Newbie: 'table' output in columns rather than matrix

Hi,

Coming to R from SAS...

Welcome!

I have a data.frame A with 2 long factors "x" and "y".  I want to get
a count of the number of rows with each level of "x" and "y" jointly.
'table' seemed like it would work, but as I have many levels, the
matrix output is pretty useless to me (and I don't care about zero
values).  How can I get output that looks like:

A$x A$y Freq
------ ----- -------
x1    y1    8
x1    y3   10
...

Thanks a ton,
Matt

See ?as.data.frame.table

Example using the 'warpbreaks' dataset:

str(warpbreaks)

'data.frame':	54 obs. of  3 variables:
 $ breaks : num  26 30 54 25 70 52 51 26 67 18 ...
 $ wool   : Factor w/ 2 levels "A","B": 1 1 1 1 1 1 1 1 1 1 ...
 $ tension: Factor w/ 3 levels "L","M","H": 1 1 1 1 1 1 1 1 1 2 ...

with(warpbreaks, table(wool, tension))

tension
wool L M H
   A 9 9 9
   B 9 9 9

as.data.frame(with(warpbreaks, table(wool, tension)))

wool tension Freq
1    A       L    9
2    B       L    9
3    A       M    9
4    B       M    9
5    A       H    9
6    B       H    9



So with your data:

  as.data.frame(with(A, table(x, y)))


See ?with also, which enables you to specify the column names 'with[in]'
the environment of the data frame, so that you need not use the '$' syntax.

HTH,

Marc Schwartz