dolfin team mailing list archive

[kent-and@xxxxxxxxx]

> On Tuesday 23 December 2008 11:16:19 Kent Andre wrote:
>> Hi, it seems that when I
>> have one GenericVector and one Vector I can
>> only add these together, not subtract them.
>>
>> I'd like to subtract them as well :)
>>
>> The following illustrate the problem:
>>
>>
>> from dolfin import *
>>
>>
>> mesh = UnitSquare(12,12)
>> V = FunctionSpace(mesh, "CG", 1)
>> v = TestFunction(V)
>> f = Function(V)
>> s = Constant(mesh, 1.0)
>>
>> L = s*v*dx
>>
>> b = assemble(L)
>>
>>
>> x = b + f.vector()
>> x = b - f.vector()
>
> This error was caused by a missing __rsub__ implementation, and should be
> fixed now.
>
> The strange thing is that the function was implemented but it returned
> NotImplemented. This give me a feeling that when I implemented the LA
> interface I excluded it by design. But I cannot think of any case where
> the
> use of __rsub__ could cause any trouble.
>
> Johan
>

Thanks!

Anyway, it should be the same as radd, shouldn't it?

Kent