[R] Aggregate individual level data to age categories

[William Dunlap]

You didn't say how you wanted to use it as a data.frame, but here is one way

d <- data.frame(
    check.names = FALSE,
    age = c(45L, 45L, 46L, 47L, 47L),
    x = c(1L, 2L, 1L, 3L, 3L))
with(d, as.data.frame(table(age,x)))

which gives:
  age x Freq
1  45 1    1
2  46 1    1
3  47 1    0
4  45 2    1
5  46 2    0
6  47 2    0
7  45 3    0
8  46 3    0
9  47 3    2

Bill Dunlap
TIBCO Software
wdunlap tibco.com


On Wed, Feb 12, 2020 at 1:12 PM stefan.duke using gmail.com <stefan.duke using gmail.com>
wrote:

> well, if I think about, its actually a simple frequency table grouped
> by age. but it should be usable a matrix or data frame.
>
> On Wed, Feb 12, 2020 at 9:48 PM <cpolwart using chemo.org.uk> wrote:
> >
> > So a pivot table?
> >
> > On 12 Feb 2020 20:39, stefan.duke using gmail.com wrote:
> >
> > Dear All,
> >
> > I have a seemingly standard problem to which I somehow I do  not find
> > a simple solution. I have individual level data where x is a
> > categorical variable with 3 categories which I would like to aggregate
> > by age.
> >
> > age x
> > 45   1
> > 45   2
> > 46   1
> > 47   3
> > 47   3
> > and so on.
> >
> > It should after transformation look like that
> >
> > age x_1 x_2 x_3
> > 45    1     0   1
> > 46    1     0   0
> > 47     0    0   2
> >
> > Basically to calculate prevalences by age categories.
> >
> > Thanks for any pointers!
> >
> > Cheers!
> >
> > ______________________________________________
> > R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > 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.
> >
> >
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

	[[alternative HTML version deleted]]