[R] Create design matrix

[Bond, Stephen]

Greetings useRs,

What is the easiest way to create a design matrix of several factor variables? Function gendata in Design seems to do that for a fitted model, but how to do that only on several factor vectors??

The result should be a df with one row for each distinct combination of levels of factors eg for (M,F) (Y,O)
We get
M Y
M O
F Y
F O

In reality I will have more than 1000 rows so doing by hand not good.
Maybe there is a way with "outer", but I couldn't see it.
All the best to everybody.

Stephen