Date: Thu, 28 Jun 2007 07:17:24 -0700
Reply-To: SK <skauchali@GMAIL.COM>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: SK <skauchali@GMAIL.COM>
Organization: http://groups.google.com
Subject: Re: Count the proportion of days with exposure in specified time
period
In-Reply-To: <1183039788.103930.221480@q75g2000hsh.googlegroups.com>
Content-Type: text/plain; charset="us-ascii"
On Jun 28, 4:09 pm, frank_diio...@yahoo.com wrote:
> On Jun 28, 9:14 am, SK <skauch...@gmail.com> wrote:
>
>
>
> > Hi there, this is a newbie-type question.
>
> > I have a longitudinal dataset of daily feeding records of infants from
> > birth to 270 days (9 months). Infant feeding (category) for the each
> > day is recorded at either exclusive breast =1), mixed feeding (=2),
> > and exclusive formula (=3). I wish to count the proportion of days a
> > child receives either 1, 2 or 3.
>
> > Data structure and intended variable after manipulation (propfeed):
>
> > id Feed
> > 1 1
> > 1 1
> > 1 2
> > 1 3
> > 2 1
> > 2 1
> > 2 1
> > 2 1
> > 3 3
> > 3 3
> > 3 3
> > etc
>
> > Desired table:
> > id propfeed1 propfeed2 propfeed3
> > 1 0.5 0.25 0.25
> > 2 1.0 0 0
> > 3 0 0 1.0
> > etc.
>
> > Could someone help guide me through this problem?
> > thank you,
>
> > SK
>
> Here's an SQL-based solution:
>
> proc sql noprint;
> create table summ as
> select sum(feed=1)/count(*) as propFeed1 format=4.2,
> sum(feed=2)/count(*) as propFeed2 format=4.2,
> sum(feed=3)/count(*) as propFeed3 format=4.2
> from propFeed
> group by id
> ;
> quit;
Thanks Frank. I will try it out and give some feedback on how it
goes. Much appreciated.
SK
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