Date:         Thu, 22 Apr 2004 14:56:17 GMT
Reply-To:     "(2B) || !(2B) Arin Chaudhuri" <spam@SPAM.NET>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "(2B) || !(2B) Arin Chaudhuri" <spam@SPAM.NET>
Organization: Road Runner - NC
Subject:      Re: Unusual sorting problem
Content-Type: text/plain; charset=us-ascii; format=flowed

Richard A. DeVenezia wrote:
> Richard A. DeVenezia wrote:
[snip]
> The normal sort is not what I want.
> I need unusual sort such that rows within each by group of y are be ordered
> by x, but the order is ascending and descending depending on y.  Y is a
> sequence 1,2,3,4...
> y=1 x's=-5 to 5
> y=2 x's=5 to -5
> y=3 x's=-5 to 5
> y=4 x's=5 to -5
> ...
>
> (Think of an old bidirectional dot matrix printer, one line was printed
> moving left to right and the next line was printed moving right to left.)
>

data foo;
   retain seed 654321;
   do y = 1 to 38;
   do x = -5 to 5;
     satellite = ranuni(seed);
     disorder = ranuni(seed);
     output;
   end;
   end;
run;

data bar;
set foo;
sortvar=(2*mod(y,2)-1)*_n_;
run;

proc sort data=bar out=sorted_foo(drop=sortvar);
by y sortvar;
run;