Re: Replacement question
- To: mathgroup at smc.vnet.net
- Subject: [mg74193] Re: Replacement question
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Wed, 14 Mar 2007 03:44:35 -0500 (EST)
- Organization: The Open University, Milton Keynes, UK
- References: <et5nnh$jhk$1@smc.vnet.net>
Brian Beckage wrote:
> I apologize for this very basic question. I understand how to use /.
> {} to replace a variable with a more complex expression, e.g., x->
> y+z. Can one move in the opposite direction to replace all
> occurrences of y+z with x? myExpression/.{y+z->x} does not seem to
> work.
That works:
In[1]:=
expr = z + y + a + b + 2*c + 2*d;
expr /. y + z -> x
Out[2]=
a + b + 2 c + 2 d + x
Now, could you, please, post an example of an expression for which the
replacement rule does not work?
Regards,
Jean-Marc