OrdinalLogisticBiplot (version 0.4)

BiplotDensity: Density plot of a data set with overlaid contours.

Description

This function draws for a set of points a density contour lines plot. The densities can be calculated for the whole set of points or for the groups defined by a nominal variable.

Usage

BiplotDensity(X, y = NULL, nlevels = max(y), grouplabels = 1:nlevels, ncontours = 6, groupcols = 1:nlevels, img = TRUE, separate = FALSE, ncolors = 20, ColorType = 4, xliml = -1, xlimu = 1, yliml = -1, ylimu = 1, plotInd = FALSE)

Arguments

X

A matrix with the coordinates for the plane in which the the contour lines will be plotted.

y

Categorical variable used for defining clusters. If NULL, the density is calculated for the whole set of points.

nlevels

Number of clusters.

grouplabels

Set of labels for the centers of each cluster. It should be a vector with "nlevels" components.

ncontours

Number of contours that will be used in the representation.

groupcols

Vector whith a set of colors for the clusters.

img

Should the density be plotted (with different colors) together with the contour lines?. Default value is TRUE.

separate

Should the density for each cluster be represented on a different picture?. Default value is FALSE.

ncolors

Number of colors for the densities.

ColorType

Type of color schema for the density image. It should be a number between 1 and 5.

xliml

Minimum value on the x-axis.

xlimu

Maximum value on the x-axis.

yliml

Minimum value on the y-axis.

ylimu

Maximum value on the y-axis.

plotInd

Should the individuals be plotted?

Examples

data(LevelSatPhd)
olbo = OrdinalLogisticBiplot(LevelSatPhd)
x = olbo$RowCoords[, 1]
y = olbo$RowCoords[, 2]
plot(x,y, cex = 0, xlim=c(-1,1),ylim=c(-1,1))
X = olbo$RowCoords
y = as.matrix(as.numeric(LevelSatPhd[,4]))
gcols = c("midnightblue","black","red","gray87")
BiplotDensity(X,y,groupcols = gcols)