R: Core-generating Function for Mosaic Plots

struc_mosaic {vcd} | R Documentation

## 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 David.Meyer@R-project.org

### 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. URL http://www.jstatsoft.org/v17/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))

[Package vcd version 1.4-4 Index]