plot,kepdf-method: Plot objects of class kepdf

Description

Functions and methods for plotting objects of kepdf-class.

Usage

# S4 method for kepdf
plot(x, y, eval.points = NULL, n.grid = NULL,
		data = NULL, add = FALSE, main = NULL, xlab = NULL, ylab = NULL, 
		zlab = NULL, col = NULL, col.data=2, type="l", props = c(75,50,25), 
		method="contour", ticktype = "detailed", indcol = NULL, 
		text.diag.panel = NULL, gap = 0.5, ...)

Value

A list containing the following elements:

eval.points: data points at which the plotted density has been evaluated
estimate: the estimated density at eval.points

Arguments

x: An object of kepdf-class;
y: Not used; for compatibility with generic plot;
eval.points: A matrix of data points at which the density to be plotted has to be evaluated; the number of columns must correspond to the dimension of the sample data used to estimate the density. If not provided, density is evaluated on a grid defined on the range of sample data.
n.grid: A vector with length set to the number of column of sample data, defining the length of the grid on which the density to be plotted is evaluated; this argument is ignored when eval.points is not NULL.
data: Data to be optionally superimposed to the density plot.
add: Logical. If TRUE, add to a current plot.
main: An overall title for the plot.
xlab: A title for the x axis.
ylab: A title for the y axis.
zlab: A title for the z axis.
col: A specification for the plotting color.
col.data: A specification for the color of data. Ignored if data is NULL.
type: What type of plot should be drawn. This argument applies when kernel density estimate is performed on unidimensional data only. Default value is "l".
props: A vector defining the fraction of the data to be included within each density level. This argument applies when kernel density estimate is performed on multidimensional data only.
method: One of c("contour", "image", "perspective"). To be used when two or higher dimensional data have been used to estimate the density.
ticktype: Character: "simple" draws just an arrow parallel to the axis to indicate direction of increase; "detailed" draws normal ticks; to be used if method="perspective" only.
indcol: Vector of the column positions to be plotted, when densities are estimated on higher than 2-dimensional data.
text.diag.panel: Text to be displayed on the diagonal panels when plotting densities estimated on higher than 2-dimensional data.
gap: Distance between subplots, when plotting densities estimated of 2-dimensional data or higher-dimensional data.
...: Further arguments to be passed to plot, image, contour, persp.

Methods

signature(x = "kepdf", y = "missing")

S4 method for plotting objects of kepdf-class.

Details

When density estimation is based on two or higher dimensional data, these functions make use of functions contour, image and persp. For densities estimated on higher than 2-d data, the pairwise marginal estimated densities are plotted for all possible pairs of coordinates or a chosen selection of them.

Examples

Run this code

#1-d example
set.seed(123)
x1 <- rnorm(50)

#normal optimal bandwidth
pdf1a <- kepdf(x1)
#shrink the smoothing parameter
pdf1b <- kepdf(x1, h=0.5*h.norm(x1))

plot(pdf1a, n.grid=50, data=x1, xlab="x1", ylim=c(0, max(c(pdf1a@estimate,
   pdf1b@estimate))))
plot(pdf1b, n.grid=50, lty=2, add=TRUE)

#2-d example
set.seed(123)
x2 <- cbind(rnorm(50),rnorm(50))

pdf2 <- kepdf(x2)

plot(pdf2, n.grid=c(50,50), data=x2)
plot(pdf2, n.grid=c(50,50), method="image")
plot(pdf2, n.grid=c(50,50), method="perspective", phi=30, theta=30)

#3-d example
set.seed(123)
x3 <- cbind(rnorm(50), rnorm(50), rnorm(50))

pdf3 <- kepdf(x3)

plot(pdf3, n.grid=c(50,50,50))
plot(pdf3, n.grid=c(50,50,50), method="image", col = terrain.colors(30))
plot(pdf3, n.grid=c(50,50,50), method="perspective", phi=30, theta=30)

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