WSE Solver Module
=================
This is a convenience class that packages common linear solvers to solve systems
of linear equations to a defined tolerance.  The Solvers use the same Modules
in this package to program the WSE once the coefficient matrix and source vector
are formed.  The implicit solution example for the diffusion equation
uses one of the `CgConstantOffDiag` variant below.  Be sure to instantiate
the class at the start of a program to initialize the necessary memory spaces.

The solvers will create `program_scratch` space for arrays and scalars.  These
memory spaces are available to users outside of the solver, but will be overwritten
when the solver is called.  This is usually ok as implicitly solving equations
involves repeated processes of forming and solving and the memory spaces during
each process is partially isolated (they share A/b and field values).  Reusing
program scratch is suitable for several intermediate calculations in the formation
steps.

.. autoclass:: WFA.WSE_Solver.BiCgStab
    :members:

.. autoclass:: WFA.WSE_Solver.Cg
    :members:

.. autoclass:: WFA.WSE_Solver.CgConstantOffDiag
    :members:

.. autoclass:: WFA.WSE_Solver.Jacobi
    :members:

.. autoclass:: WFA.WSE_Solver.JacobiConstantOffDiag
    :members: