vcdExtra (version 0.7-1)

mosaic.glmlist: Mosaic Displays for glmlist and logllmlist Objects

Description

This function provides a convenient interface for viewing mosaic displays associated with a collection of glm models for freqency tables that have been stored in a glmlist or loglmlist object. You can plot either selected models individually, or mosaics for all models in an array of viewports.

Usage

# S3 method for glmlist
mosaic(x, selection, 
  panel=mosaic,
  type=c("observed", "expected"), 
  legend=ask | !missing(selection),
  main=NULL,
  ask=TRUE, graphics=TRUE, rows, cols, newpage=TRUE,
  ...)
# S3 method for loglmlist
mosaic(x, selection, 
  panel=mosaic,
  type=c("observed", "expected"), 
  legend=ask | !missing(selection),
  main=NULL,
  ask=TRUE, graphics=TRUE, rows, cols, newpage=TRUE,
  ...)

Arguments

x

a glmlist or loglmlist object

selection

the index or name of one glm or loglm object in x. If no selection is specified, a menu of models is presented or all models are plotted.

panel

a strucplot panel function, typicially mosaic or sieve

type

a character string indicating whether the "observed" or the "expected" values of the table should be visualized

legend

logical: show a legend for residuals in the mosaic display(s)? The default behavior is to include a legend when only a single plot is shown, i.e., if ask is TRUE or a selection has been specified.

main

either a logical, or a vector of character strings used for plotting the main title. If main is a logical and TRUE, the name of the selected glm object is used.

ask

logical: should the function display a menu of models, when one is not specified in selection? If selection is not supplied and ask is TRUE (the default), a menu of model names is presented; if ask is FALSE, mosaics for all models are plotted in an array.

graphics

logical: use a graphic dialog box when ask=TRUE?

rows,cols

when ask=FALSE, the number of rows and columns in which to plot the mosaics.

newpage

start a new page? (only applies to ask=FALSE)

…

other arguments passed to mosaic.glm and ultimately to mosaic.

Value

Returns the result of mosaic.glm.

Details

Most details of the plots produced can be controlled via … arguments as shown in some of the examples below. In particular, with panel=sieve you need to also pass gp=shading_Friendly to get a color version.

References

David Meyer, Achim Zeileis, and Kurt Hornik (2006). The Strucplot Framework: Visualizing Multi-Way Contingency Tables with vcd. Journal of Statistical Software, 17(3), 1-48. http://www.jstatsoft.org/v17/i03/, available as vignette("strucplot", package="vcd").

See Also

glmlist, loglmlist, Kway

mosaic.glm, mosaic, strucplot, for the many parameters that control the details of mosaic plots.

Examples

# NOT RUN {
data(JobSatisfaction, package="vcd")

# view all pairwise mosaics
pairs(xtabs(Freq~management+supervisor+own, data=JobSatisfaction), 
    shade=TRUE, diag_panel=pairs_diagonal_mosaic)

modSat <- Kway(Freq ~ management+supervisor+own, data=JobSatisfaction, 
               family=poisson, prefix="JobSat")
names(modSat)

# }
# NOT RUN {
mosaic(modSat)              # uses menu, if interactive()
# }
# NOT RUN {
mosaic(modSat, "JobSat.1")  # model label
mosaic(modSat, 2)           # model index

# supply a formula to determine the order of variables in the mosaic
mosaic(modSat, 2, formula=~own+supervisor+management)

mosaic(modSat, ask=FALSE)   # uses viewports 

# use a different panel function, label the observed valued in the cells
mosaic(modSat, 1, main=TRUE, panel=sieve, gp=shading_Friendly, labeling=labeling_values)

data(Mental)
indep <- glm(Freq ~ mental+ses,
                family = poisson, data = Mental)
Cscore <- as.numeric(Mental$ses)
Rscore <- as.numeric(Mental$mental)

coleff <- glm(Freq ~ mental + ses + Rscore:ses,
                family = poisson, data = Mental)
roweff <- glm(Freq ~ mental + ses + mental:Cscore,
                family = poisson, data = Mental)
linlin <- glm(Freq ~ mental + ses + Rscore:Cscore,
                family = poisson, data = Mental)

# assign names for the plot labels
modMental <- glmlist(Indep=indep, ColEff=coleff, RowEff=roweff, `Lin x Lin`=linlin)
mosaic(modMental, ask=FALSE, margins=c(3,1,1,2), labeling_args=list(abbreviate_labs=5))


# }