(100*0) is used to set the initial value of each of the 100 elements of the array to zero.

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From: souga soga [mailto:souga1234@gmail.com] Sent: Tuesday, December 18, 2007 9:01 AM To: Huang, Ya Cc: SAS-L@listserv.uga.edu Subject: Re: selecting a unique set of data.

THANK YOU ALL VERY VERY MUCH, this is exactly what i need. Just had one question :why is the (100*0) needed in the array statement :-array yy(1:100) _temporary_ (100*0);

On 12/17/07, Ya Huang <ya.huang@amylin.com> wrote:

If NOT every value of X has every value of Y, or number of observation in each X varies, one way to get the unique Y is as follows, i.e., pick a Y for first x group, record it as used y, then for the next x group, check if the y has been used, if so, goes to next y in the group... temp array in the code is used to record used y value. data have; X="A001";Y=10;OUTPUT; X="A001";Y=30;OUTPUT; X="A001";Y=40;OUTPUT; X="A003";Y=10;OUTPUT; X="A003";Y=60;OUTPUT; X="A003";Y=40;OUTPUT; X="A003";Y=50;OUTPUT; X="A002";Y=10;OUTPUT; X="A002";Y=40;OUTPUT; X="A002";Y=50;OUTPUT; X="A004";Y=60;OUTPUT; X="A004";Y=40;OUTPUT; run; data need; array yy(1:100) _temporary_ (100*0); set have; retain found used; by x notsorted; if first.x then found=0; if found=0 and yy(y)=0 then do; yy(y)=1; used=y; found=1; end; if last.x then do; if found=1 then y=used; else y=.; output; end; run; proc print; run; Obs X Y found used 1 A001 10 1 10 2 A003 60 1 60 3 A002 40 1 40 4 A004 . 0 40 Note that for A004, both 60 and 40 have been used, therefore assign a missing for it. On Mon, 17 Dec 2007 22:51:01 -0500, souga soga < souga1234@GMAIL.COM> wrote: >I apologize for not being specific, anyway what i need is in your first >paragraph > >"In your example every value of X has every value of Y. If this is >accurate then sort by X Y, and select first record in first group of >X's, second record from the second group, etc. to the last group of >X's taking the last record in the group." > >Unfortunately i do not know how to program this, can someone help! > >Thanks again, >Sa > >On Dec 17, 2007 10:03 PM, <iw1junk@comcast.net> wrote: > >> Summary: Specs should precede solution. >> #iw-value=1 >> >> Souga, >> >> In your example every value of X has every value of Y. If this is >> accurate then sort by X Y, and select first record in first group of >> X's, second record from the second group, etc. to the last group of >> X's taking the last record in the group. >> >> If your example is not accurate, then it makes no sense for anyone to >> give an answer until more is known about the requirements. For >> example, suppose there are 5 distinct value of X and 4 distinct values >> of Y, then it is impossible to have every value of X in the output >> file no matter how the Y values are distributed. Consequently there >> is >> no solution when all values of X must be used. >> >> So the real question is - what do you have, and what are the >> requirements for what you want? Knowing why would also help us to >> know whether the problem is worth thinking about. >> >> It sounds like some kind of operations research problem. >> >> Ian Whitlock >> ============== >> Date: Mon, 17 Dec 2007 19:36:40 -0500 >> Reply-To: souga soga <souga1234@GMAIL.COM > >> Sender: "SAS(r) Discussion" >> From: souga soga <souga1234@GMAIL.COM> >> Subject: selecting a unique set of data. >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Hi, >> >> X="A001";Y=10;OUTPUT; >> X="A001";Y=20;OUTPUT; >> X="A002";Y=10;OUTPUT; >> X="A002";Y=20;OUTPUT; >> >> I need the output to be: >> >> X="A001";Y=10;OUTPUT; >> X="A002";Y=20;OUTPUT; >> >> ie. the value of y should not repeat for x >> >> Thanks, Sa >> >>