dolfin team mailing list archive

[Johan Hake <johan.hake@xxxxxxxxx>]

Hello!

I know this has been discussed earlier, but I cannot find a bug or blueprint 
reported for it.  

Let say I have a MixedSpace containing several global dofs (Real spaces) and 
one CG. Even if I define a form using functions defined only on the CG space 
it takes literally forever to assemble... This is because for each cell, a 
bunch of zeros are added to the global matrix, as the dofmap which defines the 
element matrix, is based on the whole MixedSpace. It would be _really_ nice if 
the size of the element matrix was based on the actuall dofs that get 
assembled.

Garth has previously mentioned that this is done to simplify the assemble 
interface, which is understandable. However, beside fixing assemble of global 
dofs in paralell this is my biggest wish for ufc/ffc/dolfin at the moment :)

Unfortunatly I know to little about the ufc/ffc part of FEniCS to say anything 
useful about what it would take to implement, but I would like to here what 
others think.

Best regards,

Johan