ffc team mailing list archive

["Martin Sandve Alnæs" <martinal@xxxxxxxxx>]

2008/6/27 Kristian Oelgaard <k.b.oelgaard@xxxxxxxxxx>:
> Quoting "Garth N. Wells" <gnw20@xxxxxxxxx>:
>
>>
>>
>> Garth N. Wells wrote:
>> > I'm observing some strange behaviour when using the inverse of a scalar.
>> > Running FFC on
>> >
>> >    P1   = FiniteElement("Lagrange", "triangle", 1)
>> >    v    = TestFunction(P1)
>> >    temp = Constant("triangle")
>> >    Tp   = 10
>> >    L    = v*temp*(1*Tp)*dx
>> >
>> > is fine, but running
>> >
>> >    P1   = FiniteElement("Lagrange", "triangle", 1)
>> >    v    = TestFunction(P1)
>> >    temp = Constant("triangle")
>> >    Tp   = 10
>> >    L    = v*temp*(1/Tp)*dx
>> >
>>
>> It looks like 1/Tp is a problem, and 1.0/Tp is OK.
>
> It's because 1/10 = 0 and 1.0/10 or 1/10.0 = 0.1 in Python...

Yes. Note that this will change in python 3.0, with // meaning integer
division and / always meaning float division.

-- 
Martin