stamp {bootstrap}

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)

Format

A data frame with 485 observations on the following variable.

Thickness

Thickness in millimeters, a numeric vector

Details

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

Note

The main example in the book is on page 227. See also the CRAN package diptest for an alternative method.

Source

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

Examples

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