Services & ResourcesWolfram ForumsMathGroup Archive

[Date Index] [Thread Index] [Author Index]

Re: Substitute variable name for value (reverse of simplification)

• To: mathgroup at smc.vnet.net
• Subject: [mg128092] Re: Substitute variable name for value (reverse of simplification)
• From: Bob Hanlon <hanlonr357 at gmail.com>
• Date: Sat, 15 Sep 2012 03:37:19 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• Delivered-to: l-mathgroup@wolfram.com
• Delivered-to: mathgroup-newout@smc.vnet.net
• Delivered-to: mathgroup-newsend@smc.vnet.net
• References: <20120914042155.1296B676B@smc.vnet.net>

Clear[var1]

var2 = 189*a^3;

Simplify[var2, var1 == 3*a]

7 var1^3

var2 /. a -> var1/3

7 var1^3

var2 /. Solve[var1 == 3*a, a][[1]]

7 var1^3


Bob Hanlon


On Fri, Sep 14, 2012 at 12:21 AM,  <mr.hagak at gmail.com> wrote:
> I need this to happen:
> var1 = 3*a
> var2 = 189*a^3
> output = 7*var1^3
>
> I can do it in very simple and specific equations doing something like
>
> substituteName2[var_,exp_] := Module[ {},
>         Solve[p==exp&&"test"==var,{p},{a}]
> ];
> test=3*a;
> substituteName2[test,7*test^3]
>
> But i need a WAY more general form of that...any ideas?
>

• References:
  • Substitute variable name for value (reverse of simplification)
    • From: mr.hagak@gmail.com