spatstat (version 1.18-4)

persp.im: Perspective Plot of Pixel Image

Description

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" (see im.object).

...

Extra arguments passed to persp.default to control the display.

colmap

Optional data controlling the colour map. See Details.

Value

• Returns the 3D transformation matrix returned by persp.default.

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).

See Also

im.object, plot.im, contour.im

Examples

# an image
   Z <- setcov(owin())
   persp(Z, colmap=terrain.colors(128), axes=FALSE, shade=0.3)