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Coding an inverse permutation

• To: mathgroup at smc.vnet.net
• Subject: [mg79078] Coding an inverse permutation
• From: Diana <diana.mecum at gmail.com>
• Date: Wed, 18 Jul 2007 02:52:42 -0400 (EDT)

Folks,

I have the following list:

aa={1, 2, 5, 3, 4, 8, 9, 7, 11, 6, 13, 17, 10, 16, 19, 15, 14, 20, 21,
23, 25, 12, 29, 31, 18, 22,
 37, 27, 26, 28, 33, 35, 32, 24, 41, 43, 30, 34, 47, 39, 38, 40, 45,
49, 44, 36, 53, 55, 46, 52,
 59, 51, 50, 56, 57, 61, 62, 42, 67, 71, 48, 58, 65, 63, 64, 68, 69,
73, 74, 54, 77, 79, 60, 76,
 83, 75, 80, 70, 81, 89, 85, 66, 95, 97, 72, 82, 91, 87}

I want to figure out a clean way to code its inverse permutation.

The inverse permutation list would start as follows:

bb={1,2,4,5,3,10,8,6, ...}

Since "3" is in position 4 of aa, position 3 of bb will be "4".
Since "5" is in position 3 of aa, position 5 of bb will be "3".

Can someone give me a suggestion as to how to code this?

Thanks, Diana

• Follow-Ups:
  • Re: Coding an inverse permutation
    • From: Sseziwa Mukasa <mukasa@jeol.com>
  • Re: Coding an inverse permutation
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>
  • Re: Coding an inverse permutation
    • From: "Carl K. Woll" <carlw@wolfram.com>