From mccauley  Tue Jan 11 01:59:17 1994
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From: Darrell McCauley <mccauley>
Sender: mccauley
To: ncressie@iastate.edu
Subject: Morista's I in 1st ed of text
Date: Tue, 11 Jan 94 01:59:13 -0500


Hello Sir,
 Recall I am using your book to code programs for the GRASS GIS. I
recently finished a program for quadrat counts. In calculating
Morista's I, my answers, relative to other indices in Table 8.3
(pg. 590), were on the order n off. Checking Ripley's _Spatial
Statistics_, he has an additional factor of n before the summation
symbol. Can you confirm or deny that there is a typo in the
equation for Morista's I (Table 8.3)?

I have really enjoy learning from material that you've written, both
the text and many journal articles. Hopefully I'll be able to get the
second edition after graduation (my apologies if this has already been
corrected or if Ripley is the one who erred).  Many thanks.

--Darrell
James Darrell McCauley, Purdue Univ, West Lafayette, IN 47907-1146, USA
mccauley@ecn.purdue.edu, mccauley%ecn@purccvm.bitnet, pur-ee!mccauley

From ncressie@iastate.edu  Sun Jan 23 12:31:44 1994
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From: ncressie@iastate.edu
To: mccauley@ecn.purdue.edu
Subject: Morisita's I
Date: Sun, 23 Jan 1994 11:31:39 -0600


Mr McCauley,
            Thank you for your recent e-mail and for alerting me to a possible
typo on p.590. You are correct - and I am happy to say I caught it for the 
revised edition. There should be an 'n' before the summation symbol in the 
numerator of Morisita's I. The correct formula does appear in the revised edition.
            Sincerely,
             Noel Cressie