# How to compute int_\Omega \nabla u *v

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.

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u.dx(0) * v * dx