# crossFactors: Crossed Factors In s20x: Functions for University of Auckland Course STATS 201/208 Data Analysis

## Description

Computes a factor that has a level for each combination of the factors 'fac1' and 'fac2'.

## Usage

 ```1 2 3 4 5 6 7``` ```crossFactors(x, fac2 = NULL, ...) ## Default S3 method: crossFactors(x, fac2 = NULL, ...) ## S3 method for class 'formula' crossFactors(formula, fac2 = NULL, data = NULL, ...) ```

## Arguments

 `x` the name of the first factor or a formula in the form `~ fac1 * fac2` `fac2` the name of the second factor - ignored if `x` is a formula. `...` Optional arguments `formula` a formula in the form `~ fac1 * fac2` `data` an optional data frame in which to evaluate the formula

## Value

Returns a vector containing the factor which represents the interaction of the given factors.

## Methods (by class)

• `default`: Crossed Factors

• `formula`: Crossed Factors

## Note

This function actually returns a `factor` now instead of a character string, so coercion into a `factor` is no longer necessary.

`factor`.
 ```1 2 3 4 5 6 7 8 9``` ```## arousal data: data(arousal.df) gender.picture = crossFactors(arousal.df\$gender, arousal.df\$picture) gender.picture ## arousal data: data(arousal.df) gender.picture = crossFactors(~ gender * picture, data = arousal.df) gender.picture ```