also be easy to do this using the opencascade wrapper in ngsolve:

from netgen.occ import *

face = Sphere((0,0,0),1).faces[0]
face *= HalfSpace((0,0,0),(0,0,1))

geo = OCCGeometry(face)

is it the same? as I am using Netgen 5.0.0. As I load the geometry, it said that

Load CSG geometry file C:/Users/suzarina sukri/Desktop/TESTING .GEO FILE/hemisphere_try.geo
read unidentified token 101 (as char: "e") string = from
read unidentified token 101 (as char: "e") string = netgen
read unidentified token 100 (as char: "d") string = netgen

Thanks a millions for replying my questions.

Hi, my advice would be to go for the current Netgen which comes with NGSolve. My guess from you output is that your version is from before the introduction of the python interface.

Christophers code is a python script rather than a geo file.

Dear,

I downloaded the new version for python and NG Solver. Is the step the same as the old version?

Before this, I just load .geo file (I modified only this file to get the basic geometry)

Load geometry-->sphere.geo(example)

So now I need to load python file or what? So sorry sir for asking too many simple question. I really hope you can reply to my questions.

Thank you so much sir for your kind reply. I really need them. :'(