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Re: define a function with variable coefficients

  • To: mathgroup at smc.vnet.net
  • Subject: [mg106041] Re: define a function with variable coefficients
  • From: "Norbert P." <bertapozar at gmail.com>
  • Date: Thu, 31 Dec 2009 03:14:47 -0500 (EST)
  • References: <hhf5mi$gqi$1@smc.vnet.net>

On Dec 30, 1:14 am, Andong He <azh... at psu.edu> wrote:
> Thank you Daniel, your response is helpful.
> But what I want is Power[z,j] instead of Superscript[z,j], because I wann=
a raise z to power 1,2,..., n, and it doesn't work!
> Again I get terms like a_(1+n)[t] and a_(2+n)[t]. So confusing!
>
> Where did I make a mistake?

As Daniel said, a_j[t] is interpreted as Pattern[a, Blank[j]][t]
because _ (underscore) has a build-in meaning in Mathematica (look up
Blank). It can't be a part of a symbol name as in other programming
languages. That's probably what's causing your problems. Use Subscript
[a,j][t] instead. As for the power, ^ will work just fine, but you
said you wanted a superscript ;)

Norbert



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