COMSOL Multiphysics™

geomsurf
Purpose
geomsurf
Create 3D geometry surface using height data defined on a grid.
Syntax
f = geomsurf(x,y,z)
f = geomsurf(z)
s = geomsurf(x,y)
Description f = geomsurf(x,y,z) creates a 3D face object f on the grid defined by x and y,
using z as height data. The surface created is identical in shape to the surface created
with the scripting command surf(x,y,z).
geomsurf uses piecewise bilinear interpolation, as does surf.
f = geomsurf(z) creates a 3D face object f, corresponding to the call surf(z).
s = geomsurf(x,y) creates a 2D solid object s corresponding to the syntax f =
geomsurf(x,y,z) with z all zeros.
Example
% Create randomly generated surface
% Create rectangular grid
[x,y]=meshgrid(-0.1:0.2:1.1,-0.4:0.2:0.4);
% Initialize random generator
randn('state',1);
% Create random height data
z=0.1*randn(size(x));
% Create 3D surface
f=geomsurf(x,y,z);
% Plot the surface
geomplot(f)
% Create approximation to a catenoidal surface
% Create grid in spherical coordinates
[theta,phi]=meshgrid(pi/8:pi/32:3*pi/8,pi/4:pi/32:pi/2);
% The conical surface is expressed in spherical coordinates
r=1;
x=r.*cos(theta)./sin(phi);
y=r.*sin(theta)./sin(phi);
z=r.*log((1+sin(phi))./sin(phi));
% Now, create the piecewise bilinear
% approximative surface
catenoid=geomsurf(x,y,z);
% Plot the surface
geomplot(catenoid)
axis equal
See Also
face3, meshgrid
240 | CHAPTER 1: COMMAND REFERENCE