group_split function

Divide into Groups

Divides a compositional matrix by groups. methods

group_split(object, ...)

## S4 method for signature 'CompositionMatrix'
split(x, f, drop = FALSE, ...)

## S4 method for signature 'LogRatio'
split(x, f, drop = FALSE, ...)

## S4 method for signature 'GroupedComposition'
group_split(object, ...)

## S4 method for signature 'GroupedLogRatio'
group_split(object, ...)

Arguments

• object, x: A CompositionMatrix object.
• ...: Currently not used.
• f: A factor in the sense that as.factor(f) defines the grouping, or a list of such factors in which case their interaction is used for the grouping (see base::split()).
• drop: A logical scalar: should levels that do not occur be dropped?

Returns

A list of CompositionMatrix objects.

Examples

## Create a data.frame
X <- data.frame(
  samples = c("A", "A", "A", "B", "B", "B", "C", "C", "C"),
  groups = c("X", "X", "X", "X", NA, NA, "Y", "Y", "Y"),
  Ca = c(7.72, 7.32, 3.11, 7.19, 7.41, 5, 4.18, 1, 4.51),
  Fe = c(6.12, 5.88, 5.12, 6.18, 6.02, 7.14, 5.25, 5.28, 5.72),
  Na = c(0.97, 1.59, 1.25, 0.86, 0.76, 0.51, 0.75, 0.52, 0.56)
)

## Coerce to a compositional matrix
Y <- as_composition(X, parts = c("Ca", "Fe", "Na"))

## Split by group
## /!\ Unassigned samples (NA) are discarded ! /!\
(s1 <- split(Y, f = X$groups))

## Better to use grouped matrix
Y <- group(Y, by = X$groups)
(s2 <- group_split(Y))

## Bind by rows
do.call(rbind, s2)

See Also

Other grouping methods: group(), group_metadata, group_subset()

Author(s)

N. Frerebeau