SystemAssembler

class dolfin.cpp.fem.SystemAssembler

Bases: dolfin.cpp.fem.AssemblerBase

This class provides an assembler for systems of the form Ax = b. It differs from the default DOLFIN assembler in that it applies boundary conditions at the time of assembly, which preserves any symmetries in A.

Constructor.

Parameters:

• const Form > a (std::shared_ptr<) –
• const Form > L (std::shared_ptr<) –
• std::shared_ptr< const DirichletBC >> bcs (std::vector<) –

assemble()

Assemble system (A, b) for (negative) increment dx, where x = x0 - dx is solution to system a == -L subject to bcs. Suitable for use inside a (quasi-)Newton solver.

Parameters:

• & A (GenericMatrix) –
• & b (GenericVector) –
• GenericVector & x0 (const) –

Return type:

void

thisown

The membership flag