s.density: 2-D scatter plot with kernel density estimation

In adegraphics: An S4 Lattice-Based Package for the Representation of Multivariate Data

2-D scatter plot with kernel density estimation

Description

This function represents a two dimensional scatter plot of points distribution. Densities' representation is based on the levelplot graphic in lattice (density's surface, filled with colors and/or contour lines).

Usage

s.density(dfxy, xax = 1, yax = 2, bandwidth = NULL, gridsize = c(450L, 450L), 
  nrpoints = 300, threshold = 0.1, col = NULL, contour = FALSE, region = !contour, 
  nclass = 8, facets = NULL, plot = TRUE, storeData = TRUE, add = FALSE, pos = -1, ...)

Arguments

dfxy	a data frame used to produce the plot
xax	an integer (or a vector) indicating which column(s) of dfxy is(are) plotted on the x-axis
yax	an integer (or a vector) indicating which column(s) of dfxy is(are) plotted on the y-axis
bandwidth	bandwidth for density calculations which is passed in parameters in the bkde2D function of the KernSmooth package
gridsize	grid dimension
nrpoints	number of points on the density image
threshold	a value between 0 and 1 to draw densities greater than this threshold. No density is visible whether it is equal to 1
col	a color or a colors vector to color densities
contour	a logical to draw contour lines
region	a logical to fill grid regions with col
nclass	number of class for density
facets	a factor splitting the rows of dfxy so that subsets of the data are represented on different sub-graphics
plot	a logical indicating if the graphics is displayed
storeData	a logical indicating if the data should be stored in the returned object. If FALSE, only the names of the data arguments are stored
add	a logical. If TRUE, the graphic is superposed to the graphics already plotted in the current device
pos	an integer indicating the position of the environment where the data are stored, relative to the environment where the function is called. Useful only if storeData is FALSE
...	additional graphical parameters (see adegpar and trellis.par.get)

Details

Density calculation is made using the kde2d function of the KernSmooth package.

Value

An object of class ADEg (subclass S2.density) or ADEgS (if add is TRUE and/or if facets or vectors for xax/yax are used).
The result is displayed if plot is TRUE.

Author(s)

Alice Julien-Laferriere, Aurelie Siberchicot [e-mail] and Stephane Dray

See Also

S2.density ADEg.S2

Examples

xx2 <- c(rnorm(50000, 1, 1), rnorm(50000, -1, 1))
yy2 <- c(rnorm(50000, -1, 0.5), rnorm(50000, 1, 0.5))
s.density(cbind(xx2, yy2), paxes.draw = TRUE, gridsize = c(200, 200), region = TRUE, 
  contour = TRUE, plabels.cex = 0, threshold = 0.05, nclass = 3, 
  col = colorRampPalette(c("lightgrey", "black"))(100))

adegraphics documentation built on Oct. 13, 2023, 5:11 p.m.