struc_mosaic {vcd}

Core-generating Function for Mosaic Plots

Description

Core-generating function for strucplot returning a function producing mosaic plots.

Usage

struc_mosaic(zero_size = 0.5, zero_split = FALSE, zero_shade = TRUE,
             zero_gp = gpar(col = 0), panel = NULL)

Arguments

zero_size

size of the bullets used for zero-entries in the contingency table (if 0, no bullets are drawn).

zero_split

logical controlling whether zero cells should be further split. If FALSE and zero_shade is FALSE, only one bullet is drawn (centered) for unsplit zero cells. If FALSE and zero_shade is TRUE, a bullet for each zero cell is drawn to allow, e.g., residual-based shadings to be effective also for zero cells.

zero_shade

logical controlling whether zero bullets should be shaded.

zero_gp

object of class "gpar" used for zero bullets in case they are not shaded.

panel

Optional function with arguments: residuals, observed, expected, index, gp, and name called by the struc_mosaic workhorse for each tile that is drawn in the mosaic. index is an integer vector with the tile's coordinates in the contingency table, gp a gpar object for the tile, and name a label to be assigned to the drawn grid object.

Details

This function is usually called by strucplot (typically when called by mosaic) and returns a function used by strucplot to produce mosaic plots.

Value

A function with arguments:

residuals

table of residuals.

observed

table of observed values.

expected

not used by struc_mosaic.

spacing

object of class "unit" specifying the space between the tiles.

gp

list of gpar objects used for the drawing the tiles.

split_vertical

vector of logicals indicating, for each dimension of the table, the split direction.

Author(s)

David Meyer [e-mail]

References

Cohen, A. (1980), On the graphical display of the significant components in a two-way contingency table. Communications in Statistics—Theory and Methods, A9, 1025–1041.

Friendly, M. (1992), Graphical methods for categorical data. SAS User Group International Conference Proceedings, 17, 190–200. http://datavis.ca/papers/sugi/sugi17.pdf

Meyer, D., Zeileis, A., and Hornik, K. (2006), The strucplot framework: Visualizing multi-way contingency tables with vcd. Journal of Statistical Software, 17(3), 1-48. doi:10.18637/jss.v017.i03 and available as vignette("strucplot").

See Also

mosaic, strucplot, structable

Examples

## Titanic data
data("Titanic")
## mosaic plot with large zeros
strucplot(Titanic, core = struc_mosaic(zero_size = 1))