How to graph an expression involving sum?

I would suggest defining a function in expanded form then compiling it:

     myfun(x) := ( mode_declare(x,float), ''(ev(coefseries,nouns)) ) $
         (that's two single-quotes, not one double-quote)
     compile(myfun)$
     plot2d( myfun, ... )

It would also be possible to convert the sum into a loop and the a[i]= into
a[i]:, but that is more work for the same result.

              -s

On Thu, Sep 8, 2011 at 16:36, dlakelan <dlakelan at street-artists.org> wrote:

> On 09/05/2011 01:08 PM, dlakelan wrote:
> > I have a solution of a differential equation in terms of some fourier
> > series. I would like to graph one of the spatially varying coefficients,
> > so I tried something like:
> ....
> > What's the right way to go about graphing something like this?
>
> I should mention that I can do ev(coefseries,nouns) to convert the "sum"
> noun into an enormous + expression, but this slows things down
> considerably. If I am trying to simply do numerical calculations with
> the expression, is there a faster way to get the evaluation than to
> carry around a big symbolic expression? Is something like a lambda
> expression like this the way to go?
>
> lambda([x],ev(coefseries,avals,nouns,z=x,numer))
>
> or does this just internally create and throw away the enormous +
> expression?
>
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