fiat team mailing list archive

["Garth N. Wells" <g.n.wells@xxxxxxxxxx>]

Hi Rob,

Should line 97 of polynomial.py  be 

 xs_dim = map( shapes.pt_maps[ myshape ][ d ]( e ) , xs )

instead of 

 xs_dim = map( shapes.pt_maps[ myshape ][ d ][ e ] , xs )?

When I make this change, the below test program works. Without making
the change, I get the "unsubscriptable object" error message (also
below).

Garth

# Test program
#
# Python modules
import sys

# FIAT modules
from FIAT.shapes import *
from FIAT.Lagrange import Lagrange
from FIAT.quadrature import *

q = make_quadrature(shapes.LINE, 1)
t = Lagrange(TRIANGLE, 1).function_space().trace_tabulate(1, 0,
q.get_points())
print t


Traceback (most recent call last):
  File "test.py", line 13, in ?
    t = Lagrange(TRIANGLE, 1).function_space().trace_tabulate(1, 0,
q.get_points())
  File "/usr/lib/python2.4/site-packages/FIAT/polynomial.py", line 97,
in trace_tabulate
    xs_dim = map( shapes.pt_maps[ myshape ][ d ][ e ] , xs )
TypeError: unsubscriptable object


On Thu, 2006-04-27 at 10:41 -0500, Robert C. Kirby wrote:
> Garth,
> I'm not sure why you get an unsubscriptable object, but
> there are at least two problems in how you are using/understanding  
> the function.
> 
> 1.) First, it's not necessarily a quadrature rule that you're  
> tabulating at, but any set of points.  This has no impact on your  
> problem.
> 2.) Second, you have to provide the one-dimensional points at which  
> to tabulate since you said "d=1".  So if you wanted the Gauss points  
> along edge number 1, you would compute the Gauss points on the  
> reference line (q=quadrature.make_quadrature(shapes.LINE,degree)),  
> and then call trace_tabulate( d , 1 , q.get_points() ).   
> Trace_tabulate maps the points on the reference line to the  
> appropriate edge.
> 
> Let me know if there is still a problem.
> 
> Rob
> 
> On Apr 27, 2006, at 10:14 AM, Garth N. Wells wrote:
> 
> > Hi Rob,
> >
> > I'm playing around with calling trace_tabulate from FFC. Before I
> > elaborate my problem, let me check that I'm on the right path with
> > trace_tabulate.
> >
> > In a nutshell, does trace_tabulate return the basis functions on
> > edge/face e of dimension d (d=2->face, d=1->edge, etc) given a
> > quadrature scheme of dimension d for an element of dimension n? (e  
> > and d
> > being the same as used in the trace_tabulate argument list).
> >
> > When I try in FFC
> >
> >   junk =  self.element.function_space().trace_tabulate(1, 1,  points)
> >
> > where
> >   self.element.function_space() is of type
> > FIAT.polynomial.ScalarPolynomialSet
> > and
> >   points = [(0.0)]
> >
> > I get the error
> >
> >   *** unsubscriptable object
> >
> > Garth
> >
> >