pluton                package: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 <URL:
     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)

