Re: substitution within a substitution list
- To: mathgroup at smc.vnet.net
- Subject: [mg88596] Re: [mg88551] substitution within a substitution list
- From: DrMajorBob <drmajorbob at att.net>
- Date: Fri, 9 May 2008 03:26:07 -0400 (EDT)
- References: <26620531.1210237667995.JavaMail.root@m08>
- Reply-to: drmajorbob at longhorns.com
subs = {a -> 1, b -> 2, c -> 2};
subs /. Rule[b, _] -> Rule[b, 20]
{a -> 1, b -> 20, c -> 2}
subs /. Rule[b, x_] -> Rule[b, 10 x]
{a -> 1, b -> 20, c -> 2}
ReplacePart[subs, {2, 2} -> 20]
{a -> 1, b -> 20, c -> 2}
etc.
Bobby
On Thu, 08 May 2008 03:13:41 -0500, Bipin <bipin.caz at googlemail.com> wrote:
> HI,
>
> I'm trying to find a way of changing the substitution values within a
> substitution list.
>
> For example, if I have the following substitution list:-
>
> subs = {a->1, b->2, c->2}
>
> I want to programmatically replace the value associated with 'b' from
> 2 to 20, ie ending up with
>
> subs = {a->1, b->20, c->2}
>
> Does anyone know of a mathematica function for doing this?
>
> Bipin.
>
>
--
DrMajorBob at longhorns.com