hasseMod: Hasse Diagram from Linear Model

In mixlm: Mixed Model ANOVA and Statistics for Education

Hasse Diagram from Linear Model

Description

This function extracts terms from a linear model object and creates a Hasse diagram of the terms. The function is useful for visualizing the structure of a linear model. If the model contains random effects, these are placed in parentheses in the diagram. Manually placed terms are supported to some extent, see example for usage.

Usage

hasseMod(object, manualTerms=NULL, manualParents=NULL, 
         meanName="M", errorName="(E)")

Arguments

object	A linear model object, e.g., lm.
manualTerms	A vector of terms that should be placed manually in the diagram.
manualParents	A list of vectors with the parents of the terms in manualTerms.
meanName	The name of the mean term (default = "M").
errorName	The name of the error term (default = "(E)").

Value

A list with the levels of the diagram and the adjacency matrix.

Author(s)

Kristian Hovde Liland

See Also

lm

Examples

# Random data
dat <- data.frame(A = factor(rep(c(1,2),32)), 
                  B = factor(rep(c(1,1,2,2),16)), 
                  C = factor(rep(c(1,1,1,1,2,2,2,2),8)), 
                  Ind = factor(rep(c(1,1,1,1,2,2,2,2),8)),
                  D = factor(rep(c(rep(1,8),rep(2,8)),4)), 
                  E = factor(rep(c(rep(1,16),rep(2,16)),2)))
dat$y = rnorm(64)

# Linear model with interactions and nested factors
mod <- lm(y~A*B*C + D + E%in%D, data=dat)
(an <- Anova(mod, type="II"))
H <- hasseMod(mod)
## Not run:  # Requires installation of Rgraphviz
library(Rgraphviz)
hasse(H$hasse, parameters=list(cluster = FALSE, arrows = "none", edgeColor = "darkred"))

## End(Not run)

# Linear model with repeated measures where Ind is nested in A
modv <- lm(y~A*r(B) + r(Ind), data=dat)
(anv <- Anova(mod, type="II"))
Hv <- hasseMod(modv, manualTerms=c("Ind"), manualParents=list(c("A")))
## Not run:  # Requires installation og Rgraphviz
hasse(Hv$hasse, parameters=list(cluster = FALSE, arrows = "none", edgeColor = "darkred"))

## End(Not run)

mixlm documentation built on Oct. 7, 2024, 9:06 a.m.