R: Function to generate a simple theme

C_03_simpleTheme {lattice} | R Documentation

## Function to generate a simple theme

### Description

Simple interface to generate a list appropriate as a theme, typically used as the `par.settings` argument in a high level call

### Usage

    simpleTheme(col, alpha,
                cex, pch, lty, lwd, font, fill, border,
                col.points, col.line,
                alpha.points, alpha.line)

### Arguments

`col, col.points, col.line` | A color specification. `col` is used for components `"plot.symbol"`, `"plot.line"`, `"plot.polygon"`, `"superpose.symbol"`, `"superpose.line"`, and `"superpose.polygon"`. `col.points` overrides `col`, but is used only for `"plot.symbol"` and `"superpose.symbol"`. Similarly, `col.line` overrides `col` for `"plot.line"` and `"superpose.line"`. The arguments can be vectors, but only the first component is used for scalar targets (i.e., the ones without `"superpose"` in their name).
`alpha, alpha.points, alpha.line` | A numeric alpha transparency specification. The same rules as `col`, etc., apply.
`cex, pch, font` | Parameters for points. Applicable for components `plot.symbol` (for which only the first component is used) and `superpose.symbol` (for which the arguments can be vectors).
`lty, lwd` | Parameters for lines. Applicable for components `plot.line` (for which only the first component is used) and `superpose.line` (for which the arguments can be vectors).
`fill` | fill color, applicable for components `plot.symbol`, `plot.polygon`, `superpose.symbol`, and `superpose.polygon`.
`border` | border color, applicable for components `plot.polygon` and `superpose.polygon`.

### Details

The appearance of a lattice display depends partly on the “theme” active when the display is plotted (see `trellis.device` for details). This theme is used to obtain defaults for various graphical parameters, and in particular, the `auto.key` argument works on the premise that the same source is used for both the actual graphical encoding and the legend. The easiest way to specify custom settings for a particular display is to use the `par.settings` argument, which is usually tedious to construct as it is a nested list. The `simpleTheme` function can be used in such situations as a wrapper that generates a suitable list given parameters in simple `name=value` form, with the nesting made implicit. This is less flexible, but straightforward and sufficient in most situations.

### Value

A list that would work as the `theme` argument to `trellis.device` and `trellis.par.set`, or as the `par.settings` argument to any high level lattice function such as `xyplot`.

### Author(s)

Deepayan Sarkar Deepayan.Sarkar@R-project.org, based on a suggestion from John Maindonald.

### See Also

`trellis.device`, `xyplot`, `Lattice`

### Examples

    str(simpleTheme(pch = 16))

    dotplot(variety ~ yield | site, data = barley, groups = year,
            auto.key = list(space = "right"),
            par.settings = simpleTheme(pch = 16),
            xlab = "Barley Yield (bushels/acre) ",
            aspect=0.5, layout = c(1,6))

[Package lattice version 0.20-6 Index]