R help - Jun 2009 - data formatting

All,

I have three columns of data: id, date, hab. I am trying to set up a matrix
that has the id as the rows, date as columns, and the hab value as the data
values.  Each id/date combination can only have one hab value.  I would like
for it to look something like this"
         date 1, date 2, date 3.
id
0001     2        1         2
0002     3         5        6

I don't know how to set this up properly. I am pretty sure dates cannot be
used in a matrix, but I can easily convert this to an integer. I am mainly
unsure of the functions to use to do this operation.

Thank you

	[[alternative HTML version deleted]]

Is this what you are after (uses the reshape package)
> # test data
> x <- expand.grid(id=1:5, date=seq(as.Date('2009-01-01'),
by='1 day',
length=5))
> x$hab <- seq(nrow(x))  # add hab
> head(x)
  id       date hab
1  1 2009-01-01   1
2  2 2009-01-01   2
3  3 2009-01-01   3
4  4 2009-01-01   4
5  5 2009-01-01   5
6  1 2009-01-02   6
> require(reshape)
> x.melt <- melt(x, measure='hab')
> cast(x.melt, id ~ date)
  id 2009-01-01 2009-01-02 2009-01-03 2009-01-04 2009-01-05
1  1          1          6         11         16         21
2  2          2          7         12         17         22
3  3          3          8         13         18         23
4  4          4          9         14         19         24
5  5          5         10         15         20         25


On Sat, Jun 27, 2009 at 7:40 PM, James Martin
<just.struttin@gmail.com>wrote:
> All,
>
> I have three columns of data: id, date, hab. I am trying to set up a matrix
> that has the id as the rows, date as columns, and the hab value as the data
> values.  Each id/date combination can only have one hab value.  I would
> like
> for it to look something like this"
>         date 1, date 2, date 3.
> id
> 0001     2        1         2
> 0002     3         5        6
>
> I don't know how to set this up properly. I am pretty sure dates cannot
be
> used in a matrix, but I can easily convert this to an integer. I am mainly
> unsure of the functions to use to do this operation.
>
> Thank you
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> 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<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

	[[alternative HTML version deleted]]