Date:         Wed, 27 Nov 2002 17:12:32 +0000
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: Delete data set based on max value of a var
Comments: To: pudding_man@lycos.com
In-Reply-To:  <AIPFDOMDDNFABAAA@mailcity.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 10:14 27/11/02 -0600, Puddin' Man wrote (in part):

>Well, yes, I can see that now. I suppose.
>
>And, yes, to compute the max, one must read the target field
>for all the recs. Same for the min.

For max, yes, but not necessarily for min.  If one knows that there cannot
be any negative numbers, and if the range of possible numbers encompasses
zero, then the first discovery of a zero value means that the minimum must
be zero, so one doesn't necessarily have to read all the
observations.  Indeed, the minimum possible value does not have to be zero
for that to be the case.  If one knows that, for example, the minimum
possible value is 1 (or even 1.32!), then the first discovery of that value
constitutes discovery of the minimum value.

>I guess the mistake I made was in assuming that y'all
>were attempting to address "the problem as stated".

Well, I was - but, as you go on to say, there appear to be varying
interpretations of what was 'stated'!  I went by the title and the initial
statement of the problem, whereas others (like you) concentrated on the one
'example' of the problem that was quoted.  Goodness knows which of us most
correctly read Paula's mind :-)

Kind Regards


John

----------------------------------------------------------------
Dr John Whittington,       Voice:    +44 (0) 1296 730225
Mediscience Services       Fax:      +44 (0) 1296 738893
Twyford Manor, Twyford,    E-mail:   John.W@mediscience.co.uk
Buckingham  MK18 4EL, UK             mediscience@compuserve.com
----------------------------------------------------------------