triax.plot {plotrix}R Documentation

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"),
 show.legend=FALSE,label.points=FALSE,point.labels=NULL,
 col.symbols="black",pch=par("pch"),...)

Arguments

x Matrix where each row is three proportions or percentages that must sum to 1 or 100 respectively.
main The title of the soil texture 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. 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.
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.
... Additional arguments passed to points.

Details

triax.plot displays a triangular plot area on which proportions or percentages are displayed. An optional grid may also be displayed.

Value

A list of the x,y positions plotted.

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.plot will complain appropriately. Note also that triax.plot will only display properly in a square plot, which is forced by par(pty="s").

Author(s)

Jim Lemon

See Also

triax.points,triax.abline, thigmophobe.labels

Examples

 data(soils)
 triax.plot(soils[1:10,],main="DEFAULT")
 if(dev.interactive()) par(ask=TRUE)
 triax.plot(soils[1:10,],main="PERCENTAGES",
  tick.labels=seq(10,90,by=10),pch=3)
 main.title<- 
 triax.plot(soils[1:6,],main="GRID AND LEGEND",show.grid=TRUE,
  show.legend=TRUE,col.symbols=1:6,pch=4)
 if(dev.interactive()) par(ask=FALSE)

[Package plotrix version 2.1-5 Index]