Date:         Sat, 29 Sep 2001 17:49:44 +0100
Reply-To:     John Whittington <John.W@MEDISCIENCE.CO.UK>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         John Whittington <John.W@MEDISCIENCE.CO.UK>
Subject:      Re: VALUE
Comments: To: "Stanley A. Gorodenski" <vvgsgor@DE.STATE.AZ.US>
In-Reply-To:  <E15mzq9-0002Bt-00@relay1.netnames.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 08:43 28/09/01 -0700, Stanley A. Gorodenski wrote:

>With regard to the Lag() function, I would like to add that in SPSS I use
>their lag function conditionally, and with great
>complexity (to me), without any problems.  I wish SAS' lag function worked
>as good as SPSS'.

It's quite a long time since I used SPSS to any extent.  Can you briefly
remind me how the SPSS lag function works?  Does it simply refer to 'the
previous observation' in the intuitive fashion?  If so, that is obviously
more straightforward (and would remove the pitfall that so many people fall
into with SAS) - but, of course, by the same token is 'less
versatile'.  Perhaps to some people's surprise, I do quite often
deliberately use conditionally executed LAGn() functions in SAS, to good
effect - and the equivalent would presumably be more difficult to code in a
language using an 'intuitative' lag function.

In any event, the only reason I raised the lag function issue was to
illustrate the fact that, even if some programming practice is 'dangerous
in the hands of someone who doesn't understand what they are doing', that
does not mean that it should not be utilised by someone who DOES
'understand what they are doing'.

Kind Regards,


John

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