persp3D function

Perspective plot with colour levels

This function draws a perspective plot of a surface with different levels in different colours.

persp3D(x, y, z, theta = 30, phi = 20, d = 5, expand = 2/3,
        xlim = range(x, finite = TRUE), ylim = range(y, finite = TRUE), 
        zlim = range(z, finite = TRUE), levels = pretty(zlim, nlevels),
        nlevels = 20, col.palette = jet.colors, border = NA, 
        ticktype = "detailed", xlab = NULL, ylab = NULL, zlab = NULL, 
        ...)

Arguments

• x, y: locations of grid lines at which the values in z are measured. These must be in ascending order. By default, equally spaced values from 0 to 1 are used. If x is a list, its components x$x and x$y are used for x and y, respectively.
• z: a matrix containing the values to be plotted (NAs are allowed).
• theta, phi: angles defining the viewing direction. theta gives the azimuthal direction and phi the colatitude.
• d: a value which can be used to vary the strength of the perspective transformation.
• expand: a expansion factor applied to the z coordinates.
• xlim, ylim, zlim: x-, y- and z-limits for the axes.
• levels: a vector of values specifying the levels to be used for plotting the surface with different colours.
• nlevels: a value specifying the number of levels to be used for plotting. This value is used if levels argument is not specified.
• col.palette: the colour palette used for plotting.
• border: the colour of the line drawn around the surface facets. By default is set to NA so no borders are drawn.
• ticktype: a character specifying the type of axes tickmarks. By default "detailed" ticks are drawn.
• xlab, ylab, zlab: character strings specifying the titles for the axes.
• ...: Further arguments passed to the function persp.

Details

This function enhances the default perspective plot for drawing 3-dimensional surfaces.

Returns

Return a list with the following elements: - persp: the viewing transformation matrix (see persp);

• levels: a vector of values giving the levels used for plotting the surface;

• colors: a vector of strings giving the colour used for plotting the surface.

Author(s)

Luca Scrucca

See Also

persp

Examples

y <- x <- seq(-10, 10, length=60)
f <- function(x,y) { r <- sqrt(x^2+y^2); 10 * sin(r)/r }
z <- outer(x, y, f)
persp3D(x, y, z, theta = 30, phi = 30, expand = 0.5)
persp3D(x, y, z, col.palette = heat.colors, phi = 30, theta = 225, 
        box = TRUE, border = NA, shade = .4)
x1 <- seq(-3,3,length=50)
x2 <- seq(-3,3,length=50)
y <- function(x1, x2) sin(x1)+cos(x2)
persp3D(x1, x2, outer(x1,x2,y), zlab="y", theta = 150, phi = 20, expand = 0.6)