R: Legend Functions for Strucplots

legends {vcd} | R Documentation

## Legend Functions for Strucplots

### Description

These functions generate legend functions for residual-based shadings.

### Usage

    legend_resbased(fontsize = 12, fontfamily = "",
      x = unit(1, "lines"), y = unit(0.1,"npc"),
      height = unit(0.8, "npc"),
      width = unit(0.7, "lines"),
      digits = 2, check_overlap = TRUE, text = NULL,
      steps = 200, ticks = 10, pvalue = TRUE,  range = NULL)
    legend_fixed(fontsize = 12, fontfamily = "", x = unit(1, "lines"), y = NULL,
      height = NULL, width = unit(1.5, "lines"), steps = 200,
      digits = 1, space = 0.05, text = NULL, range = NULL)

### Arguments

`fontsize` | fontsize of title and p-value text.
`fontfamily` | fontfamily of all text.
`x, y` | objects of class `"unit"` indicating the coordinates of the title. For `legend_fixed`, the default for `y` is computed as to leave enough space for the specified `text`.
`height, width` | object of class `"unit"` indicating the height/width of the legend. For `legend_fixed`, the default for `y` is computed as to align upper margins of legend and actual plot.
`digits` | number of digits for the scale labels.
`check_overlap` | logical indicating whether overlap of scale labels should be inhibited or not.
`space` | For `legend_fixed` only: proportion of space between the tiles.
`text` | character string indicating the title of the legend.
`steps` | granularity of the color gradient.
`ticks` | number of scale ticks.
`pvalue` | logical indicating whether the p-value should be visualized under the scale or not.
`range` | Numeric vector of length 2 for setting the legend range. Computed from the residuals if omitted. `NA` values are replaced by the corresponding minimum / maximum of the residuals.

### Details

These functions generate legend functions for residual-based shadings, visualizing deviations from expected values of an hypothesized independence model. Therefore, the legend uses a supplied shading function to visualize the color gradient for the residuals range. `legend_fixed` is inspired by the legend used in `mosaicplot`. For more details on the shading functions and their return values, see `shadings`.

### Value

A function with arguments:

`residuals` | residuals from the fitted independence model to be visualized.
`shading` | shading function computing colors from residuals (see details).
`autotext` | character vector indicating the title to be used when no `text` argument is specified. Allows strucplot to generate sensible defaults depending on the residuals type.

### Author(s)

David Meyer David.Meyer@R-project.org

### References

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")`.

Meyer, D., Zeileis, A., Hornik, K. (2003), Visualizing independence using extended association plots. Proceedings of the 3rd International Workshop on Distributed Statistical Computing, K. Hornik, F. Leisch, A. Zeileis (eds.), ISSN 1609-395X. https://www.R-project.org/conferences/DSC-2003/Proceedings/

### See Also

`structable`, `shadings`

### Examples

    data("Titanic")

    mosaic(Titanic, shade = TRUE, legend = legend_resbased)
    mosaic(Titanic, shade = TRUE, legend = legend_fixed, gp = shading_Friendly)

[Package vcd version 1.4-4 Index]