Re: Dolfin mesh conversion functions [was: Re: Welcome GSoC students!]

[c.]

On 7 Jun 2013, at 21:36, Juan Pablo Carbajal <address@hidden> wrote:

> On Fri, Jun 7, 2013 at 7:25 PM, Marco Vassallo
> <address@hidden> wrote:
>> I was thinking about other possibilities for the refinement.. maybe a
>> boolean vector of size equal to the number of cells which says if a cell has
>> to be refined or not? or maybe something related to the label of the border
>> ?
> 
> User-controlled refinement that I have found useful is given by a
> property of element/face/edge/vertex that indicates the maximum level
> of refinement, the meaning of "level of refinement" would depend on
> the refining method, e.g. subdivision of element would require level
> of refinement to be an integer value where 0 indicates no division and
> 4 indicates at most 4 subdivision (i.e. final size of elements L/k^4,
> where k is given by how elements are divided).

that would be cool, but unfortunately dolfin does not seem this functionality:
http://fenicsproject.org/documentation/dolfin/dev/python/programmers-reference/mesh/refinement/refine.html

the python interface takes as an input parameter a function that returns true 
if a cell is to be refined and false otherwise.
in Octave I'd say we can use an arry of logicals or a function handle or allow 
either of the two and check which one was passed.

> If refinement is base don some estimation of the error, then I guess a
> boolean is ok, since the user can't control the level of refinement,
> but only the global error tolerance.

c.