mfrow {snippets}R Documentation

Recursive grid layout functions for graphics

Description

mfrow and mfcol setup a multi-figure layout scheme on a grid in the current graphics device. Unlike other layout methods the schemes can be used recursively to create complex layouts with very simple commands.

Usage

mfrow(rows, cols, n, asp = 1, add = FALSE, times = NA,
      fig = if (add) par("fig") else c(0, 1, 0, 1), ...)
mfcol(rows, cols, n, asp = 1, add = FALSE, times = NA,
      fig = if (add) par("fig") else c(0, 1, 0, 1), ...)

Arguments

rows

either a numeric vector of length one defining the number of equally spaced rows or a vector specifying the relative height of each row.

cols

either a numeric vector of length one defining the number of equally spaced columns or a vector specifying the relative width of each row.

n

if rows and cols are both not specified, then n specifies the minimal number of cells that the layout should contain. In that case rows and cols are computed such that their product is at least n and the resulting aspect ratio of the figures is as close to asp as possible.

asp

numeric, desired aspect ratio of the figures when n is used to specify the grid

add

logical, if TRUE then the layout scheme is added to the layout stack, allowing recursive layouts. Otherwise the currently layout is replaced with the new grid layout.

times

number of times this layout should be applied or NA for unlimited. Any number larger than 1e6 is interpreted as NA.

fig

boundaries of the figure that will be split using this layout scheme.

...

additional arguments that will be passed to par when a new figure is setup.

Details

mfrow and mfcol have a similar effect as the corresponding graphics parameters, but they are more flexible (allowing individual withs and heights) and construct a scheme that can be used recursively with add = TRUE.

Note that the scheme layout method is incompatible with all other layout methods that are not based on the scheme stack, such as par(mfrow) or layout. It can be to a degree combined with split.screen with add = TRUE if used as a sub-layout thereof since screen uses a co-operative manipulation of figures. However, in that case you should make sure that the stack layout does not overflow (i.e., you plot only at most as many plots as there are figures) or it will clear the device.

Value

object of the class scheme.

Note

All layout functions require R 2.13.0 or higher! If plots seemingly don't move from the first figure then you either have old version or other code has removed the neessary "before.plot.new" hook.

Author(s)

Simon Urbanek

Examples

  ## one advantage is that you can simply specify the number of plots
  ## the layout will then depend on the aspect ratio of the device
  mfrow(n=8)
  par(mar=c(2,2,0,0))
  for (i in 1:8) plot(rnorm(100), rnorm(100), col=i, pch=19)

  ## or you can create recursive layouts
  mfrow(2, 4)                  ## 4 x 2 base grid
  mfrow(c(1, 4), 1, add=TRUE)  ## each cell split asymetrically 1:4

  par(mar=rep(0,4))
  for (i in 1:8) {
     plot(0:1, 0:1, type='n', axes=FALSE); rect(0,0,1,1); text(0.5, 0.5, i)
     plot(rnorm(100), rnorm(100), col=i, pch=19, axes=FALSE)
  }

[Package snippets version 0.1-1 Index]