These functions checks whether two factors are (fully) crossed
or nested, i.e. if each level of one factor occurs in combination with
each level of the other factor (is_crossed()
) resp. if each
category of the first factor co-occurs with only one category of the
other (is_nested()
). is_cross_classified()
checks if one
factor level occurs in some, but not all levels of another factor.
is_crossed(f1, f2) is_nested(f1, f2) is_cross_classified(f1, f2)
f1 | Numeric vector or |
---|---|
f2 | Numeric vector or |
Logical. For is_crossed()
, TRUE
if factors are (fully)
crossed, FALSE
otherwise. For is_nested()
, TRUE
if
factors are nested, FALSE
otherwise. For is_cross_classified()
,
TRUE
, if one factor level occurs in some, but not all levels of
another factor.
If factors are nested, a message is displayed to tell whether f1
is nested within f2
or vice versa.
Grace, K. The Difference Between Crossed and Nested Factors. (web)
# crossed factors, each category of # x appears in each category of y x <- c(1,4,3,2,3,2,1,4) y <- c(1,1,1,2,2,1,2,2) # show distribution table(x, y)#> y #> x 1 2 #> 1 1 1 #> 2 1 1 #> 3 1 1 #> 4 1 1# check if crossed is_crossed(x, y)#> [1] TRUE# not crossed factors x <- c(1,4,3,2,3,2,1,4) y <- c(1,1,1,2,1,1,2,2) # show distribution table(x, y)#> y #> x 1 2 #> 1 1 1 #> 2 1 1 #> 3 2 0 #> 4 1 1# check if crossed is_crossed(x, y)#> [1] FALSE# nested factors, each category of # x appears in one category of y x <- c(1,2,3,4,5,6,7,8,9) y <- c(1,1,1,2,2,2,3,3,3) # show distribution table(x, y)#> y #> x 1 2 3 #> 1 1 0 0 #> 2 1 0 0 #> 3 1 0 0 #> 4 0 1 0 #> 5 0 1 0 #> 6 0 1 0 #> 7 0 0 1 #> 8 0 0 1 #> 9 0 0 1# check if nested is_nested(x, y)#>#> [1] TRUEis_nested(y, x)#>#> [1] TRUE# not nested factors x <- c(1,2,3,4,5,6,7,8,9,1,2) y <- c(1,1,1,2,2,2,3,3,3,2,3) # show distribution table(x, y)#> y #> x 1 2 3 #> 1 1 1 0 #> 2 1 0 1 #> 3 1 0 0 #> 4 0 1 0 #> 5 0 1 0 #> 6 0 1 0 #> 7 0 0 1 #> 8 0 0 1 #> 9 0 0 1# check if nested is_nested(x, y)#> [1] FALSEis_nested(y, x)#> [1] FALSE# also not fully crossed is_crossed(x, y)#> [1] FALSE# but partially crossed is_cross_classified(x, y)#> [1] TRUE