Message-ID: <51484A33.6080709@online.de>
Date: 2013-03-19T11:21:23Z
From: Kulupp
Subject: fisher.alpha warnings
I have two vectors (a and b) with counts of animals and wanted to
calculate fisher's alpha:
library(vegan)
a <- c(2043, 1258, 52, 1867, 107, 1624, 2, 157, 210, 402, 5, 107, 267,
2, 13683)
b <- c(2043, 1258, 52, 1867, 107, 1624, 2, 157, 210, 402, 5, 107, 267,
2, 3000)
fisher.alpha(a)
fisher.alpha(b)
fisher.alpha(a) gave the following warnings:
> fisher.alpha(a)
[1] 1.572964
Warnmeldungen:
1: In log(p) : NaNs wurden erzeugt
2: In log(1 - x) : NaNs wurden erzeugt
3: In nlm(Dev.logseries, n.r = n.r, p = p, N = N, hessian = TRUE, ...) :
NA/Inf durch gr??te positive Zahl ersetzt
fisher.alpha(b) gave no warnings (note: only the last number in the
vector 'b' differs from 'a'!)
Why did vector 'a' gave warnings and what does that mean for the
validity of the calculated alpha-value?