ffc team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

Yes, it should be supported for vector-valued Functions, but it's not
supported for general expressions:

	  mean(f)       # ok
	  mean(f + g)   # not ok
	  mean(grad(f)) # not ok	  

How have you used it in the form? If it's just mean(f) where f is a
vector-valued function, then it should work.

/Anders


On Wed, Dec 21, 2005 at 01:28:46PM +0100, Johan Hoffman wrote:
> Anders,
> 
> Is the mean() function in FFC not supported for vector functions? Or am I
> missing something?
> 
> /Johan
> 
> 
> 
> 
> na41>ffc Poisson.form
> This is FFC, the FEniCS Form Compiler, version 0.2.4.
> For further information, go to http://www/fenics.org/ffc/.
> Parsing Poisson.form
> Output written to Poisson.py
> 
> Compiling form: (dXa0/dx0)(dXa1/dx0) | ((d/dXa0)vi0)*((d/dXa1)vi1)*dX +
> (dXa0/dx 1)(dXa1/dx1) | ((d/dXa0)vi0)*((d/dXa1)vi1)*dX
> Finite element of test space:  Lagrange finite element of degree 1 on a
> Triangle  with 1 components
> Finite element of trial space: Lagrange finite element of degree 1 on a
> Triangle  with 1 components
> Compiling tensor representation for interior
> Hard signatures match for terms 0 and 1, factorizing
> Computing reference tensor, this may take some time...
> ................................................................................
> Reference tensor computed in 0.00739 seconds.
> Compiling tensor representation for boundary
> Hard signatures match for terms 0 and 1, factorizing
> 
> Compiling form: w0_a0 | vi0*va0*dX
> Finite element of test space:  Lagrange finite element of degree 1 on a
> Triangle  with 1 components
> Finite elements for functions: [Lagrange finite element of degree 1 on a
> Triangl e with 1 components]
> Compiling tensor representation for interior
> Computing reference tensor, this may take some time...
> ................................................................................
> Reference tensor computed in 0.012 seconds.
> Compiling tensor representation for boundary
> 
> Generating output for DOLFIN
> Output written to Poisson.h
> na41>cd
> na41>cd local/dolfin/src/modules/navierstokes/dolfin/
> na41>ffc NSEContinuity.form
> This is FFC, the FEniCS Form Compiler, version 0.2.4.
> For further information, go to http://www/fenics.org/ffc/.
> Parsing NSEContinuity.form
> Output written to NSEContinuity.py
> 
> *** Error at w0_a69 | va69[a7]
> *** Mean values are only supported for Functions.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> # Copyright (c) 2005 Johan Hoffman (hoffman@xxxxxxxxxxxx)
> # Licensed under the GNU GPL Version 2
> #
> # The contiuity equation for the incompressible
> # Navier-Stokes equations using cG(1)cG(1)
> #
> # Compile this form with FFC: ffc NSEContinuity.form.
> 
> name = "NSEContinuity"
> #scalar = FiniteElement("Lagrange", "triangle", 1)
> #vector = FiniteElement("Vector Lagrange", "triangle", 1)
> #constant_scalar = FiniteElement("Discontinuous Lagrange", "triangle", 0)
> #constant_vector = FiniteElement("Discontinuous vector Lagrange",
> "triangle", 0)
> scalar = FiniteElement("Lagrange", "tetrahedron", 1)
> vector = FiniteElement("Vector Lagrange", "tetrahedron", 1)
> #constant_vector = FiniteElement("Discontinuous vector Lagrange",
> "tetrahedron", 0)
> constant_scalar = FiniteElement("Discontinuous Lagrange", "tetrahedron", 0)
> 
> q            = BasisFunction(scalar)
> p            = BasisFunction(scalar)
> #um           = Function(constant_vector)
> uc           = Function(vector)
> f            = Function(vector)
> 
> delta1       = Function(constant_scalar)        # stabilization
> 
> i0 = Index()
> i1 = Index()
> i2 = Index()
> 
> a = delta1*dot(grad(q), grad(p))*dx;
> L = delta1*dot(grad(q), f)*dx - q*uc[i0].dx(i0)*dx -
> delta1*q.dx(i0)*mean(uc[i1])*uc[i0].dx(i1)*dx
> #L = delta1*dot(grad(q), f)*dx - q*uc[i0].dx(i0)*dx -
> delta1*q.dx(i0)*um[i1]*uc[i0].dx(i1)*dx
> 
> #a = delta1*q.dx(i0)*p.dx(i0)*dx
> #L = delta1*q.dx(i0)*f[i0]*dx - delta1*q.dx(i0)*uc[i1]*uc[i0].dx(i1)*dx -
> q*uc[i0].dx(i0)*dx
> 
> 
> 
> 
> 
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> 

-- 
Anders Logg
Research Assistant Professor
Toyota Technological Institute at Chicago
http://www.tti-c.org/logg/