centipede.plot {plotrix} | R Documentation |
Displays a centipede plot on the current graphics device.
centipede.plot(segs,midpoint="mean",lower.limit="std.error", upper.limit="std.err",left.labels=NULL,right.labels=NULL,sort.segs=TRUE, main="",xlab="",vgrid=NA,mar=NA,col=par("fg"),bg="green",...)
segs |
a matrix of midpoints and limits calculated by
get.segs . |
midpoint |
The function to use in calculating the midpoint of each segment. |
lower.limit |
The functions to use in calculating the lower limits for each subset of the data. |
upper.limit |
The functions to use in calculating the upper limits. |
left.labels |
The variable or subset labels to place at the left margin of the plot. Default values are provided. |
right.labels |
The variable or subset labels to place at the right margin of the plot. |
sort.segs |
Whether to sort the segments in ascending order. |
main |
Optional title for the plot. |
xlab |
Optional x axis label for the plot. |
vgrid |
Optional vertical line(s) to display on the plot. |
mar |
Margin widths for the plot. Defaults to c(4,5,1,4) or c(4,5,3,4) if there is a title. |
col |
The color(s) of the limit lines and borders of the midpoint markers. |
bg |
The color(s) to fill the midpoint markers. |
... |
additional arguments passed to plot . |
centipede.plot
displays one or more midpoints and limits as
filled circles with horizontal error bars. It places labels on the left and
right sides of the plot. If these labels are long, it may be necessary to
pass explicit values to the mar
argument to leave enough room.
Similarly, centipede plots typically have a large number of subsets, and it may be necessary to start the graphics device with an aspect ratio that will prevent crowding of the labels when over 30 segments are displayed.
The matrix segs
may be entered manually or read from a file.
The first row specifies midpoints, the second and third rows the lower
and upper limits respectively and the fourth row the number of valid
observations.
nil.
This type of plot is also known as a caterpillar plot or a league table.
Jim Lemon
testcp<-list("",40) for(i in 1:40) testcp[[i]]<-rnorm(sample(1:8,1)*50) segs<-get.segs(testcp) centipede.plot(segs,main="Test centipede plot",vgrid=0)