bootstrap (version 2014.4)

stamp: Data on Thickness of Stamps

Description

Thickness in millimeters of 485 postal stamps, printed in 1872. The stamp issue of that year was thought to be a "philatelic mixture", that is, printed on more than one type of paper. It is of historical interest to determine how many different types of paper were used.

Usage

data(stamp)

concept

• mode
• kernel density estimation
• stamp

source

Efron, B. and Tibshirani, R. (1993) An Introduction to the Bootstrap. Chapman and Hall, New York, London.

Details

In the book, this is used to exemplify determination of number of modes. It is also used for kernel density estimation.

Examples

summary(stamp)
with(stamp, {hist(Thickness);
             plot(density(Thickness), add=TRUE)})