I don't know if Nedelec elements have been tested with FFC. Start with 
something simpler.

Garth

Evan Lezar wrote:
> Hi there
> 
> I have implemented a simple test case and have attached it.  In writing 
> it, I made a discovery.  The vector that is passed as a list of 
> coefficients to the function constructor (h_e in the example) needs to 
> be a multidimensional array with the first dimension 1.  If one swaps 
> the dimensions (1, num_dofs) on line 26, then the test crashes when 
> field.eval is called.
> 
> However, according to me, the eval function does not work as expected.  
> Since the list of coefficients is zero and the function should be 
> evaluated as the weighted sum of the basis functions using the 
> coefficients as weights, this means that the function value returned for 
> any position within the mesh should be zero.  However, the first 
> component (let us say x) of H is always -1 and the second component is 
> not changed and retains the value that was assigned to it before the 
> call to evaluate.
> 
> I will see about getting a C++ test up and running to test the same thing.
> 
> Please let me know if there are any other questions.
> Evan
> 
> On Thu, Aug 21, 2008 at 6:06 PM, Evan Lezar <[EMAIL PROTECTED] 
> <mailto:[EMAIL PROTECTED]>> wrote:
> 
> 
> 
>     On Thu, Aug 21, 2008 at 5:49 PM, Ola Skavhaug <[EMAIL PROTECTED]
>     <mailto:[EMAIL PROTECTED]>> wrote:
> 
>         Evan Lezar skrev den 21/08-2008 følgende:
>          > Thanks for the speedy replies from all of you.
>          >
>          > Firstly platform information
>          >
>          > I am running ubuntu hardy, gcc version 4.2.3, swig 1.3.33,
>         python 2.5 with
>          > release versions of numpy and scipy.  I am building dolfin
>         directly from
>          > source with mpi, but have not enabled petsc or any of the
>         other optional
>          > packages.
>          >
>          > What other information do you require?
>          >
>          > In terms of my specific problem, see the following code snippet:
>          >
>          > from dolfin import *
>          > import numpy as N
>          >
>          > mesh = UnitSquare(4,4)
>          > element = FiniteElement("Nedelec", "triangle", 0)
>          >
>          > ### Code to assemble system matrices and solve an eigenvalue
>         problem
>          >
>          > # h_e is an array of coefficients associated with the degrees
>         of freedom in
>          > the system obtained from the eigenvectors V
>          > h_e = V[:,sorted_index[first_index]]
>          >
>          > # setup a function to evaluate - the solution of the magnetic
>         field
>          > field = Function(element, self.mesh, h_e)
>          >
>          > # arbitrary point to evaluate the field
>          > points = N.array((0.5,0.25))
>          > # array to store the field value at a point
>          > H = N.array((0.0,0.0))
>          >
>          > print "pre_eval"
>          >
>          > #evaluate the function
>          > field.eval(H, points)
>          >
>          > # Ouput the field at the point
>          > print "H",
>          > print H
>          >
>          >
>          > When I run this code, I get the following output:
>          >
>          > pre_eval
>          > [labby:25160] *** Process received signal ***
>          > [labby:25160] Signal: Segmentation fault (11)
>          > [labby:25160] Signal code: Address not mapped (1)
>          > [labby:25160] Failing at address: 0xde8f58ec
>          > [labby:25160] [ 0] [0xb7f81440]
>          > [labby:25160] [ 1] /usr/bin/python(PyEval_EvalCodeEx+0x6e7)
>         [0x80cb0d7]
>          > [labby:25160] [ 2] /usr/bin/python(PyEval_EvalFrameEx+0x565e)
>         [0x80c92de]
>          > [labby:25160] [ 3] /usr/bin/python(PyEval_EvalCodeEx+0x6e7)
>         [0x80cb0d7]
>          > [labby:25160] [ 4] /usr/bin/python(PyEval_EvalFrameEx+0x565e)
>         [0x80c92de]
>          > [labby:25160] [ 5] /usr/bin/python(PyEval_EvalCodeEx+0x6e7)
>         [0x80cb0d7]
>          > [labby:25160] [ 6] /usr/bin/python(PyEval_EvalCode+0x57)
>         [0x80cb227]
>          > [labby:25160] [ 7] /usr/bin/python(PyRun_FileExFlags+0xf8)
>         [0x80ea6d8]
>          > [labby:25160] [ 8] /usr/bin/python(PyRun_SimpleFileExFlags+0x199)
>          > [0x80ea979]
>          > [labby:25160] [ 9] /usr/bin/python(Py_Main+0xa35) [0x8059335]
>          > [labby:25160] [10] /usr/bin/python(main+0x22) [0x80587f2]
>          > [labby:25160] [11]
>         /lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe0)
>          > [0xb7de8450]
>          > [labby:25160] [12] /usr/bin/python [0x8058761]
>          > [labby:25160] *** End of error message ***
>          >
>          > With a previous build I have gotten different output and was
>         able to
>          > actually display the contents of H, but it would shill crash
>         once the method
>          > where the code was being run was terminated.  I logged a bug
>         against it at
>          > http://www.fenics.org/cgi-bin/bugzilla/show_bug.cgi?id=55
>          >
>          > As I said in my mail, I see myself using fenics in the long
>         run and would
>          > like to get involved as much as possible, but some pointers
>         as to where to
>          > start would be much apprciated.
> 
>         Have you implemented the C++ version as well, such that you know
>         that what you
>         do is correct? 
> 
> 
>         Clearly, we are not catching what's going wrong here (missing
>         check of some
>         sort).
> 
>         My guess is that the error occurs in
>         site-packages/dolfin/function.py, when
>         the Function is initialized. Can you boil down the example to a
>         shorter script
>         and post it to this list? I'll have a look at it.
> 
>         Ola
> 
> 
>     Hi
> 
>     I have not implemented a C++ version, but I will look into it - I am
>     a little more comfortable with python at the moment, but I suppose I
>     need to jump into the deep end :)
> 
>     I will write a simple example script and then attach that.
> 
>     Evan
> 
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> DOLFIN-dev mailing list
> [email protected]
> http://www.fenics.org/mailman/listinfo/dolfin-dev

_______________________________________________
DOLFIN-dev mailing list
[email protected]
http://www.fenics.org/mailman/listinfo/dolfin-dev

Reply via email to