Re: A simple swap function
- To: mathgroup at smc.vnet.net
- Subject: [mg2165] Re: A simple swap function
- From: ianc (Ian Collier)
- Date: Wed, 11 Oct 1995 01:58:41 -0400
- Organization: Wolfram Research, Inc.
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
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Ian Collier
Technical Sales Support
Wolfram Research, Inc.
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tel:(217)-398-0700 fax:(217)-398-0747 ianc at wri.com
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