Peng,
You can create all the attributes you want, with one headache: R does
not keep attributes across subsetting operations so you need to write
classes and "[.something" methods when attributions need to be kept or
adjusted upon subsetting rows.
The Hmisc package uses attributes such as label, units, imputed. You
might look at the code to see how it did that. For example, label(x)
will use attr(x, 'label') to fetch the 'label' attribute. There are
attribute-setting functions there too.
Frank
Peng Yu wrote:
Hi,
According to the example below this email, attr(x,"names") is the same
as names(x). I am wondering how many attributes there are of a given
variable. How to find out what they are? Can I always use
some_attribute(x) instead of attr(x, "some_attribute")?
Regards,
Peng
x=c(1,2,3)
attr(x,"names")=c("a","b","c")
x
a b c
1 2 3
y=c(1,2,3)
names(y)=c("a","b","c")
y
a b c
1 2 3
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
--
Frank E Harrell Jr Professor and Chair School of Medicine
Department of Biostatistics Vanderbilt University
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
