Re: 2D pattern matching
- To: mathgroup at smc.vnet.net
- Subject: [mg77252] Re: 2D pattern matching
- From: dh <dh at metrohm.ch>
- Date: Wed, 6 Jun 2007 06:57:18 -0400 (EDT)
- References: <f43dm5$f8$1@smc.vnet.net>
Hi Alex,
As your patterns spans more than one row, you must specify a global
pattern for the whole array, Therefore, if you have more than one block
of "1" you must use ReplaceRepeated. E.g. asssuming your array is in a:
a//.{x1:{__}..,{y1:___,1,1,y2___},{z1:___,1,1,z2___},x2:{__}..}->{x1,{y1,a1,a2,y2},{z1,a3,a4},x2}
hope this helps, Daniel
alexxx.magni at gmail.com wrote:
> hi everybody,
>
> do you know how to do a pattern match involving 2D matrices?
> If e.g. you have a list
>
> a = {{0, 0, 0, 0, 0, 0}, {0, 1, 0, 0, 0, 0}, {0, 1, 0, 1, 1, 0}, {0,
> 0, 0, 1, 1, 0}, {0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0}}
>
> i.e.
> 0 0 0 0 0 0
> 0 1 0 0 0 0
> 0 1 0 1 1 0
> 0 0 0 1 1 0
> 0 0 0 0 0 0
>
> is it possible for me to write a rule by which I am able to find the
> 2x2 square of 1's, and replace it with something else?
>
> I studied all I could on patterns, but didnt find an answer...
>
> thanks for ANY help
>
> Alessandro Magni
>
>