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Last data update: 2014.03.03

R: Kernel density estimation for two continuous variables.

plotDensity3d.fnc

R Documentation

Kernel density estimation for two continuous variables.

Description

The densities of two continuous variables is first computed using the density function from package stats. The outer product of the two densities is computed, which can be plotted as a contour map, a perspective plot, or a dynamic 3d perspective graph.

Usage

plotDensity3d.fnc(x, y, plot.type = "contour", color = "terrain", 
xlab = NULL, ylab = NULL, zlab = NULL, main = NULL, cex = 1, alpha = 1, 
lit = TRUE, theta = 0, phi = 0, bw = "nrd0", adjust = 1, kernel = c("gaussian", 
"epanechnikov", "rectangular", "triangular", "biweight", "cosine", 
"optcosine"), weights = NULL, window = kernel, width, give.Rkern = FALSE, 
n = 50, from, to, cut = 3, na.rm = FALSE, ...)

Arguments

`x, y`	Numeric vectors.
`plot.type`	The type of plot to make. Can be any of `"contour"` (default), `"persp"`, or, if package `rgl` is available, `"persp3d"`.
`color`	The colour scheme to use for plots. One of “`topo`”, “`heat`”, “`cm`”, “`terrain`”, “`gray`” or “`bw`”. Schemes “`gray`” and “`bw`” also modify the colors used.
`xlab, ylab, zlab`	Titles for the axes. N.B. These must be character strings; expressions are not accepted. Numbers will be coerced to character strings.
`main`	The main title on top of the plot.
`cex`	The size of label and main text.
`alpha`	For `plot.type = "persp3d"`, alpha values between 0.0 (fully transparent) to 1.0 (opaque) for the main 3d surface.
`lit`	Logical, specifying if lighting calculation should take place on geometry.
`theta`	Angle defining the viewing direction. `theta` gives the azimuthal direction. Used only if `plot.type = "persp"`.
`phi`	Angle defining the viewing direction. `phi` gives the colatitude. Used only if `plot.type = "persp"`.
`bw, adjust, kernel, weights, window, width, give.Rkern, n, from, to, cut, na.rm`	See help page to function `density`.
`...`	Further arguments passed to functions `image`, `contour`, `persp`, or `persp3d`.

Details

See help page to the density function as well as to Duncan Murdoch's persp3d function for more information. To save screenshots of "persp3d" plots (after plotting), use function rgl.snapshot (produces png files) or function rgl.postscript (produces eps files).

Value

Either a contour map or a (dynamic) perspective plot. Invisibly returns

`x`	The numeric vector supplied in argument `x`.
`y`	The numeric vector supplied in argument `y`.
`xd`	The density object tied to vector `x`.
`yd`	The density object tied to vector `y`.
`mat`	The outer product of the `x` and `y` densities in matrix format.
`col`	The color used for plotting.

Author(s)

Antoine Tremblay, Dalhousie University, trea26@gmail.com.

Examples

# see example in LMERConvenienceFunctions help page.