| curve {base} | R Documentation |
Draw Function Plots
Description
Draws a curve corresponding to the given function or expression
(in x) over the interval [from,to].
Usage
curve(expr, from, to, n=101, add=FALSE, type="l", ylab = NULL, log=NULL, ...)
plot.function(fn, from=0, to=1, n=101, ...)
Arguments
expr |
an expression written as a function of |
fn |
a ‘vectorizing’ numeric R function. |
from, to |
the range over which the function will be plotted. |
n |
integer; the number of x values at which to evaluate. |
add |
logical; if |
... |
graphical parameters can also be specified as arguments.
|
Details
The evaluation of expr is at n points equally spaced
over the range [from, to].
The points determined in this way are then joined with
straight lines.
fn(x) or expr (with x inside) must return a
numeric of the same length as x.
This used to be a quick hack which seems to serve a useful purpose, but can give bad results for functions which are not smooth.
Value
NULL. For “expensive” expressions, you should use smarter tools.
See Also
splinefun for spline interpolation, lines.
Examples
par(mfrow=c(2,2))
curve(x^3-3*x, -2, 2)
curve(x^2-2, add = TRUE, col = "violet")
curve(sin, -pi, 3*pi)
plot(cos)
chippy <- function(x) sin(cos(x)*exp(-x/2))
curve(chippy, -8, 7, n=2001)
for(ll in c("","x","y","xy"))
curve(log(1+x), 1,100, log=ll, sub=paste("log=",ll))