stars {base}R Documentation

Star Plots and Segment Diagrams of Multivariate Data

Description

Star plots or segment diagrams are created on the current graphics device.

Usage

stars(x, full = TRUE, scale = TRUE, radius = TRUE, labels =
      dimnames(x)[[1]], locations = NULL, xlimit = NULL, ylimit = NULL,
      len = 1, colors = NULL, key.loc = NULL, key.labels = NULL,
      draw.segments = FALSE, draw.axes = FALSE, ...)

Arguments

x matrix of data. One segment plot will be produced for each row of the matrix. Missing values (NA) are allowed, but they are treated as if they were 0.
full logical flag: if TRUE, the segment plots will occupy a full circle. Otherwise, they occupy the (upper) semicircle only.
scale logical flag: if TRUE, the columns of the data matrix are scaled independently so that the maximum value in each column is 1 and the minimum is 0. If FALSE, the presumption is that the data have been scaled by some other algorithm to the range [0,1].
radius logical flag: in TRUE, the radii corresponding to each variable in the data will be drawn.
labels vector of character strings for labeling the plots. Unlike the S function stars, no attempt is made to construct labels if labels = NULL.
locations two column matrix with the x and y coordinates used to place each of the segment plots. If locations is NULL the segment plots will be placed in a rectangular grid.
xlimit vector with the range of x coordinates to plot.
ylimit vector with the range of y coordinates to plot.
len scale factor for the length of radii or segments.
colors vector of integers, each of which specifies a color for one of the segments. Ignored if draw.segments = FALSE
key.loc vector with x and y coordinates of the unit key.
key.labels vector of character strings for labeling the segments of the unit key. If omitted, the second component of dimnames(x) is used, if available.
draw.axes logical flag: if TRUE axes are added to the plot.
... any other arguments, typically arguments to par.

Details

Missing values are treated as 0.

Each star plot or segment diagram represents one row of the input x. Variables (columns) start on the right and wind counterclockwise around the circle. The size of the (scaled) column is shown by the distance from the center to the point on the star or the radius of the segment representing the variable.

Only one page of output is produced.

Note

This code started life as spatial star plots by David A. Andrews. See http://www.stat.rice.edu/~andrewsd/software/software.html.

Author(s)

Thomas S. Dye

Examples

data(mtcars)
stars(mtcars[, 1:7], len = 0.8, key.loc = c(12, 2),
      main = "Motor Trend Cars", full = FALSE) 

stars(mtcars[, 1:7], len = 0.8, key.loc = c(12, 2),
      main = "Motor Trend Cars", draw.segments = TRUE)

data(USJudgeRatings)
stars(USJudgeRatings, labels = abbreviate(case.names(USJudgeRatings)),
      key.loc = c(13, 1.5), main = "Judge not ...", len = 0.8)

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