groupparts {compositions} | R Documentation

## Group amounts of parts

### Description

Groups parts by amalgamation or balancing of their amounts or proportions.

### Usage

    groupparts(x,...)
    ## S3 method for class 'acomp':
    groupparts(x,...,groups=list(...))
    ## S3 method for class 'rcomp':
    groupparts(x,...,groups=list(...))
    ## S3 method for class 'aplus':
    groupparts(x,...,groups=list(...))
    ## S3 method for class 'rplus':
    groupparts(x,...,groups=list(...))

### Arguments

`x` | an amount/compositional dataset
`...` | further parameters to use (actually ignored)
`groups` | a list of numeric xor character vectors, each giving a group of parts

### Details

In the real geometry grouping is done by amalgamation (i.e. adding the parts). In the Aitchison-geometry grouping is done by taking geometric means. The new parts are named by named formal arguments. Not-mentioned parts remain ungrouped.

### Value

a new dataset of the same type with each group represented by a single column

### Missing Policy

For the real geometries, SZ and BDL are considered as 0, and MAR and MNAR are kept as missing of the same type. For the relative geometries, a BDL is a special kind of MNAR, whereas a SZ is qualitatively different (thus a balance with a SZ has no sense). MAR values transfer their MAR property to the resulting new variable.

### Author(s)

K.Gerald v.d. Boogaart http://www.stat.boogaart.de, Raimon Tolosana-Delgado

### References

Egozcue, J.J. and V. Pawlowsky-Glahn (2005) Groups of Parts and their Balances in Compositional Data Analysis, Mathematical Geology, in press

### See Also

`aplus`

### Examples

    data(SimulatedAmounts)
    groupparts(acomp(sa.lognormals5),A=c(1,2),B=c(3,4),C=5)
    groupparts(aplus(sa.lognormals5),B=c(3,4),C=5)
    groupparts(rcomp(sa.lognormals5),A=c("Cu","Pb"),B=c(2,5))
    groupparts(rplus(sa.lognormals5),1:5)

[Package compositions version 0.91-6 Index]