Date:         Thu, 9 Apr 2009 12:53:08 -0400
Reply-To:     Kevin Viel <citam.sasl@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Kevin Viel <citam.sasl@GMAIL.COM>
Subject:      Re: Means

On Wed, 8 Apr 2009 12:04:09 -0400, Randy <randistan69@HOTMAIL.COM> wrote:

>My data is as follows:
>
>date   time        ID         VarA
>Mar1    9:00       XA          45
>Mar1    9:00       XA          16
>Mar1    10:00      XA          34
>Mar1    10:01      XB          16
>Mar1    10:02      XD          17
>Mar1    10:05      XM          18
>Mar1    10:05      XM          19
>Mar1    10:34      XM          20
>
>I want to sum and get the average of these variables.  But every ID at the
>same time has to be grouped as one, before I take the average of these
>variables. So for example, on Mar1 XA at 9:00 has to be grouped as one,
and
>so should XM at 10:05.  So the data set should first look like before I
take
>the averages.
> date   time        ID         VarA
>Mar1    9:00       XA          61
>Mar1    10:00      XA          34
>Mar1    10:01      XB          16
>Mar1    10:02      XD          17
>Mar1    10:05      XM          37
>Mar1    10:34      XM          20
>
>This operation can be performed in two data steps.  Is there a way to do
it
>in one data step?

In one data step?  Sure, and you have already received some suggestions.
You could also do it with the MEAN procedure, if you use it twice.  This
has several advantages, including ease of maintainence and it is rather
concise.

What is the purpose of this analysis?  Why do you have multiple
observations for some and uneven time intervals?  As either a reviewer or
a reader, information concerning the percision, i.e. CV and number of
observations, would be valuable.

Replacing a series of observations with the mean of them might be more
accurate, but what about the other observations that have only one
measurement?

HTH,

Kevin