Re: Getting numerical values from a closed form integration?

Thank you, Francois and Bill, both solutions work fine.  I'm still getting
my head around the concept of an "expression" as a type.  Integer, Float,
Complex, List, String... they're all very well, but I'm still very unsure
about "expression".  (Also still very unsure about lots of other things,
too).

cheers,
Alasdair

On 7/12/07, Bill Page <[email protected]> wrote:
>
> On 12 Jul 2007 12:58:49 +0200, Francois Maltey wrote:
> > > For example:
> > >
> > > integrate(sin(2*x),x=-%pi/3..4*%pi/7)
> > >
> > > The answer is in closed form, but I can't convert it to a float.  At
> least:
> > >
> > > integrate(sin(2*x),x=-%pi/3..4*%pi/7)::Float
> >
> > Try
> >
> > numeric integrate(sin(2*x),x=-%pi/3..4*%pi/7)
> >
> > I get 0.20048...
>
> I think that is a good solution. But one thing to keep in mind perhaps
> for later use is that often when
>
>   integrate(sin(2*x),x=-%pi/3..4*%pi/7)::Float
>
> fails, the following similar coercion will work
>
>   integrate(sin(2*x),x=-%pi/3..4*%pi/7)::Expression Float
>
> I think the issue is a certain weakness in Axiom's system of coercions.
>
> > Don't you find a strong typed CAS is nice for mathematics
> > even if the final user is a little bored...
> >
>
> Francois, could you expand this comment? I am not sure what point you
> are making when you say "bored". :-)
>
> Regards,
> Bill Page.
>

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