Date:         Mon, 21 Jan 2008 22:48:06 -0500
Reply-To:     "Howard Schreier <hs AT dc-sug DOT org>" <nospam@HOWLES.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "Howard Schreier <hs AT dc-sug DOT org>" <nospam@HOWLES.COM>
Subject:      Re: Largest value in a symmetric matrix

On Mon, 21 Jan 2008 12:53:13 +0100, Stefan Pohl <stefan.pohl@ISH.DE> wrote:

>Hi SAS-group,
>
>I want to know which is the largest value in the following matrix
>
>id  var1 var2 var3 var4
>1   0    1    2    1
>2   1    0    5    4
>3   2    5    0    3
>4   1    4    3    0
>
>the matrix is symmetric
>
>How can I do this?
>
>Thank you for any help.
>
>Stefan.

   data matrix;
   input
id  var1 var2 var3 var4 ; cards;
1   0    1    2    1
2   1    0    5    4
3   2    5    0    3
4   1    4    3    0
   ;

A couple of ways to do it with PROCs ...

A single SQL statement, but the columns have to be explicitly listed:

   proc sql;
   select max ( max( var1,var2,var3,var4 ) ) from matrix;
   quit;

Two steps:

   data halfbaked / view=halfbaked;
   set matrix;
   maxacross = max ( of var : );
   run;

   proc means data=halfbaked max;
   var maxacross;
   run;