stiff.FEM {SpatialfdaR}

Compute the stiffness matrix for a finite element basis.

Description

stiff.FEM produces the stiffness matrix containing integrals of products of second partial derivatives of the nodal functions.

Usage

  stiff.FEM(FEMbasis)

Arguments

FEMbasis

A List object produced by function create.FEM.basis. It contains:

• orderThe order of the element (1 or 2).

• nodesCoordinates of node points.

• nodeindexIndices of node points for each element.

• jvecjacobian of the affine transformation of each element to the master element.

Value

A matrix K0: the NNOD by NNOD matrix of sums of products of nodal basis functions. For each element i, the integral of the product of the j'th and k'th second partial derivatives of the shape functions over the i'th element is computed. Then that value is the (nodeindex[i,j],nodeindex[i,k])th entry of the i'th elemental stiff matrix.

Author(s)

Jim Ramsay

References

Sangalli, Laura M., Ramsay, James O., Ramsay, Timothy O. (2013), Spatial spline regression models, Journal of the Royal Statistical Society, Series B, 75, 681-703.

See Also

mass.FEM