WWGbook (version 1.0.0)

autism: autism data in Chapter 6

Description

The data comes from researchers at the University of Michigan as part of a prospective longitudinal study of 214 children.

Usage

data(autism)

References

Oti, R., Anderson, D., Risi, S., Pickles, A. & Lord, C., Social Trajectories Among Individuals with Autism Spectrum Disorders, Developmental Psychopathology (under review), 2006. West, B., Welch, K. & Galecki, A, Linear Mixed Models: A Practical Guide Using Statistical Software, Chapman Hall / CRC Press, first edition, 2006.

Examples

attach(autism)

###Figure 6.1: Observed VSAE values plotted against age for children in each SICD group. 

sicdegp.f <- factor(sicdegp)
age.f <- factor(age)

# Add the new variables to a new data frame object.
autism.updated <- data.frame(autism, sicdegp.f, age.f)

library(lattice)  # Load the library for trellis graphics.
 
# Load the nlme library, which is required for the 
# plots below as well as for subsequent models.
library(nlme)

autism.g1 <- groupedData(vsae ~ age | childid, 
outer = ~ sicdegp.f, data = autism.updated)

plot(autism.g1, display = "childid", outer = TRUE, aspect = 2, key = FALSE, xlab = "Age (Years)", ylab = "VSAE", 
main = "Individual Data by SICD Group")