[petsc-users] Appending to vector / numerical continuation / slepc

[Jose E. Roman]

El 05/10/2011, a las 19:46, Kevin Green escribió:

> Greetings,
> 
> I was just wondering what the simplest way to create a new N+k dim where the first N come from a DA.  It seems to me that I would have to go the round about way of getting the array, then writing that to the first N components of the new vector... I think there would be a bit of a pain for the parallel case when doing this though, like in managing the change in the local sizes when going from N to N+k... perhaps it's not that tricky.  Also, with DAs I don't have to worry about orderings, correct?
> 
> Essentially I want to get pseudo-arclength continuation working using the SNES solver.  Another option I'm thinking is that rather than using an extended vector, I could use a MatShell where the added components are located within its context, and updated upon matmult...since k is typically small, this seems reasonable.  Do you know of any code/projects that make use of the SNES module for continuation?  Any thoughts on what would be the better or simpler way of doing this?
> 
> I'm using petsc-3.1 right now, as I also need slepc...which hasn't been updated to work with 3.2 yet, as far as I know.  I'm fairly new to petsc/slepc... so I have to ask, what is the timescale like between the release of a new petsc, and update of slepc?  Or is there a way to get slepc working with the new release?

slepc-3.2 will be out in a few weeks. Meanwhile, you can use slepc-dev (see instructions at http://www.grycap.upv.es/slepc/download/ ).

Jose


> 
> Cheers,
> Kevin