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Re: [DOLFIN-DEV] Some Iterative Linear Solver Doubts.

 



Anders Logg wrote:
On Thu, Sep 25, 2008 at 12:41:33PM +0100, Garth N. Wells wrote:
Nuno David Lopes wrote:
Is there a simple way of setting an initial guess for an Iterative LinearSolver? In Umfpack and PETSc the default initial guess is the zero vector right?
At the moment, yes (note the UMFPACK is an LU solver, so an initial guess doesn't do anything).

It's very simple, and I've been meaning to add an option for using an initial guess. It's also useful for Newton solvers. I'll add something in the next few days.

Garth

It would be natural to let the x argument always be the initial
guess. I thought we already did this.

Would it be enough to make sure that Vector::init() does not reset the
values to zero?


Yes.

The danger is if someone sends an uninitialised vector to the solver.

Garth



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