Re: Variables[] in general expressions
- To: mathgroup at smc.vnet.net
- Subject: [mg20057] Re: [mg20024] Variables[] in general expressions
- From: BobHanlon at aol.com
- Date: Wed, 29 Sep 1999 03:33:21 -0400
- Sender: owner-wri-mathgroup at wolfram.com
Kenneth,
expr = y + Sin[n*Pi*x] * Exp[-x*z];
If you want all Symbols
Union[Cases[expr, _Symbol, Infinity]]
{\[ExponentialE], n, \[Pi], x, y, z}
If only variables,
Union[Cases[expr, _?(MemberQ[Names["`*"], ToString[#]] &), Infinity]]
{n, x, y, z}
Bob Hanlon
In a message dated 9/25/1999 5:54:25 AM, kmr1004 at hermes.cam.ac.uk writes:
>Is there any way of extracting a list of variables from a general
>expression, not just a polynomial? I want something which will do,
>e.g.
>
>In AllVariables[y + Exp[x]]
>Out {y,x}
>