aggregate: Compute Summary Statistics of Data Subsets

In nexus: Sourcing Archaeological Materials by Chemical Composition

Compute Summary Statistics of Data Subsets

Description

Splits the data into subsets, computes summary statistics for each, and returns the result.

Usage

## S4 method for signature 'CompositionMatrix'
aggregate(x, by, FUN, ..., simplify = TRUE, drop = TRUE)

## S4 method for signature 'GroupedComposition'
aggregate(x, FUN, ..., simplify = TRUE)

Arguments

x	A CompositionMatrix object.
by	A vector or a list of grouping elements, each as long as the variables in x (see group()).
FUN	A function to compute the summary statistics.
...	Further arguments to be passed to FUN.
simplify	A logical scalar: should the results be simplified to a matrix if possible?
drop	A logical scalar indicating whether to drop unused combinations of grouping values.

Value

A matrix.

Author(s)

N. Frerebeau

See Also

Other statistics: condense(), covariance(), dist, mahalanobis(), margin(), mean(), pip(), quantile(), scale(), variance(), variance_total(), variation()

Examples

## Data from Aitchison 1986
data("slides")

## Coerce to a compositional matrix
coda <- as_composition(slides)

## Compositional mean by slide
aggregate(coda, by = slides$slide, FUN = mean)

## Metric variance by slide
aggregate(coda, by = slides$slide, FUN = variance_total)

nexus documentation built on June 8, 2025, 11:12 a.m.