Plot a Colour Map
Displays a colour map as a colour ribbon
## S3 method for class 'colourmap': plot(x, ..., main, xlim = NULL, ylim = NULL, vertical = FALSE, axis = TRUE, labelmap=NULL, gap=0.25, add=FALSE)
- Colour map to be plotted. An object of class
- Graphical arguments passed to
- Main title for plot. A character string.
- Optional range of
xvalues for the location of the colour ribbon.
- Optional range of
yvalues for the location of the colour ribbon.
- Logical flag determining whether the colour ribbon
is plotted as a horizontal strip (
FALSE) or a vertical strip (
- Logical flag determining whether an axis should be plotted showing the numerical values that are mapped to the colours.
- Function. If this is present, then the labels on the plot,
which indicate the input values corresponding to particular colours,
will be transformed by
labelmapbefore being displayed on the plot. Typically used to simplify or shor
- Distance between separate blocks of colour, as a fraction of the width of one block, if the colourmap is discrete.
- Logical value indicating whether to add the colourmap to the
existing plot (
add=TRUE), or to start a new plot (
add=FALSE, the default).
This is the plot method for the class
An object of this class
(created by the function
represents a colour map or
colour lookup table associating colours with each data value.
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
the width of one block.
To annotate an existing plot with an explanatory colour ribbon
or colour legend,
add=TRUE and use the arguments
ylim to control the physical position of the ribbon
on the plot.
Labels explaining the colour map are
axis and can be modified by
specifying arguments that will be passed to this function.
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)