From ihaka@stat.auckland.ac.nz  Fri Apr  9 08:23:40 1999
From: ihaka@stat.auckland.ac.nz (Ross Ihaka)
Date: Fri, 9 Apr 1999 19:23:40 +1200 (NZST)
Subject: Error in ppois function (PR#161)
In-Reply-To: <Pine.GSO.4.05.9904090652020.28479-100000@auk.stats>
Message-ID: <Pine.BSF.3.96.990409191434.3007A-100000@g.ihaka.slip.auckland.ac.nz>


On Fri, 9 Apr 1999, Prof Brian D Ripley wrote:

>      ppois(q, lambda)
> 
> where q is undefined! It should only be defined for integers. Similarly, x
> should only be integers.

Ummmm.  I guess I see the argument for dpois, but I thought the
distribution function was defined for all values.  Wouldn't it be in order
to apply the integer argument function to floor(q) perhaps?

This seems to be what S does.

	> ppois(1.5, 2)
	[1] 0.4060058
	> ppois(1.1, 2)
	[1] 0.4060058


	Ross


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Error in ppois function (PR#161)
Ross Ihaka