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Re: transforming a rule of lists to a list of rules

  • To: mathgroup at smc.vnet.net
  • Subject: [mg69161] Re: [mg69098] transforming a rule of lists to a list of rules
  • From: Ken Levasseur <klevasseur at mac.com>
  • Date: Thu, 31 Aug 2006 04:39:31 -0400 (EDT)
  • References: <200608301032.GAA27888@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

This doesn't test for whether the two lists have equal lengths, but  
that would be easy to add:

In[15]:=
delist = #1 /. {({a__} -> {b__}) :> (Rule @@ #1 & ) /@ Transpose 
[{{a}, {b}}]} &

Out[15]=
#1 /. {({a__} -> {b__}) :> (Rule @@ #1 & ) /@ Transpose[{{a}, {b}}]} &

In[16]:=
delist[{a, b, c} -> {0, 3, x}]

Out[16]=
{a -> 0, b -> 3, c -> x}

On Aug 30, 2006, at 6:32 AM, Ken Senior wrote:

> Hello everyone.
>
> Does anyone know a way to transform a rule involving a list into a  
> list
> of individual rules, that is to interpret the rule elementwise?  For
> example, given
>
>    {a,b,c} -> {0,3,x}
>
> is there a transformation which will turn this into
>
>    {a->0, b->3, c->x}
>
> Thanks for the help!
>
> Ken
>

Ken Levasseur
UMass Lowell

Please avoid sending me Word or PowerPoint attachments.
See http://www.gnu.org/philosophy/no-word-attachments.html


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