plot.clusmca {clustrd}

Plotting function for clusmca() output.

Description

Plotting function that creates a scatterplot of the object scores and/or the attribute scores and the cluster centroids. Optionally, the function returns a series of barplots showing the standardized residuals per attribute for each cluster.

Usage

## S3 method for class 'clusmca'
plot(x, dims = c(1,2), what = c(TRUE,TRUE),
cludesc = FALSE, topstdres = 20, objlabs = FALSE, attlabs = NULL, 
subplot = FALSE, max.overlaps=10, ...)

Arguments

x

Object returned by clusmca()

dims

Numerical vector of length 2 indicating the dimensions to plot on horizontal and vertical axes respectively; default is first dimension horizontal and second dimension vertical

what

Vector of two logical values specifying the contents of the plots. First entry indicates whether a scatterplot of the objects is displayed in principal coordinates. Second entry indicates whether a scatterplot of the attribute categories is displayed in principal coordinates. Cluster centroids are always displayed. The default is c(TRUE, TRUE) and the resultant plot is a biplot of both objects and attribute categories with gamma-based scaling (see van de Velden et al., 2017)

cludesc

A logical value indicating whether a series of barplots is produced showing the largest (in absolute value) standardized residuals per attribute for each cluster (default = FALSE)

topstdres

Number of largest standardized residuals used to describe each cluster (default = 20). Works only in combination with cludesc = TRUE

objlabs

A logical value indicating whether object labels will be plotted; if TRUE row names of the data matrix are used (default = FALSE). Warning: when TRUE, execution time of the plotting function will increase dramatically as the number of objects gets larger

attlabs

Vector of custom attribute labels; if not provided, default labeling is applied

subplot

A logical value indicating whether a subplot with the full distribution of the standardized residuals will appear at the bottom left corner of the corresponding plots. Works only in combination with cludesc = TRUE

max.overlaps

Maximum number of text labels allowed to overlap. Defaults to 10

...

Further arguments to be transferred to clusmca()

Value

The function returns a ggplot2 scatterplot of the solution obtained via clusmca() that can be further customized using the ggplot2 package. When cludesc = TRUE the function also returns a series of ggplot2 barplots showing the largest (or all) standardized residuals per attribute for each cluster.

References

Hwang, H., Dillon, W. R., and Takane, Y. (2006). An extension of multiple correspondence analysis for identifying heterogenous subgroups of respondents. Psychometrika, 71, 161-171.

Iodice D'Enza, A., and Palumbo, F. (2013). Iterative factor clustering of binary data. Computational Statistics, 28(2), 789-807.

van de Velden M., Iodice D'Enza, A., and Palumbo, F. (2017). Cluster correspondence analysis. Psychometrika, 82(1), 158-185.

See Also

plot.cluspca, plot.cluspcamix

Examples

data("mybond")
#Cluster Correspondence Analysis with 3 clusters in 2 dimensions after 10 random starts
outclusCA = clusmca(mybond[,8:10], 3, 2, nstart = 100, seed = 234)
#Save the ggplot2 scatterplot  
map = plot(outclusCA, max.overlaps = 40)$map
#Customization (adding titles)
map + ggtitle(paste("Cluster CA plot of the James bond categorical data: 3 clusters of sizes ", 
                    paste(outclusCA$size, collapse = ", "),sep = "")) + 
    xlab("Dim. 1") + ylab("Dim. 2") + 
    theme(plot.title = element_text(size = 10, face = "bold", hjust = 0.5))
    
data("mybond")
#i-FCB with 3 clusters in 2 dimensions after 10 random starts
outclusCA = clusmca(mybond[,8:10], 3, 2, method = "iFCB", nstart= 10)
#Scatterlot with the observations only (dimensions 1 and 2) 
#and cluster description plots showing the 20 largest std. residuals 
#(with the full distribution showing in subplots)
plot(outclusCA, dim = c(1,2), what = c(TRUE, FALSE), cludesc = TRUE, 
subplot = TRUE)