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Re: Re: integral transform definition

  • To: mathgroup at smc.vnet.net
  • Subject: [mg33195] Re: [mg33154] Re: integral transform definition
  • From: Roberto Brambilla <rlbrambilla at cesi.it>
  • Date: Thu, 7 Mar 2002 02:24:03 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

Hi Jeans, hi all, 

you are right. In writing the email I made a sintax error, but in the notebook
I had the correct definition (this is only a simple demonstrative example):

     Kern[a_, p_, q_]:=Sin[a p q].

The transform definition is 

(A)  MyTransf[n_, func_, s_, t_] := Integrate[Kern[n, t, s] func[s], {s, 0,
2 Pi}] 

The 'dummy' variable of integration, s, is imposed as an argument in the
case the 
integral is not explicitly solved (and I want see it in the echo on the
screen). 
I try (A) with a function depending on some parameters list w, es. foo[w,t]
You suggest a pure function usage 

 (B)  MyTransf[m, foo[w, #]&, s, t]  (*a function of t*)

Applying again the transform I have to integrate in t so that

      MyTransf[n, MyTransf[m, foo[w, #]&, s, #]&, t, x] (*a function of x*)

a not intuitive formula. I would prefer a new definition so that I can have
instead of (B) 

(B')  newMyTransf[m, foo[w, s], s, t]

avoiding pure function since in this case applying the successive transform
I can write 

      newMyTransf[n, newMyTransf[m, foo[w, s], s, t], t, x]

where the integration variables clearly appear coupled.
How can I modify definition (A) to allow an usage like (B') ? 

More generally this problem happens every time a function is called as an
argument of another function
(and so on) and we want to maintain flexibility in renaming the independent
variables.

Best regards
Roberto


Roberto Brambilla
CESI
Via Rubattino 54
20134 Milano
tel +39.02.2125.5875
fax +39.02.2125.5492
rlbrambilla at cesi.it



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