Hello,

I need to compute some integrals as u’v in V.F. How do I compute this kind of integrals in Fenics?

When you say `u'`

do you mean \nabla u? And if so, is your problem a 1D, 2D or 3D problem?

In variational forms, all integrals are scalar values, I.e. you cannot compute \int_\Omega \nabla I v \mathrm{d}x If the problem is not is 1D.

If the problem is 1D, `u'(x)=u.dx(0)`

in ufl syntax.

1 Like

Thanks for the answer.

suppose that I want to solve

u’’ - 2u’+u = exp(x)

by Fenics. In V.F an integral appear as

\int_0^1 u’v dx

I need to know how to compute this integral in Fenics

Regards

Have you tried:

`u.dx(0) * v * dx`

2 Likes

Thanks. It worked. much appreciated.