Calculates the degrees of freedom based on an designmatrix for a (log liniear) CFA model.
#' @details No details
Usage
df_des_cfa(des)
Arguments
des
a designmatrix (object of class "matrix") as returned by function design_cfg_cfa.
Value
An object of class "integer" giving the degrees of freedom for the designmatrix defined in argument des.
References
No references in the moment
Examples
#######################################
# degrees of freedom for designmatrix with three main effects.
# three variables with two categories each.
df_des_cfa(design_cfg_cfa(kat=c(2,2,2)))
# two variables with two categories each and one variable
# with 7 categories (Linert LSD example).
df_des_cfa(design_cfg_cfa(kat=c(2,2,7)))
###########
# degrees of freedom for designmatrix with three main effects
# and three 'two by two'interactions.
# and tripple interaction --> saturated model --> df=0
# three variables with two categories each.
df_des_cfa(design_cfg_cfa(kat=c(2,2,2),form="~ V1 + V2 + V3 + V1:V2 + V1:V3 + V2:V3 + V1:V2:V3"))
#######################################