spatstat.geom (version 3.6-0)

plot.colourmap: Plot a Colour Map

Description

Displays a colour map as a colour ribbon

Usage

# S3 method for colourmap
plot(x, ...,
       main, xlim = NULL, ylim = NULL, vertical = FALSE,
       axis = TRUE, side = if(vertical) "right" else "bottom",
       labelmap=NULL, gap=0.25, add=FALSE, increasing=NULL, nticks=5,
       at=NULL, box=NULL)

Value

None.

Details

This is the plot method for the class "colourmap". An object of this class (created by the function colourmap) represents a colour map or colour lookup table associating colours with each data value.

The command plot.colourmap displays the colour map as a colour ribbon or as a colour legend (a sequence of blocks of colour). This plot can be useful on its own to inspect the colour map.

If the domain of the colourmap is an interval of real numbers, the colourmap is displayed as a continuous ribbon of colour. If the domain of the colourmap is a finite set of inputs, the colours are displayed as separate blocks of colour. The separation between blocks is equal to gap times the width of one block.

To annotate an existing plot with an explanatory colour ribbon or colour legend, specify add=TRUE and use the arguments xlim and/or ylim to control the physical position of the ribbon on the plot.

Labels explaining the colour map are drawn by axis and can be modified by specifying arguments that will be passed to this function.

The argument increasing indicates whether the colourmap should be displayed so that the input values are increasing with the spatial coordinate: that is, increasing from left to right (if vertical=FALSE) or increasing from bottom to top (if vertical=TRUE). If increasing=FALSE, this ordering will be reversed. The default is increasing=TRUE in all cases except when vertical=TRUE and the domain of the colourmap is a finite set of discrete inputs.

See Also

colourmap

Examples

  co <- colourmap(rainbow(100), breaks=seq(-1,1,length=101))
  plot(co)
  plot(co, col.ticks="pink")
  ca <- colourmap(rainbow(8), inputs=letters[1:8])
  plot(ca, vertical=TRUE)
  ## logarithmic colour map
  cl <- colourmap(rainbow(25), range=c(0.1, 1000), compress=log10)
  plot(cl)