ffc team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

Martin Sandve Alnæs wrote:
> 2007/10/12, Martin Sandve Alnæs <martinal@xxxxxxxxx>:
> > 1) What is wrong with this form?

You take a dot product of a scalar with a vector (or a vector with a 
matrix in the vector case).

> > 2) If it's a user mistake and not an ffc bug, ffc should raise an
> > exception and not return None

Yes. Looking at operators.py, the "else" clause seems to be missing for 
the dot function.

/Anders


> > from ffc import *
> >
> > fe = FiniteElement("Lagrange", "triangle", 1)
>
> This should be:
> fe = VectorElement("Lagrange", "triangle", 1)
> but it doesn't change the None returned from dot.
>
> > v  = TestFunction(fe)
> > u  = TrialFunction(fe)
> > w  = Function(fe)
> >
> > Dw = grad(w)
> > Du = grad(u)
> >
> > uDw = dot(u, Dw)
> >
> > print u
> > print Dw
> > print uDw # None!
>
> Output:
>
> vi-1
> [[w0_a9(dXa11/dx0) | ((d/dXa11)va9[0]), w0_a12(dXa14/dx1) |
> ((d/dXa14)va12[0])], [w0_a15(dXa17/dx0) | ((d/dXa17)va15[1]),
> w0_a18(dXa20/dx1) | ((d/dXa20)va18[1])]]
> None
>
>
> > wDu = dot(w, Du)
> >
> > a = dot(v, uDw+wDu) * dx
> >
> >
> >
> > --
> > Martin