aggregate function

Compute Summary Statistics of Data Subsets

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

## 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.

Returns

A matrix.

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)

See Also

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

Author(s)

N. Frerebeau