Johan Jansson wrote: > Anders Logg wrote: >> On Mon, Dec 03, 2007 at 01:05:51AM +0100, DOLFIN wrote: >> >> >>> changeset: 3430:4fa0790a4fc34d3abac3079644368813a252ac61 >>> parent: 3428:7967082310c3ab03df9d812a6f471dcf988e7b4e >>> user: "Johan Jansson <[EMAIL PROTECTED]>" >>> date: Sun Dec 02 20:17:50 2007 +0100 >>> files: src/kernel/ode/MonoAdaptiveJacobian.cpp >>> src/kernel/ode/MonoAdaptiveNewtonSolver.cpp src/kernel/ode/ODE.cpp >>> src/kernel/ode/TimeSlabJacobian.cpp >>> src/kernel/ode/dolfin/MonoAdaptiveJacobian.h >>> src/kernel/ode/dolfin/MonoAdaptiveNewtonSolver.h >>> src/kernel/ode/dolfin/ODE.h src/kernel/ode/dolfin/TimeSlabJacobian.h >>> src/kernel/parameter/dolfin/DefaultParameters.h >>> description: >>> ODE: >>> >>> Added support for computing the Jacobian as a sparse matrix (only for >>> mono-adaptive dG(0) and cG(1) so far, and only for PETSc). >>> >> Why PETSc? The ODE solvers are tied to uBlas so the vectors won't be >> parallel. >> >> How and when should this be used? Does it change anything in the >> computation that the ODE solver does, or is it just a utility function >> for computing the Jacobian that a user can call? >> > Ideally the ODE solver should support both uBlas and PETSc, I think the > plan should be to transition to a general implementation if we start to > use it more for PDE. PETSc has a higher priority than uBlas though, > since that's what we use for large computations (due to efficiency and > robustness), and since it's parallel while uBlas is not. >
Why don't you try to implement it through the common interface? We'll soon have more linear algebra back-ends (e.g. Trilinos). Garth > The sparse Jacobian matrix is used in the mono-adaptive Newton case when > the option "ODE matrix-free jacobian" is set to false. The way I've > implemented time-dependent PDE with the ODE solver is that the form for > the Jacobian is supplied, and a TimeDependentPDE class provides ODE::J() > and ODE::Jmatrix() based on this form. > > Johan > > _______________________________________________ > DOLFIN-dev mailing list > [email protected] > http://www.fenics.org/mailman/listinfo/dolfin-dev _______________________________________________ DOLFIN-dev mailing list [email protected] http://www.fenics.org/mailman/listinfo/dolfin-dev
