persp.im
Perspective Plot of Pixel Image
Displays a perspective plot of a pixel image.
Usage
## S3 method for class 'im':
persp(x, \dots, colmap=NULL)
Arguments
- x
- The pixel image to be plotted.
An object of class
"im"
(seeim.object
). - ...
- Extra arguments passed to
persp.default
to control the display. - colmap
- Optional data controlling the colour map. See Details.
Details
This is the persp
method for the class "im"
.
The pixel image x
must have real or integer values.
These values are treated as heights of a surface, and the
surface is displayed as a perspective plot on the current plot device,
using equal scales on the x
and y
axes.
The optional argument colmap
gives an easy way to display
different altitudes in different colours (if this is what you
want). If colmap
is a character vector, then the range of
altitudes in the perspective plot will be divided into
length(colmap)
intervals, and those parts of the surface
which lie in a particular altitude range will be assigned
the corresponding colour from colmap
. Alternatively if
colmap
is a list with entries breaks
and col
,
then colmap$breaks
determines the breakpoints of the altitude
intervals, and colmap$col
provides the corresponding colours.
Graphical parameters controlling the perspective plot
are passed through the ...
arguments
directly to the function persp.default
.
See the examples in persp.default
or in
demo(persp)
.
Value
- Returns the 3D transformation matrix
returned by
persp.default
.
See Also
Examples
# an image
Z <- setcov(owin())
persp(Z, colmap=terrain.colors(128), axes=FALSE, shade=0.3)