| triplot {TeachingDemos} | R Documentation |
Create (or add to) a trilinear plot of 3 proportions that sum to 1.
triplot(x, y = NULL, z = NULL, labels = dimnames(x)[[2]], txt =
dimnames(x)[[1]], legend = NULL, legend.split = NULL, inner = TRUE, inner.col = c("lightblue", "pink"), inner.lty = c(2, 3), add = FALSE, main = "", ...)
x |
Vector or matrix of up to 3 columns. |
y |
Vector (if x is a vector). |
z |
Vector (if x is a vector). |
labels |
Labels for the 3 components (printed at corners). |
txt |
Vector of text strings to be plotted instead of points. |
legend |
Labels for the data points |
legend.split |
What proportion of the labels will go on the left. |
inner |
Logical, should the inner reference lines be plotted. |
inner.col |
Colors for the 2 inner triangles. |
inner.lty |
Line types for the 2 inner triangles. |
add |
Add points to existing plot (TRUE), or create a new plot (FALSE). |
main |
Main title for the plot. |
... |
Additional arguments passed on to points or text. |
Trilinear plots are useful for visualizing membership in 3 groups by plotting sets of 3 proportions that sum to 1 within each set.
The data can be passed to the function as a matrix with either 2 or 3
columns, or as seperate vectors to x, y, and optionaly
z. If 2 columns are passed in, then they must be between 0 and
1 and the 3rd column will be created by subtracting both from 1. If 3
columns of data are given to the function then each will be divided by
the sum of the 3 columns (they don't need to sum to 1 before being
passed in).
An invisible matrix with 2 columns and the same number of rows as x
corresponding to the points plotted (after transforming to 2
dimensions).
The return matrix can be passed to identify for labeling of
individual points.
Using type='n' and add=FALSE will return the transformed
points without doing any plotting.
Greg Snow greg.snow@intermountainmail.org
Allen, Terry. Using and Interpreting the Trilinear Plot. Chance. 15 (Summer 2002).
triangle.plot in package ade4,
ternaryplot in package vcd, tri in package cwhtool,
soil.texture and triax.plot in package plotrix.
triplot(USArrests[c(1,4,2)])
tmp <- triplot(USArrests[c(1,4,2)],txt=NULL)
## Not run: identify(tmp, lab=rownames(USArrests) )
tmp <- rbind( HairEyeColor[,,'Male'], HairEyeColor[,,'Female'])
tmp[,3] <- tmp[,3] + tmp[,4]
tmp <- tmp[,1:3]
triplot(tmp, legend=rep(c('Male','Femal'),each=4),
col=rep(c('black','brown','red','yellow'),2))