[R] Measurement units inside a data frame

[Tribo Laboy]

Thanks Gabor,

In fact I am currently using the first option in your nicely
summarized reply. But many of the automatic plotting functions use the
column labels for labeling the plots and sometimes it is just a bit
inconvenient. Your second option is what Gavin also suggested and I
guess I will go with that after having a look at the Hmisc package.

Thanks for the help.


On Thu, Feb 7, 2008 at 7:59 PM, Gabor Grothendieck
<ggrothendieck at gmail.com> wrote:
> 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,
>