add_dummy_variables: Add Dummy Variables for Piecewise Linear Models

In scan: Single-Case Data Analyses for Single and Multiple Baseline Designs

Add Dummy Variables for Piecewise Linear Models

Description

Adds dummy variables to an scdf for calculating piecewise linear models.

Usage

add_dummy_variables(
  scdf,
  model = c("W", "H-M", "B&L-B"),
  contrast_level = c("first", "preceding"),
  contrast_slope = c("first", "preceding")
)

Arguments

scdf	A single-case data frame. See scdf() to learn about this format.
model	Model used for calculating the dummy parameters (see Huitema & McKean, 2000). Default is model = "W". Possible values are: "B&L-B", "H-M", "W", and deprecated "JW".
contrast_level	Either "first", "preceding" or a contrast matrix. If NA contrast_level is a copy of contrast.
contrast_slope	Either "first", "preceding" or a contrast matrix. If NA contrast_level is a copy of contrast.

Details

This function creates dummy variables for phase levels and phase slopes according to the specified piecewise regression model. It supports different contrast coding schemes for both level and slope contrasts.

Examples

add_dummy_variables(
 scdf = exampleABC, 
 model = "W", 
 contrast_level = "first", 
 contrast_slope = "first"
)

scan documentation built on April 1, 2026, 9:06 a.m.