[R] How to make a matrix of a number of factors?

[baptiste auguie]

Hi,

Try this,

do.call(expand.grid, lapply(7:3, seq, from=1))


HTH,

baptiste


2009/11/22 Peng Yu <pengyu.ut at gmail.com>:
> I use the following code to generate a matrix of factors. I'm
> wondering if there is a way to make it more general so that I can have
> any number of factors (not necessarily 5).
>
> a=3
> b=4
> c=5
> d=6
> e=7
>
> A=1:a
> B=1:b
> C=1:c
> D=1:d
> E=1:e
>
> X=matrix(nr=a*b*c*d*e,nc=5)
>
> for(i_a in 1:a-1) {
>  for(i_b in 1:b-1) {
>    for(i_c in 1:c-1) {
>      for(i_d in 1:d-1) {
>        for(i_e in 1:e-1) {
>          X[(((i_a * b + i_b) * c + i_c) * d + i_d) * e + i_e + 1, ] =
> c(i_a+1, i_b+1, i_c+1, i_d+1, i_e+1)
>        }
>      }
>    }
>  }
> }
> print(X)
>
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