Re: Replace list element based on a condition how to
- To: mathgroup at smc.vnet.net
 - Subject: [mg106658] Re: Replace list element based on a condition how to
 - From: Bill Rowe <readnews at sbcglobal.net>
 - Date: Wed, 20 Jan 2010 06:49:27 -0500 (EST)
 
On 1/19/10 at 5:13 AM, canopus56 at yahoo.com (Canopus56) wrote:
>Q1. Is there a way to replace a list based on a condition?
>I have a list of integers -
>lst1 = {18, 19, 20, 21, 22, 23, 0, 1, 2, 3}
>that I would like to replace with the following rule -
>fncHourFix[h_] := If[(h - 6) < 0, h - 6 + 24, h - 6];
>but the replace function -
>lst2 = lst1 /. {i_} :> fncHourFix[{i}]
>- bombs out.
>I've tried several variants. Any pointers would be appreciated.
The problem is the pattern {i_}. Change this to i_Integer and
things work fine. That is
In[4]:= lst1 /. n_Integer :> fncHourFix[n]
Out[4]= {12,13,14,15,16,17,18,19,20,21}