spider: Make "radar" or "spider" plots.

Description

Radar plots and spider plots are just two of the many ways to show multivariate data. radar plots correlations as vectors ranging in length from 0 (corresponding to r=-1) to 1 (corresponding to an r=1). The vectors are arranged radially around a circle. Spider plots connect the end points of each vector. The plots are most appropriate if the variables are organized in some meaningful manner.

Usage

spider(y,x,data,labels=NULL,rescale=FALSE,center=FALSE,connect=TRUE,overlay=FALSE,
    scale=1,ncolors=31,fill=FALSE,main=NULL,...)
radar(x,labels=NULL,center=FALSE,connect=FALSE,scale=1,ncolors=31,fill=FALSE,
     add=FALSE,linetyp="solid", main="Radar Plot",...)

Arguments

The y variables to plot. Each y is plotted against all the x variables

The x variables defining each line. Each y is plotted against all the x variables

data

A correlation matrix from which the x and y variables are selected

labels

Labels (assumed to be colnames of the data matrix) for each x variable

rescale

If TRUE, then rescale the data to have mean 0 and sd = 1. This is used if plotting raw data rather than correlations.

center

if TRUE, then lines originate at the center of the plot, otherwise they start at the mid point.

connect

if TRUE, a spider plot is drawn, if FALSE, just a radar plot

scale

can be used to magnify the plot, to make small values appear larger.

ncolors

if ncolors > 2, then positive correlations are plotted with shades of blue and negative correlations shades of red. This is particularly useful if fill is TRUE. ncolors should be an odd number, so that neutral values are coded as white.

fill

if TRUE, fill the polygons with colors scaled to size of correlation

overlay

If TRUE, plot multiple spiders on one plot, otherwise plot them as separate plots

add

If TRUE, add a new spider diagram to the previous one.

linetyp

see lty in the par options

main

A label or set of labels for the plots

…

Additional parameters can be passed to the underlying graphics call

Value

Either a spider or radar plot

Details

Displaying multivariate profiles may be done by a series of lines (see, e.g., matplot), by colors (see, e.g., cor.plot, or by radar or spider plots.

To show just one variable as a function of several others, use radar. To make multiple plots, use spider. An additional option when comparing just a few y values is to do overlay plots. Alternatively, set the plotting options to do several on one page.

Examples

Run this code

# NOT RUN {
op <- par(mfrow=c(3,2))
spider(y=1,x=2:9,data=Thurstone,connect=FALSE) #a radar plot
spider(y=1,x=2:9,data=Thurstone) #same plot as a spider plot
 spider(y=1:3,x=4:9,data=Thurstone,overlay=TRUE)
 #make a somewhat oversized plot
spider(y=26:28,x=1:25,data=cor(bfi,use="pairwise"),fill=TRUE,scale=2) 
par(op)
# }