Re: ReplaceAll strange behaviour
- To: mathgroup at smc.vnet.net
- Subject: [mg9340] Re: ReplaceAll strange behaviour
- From: Hein Hundal <junkmail at vicon.net>
- Date: Sat, 1 Nov 1997 03:33:26 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Gadi Oron wrote:
>
> Hello,
>
> Can anybody enlighten me with the following strange result?
>
> In:= {{1,2},{2,3}} /. {x_ /; Head[x]!=List,y_}:> Circle[{x,y},1] Out:=
> {{1,2},{2,3}}
> [snip]
The problem occurs because (Integer != List) does not return True.
Instead you want to uses =!=. The following expression works on my
machine w/ Mathematica 3.0.
{{1,2},{2,3}} /. {x_ /; Head[x]=!=List,y_}:> Circle[{x,y},1]
Cheers,
Hein
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