A vector containing the cluster assignment for each record in
the clustering data.
data.pts
If TRUE the point for each record is plotted.
centroids
If TRUE the centroid for each cluster is plotted.
choices
length 2 vector specifying the components to plot.
scale
The variables scaled by lambda ^ scale and the observations
are scaled by lambda ^ (1-scale), where lambda are the eigen
values of the principal components solution. scale should be between
0 and 1.
pc.biplot
If true, then lambda = 1 and the observations are are
scaled up the sqrt(n) and the variables scaled down by sqrt(n). In this case
the inner product between variables approximate covariances, and the
distances between observations approximate Mahalanobis distance. Gabriel
refers to this as a "principal component biplot".
var.axes
If TRUE the second set of points have arrows
representing them as (unscaled) axes.
col
A vector of length 2 giving the colours for the first and
second set of points respectively (and the corresponding axes). If a
single colour is specified it will be used for both sets. If
missing the default colour is looked for in the
palette: if there it and the next colour as used,
otherwise the first two colours of the paletter are used.
cex
The character expansion factor used for labelling the
points. The labels can be of different sizes for the two sets by
supplying a vector of length two.
xlabs
A vector of character strings to label the first set of
points: the default is to use the row dimname of x, or
1:n is the dimname is NULL.
ylabs
A vector of character strings to label the second set of
points: the default is to use the row dimname of y, or
1:n is the dimname is NULL.
expand
An expansion factor to apply when plotting the second set
of points relative to the first. This can be used to tweak the
scaling of the two sets to a physically comparable scale.
arrow.len
The length of the arrow heads on the axes plotted in
var.axes is true. The arrow head can be suppressed by
arrow.len = 0.
xlim, ylim
Limits for the x and y axes in the units of the
first set of variables.
main, sub, xlab, ylab, ...
graphical parameters.
Details
This function is a reworking of biplot in order to allow the cluster
centroids of a clustering solution to be displayed as well as the individual
data points. If both data.pts and centroids are set to
FALSE then only the variable directional vectors are displayed.
Graphical parameters can also be given to biplot.
Side Effects
a plot is produced on the current graphics device.