Hi Patrick,
w**2 doesn't work because w is a vector valued expression.
This should have been detected already at w**2, I'll take a look at that.
Instead, try:
f = inner(w, w)/2*dx
Setting
L, a = F, J
should work fine, or you can do
forms = [F, J]
at the end of the form file (then you can define as many forms as you
like in one file).
Martin
On Sat, Jun 6, 2009 at 7:05 PM, Patrick Riesen<priesen@xxxxxxxxxxxxxxx> wrote:
hello
following the example in the ufl manual it's possible to do things like
element = VectorElement("CG", cell, 3)
w = Function(element)
f = w**2/2*dx
F = derivative(f, w)
J = derivative(F, w)
but how do i give e.g. F and/or J to the forms a and L to get the code?
when i tried just e.g. a = F it get
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
f = [[ v_{-1}[4], v_{-1}[5] ]]
g = 2
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Expecting scalar expression f in f**g.
*** Expecting scalar expression f in f**g.
thanks for the help,
patrick
Anders Logg wrote:
Yes, the bilinear form should be the linearized nonlinear form (not
minus).
Note that with UFL, it's now possible to just write down the nonlinear
form
(v, F(u)) = 0 for all v
and then let UFL compute the linearization.
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