dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Mon, Mar 31, 2008 at 02:26:45PM +0200, Kristen Kaasbjerg wrote:
> Hi,
> 
> I would like to plot a function that is the difference between a 
> DiscreteFunction and a UserFunction. Can this be done in any smart ways ?
> 
> The only way I can think of is to create a new user defined function 
> that contains the two Functions above, which does the subtraction in the 
> eval function, and then save this function to vtk format.
> This, however, will call the eval method of the DiscreteFunction which 
> includes cell searching etc. Just sounds a bit cumbersome to me when the 
> mesh contains say 500.000 elements.
> 
> Kristen

I would recommend to project the difference to an appropriate finite
element space and then plot the projection.

-- 
Anders