Re: How to manipulate globals in a function?
- To: mathgroup at smc.vnet.net
- Subject: [mg73715] Re: [mg73665] How to manipulate globals in a function?
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Sun, 25 Feb 2007 04:39:35 -0500 (EST)
- Reply-to: hanlonr at cox.net
Use HoldFirst to make the first argument to Moo a Symbol vice a List.
ClearAll[Moo];
SetAttributes[Moo,{HoldFirst}];
Moo[A_Symbol,i_Integer?Positive]:=A[[i]]=7;
A=Table[Random[],{5}];
Moo[A,1];
Verifying that A has been modified:
A
{7,0.359118,0.568554,0.0996048,0.856377}
Bob Hanlon
---- davisjf at gmail.com wrote:
> I am trying to write code to manipulate a global array in a function.
> How do something like this:
>
> Moo [A_List, i_Integer] :=
>
> A[[i]] = 7;
>
> Moo[A, 1]
>
> This fails. But, if I do this without a funciton it works.
>
> i=1
> A[[i]] = 7
>
> JD