Plot Step Functions
Usage
plot.stepfun(Fn, x, xlim, xlab = "x", ylab = "f(x)", main = NULL,
add = FALSE, verticals = TRUE, do.points = TRUE,
pch = par("pch"), col.points=par("col"), cex.points=par("cex"),
col.hor = par("col"), col.vert= par("col"), ...)
Arguments
Fn
|
an R object inheriting from "stepfun".
|
x
|
numeric vector of abscissa values at which to evaluate
Fn. Defaults to knots(Fn) restricted to xlim.
|
xlim
|
numeric(2); range of x values to use.
|
add
|
logical; if TRUE only add to an existing plot.
|
verticals
|
logical; if TRUE, draw vertical lines at steps.
|
do.points
|
logical; if true, also draw points at the
(xlim restricted) knot locations.
|
pch
|
character; point character if do.points.
|
col.points
|
character or integer code; color of points if do.points.
|
cex.points
|
numeric; character expansion factor if do.points.
|
col.hor
|
color of horizontal lines.
|
col.vert
|
color of vertical lines.
|
xlab,ylab
|
labels of x and y axis.
|
main
|
main title.
|
...
|
further arguments of plot(.), or if(add)
segments(.).
|
Description
Method of the generic plot for stepfun
objects and utility for plotting piecewise constant functions.Value
A list with two components
t
|
abscissa (x) values, including the two outermost ones.
|
y
|
y values `in between' the t[].
|
Author(s)
Martin Maechler <maechler@stat.math.ethz.ch>, 1990,
1993; ported to R, 1997.See Also
ecdf for empirical distribution functions as
special step functions,
approxfun and splinefun.Examples
y0 <- c(1,2,4,3)
sfun0 <- stepfun(1:3, y0, f = 0)
sfun.2 <- stepfun(1:3, y0, f = .2)
sfun1 <- stepfun(1:3, y0, f = 1)
tt <- seq(0,3, by=0.1)
op <- par(mfrow=c(2,2))
plot(sfun0); plot(sfun0, x=tt, add=T, col.h="bisque")
plot(sfun.2);plot(sfun.2,x=tt, add=T, col.h="orange")
plot(sfun1); plot(sfun1, x=tt, add=T, col.h="coral")
##-- This is revealing :
plot(sfun0, verticals= FALSE,
main = "stepfun(x, y0, f=f) for f = 0, .2, 1")
for(i in 1:3)
plot(list(sfun0,sfun.2,sfun1)[[i]], add=TRUE, col.h=i, col.v=i)
legend(2.5, 1.9, paste("f =", c(0,0.2,1)), col=1:3, lty=1, y.inter=1); par(op)
##-- this works too (automatic call to ecdf(.)):
plot.stepfun(rt(50, df=3), col.vert = "gray20")