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Building a list

• To: mathgroup at smc.vnet.net
• Subject: [mg47114] Building a list
• From: Mark Coleman <mark at markscoleman.com>
• Date: Fri, 26 Mar 2004 03:56:00 -0500 (EST)
• Sender: owner-wri-mathgroup at wolfram.com

Greetings,

I've got a relatively simple function f[a_,b_,c_,d_], where a and b are  
integers and c and d are lists (of reals), and f returns a real.

I need to evaluate f on (potentially long) sets of lists and calculate  
a square "matrix" from the possible permutations of the elements in the  
lists. For instance

If

xlist={x1,x2,x3}


I need to calculate

{{f[a,b,x1,x1],f[a,b,x1,x2],f[a,b,x1,x3]},{f[a,b,x2,x1],f[a,b,x2,x2],f[a 
,b,x2,x3]},{f[a,b,x3,x1],f[a,b,x3,x2],f[a,b,x3,x3]}}

Note that f[a,b,c,d] does not equal f[a,b,d,c].

My first reaction was that Outer[] might do this, but I cannot seem to  
get it to work. I'd appreciate any suggestions.

Thanks,

Mark

• Follow-Ups:
  • Re: Building a list
    • From: Tomas Garza <tgarza01@prodigy.net.mx>
  • Re: Building a list
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>
  • Re: Building a list
    • From: Sseziwa Mukasa <mukasa@jeol.com>