labsegs {caroline}

R Documentation

Buffered Segments for Point Labels

Description

This function is a wrapper for segments which trigonometrically shortens the lines that are near the "1" end so as not to cluter or overplot the text label it is attached to.

Usage

labsegs(x0, y0, x1, y1, buf=.3, ...)

Arguments

x0	initial x point coordinate
y0	initial x point coordinate
x1	initial x point coordinate
y1	initial x point coordinate
buf	the buffer between the label at point "1" and the actual segment
...	other parameters passed to segments.

See Also

segments

Examples

x <- rnorm(1000,0,.5)
y <- rnorm(1000,-.3,.15)

labdb <- data.frame(x=seq(-.5,.5,by=.5), y=rep(.85,3))
xlims <- c(-1,1)
ylims <- c(-.5,1)

x0.lbd <- x[rev(order(y))][1:3]
y0.lbd <- y[rev(order(y))][1:3]

par(mfrow=c(1,2))
plot(x,y, xlim=xlims, ylim=ylims, main='segments')
segments(x0=x0.lbd, y0=y0.lbd, x1=labdb$x, y1=labdb$y, col=rainbow(3), lwd=3)
text(x=labdb$x, y=labdb$y, labels=letters[1:3], cex=3, col=rainbow(3))

plot(x,y, xlim=xlims, ylim=ylims, main='labsegs')
labsegs(x0=x0.lbd, y0=y0.lbd, x1=labdb$x, y1=labdb$y, col=rainbow(3), lwd=3, buf=.07)
text(x=labdb$x, y=labdb$y, labels=letters[1:3], cex=3, col=rainbow(3))

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