I would look at the instant side. Or in ffc.jitobject. repr of a form is
not used anywhere.

Martin
Den 11. mars 2013 18:20 skrev "Johan Hake" <email address hidden>
følgende:

> On 03/11/2013 04:31 PM, Marie Rognes wrote:
> > On 03/11/2013 04:07 PM, Johan Hake wrote:
> >> Are you sure this is a bug?
> >
> > Pretty sure, yes.
> >
> >> In the first example the Expression is generated without setting the
> >> degree. If this is auto chosen to 2 it should make perfectly sense they
> >> give the same results.
> >
> > Yes. But the problem is that the Expression with degree=2 gives
> > different results depending on what has been compiled before it.
> >
> >> Change degree to something else and you will have
> >> a different results.
> >
> > Did you read the problem carefully? Look at (*) and (**).  Both of these
> > correspond to setting degree=2 explicitly. The numbers should therefore
> > be the same. They are not, which is highly disturbing. (*) is produced
> > after doing instant-clean, running with auto degree, and running with
> > degree = 2 (which seems to reuse the auto degree code); while (**) is
> > produced after doing instant-clean and directly running with degree=2.
>
> Ok, I see it now. Pretty disturbing yes.
>
> How can we find out what degree is chosen for the expression when it is
> autogenerated? Is it during preprocess? Is it still so that it is the
> repr of the preprocessed form that determines if a form will get
> recompiled?
>
> from dolfin import *
>
> mesh = UnitSquareMesh(16,16)
> V = FunctionSpace(mesh, 'CG', 2)
> w = TestFunction(V)
> f = Expression("x[0]*x[0] + 2*x[1]*x[1]")
> L = inner(w, f)*dx
> b = assemble(L)
>
> print "Preprocessed:", repr(L.form_data().preprocessed_form)
> print "Not preprocessed:", repr(L)
>
> Prints:
> Preprocessed: Form([Integral(Product(Argument(FiniteElement('Lagrange',
> Domain(Cell('triangle', 2), 'triangle_multiverse', 2, 2), 2, None), -2),
> Coefficient(FiniteElement('Lagrange', None, None, None), 0)), 'cell',
> 'otherwise', None, None)])
> Not preprocessed:
> Form([Integral(Product(Argument(FiniteElement('Lagrange',
> Domain(Cell('triangle', 2), 'triangle_multiverse', 2, 2), 2, None), -2),
> Coefficient(FiniteElement('Lagrange', None, None, None), 0)), 'cell',
> 'everywhere', None, None)])
>
> Where it is clear that the Coefficient of the first form has not got any
> degree. Shouldn't it have got one?
>
> Johan
>
>
> > --
> > Marie
> >
> >
> >> Johan
> >>
> >> On 03/11/2013 10:06 AM, Marie Rognes wrote:
> >>> Public bug reported:
> >>>
> >>> There seems to be something seriously wrong with either DOLFIN-FFC jit
> >>> compilation or caching or instant.
> >>>
> >>> To reproduce, for instance consider the following code snippet and do
> >>> the following
> >>>
> >>> (1): Run instant-clean
> >>>
> >>> (2): Run script unmodified.
> >>>
> >>> Output is:
> >>>
> >>> Calling FFC just-in-time (JIT) compiler, this may take some time.
> >>> Calling DOLFIN just-in-time (JIT) compiler, this may take some time.
> >>> Calling FFC just-in-time (JIT) compiler, this may take some time.
> >>> Calling FFC just-in-time (JIT) compiler, this may take some time.
> >>> Solving linear system of size 1089 x 1089 (PETSc Krylov solver).
> >>> 40.4757877531
> >>>
> >>> (3) Uncomment commented lines and run.
> >>>
> >>> Output is:
> >>>
> >>> Solving linear system of size 1089 x 1089 (PETSc Krylov solver).
> >>> 40.4757877531
> >>> Solving linear system of size 1089 x 1089 (PETSc Krylov solver).
> >>> 40.4757877531 (*)
> >>>
> >>> (4) Run instant-clean, comment out lines defining f, g, and 1st print.
> >>> Run.
> >>>
> >>> Output is
> >>> Calling FFC just-in-time (JIT) compiler, this may take some time.
> >>> Calling DOLFIN just-in-time (JIT) compiler, this may take some time.
> >>> Calling FFC just-in-time (JIT) compiler, this may take some time.
> >>> Calling FFC just-in-time (JIT) compiler, this may take some time.
> >>> Solving linear system of size 1089 x 1089 (PETSc Krylov solver).
> >>> 40.490263582 (**)
> >>>
> >>> Problem: The last two floats, tagged by (*) and (**), should be the
> >>> same: they are not.
> >>>
> >>> Code snippet:
> >>>
> >>> --
> >>>
> >>>
> >>> from dolfin import *
> >>> mesh = UnitSquareMesh(16,16)
> >>> V = FunctionSpace(mesh, 'CG', 2)
> >>>
> >>> f = Expression("x[0]*x[0] + 2*x[1]*x[1]")
> >>> g = project(f, V)
> >>> print g.vector().norm("l2")
> >>>
> >>> #f2 = Expression("x[0]*x[0] + 2*x[1]*x[1]", degree=2)
> >>> #g2 = project(f2, V)
> >>> #print g2.vector().norm("l2")
> >>>
> >>>
> >>> --
> >>>
> >>> ** Affects: dolfin
> >>>       Importance: Undecided
> >>>           Status: New
> >>>
> >
>
> --
> You received this bug notification because you are a member of DOLFIN
> Core Team, which is subscribed to DOLFIN.
> https://bugs.launchpad.net/bugs/1153508
>
> Title:
>   Strange results in JIT compilation
>
> Status in DOLFIN:
>   Confirmed
>
> Bug description:
>   There seems to be something seriously wrong with either DOLFIN-FFC jit
>   compilation or caching or instant.
>
>   To reproduce, for instance consider the following code snippet and do
>   the following
>
>   (1): Run instant-clean
>
>   (2): Run script unmodified.
>
>   Output is:
>
>   Calling FFC just-in-time (JIT) compiler, this may take some time.
>   Calling DOLFIN just-in-time (JIT) compiler, this may take some time.
>   Calling FFC just-in-time (JIT) compiler, this may take some time.
>   Calling FFC just-in-time (JIT) compiler, this may take some time.
>   Solving linear system of size 1089 x 1089 (PETSc Krylov solver).
>   40.4757877531
>
>   (3) Uncomment commented lines and run.
>
>   Output is:
>
>   Solving linear system of size 1089 x 1089 (PETSc Krylov solver).
>   40.4757877531
>   Solving linear system of size 1089 x 1089 (PETSc Krylov solver).
>   40.4757877531 (*)
>
>   (4) Run instant-clean, comment out lines defining f, g, and 1st print.
>   Run.
>
>   Output is
>   Calling FFC just-in-time (JIT) compiler, this may take some time.
>   Calling DOLFIN just-in-time (JIT) compiler, this may take some time.
>   Calling FFC just-in-time (JIT) compiler, this may take some time.
>   Calling FFC just-in-time (JIT) compiler, this may take some time.
>   Solving linear system of size 1089 x 1089 (PETSc Krylov solver).
>   40.490263582 (**)
>
>   Problem: The last two floats, tagged by (*) and (**), should be the
>   same: they are not.
>
>   Code snippet:
>
>   --
>
>
>   from dolfin import *
>   mesh = UnitSquareMesh(16,16)
>   V = FunctionSpace(mesh, 'CG', 2)
>
>   f = Expression("x[0]*x[0] + 2*x[1]*x[1]")
>   g = project(f, V)
>   print g.vector().norm("l2")
>
>   #f2 = Expression("x[0]*x[0] + 2*x[1]*x[1]", degree=2)
>   #g2 = project(f2, V)
>   #print g2.vector().norm("l2")
>
>
>   --
>
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