m_mform_constraint_abstract Module Reference

Module containing an object representing a local linear constraint (i.e., one that acts on only part of the m-form) that can be imposed on an m-form function (MFormFun) More...

Data Types
interface	mform_constraint_local_init
type	mformconstraintlocal
	The object that represents linear constrains imposed locally (i.e., only acting on inds) on the coefficients of an mform. More...

Detailed Description

Module containing an object representing a local linear constraint (i.e., one that acts on only part of the m-form) that can be imposed on an m-form function (MFormFun)

We consider a homogeneous linear constraint of the form C * u[inds] = 0, is considered, where u is the vector of unknowns of a tensor product B-spline, C is a wide matrix and inds is a list of indices on which the constraint is applied.

Two methods for imposing the constraint are considered:

• using an extraction matrix E which spans the nullspace of C: C * E = 0.
• using a projector P which projects the coefficients onto the nullspace of C: P = E (F^T * E)^(-1) F^T, where F is a matrix for which F^T * E is invertible.

The current implementation restricts the domain decomposition in such a way that the local constraint acts on the coefficients of an m-form that are local to the current rank