twoord.plot: Plot with two ordinates

Description

Two sets of values are displayed on the same plot with different ordinate scales on the left and right.

Usage

twoord.plot(lx,ly,rx,ry,data=NULL,xlim=NULL,lylim=NULL,rylim=NULL,
 mar=NULL,lcol=1,rcol=2,xlab="",ylab="",rylab="",lpch=1,rpch=2,
 type="b",...)

Arguments

lx,ly,rx,ry

y and optional x values for the plot

data

an optional data frame from which to obtain the above values

xlim

optional x limits as in plot

lylim,rylim

optional y limits for the left and right axes respectively

mar

optional margin adjustment, defaults to c(5,4,4,4)

lcol,rcol

colors to distinguish the two sets of values

xlab,ylab

axis labels as in plot

rylab

label for the right axis

lpch,rpch

plot symbols to distinguish the two sets of values

type

as in plot

...

additional arguments passed to axis.

Value

Details

twoord.plot automates the process of displaying two sets of values that have different ranges on the same plot. It is principally useful in illustrating some relationship between the values across the observations. It is assumed that the lx and rx values are at least adjacent, and probably overlapping. It is best to pass all the arguments lx, ly, rx, ry, but the function will attempt to substitute sensible x values if one or two are missing.

Examples

Run this code

twoord.plot(2:10,seq(3,7,by=0.5)+rnorm(9),
  1:15,rev(60:74)+rnorm(15),xlab="Sequence",
  ylab="Ascending values",rylab="Descending values",
  main="Test of twoord.plot")