dolfin team mailing list archive

[Murtazo Nazarov <murtazo@xxxxxxxxxx>]

Anders Logg wrote:
> Question #103034 on DOLFIN changed:
> https://answers.launchpad.net/dolfin/+question/103034
>
>     Status: Open => Answered
>
> Anders Logg proposed the following answer:
> On Wed, Mar 03, 2010 at 02:36:59AM -0000, Murtazo Nazarov wrote:
>   
> > New question #103034 on DOLFIN:
> > https://answers.launchpad.net/dolfin/+question/103034
> >
> > Hi,
> >
> > I am wondering how to compute an L1-norm, and L_inf norm of a functional on the cell. For instance how to compute
> >
> > 1. ||\div(Pu)||_{L_\infty} ?
> >     
>
> Try projecting div(Pu) onto piecewise constants and then pick the
> largest absolute value in the vector.
>
>   

I need L_inf norm on the cell. With this way, doesn't give the L_inf for 
the entire domain?

murtazo

> > 2. ||\div(Pu)||_{L_1} ?
> >     
>
> Try
>
> M = abs(div(Pu))*dx
>
> --
> Anders
>
>
>   
> > where u is velocity (vector) and P is pressure (scalar). L2 norm is obvious to do.
> >
> > I use C++ interface
> >
> >     
>
>