fs.test.3D {fdaPDE}

FELSPLINE 3D test function

Description

Implements a finite area test function based on one proposed by Tim Ramsay (2002) and by Simon Wood (2008) in 3D.

Usage

fs.test.3D(x, y, z, r0 = 0.25, r = 1.25, l = 5, b = 1, exclude = FALSE)

Arguments

x, y, z

Points at which to evaluate the test function.

r0

The test domain is a sort of bent sausage. This is the radius of the inner bend.

r

The radius of the curve at the centre of the sausage.

l

The length of an arm of the sausage.

b

The rate at which the function increases per unit increase in distance along the centre line of the sausage.

exclude

Should exterior points be set to NA?

Value

Returns function evaluations, or NAs for points outside the horseshoe domain.

Examples

library(fdaPDE)

data(horseshoe2.5D)
mesh = horseshoe2.5D
FEMbasis=create.FEM.basis(mesh)

# Evaluation at nodes
sol_exact=fs.test.3D(mesh$nodes[,1],mesh$nodes[,3],mesh$nodes[,2])
plot(FEM(sol_exact, FEMbasis))