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Re: local symbols inside Module

• To: mathgroup at smc.vnet.net
• Subject: [mg55988] Re: [mg55950] local symbols inside Module
• From: "Wolf, Hartmut" <Hartmut.Wolf at t-systems.com>
• Date: Wed, 13 Apr 2005 01:10:12 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

 

>-----Original Message-----
>From: OT [mailto:montoz at iol.it] 
To: mathgroup at smc.vnet.net
>Sent: Tuesday, April 12, 2005 11:26 AM
>To: mathgroup at smc.vnet.net
>Subject: [mg55988] [mg55950] local symbols inside Module
>
>Hi all, I have some problems in working with local variables inside 
>Module: I wrote this function:
>
>RealLinearCombination[v_List]:=Module[{d,coeffs},
>d=Legth[v];
>
>coeff=Table[ToExpression["c"<>ToString[k]],{k,d}];
>
>coeffs=coeffs/.Solve[eqns,coeffs];
>
>...
>...
>
>]
>
>The function works, but has a big limitation: the elements of the list 
>coeffs are not local symbols!
>
>Since the elements of the list coeffs are not local variables, 
>if I run 
>my function when I have already initialized a symbol like 
>c3=Pi, say, I 
>get an error because mathematica tries to execute 
>Solve[eqns,{c1,c2,Pi,c4,...,cd}] since c3 has been already initialized 
>as a number.
>
>So, my question is: how can I initialize a local list of symbols
>{c1,...cd} inside a Module, when d is an argument supplied to 
>the Module 
>itself?
>
>Thanks for every answer!
>
>

Look up Help Unique, this generates unique symbols e.g. as you may use
for coeffs.

--
Hartmut Wolf