perm {GLMsData}

Permeability of building materials

Description

The permeability of building materials

Usage

data(perm)

Format

A data frame with 81 observations on the following 3 variables.

Day

the day; a factor with levels 1 up to 9

Mach

the machine used for measurement; a factor with levels A, B or C

Perm

the permeability in seconds: a numeric vector

Details

The data give the average permeability (in seconds) of eight sheets of building materials, using random samples of 81 sheets in three machines over nine days, with three measurements for each machine–day combination.

Source

Bent Joergensen (1992) Exponential dispersion models and extensions: A review. International Statistical Review, 60(1), 5–20.

References

A. Hald (1952) Statistical theory with engineering applications. New York: Wiley.

Examples

   data(perm)
   summary(perm)