Contents

buildfactor()

Usage:

a <- buildfactor(jsub, dims), integer jsub > 0, dims a vector of
  positive integers, length(dims) >= jsub

Keywords: anova, factorial

fac_j <- buildfactor(j, dims) creates a factor corresponding to the
values of subscript j for a balanced factorial design.  dims must be a
vector of positive integers and j must be a positive integer <= k =
length(dims).

fac_j will be a factor with dims[j] levels, with length(fac_j) =
prod(dims), the product of the elements of dims.  fac_j may be used in
an ANOVA of a factorial experiment where each case is identified by k
subscripts with the first changing fastest and the last changing
slowest, with subscript i running from 1 to dims[i].

Example:
  Cmd> dims <- vector(2,3,2)

  Cmd> fac_1 <- buildfactor(1,dims)

  Cmd> fac_2 <- buildfactor(2,dims)

  Cmd> fac_3 <- buildfactor(3,dims)

  Cmd> list(fac_1,fac_2,fac_3)
  fac_1           REAL   12    FACTOR with 2 levels
  fac_2           REAL   12    FACTOR with 3 levels
  fac_3           REAL   12    FACTOR with 2 levels

  Cmd> print(fac_1,fac_2,fac_3,format:"2.0f")
  fac_1:
  (1)  1  2  1  2  1  2  1  2  1  2  1  2
  fac_2:
  (1)  1  1  2  2  3  3  1  1  2  2  3  3
  fac_3:
  (1)  1  1  1  1  1  1  2  2  2  2  2  2

These factors could be used in analysis of a single replicate of a 2 by
3 by 2 design in standard order, say by anova("y=fac_1+fac_2+fac_3").

See also factor(), makefactor(), rep()