Date: Mon, 10 Jan 2000 22:07:26 +0100
Reply-To: "Christian F.G. Schendera" <schendera@NIKOCITY.DE>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: "Christian F.G. Schendera" <schendera@NIKOCITY.DE>
Subject: simultaneous computation of two functions of annual developments
in percentages (first solved, second perhaps)
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Obviously I suffered from a heavy programmer's block. Over the weekend I
sent the following two questions. The first is solved for sure (about the
second I am a bit unsure):
>I have to compute two annual developments in percentages. Both computations
>have their peculiarities. As the second bases on the first analysis, it
>would be wonderful to code them it in such a way that both questions could
>be analyzed simultaneously.
>1. Difference within (!) each YEARPAIR (see note below) in percentages (per
>BIRDTYPE and METHOD).
SOLUTION (very easy)
: PDIFF = QJ2 - QJ1 ;
PCTDIFF = (PDIFF/QJ1)*100 ;
Output looks like this:
OBS JAHRPAAR JAHR1 JAHR2 VOGELART METHODE
QJ1 QJ2 PDIFF PCTDIFF
1 92/93 1992 1993 Amsel L
16.5 21.5 5.0 30.303
2 92/93 1992 1993 Bachstelze L
18.5 12.0 -6.5 -35.135
3 92/93 1992 1993 Baumpieper L
>2. Now I want to standardize the obtained % differences. The start value is
>100%, then I apply the PCTDIFFS to the 100%. Result could look like this
>BIRDTYPE METHOD 92/93
>blackbird L +124.24 (+24.24 to start value 100%)
>finch P ................
Here I use the lag function (although I am not very sure if there is a more
data PCTVLF2 ;
set PCTVLF1 ;
by VOGELART METHODE ;
if first.METHODE then PCTDEV=100 ;
else PCTDEV =(PCTDIFF/a*100)-100 ;
put PCTDEV = ;
Hints very welcome.