Re: [Maxima-discuss] strange behavior matchdeclare/defrule

[Richard F. <fa...@be...>]

I haven't looked at your program in detail, but  it is highly
unlikely that you should be doing a matchdeclare inside a function.

It should be used on the top level, and not used to declare local variables.

RJF


On 4/21/2014 1:54 AM, Dimiter Prodanov wrote:
> Dear all,
>
> I am truing to implement a Fourier trnasform package in Maxima
>
> I came across the follwing problem. I can't make this code to work as 
> I expect
>
> ( "modulation by exp ",
> matchdeclare( [t, f], atom, V, lambda([u], not atom(u)), it, complexp ),
>     defrule (simftexpmod, FT (V*exp(it)), ftmodsim2 (V, exp(it), t )),
>     defrule (simftexpmod, IFT (V*exp(it)), iftmodsim2 (V, exp(it), f )),
>
>     ftmodsim2(V, fn, s):=opmodsimp2(V, fn, s, FT),
>     iftmodsim2(V, fn, s):=opmodsimp2(V, fn, s, IFT),
>
>     opmodsimp2(V, fn, s, OP ):= block( [ %B, res ],
>         matchdeclare( %B , lambda([x], freeof(s, x) ), s, atom, g, 
> symbolp),
>         defmatch (opexp,  exp(%B*s), s),
>         res: opexp(fn, s),
>         if (res#false) then (
>             "print (%B)",
>             return ([OP(V), 1, [%B, exp]])
>         )
>         else return (OP(V*fn))
>     )
> )$
>
> complexp (u) := not atom(u) and not listp(u) and not freeof(%i, u)$
>
> Output:
>
>  correct:
> >> ftmodsim2(u(t), exp(%i*a*t), t);
> >> [FT(u(t)),1,[%i*a,exp]]
>
> wrong:
> >> simftexpmod(FT(u(t)*exp(%i*t)));
> >> false
>
> I had similar problems also for other rules  where the solution was 
> either to unnecessary broaden the scope or to define global variables 
> with unique names and thus limit the scope artificially.
>
> best regards,
>
> Dimiter
>
>
>
>
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