asbio (version 1.9-7)

anscombe: Anscombe's quartet

Description

A set of four bivariate datasets with the same conditional means, conditional variances, linear regressions, and correlations, but with dramatically different forms of association.

Usage

data(anscombe)

Format

A data frame with 11 observations on the following 8 variables.

x1

The first conditional variable in the first bivariate dataset.

y1

The second conditional variable in the first bivariate dataset.

x2

The first conditional variable in the second bivariate dataset.

y2

The second conditional variable in the second bivariate dataset.

x3

The first conditional variable in the third bivariate dataset.

y3

The second conditional variable in the third bivariate dataset.

x4

The first conditional variable in the fourth bivariate dataset.

y4

The second conditional variable in the fourth bivariate dataset.

Details

Anscombe (1973) used these datasets to demonstrate that summary statistics are inadequate for describing association.

References

Anscombe, F. J. (1973) Graphs in statistical analysis. American Statistician 27 (1): 17-21.

Examples

# dev.new(height=3.5)
op <- par(mfrow=c(1,4),mar=c (0,0,2,3), oma = c(5, 4.2, 0, 0))
with(anscombe, plot(x1, y1, xlab = "", ylab = "", main = bquote(paste(italic(r),
" = ",.(round(cor(x1, y1),2)))))); abline(3,0.5) 
with(anscombe, plot(x2, y2, xlab = "", ylab = "",, main = bquote(paste(italic(r),
" = ",.(round(cor(x2, y2),2)))))); abline(3,0.5) 
with(anscombe, plot(x3, y3, xlab = "", ylab = "",, main = bquote(paste(italic(r),
" = ",.(round(cor(x3, y3),2)))))); abline(3,0.5) 
with(anscombe, plot(x4, y4, xlab = "", ylab = "",, main = bquote(paste(italic(r),
" = ",.(round(cor(x4, y4),2)))))); abline(3,0.5) 
mtext(expression(italic(y[1])),side=1, outer = TRUE, line = 3)
mtext(expression(italic(y[2])),side=2, outer = TRUE, line = 2.6)
mtext("(a)",side=3, at = -42, line = .5)
mtext("(b)",side=3, at = -26, line = .5)
mtext("(c)",side=3, at = -10.3, line = .5)
mtext("(d)",side=3, at = 5.5, line = .5)
par(op)