pluton {cluster} | R Documentation

## Isotopic Composition Plutonium Batches

### Description

The `pluton` data frame has 45 rows and 4 columns, containing percentages of isotopic composition of 45 Plutonium batches.

### Usage

    data(pluton)

### Format

This data frame contains the following columns:

Pu238
  the percentages of (238)Pu, always less than 2 percent.
Pu239
  the percentages of (239)Pu, typically between 60 and 80 percent (from neutron capture of Uranium, (238)U).
Pu240
  percentage of the plutonium 240 isotope.
Pu241
  percentage of the plutonium 241 isotope.

### Details

Note that the percentage of plutonium~242 can be computed from the other four percentages, see the examples.

In the reference below it is explained why it is very desirable to combine these plutonium patches in three groups of similar size.

### Source

Available as ‘`pluton.dat`’ from the archive currently http://www.agoras.ua.ac.be/datasets/clusplot-examples.tar.gz.

### References

Rousseeuw, P.J. and Kaufman, L and Trauwaert, E. (1996) Fuzzy clustering using scatter matrices, Computational Statistics and Data Analysis 23(1), 135–151.

### Examples

    data(pluton)

    hist(apply(pluton,1,sum), col = "gray") # between 94% and 100%
    pu5 <- pluton
    pu5$Pu242 <- 100 - apply(pluton,1,sum) # the remaining isotope.
    pairs(pu5)

[Package cluster version 1.11.0 Index]