quantreg (version 5.98)

Bosco: Boscovich Data

Description

Boscovich data used to estimate the ellipticity of the earth. There are five measurements of the arc length of one degree of latitude taken at 5 different latitudes. See Koenker (2005) for further details and references.

Usage

data(Bosco)

Format

A data frame containing 5 observations on 2 variables

x

sine squared of latitude measured in degrees

y

arc length of one degree of latitude measured in toise - 56,700, one toise approximately equals 1.95 meters.

References

Koenker, R. (2005), "Quantile Regression", Cambridge.

Examples

data(Bosco)
plot(0:10/10,0:10*100,xlab="sin^2(latitude)",
        ylab="arc-length of 1 degree of latitude",type="n")
points(Bosco)
text(Bosco, pos = 3, rownames(Bosco))
z <- rq(y ~ x, tau = -1, data = Bosco)
title("Boscovitch Ellipticity of the Earth Example")
xb <- c(.85,.9,.6,.6)
yb <- c(400,600,450,600)
for(i in 1:4){
        abline(c(z$sol[4:5,i]))
        interval <- paste("t=(",format(round(z$sol[1,i],2)),",",
                format(round(z$sol[1,i+1],2)),")",delim="")
        text(xb[i],yb[i],interval)
        }