Message-ID: <Pine.OSF.4.31.0401252356550.6135-100000@harry.molgen.mpg.de>
Date: 2004-01-25T22:58:41Z
From: Wolski
Subject: 'Math' group generic functions. Cant explain behaviour of 'log'.
Hi!
Out of all 'Math' group generic functions(?Math) the log function has
a different behaviour. See example bellow.
Whats the reason?
Platfom Windows 2000.
R : Copyright 2003, The R Foundation for Statistical Computing
Version 1.8.1 (2003-11-21), ISBN 3-900051-00-3
>setClass("track",representation(x="numeric",y="numeric"))
>setMethod("Math","track",function(x)
+ {
+ x at y=callGeneric(x at y)
+ x
+ }
+ )
>xx<-new("track",x=1:10,y=-(1:10))
>xx<-abs(xx)
>sqrt(xx)
An object of class "track"
Slot "x":
[1] 1 2 3 4 5 6 7 8 9 10
Slot "y":
[1] 1.000000 1.414214 1.732051 2.000000 2.236068 2.449490 2.645751
2.828427
[9] 3.000000 3.162278
>log(xx)
Error in log(x) : Non-numeric argument to mathematical function
Sincerely Eryk