[R] multiple crosstabulation

[Niklaus Kuehnis]

Hi,

Two questions:

1) I have a data.frame of binary factors (x, y, z, ...) and would 
like to do tables like "table(a,b)" for any combination of factors, 
2 by 2. I.e. I'm looking for the equivalent of

table(x,y)
table(x,z)
table(y,z)
...

Is there a simple way to do this?

2) Similar to the above: I have the same data.frame of binary 
factors and would like to do tables like "table(a,b)" for the 
combinations of one factor(x) with all the others, i.e. the 
equivalent of

table(x,y)
table(x,z)
table(x, ...)
table(x, ...)
...

---------------
table(data.frame) gives too many tables, i.e. it gives 2-by-2 tables 
for all the combinations of all the factors. Most of these tables 
contain only zeros. The factor levels are named differently for each 
factor, so apply(data.frame, 2, table) doesn't make sense.

Any help appreciated,
Niklaus