10 Oct
                
                    2016
                
            
            
                10 Oct
                
                '16
                
            
            
            
        
    
                6:29 p.m.
            
        On 10 Oct 2016, at 18:19, Colin Cotter <colin.cotter@imperial.ac.uk> wrote:
OK, this is the problem then - you need to find an appropriate preconditioner.
You need to start by finding an appropriate preconditioner for the system without the R space part.
Lawrence: once that is done, is there anything special to do to incorporate it into the system with the R space part [asking because you seem to have thought about this previously], or do we just recommend block preconditioning in this case?
I think you could use block first. It's easier. Otherwise I think the firedrake webpages sketch how to do sherman-morrison. Lawrence