[R] From THE R BOOK -> Warning: In eval(expr, envir, enclos) : non-integer #successes in a binomial glm!

[Robert A LaBudde]

At 12:08 PM 3/30/2010, David Winsemius wrote:
><snip>
>I don't understand this perspective. You bought Crowley's book so he
>is in some minor sense in debt to you.  Why should you think it is
>more appropriate to send your message out to thousands of readers of 
>r- help around the world (some of whom have written books that you did
>not buy) before sending Crowley a question about his text?

In fairness to Michael Crawley, whose books are useful and very clear 
(although not well-liked on this list for some reason):

1. The "example" quoted by Corrado Topi is not an actual example. 
Instead is an isolated line of code given to illustrate the 
simplicity of glm() syntax and its relation to lm() syntax. This is 
in a short general topic overview chapter on GLMs meant to introduce 
concepts and terminology, not runnable code.

2. The "example" chapter is followed in the book by individual 
chapters on each type of GLM covered (count data, count data in 
tables, proportion data, binary response variables). If Corrado Topi 
had looked in the relevant chapter, he would find numerous worked out 
examples with runnable code.

Corrado Topi made an error in trying to run an isolated line of code 
without antecedent definitions, which almost never works in any 
programming system. Michael Crawley made a mistake in judgment in 
assuming that detail later will suffice for generality now.

My advice to Corrado Topi is engage in some forward referencing, and 
read chapters 16 and 17 before deciding which example code to run.

================================================================
Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: ral at lcfltd.com
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