# interaction.positioned: interaction method for positioned factors. In HH: Statistical Analysis and Data Display: Heiberger and Holland

## Description

This is intended to be a method for `interaction` for positioned factors. Since `interaction` is not currently implemented as a generic, `interaction.positioned` is a standalone function. The result is assigned a `position`. The position for each interaction level is the position of the corresponding `a` factor plus a scaled level of the `b` factor. The default scale is .1.

## Usage

 ```1 2 3 4``` ```interaction.positioned(..., ## exactly two factors drop = FALSE, sep = ".", b.offset=0, b.scale=.1) ```

## Arguments

 `...` exactly two factors. The first factor `a` is used as the major factor in sort order. The second factor `b` is used as minor factor in sort order. `b.offset` amount added to `position(b)` to adjust appearance. `b.scale` scale to relate units of `position(a)` to units of `position(b)`. `drop, sep` See `factor`.

## Value

`"positioned"` object containing the ordinary interaction with a `"position"` attribute.

## Author(s)

Richard M. Heiberger <rmh@temple.edu>

`positioned`.
 ```1 2 3 4 5``` ```a <- positioned(letters[c(1,2,3,1,2,3)], value=c(1,4,9)) b <- positioned(LETTERS[c(4,4,4,5,5,5)], value=c(1,2)) a.b <- interaction.positioned(a, b) a.b.2 <- interaction.positioned(a, b, b.scale=.2) b.a <- interaction.positioned(b, a) ```