Re: A simple swap function
- Subject: [mg2165] Re: A simple swap function
- From: ianc (Ian Collier)
- Date: Wed, 11 Oct 1995 05:58:41 GMT
- Approved: usenet@wri.com
- Distribution: local
- Newsgroups: wri.mathgroup
- Organization: Wolfram Research, Inc.
- Sender: daemon at wri.com ( )
In article <44qj8g$s22 at ralph.vnet.net>, valentin at wam.umd.edu (William F.
Campbell) wrote:
> I think I must be missing something straightforward. I want a function
> to swap the values of 2 lists. I defined ab={a,b}, and ba={b,a}, and
> swap[v1_,v2_]:=Module[{temp=v1},v1=v2;v2=temp;], and I get an Iteration
> limit exceeded error. When I look at ab, it looks like {Hold[a],Hold[b]}
> (or maybe {Hold[b],Hold[a], I don't remember), and ba looks opposite. When
> I tried to use the same function on numbers, it didn't work either. What's
> wrong with what I'm doing, and how can I do what I want to do?
Well, in this example you can simply use the Reverse function to
swap your values:
In[9]:=
ab = {a,b}
Out[9]=
{a, b}
In[10]:=
ba = Reverse[ ab ]
Out[10]=
{b, a}
I hope this helps.
--Ian
-----------------------------------------------------------
Ian Collier
Technical Sales Support
Wolfram Research, Inc.
-----------------------------------------------------------
tel:(217)-398-0700 fax:(217)-398-0747 ianc at wri.com
Wolfram Research Home Page: http://www.wri.com/
-----------------------------------------------------------