```Date: Wed, 27 Nov 2002 17:12:32 +0000 Reply-To: John Whittington Sender: "SAS(r) Discussion" From: John Whittington Subject: Re: Delete data set based on max value of a var Comments: To: pudding_man@lycos.com In-Reply-To: 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 ---------------------------------------------------------------- ```

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