plotxyy plots two vectors of numbers against single x-axis

plotxyy plots two plots on the single graph so that they share the x-axis. The first series is plotted on the left vertical axis and the second on the right-hand axis.

Usage

plotxyy(
  x1,
  x2 = x1,
  y1,
  y2,
  xlab = "",
  ylab1 = "",
  ylab2 = "",
  cex = 0.85,
  fnt = 7,
  colour = c(1, 2),
  defpar = FALSE
)

Arguments

x1: the x values for the first variable. Always use the variable that has the widest x-axis values as the first variable to ensure all values are plotted.
x2: the x values for the second variable.
y1: the left-hand axis values
y2: the right-hand axis values
xlab: the x label, default=""
ylab1: the left-hand y label, default=""
ylab2: the right-hand y label, default=""
cex: the size of font on the axes, default=0.85
fnt: the font used on axes, default=7 (bold times)
colour: a vector of two values for the colour of each line, default=c(1,2) black and red
defpar: should the internal 'par' statement be used = defpar=TRUE, or the default=FALSE, which means the plot 'par' will be defined outside the plot.

Value

nothing but it plots a graph

Examples

x <- 1:20
yval1 <- rnorm(20,mean=5,sd=1)
yval2 <- rnorm(20,mean=10,sd=1)
plotxyy(x1=x,y1=yval1,y2=yval2,ylab1="mean=5",ylab2="mean=10")