fillLines: Fill the area between lines

In AEBilgrau/Bmisc: Biostatistical miscellaneous functions

Description

This function fills or shades the area between two curves or under a curve.

Usage

fillLines(x, y1, y2 = rep(0, length(x)), ...)

Arguments

x	A numeric vector of x-coordinates.
y1	A numeric vector of y-coordinates.
y2	A numeric vector of y-coordiantes. Defaults to zero.
...	Arguments passed to polygon.

Details

The function fills or shades the area between two lines as drawn by lines(x, y1) and lines(x, y2). If y2 is not supplied the area between the curve and the x-axis is drawn. A seen in the examples, a neat trick to get the area under the curve is to set y2 = rep(-Inf, length(x)).

Author(s)

Anders Ellern Bilgrau <anders.ellern.bilgrau (at) gmail.com>

See Also

polygon

Examples

# Random example 1
x  <- seq(-2*pi, 2*pi, length.out = 100)
y1 <- cos(x)
y2 <- sin(4*x) - x^2 + 10
plot(x, type = "n", ylim = range(c(y1, y2)), xlim = range(x),
     ylab = "y", xlab = "x")
fillLines(x, y1, y2, col = "tomato", border = NA)
fillLines(x, pmin(y1, y2), rep(-Inf, length(x)), 
col = "steelblue", border = NA)
lines(x, y1, lty = 2, lwd = 2)
lines(x, y2, lty = 3, lwd = 2)

# Pursuit curve
x <- seq(0.01, 3, by = 0.01)
y <- 2*x^2 - log(x)
plot(x, y, type = "n", ylim = c(0, max(y)))
fillLines(x, y, density = 10, angle = -30, col = "orange")

# The super egg
p <- 5/2
h <- 1
r <- 3/4*h
x <- seq(-r, r, by = 0.001)
y1 <- h^p*(1 - abs(x/r)^p)^(1/p)
y2 <- -y1
plot(1, type = "n", xlim = c(-r,r), ylim = c(-h, h), asp = 1,
     xlab = "", ylab = "")
fillLines(x, y1, y2, col = "gold", lwd = 2, border = "orange") 

AEBilgrau/Bmisc documentation built on May 5, 2019, 11:28 a.m.