RE: Variables[] in general expressions
- To: mathgroup at smc.vnet.net
- Subject: [mg20048] RE: [mg20024] Variables[] in general expressions
- From: "Ersek, Ted R" <ErsekTR at navair.navy.mil>
- Date: Sat, 25 Sep 1999 18:46:10 -0400
- Sender: owner-wri-mathgroup at wolfram.com
Ken Rice wrote:
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Is there any way of extracting a list of variables from a general
expression, not just a polynomial? I want something which will do,
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The code below should work nicely.
In[1]:=
AllVariables[expr_]:=Union[Cases[expr,_Symbol?(Not[NumericQ[#]]&),{1,Infinit
y}]]
In[2]:=
AllVariables[ y+Exp[y+x *y]+Sqrt[y]+Pi/2 ]
Out[2]=
{x,y}
Note, Cases can do much more than this.
I provide many examples at the web page below.
-----------------------------
Regards,
Ted Ersek
For Mathematica tips, tricks see
http://www.dot.net.au/~elisha/ersek/Tricks.html