+----------+-------------------+
| pluton   | 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 <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)

