geometry (version 0.2-0)

mesh.functions: Special Distance Functions

Description

Elementary distance functions, usefull for defining distance functions of more complex regions.

Usage

mesh.dcircle(p, radius = 1, ...)
mesh.dsphere(p, radius = 1, ...)mesh.drectangle(p, x1 = -1/2, y1 = -1/2, x2 = 1/2, y2 = 1/2, ...)mesh.diff(p, regionA, regionB, ...)mesh.intersect(p, regionA, regionB, ...)mesh.union(p, regionA, regionB, ...)

Arguments

p

A matrix with 2 columns (3 in mesh.dsphere), each row representing a point in the plane.

radius

radius of circle

x1

lower left corner of rectangle

y1

lower left corner of rectangle

x2

upper right corner of rectangle

y2

upper right corner of rectangle

regionA

vectorized function describing region A in the union / intersection / difference

regionB

vectorized function describing region B in the union / intersection / difference

...

additional arguments passed to regionA and regionB

Value

• a vector of length nrow(p) containing the signed distances

Details

regionA and regionB must accept a matrix p with 2 columns as their first argument, and must return a vector of length nrow(p) containing the signed distances of the supplied points in p to their respective regions.

References

http://www-math.mit.edu/~persson/mesh/ P.-O. Persson, G. Strang, A Simple Mesh Generator in MATLAB. SIAM Review, Volume 46 (2), pp. 329-345, June 2004

See Also

distmesh2d

Examples

example(distmesh2d)