| plot.stepfun {stats} | R Documentation |
Method of the generic plot for stepfun
objects and utility for plotting piecewise constant functions.
## S3 method for class 'stepfun':
plot(x, xval, xlim, ylim,
xlab = "x", ylab = "f(x)", main = NULL,
add = FALSE, verticals = TRUE, do.points = TRUE,
pch = par("pch"), col = par("col"),
col.points = col, cex.points = par("cex"),
col.hor = col, col.vert = col,
lty = par("lty"), lwd = par("lwd"), ...)
## S3 method for class 'stepfun':
lines(x, ...)
x |
an R object inheriting from "stepfun". |
xval |
numeric vector of abscissa values at which to evaluate
x. Defaults to knots(x) restricted to xlim. |
xlim, ylim |
limits for the plot repion: see
plot.window. Both have sensible defaults defaults if
omitted. |
xlab, ylab |
labels for x and y axis. |
main |
main title. |
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 |
default color of all points and lines. |
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. |
lty, lwd |
line type and thickness for all lines. |
... |
further arguments of plot(.), or if(add)
segments(.). |
A list with two components
t |
abscissa (x) values, including the two outermost ones. |
y |
y values ‘in between’ the t[]. |
Martin Maechler maechler@stat.math.ethz.ch, 1990, 1993; ported to R, 1997.
ecdf for empirical distribution functions as
special step functions,
approxfun and splinefun.
require(graphics)
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, right = TRUE)
tt <- seq(0,3, by=0.1)
op <- par(mfrow=c(2,2))
plot(sfun0); plot(sfun0, xval=tt, add=TRUE, col.hor="bisque")
plot(sfun.2);plot(sfun.2,xval=tt, add=TRUE, col = "orange")# all colors
plot(sfun1);lines(sfun1, xval=tt, col.hor="coral")
##-- This is revealing :
plot(sfun0, verticals= FALSE,
main = "stepfun(x, y0, f=f) for f = 0, .2, 1")
for(i in 1:3)
lines(list(sfun0,sfun.2,stepfun(1:3,y0,f = 1))[[i]], col=i)
legend(2.5, 1.9, paste("f =", c(0,0.2,1)), col=1:3, lty=1, y.intersp=1)
par(op)
# Extend and/or restrict 'viewport':
plot(sfun0, xlim = c(0,5), ylim = c(0, 3.5),
main = "plot(stepfun(*), xlim= . , ylim = .)")
##-- this works too (automatic call to ecdf(.)):
plot.stepfun(rt(50, df=3), col.vert = "gray20")