[R] Measurement units inside a data frame

[Gabor Grothendieck]

Here are 3 possibilities where the examples use the builtin data set
BOD:

#1. Use column headings

> names(BOD) <- paste(names(BOD), c("days", "mg/l"), sep = "_")
> BOD
  Time_days demand_mg/l
1         1         8.3
2         2        10.3
3         3        19.0
4         4        16.0
5         5        15.6
6         7        19.8

#2. add a "units" attribute to each column

> attr(BOD$Time, "units") <- "days"
> attr(BOD$demand, "units") <- "mg/l"
> attr(BOD$Time, "units")
[1] "days"

#3. See ?units in the Hmisc package which
basically does #2 for you.

library(Hmisc)
example(units)


On Feb 7, 2008 5:32 AM, Tribo Laboy <tribolaboy at gmail.com> wrote:
> Hello,
>
> I was wondering if there was an easy way to put information about the
> measurement units used for each column of a data frame ...
>
> Thanks for any pointers,