acompmargin {compositions} | R Documentation |

## Marginal compositions in Aitchison Compositions

### Description

Compute marginal compositions of selected parts, by computing the rest as the geometric mean of the non-selected parts.

### Usage

```
acompmargin(X,d=c(1,2),name="*",pos=length(d)+1,what="data")
```

### Arguments

`X` |
composition or dataset of compositions |

`d` |
vector containing the indices xor names of the columns selected |

`name` |
The new name of the amalgamation column |

`pos` |
The position where the new amalgamation column should be stored. This defaults to the last column. |

`what` |
The role of X either |

### Details

The amalgamation column is simply computed by taking the
geometric mean of the non-selected components. This is
consistent with the `acomp`

approach and gives clear ternary
diagrams. However, this geometric mean is difficult to interpret.

### Value

A closed compositions with class `"acomp"`

containing the
variables given by `d`

and the the amalgamation column.

### Missing Policy

MNAR has the highest priority, MAR afterwards, and WZERO (BDL,SZ) values are considered as 0 and finally reported as BDL.

### Author(s)

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

### References

Vera Pawlowsky-Glahn (2003) personal communication. Universitat de Girona.

van den Boogaart, K.G. and R. Tolosana-Delgado (2008)
"compositions": a unified R package to analyze Compositional Data,
*Computers & Geosciences*, 34 (4), pages 320-338,
doi: 10.1016/j.cageo.2006.11.017.

### See Also

### Examples

```
data(SimulatedAmounts)
plot.acomp(sa.lognormals5,margin="acomp")
plot.acomp(acompmargin(sa.lognormals5,c("Pb","Zn")))
plot.acomp(acompmargin(sa.lognormals5,c(1,2)))
```

*compositions*version 2.0-8 Index]