Hi,
x <- 1L
class(x) <- c("myInt", "integer")
is(x)
Error in inherits(x, "factor") :
argument "class2" is missing, with no default
The problem arises when is() is used with only one argument (object)
which has more than one class reported by class(object).
In the code is() does use variable "class2" before checking for its
presence.
Reversing the order of checks
is2 <- function(object, class2) {
cl <- class(object)
if (missing(class2))
return(extends(cl))
if (length(cl) > 1)
return(class2 %in% cl)
if (.identC(cl, class2) || .identC(class2, "ANY"))
return(TRUE)
ext <- possibleExtends(cl, class2)
if (is.logical(ext))
ext
else if ([EMAIL PROTECTED])
TRUE
else [EMAIL PROTECTED](object)
}
is2(x)
[1] "myInt" "integer"
This is not sufficient, though:
utils::data(npk, package="MASS")
ret <- aov(yield ~ block + N*P*K, npk)
is2(ret)
[1] "aov" "lm" "lm" "mlm" "oldClass" "oldClass"
with duplicate class names
due to
extends(class(ret))
[1] "aov" "lm" "lm" "mlm" "oldClass" "oldClass"
so something different would be needed.
Best,
Matthias
> sessionInfo()
R version 2.7.0 RC (2008-04-15 r45347)
i686-pc-linux-gnu
locale:
[EMAIL
PROTECTED];LC_NUMERIC=C;LC_TIME=C;LC_COLLATE=C;LC_MONETARY=C;LC_MESSAGES=C;[EMAIL
PROTECTED];LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;[EMAIL
PROTECTED];LC_IDENTIFICATION=C
attached base packages:
[1] stats graphics grDevices datasets utils methods base
--
Matthias Burger Project Manager/ Biostatistician
Epigenomics AG Kleine Praesidentenstr. 1 10178 Berlin, Germany
phone:+49-30-24345-371 fax:+49-30-24345-555
http://www.epigenomics.com [EMAIL PROTECTED]
--
Epigenomics AG Berlin Amtsgericht Charlottenburg HRB 75861
Vorstand: Geert Nygaard (CEO/Vorsitzender), Dr. Kurt Berlin (CSO)
Oliver Schacht PhD (CFO), Christian Piepenbrock (COO)
Aufsichtsrat: Prof. Dr. Dr. hc. Rolf Krebs (Chairman/Vorsitzender)
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
