sjmisc (version 1.8)

is_nested: Check whether two factors are nested

Description

This function checks whether two factors are nested, i.e. if each category of the first factor co-occurs with only one category of the other.

Usage

is_nested(f1, f2)

Arguments

f1

Numeric vector or factor.

f2

Numeric vector or factor.

Value

Logical, TRUE if factors are nested, FALSE otherwise.

References

Grace, K. The Difference Between Crossed and Nested Factors. (web)

See Also

is_crossed

Examples

# 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)
# check if nested
is_nested(x, y)
is_nested(y, x)

# 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)
# check if nested
is_nested(x, y)
is_nested(y, x)