triax.plot: Triangle plot

In plotrix/plotrix: Various Plotting Functions

Triangle plot

Description

Display a triangle plot with optional grid.

Usage

 triax.plot(x=NULL,main="",at=seq(0.1,0.9,by=0.1),
 axis.labels=NULL,tick.labels=NULL,col.axis="black",cex.axis=1,
 cex.ticks=1,
 align.labels=TRUE,show.grid=FALSE,col.grid="gray",lty.grid=par("lty"),
 cc.axes=FALSE,show.legend=FALSE,label.points=FALSE,point.labels=NULL,
 col.symbols="black",pch=par("pch"),mar=c(5,2,4,2),no.add=TRUE,...)

Arguments

x	Matrix where each row is three proportions or percentages that must sum to 1 or 100 respectively.
main	The title of the triangle plot. Defaults to nothing.
at	The tick positions on the three axes.
axis.labels	Labels for the three axes in the order left, right, bottom. Defaults to the column names.
tick.labels	The tick labels for the three axes as a list with three components l, r and b (left, right and bottom). Defaults to argument ‘⁠at⁠’ (proportions).
col.axis	Color of the triangular axes, ticks and labels.
cex.axis	Character expansion for axis labels.
cex.ticks	Character expansion for the tick labels.
align.labels	Logical - whether to align axis and tick labels with the axes.
show.grid	Whether to display grid lines at the ticks.
col.grid	Color of the grid lines. Defaults to gray.
lty.grid	Type of line for the grid.
cc.axes	Whether axes and axis ticks should be clockwise or counterclockwise.
show.legend	Logical - whether to display a legend.
label.points	Logical - whether to call ‘⁠thigmophobe.labels⁠’ to label the points.
point.labels	Optional labels for the points and/or legend.
col.symbols	Color of the symbols representing each value.
pch	Symbols to use in plotting values.
mar	Margins for the triangle plot.
no.add	Whether to restore the previous plotting parameters (‘⁠TRUE⁠’) or leave them, allowing more points to be added.
...	Additional arguments passed to ‘⁠points⁠’.

Details

‘⁠triax.plot⁠’ displays a triangular plot area on which proportions or percentages are displayed. A grid or legend may also be displayed.

Value

A list containing ‘⁠xypos⁠’ (the ‘⁠x,y⁠’ positions plotted) and ‘⁠oldpar⁠’ (the plotting parameters at the time ‘⁠triax.plot⁠’ was called).

Note

A three axis plot can only properly display one or more sets of three proportions that each sum to 1 (or percentages that sum to 100). Other values may be scaled to proportions (or percentages), but unless each set of three sums to 1 (or 100), they will not plot properly and ‘⁠triax.points⁠’ will complain appropriately. Note also that ‘⁠triax.plot⁠’ will only display properly in a square plot, which is forced by ‘⁠par(pty="s")⁠’.

In case the user does want to plot values with different sums, the axis tick labels can be set to different ranges to accomodate this. ‘⁠triax.points⁠’ will still complain, but it will plot the values.

If planning to add points with ‘⁠triax.points⁠’ call ‘⁠triax.plot⁠’ with ‘⁠no.add=FALSE⁠’ and restore plotting parameters after the points are added.

Author(s)

Jim Lemon - thanks to Ben Daughtry for the info on counterclockwise axes.

See Also

triax.points, triax.abline, thigmophobe.labels

Examples

 data(soils)
 triax.plot(soils[1:10,],main="DEFAULT")
 triax.plot(soils[1:10,],main="PERCENTAGES (Counterclockwise axes)",
  tick.labels=list(l=seq(10,90,by=10),r=seq(10,90,by=10),b=seq(10,90,by=10)),
  pch=3,cc.axes=TRUE)
 triax.return<-triax.plot(soils[1:6,],main="GRID AND LEGEND",
  show.grid=TRUE,show.legend=TRUE,col.symbols=1:6,pch=4)
 # triax.plot changes a few parameters
 par(triax.return$oldpar)

plotrix/plotrix documentation built on Feb. 19, 2024, 8:16 a.m.