R: X Window System Graphics

x11 {grDevices} | R Documentation

## X Window System Graphics

### Description

`X11` starts a graphics device driver for the X Window System (version 11). This can only be done on machines that run X. `x11` is recognized as a synonym for `X11`.

### Usage

    X11(display = "", width = 7, height = 7, pointsize = 12,
        gamma = getOption("gamma"), colortype = getOption("X11colortype"),
        maxcubesize = 256, bg = "transparent", canvas = "white",
        fonts = getOption("X11fonts"), xpos = NA, ypos = NA)

### Arguments

`display` | the display on which the graphics window will appear. The default is to use the value in the user's environment variable DISPLAY.
`width, height` | the width and height of the plotting window, in inches. See also Resources.
`pointsize` | the default pointsize to be used.
`gamma` | the gamma correction factor. This value is used to ensure that the colors perceived are linearly related to RGB values (see `hsv`). By default this is taken from `options("gamma")`, or is 1 (no correction) if that is unset (which is the usual case).
`colortype` | the kind of color model to be used. The possibilities are `"mono"`, `"gray"`, `"pseudo"`, `"pseudo.cube"` and `"true"`. Ignored if an `X11` device is already open.
`maxcubesize` | can be used to limit the size of color cube allocated for pseudocolor devices.
`bg` | color. The default background color.
`canvas` | color. The color of the canvas, which is visible only when the background color is transparent.
`fonts` | X11 font description strings into which weight, slant and size will be substituted. There are two, the first for fonts 1 to 4 and the second for font 5, the symbol font. See section Fonts.
`xpos, ypos` | initial position of the top left corner of the window, in pixels. Negative values are from the opposite corner, e.g. `xpos=-100` says the top right corner should be 100 pixels from the right edge of the screen. If `NA`, successive devices are cascaded in 20 pixel steps from the top left. See also Resources.

### Details

By default, an X11 device will use the best color rendering strategy that it can. The choice can be overridden with the `colortype` parameter. A value of `"mono"` results in black and white graphics, `"gray"` in grayscale and `"true"` in truecolor graphics (if this is possible). The values `"pseudo"` and `"pseudo.cube"` provide color strategies for pseudocolor displays. The first strategy provides on-demand color allocation which produces exact colors until the color resources of the display are exhausted. The second causes a standard color cube to be set up, and requested colors are approximated by the closest value in the cube. The default strategy for pseudocolor displays is `"pseudo"`.

Note: All `X11` devices share a `colortype` which is set by the first device to be opened. To change the `colortype` you need to close all open `X11` devices then open one with the desired `colortype`.

With `colortype` equal to `"pseudo.cube"` or `"gray"` successively smaller palettes are tried until one is completely allocated. If allocation of the smallest attempt fails the device will revert to `"mono"`.

Line widths as controlled by `par(lwd=)` are in multiples of the pixel size, and multiples < 1 are silently converted to 1.

`pch="."` with `cex = 1` corresponds to a rectangle of sides the larger of one pixel and 0.01 inch.

The initial size and position are only hints, and may not be acted on by the window manager.

### Fonts

An initial/default font family for the device can be specified via the `fonts` argument, but if a device-independent R graphics font family is specified (e.g., via `par(family=)` in the graphics package), the X11 device makes use of the X11 font database (see `X11Fonts`) to convert the R graphics font family to an X11-specific font family description.

X11 chooses fonts by matching to a pattern, and it is quite possible that it will choose a font in the wrong encoding or which does not contain glyphs for your language (particularly common in `iso10646-1` fonts).

The `fonts` argument is a two-element character vector, and the first element will be crucial in successfully using non-Western-European fonts. Settings that have proved useful include

`"-*-mincho-%s-%s-*-*-%d-*-*-*-*-*-*-*"` for CJK languages and `"-cronyx-helvetica-%s-%s-*-*-%d-*-*-*-*-*-*-*"` for Russian.

For UTF-8 locales, the `XLC_LOCALE` databases provide mappings between character encodings, and you may need to add an entry for your locale (e.g. Fedora Core 3 lacked one for `ru_RU.utf8`).

### Resources

The standard X11 resource `geometry` can be used to specify the window position and/or size, but will be overridden by values specified as arguments. The class looked for is `R_x11`. Note that the resource specifies the width and height in pixels and not in inches. See for example http://web.mit.edu/answers/xwindows/xwindows_resources.html and perhaps man X (or http://www.xfree86.org/current/X.7.html). An example line in ‘~/.Xresources’ might be

    R_x11*geometry: 900x900-0+0

that specifies a 900 x 900 pixel window at the top right of the screen.

### See Also

`Devices`, `X11Fonts`.

[Package grDevices version 2.6.2 Index]