aggregate_to_pref_suff_byname: Aggregate a matrix to prefixes or suffixes of row and/or...

In matsbyname: An Implementation of Matrix Mathematics that Respects Row and Column Names

Aggregate a matrix to prefixes or suffixes of row and/or column names

Description

Row and column names are often constructed in the form prefix_start prefix prefix_end suffix_start suffix suffix_end and described by a notation vector. (See notation_vec().) This function performs aggregation by prefix or suffix according to a notation vector.

Usage

aggregate_to_pref_suff_byname(
  a,
  aggregation_map = NULL,
  keep,
  margin = c(1, 2),
  notation,
  pattern_type = "exact"
)

Arguments

a	A matrix of list of matrices to be aggregated by prefix or suffix.
aggregation_map	See aggregate_byname().
keep	See rename_to_pref_suff_byname()
margin	the dimension over which aggregation is to be performed; 1 for rows, 2 for columns, or c(1, 2) for both.
notation	See notation_vec().
pattern_type	See aggregate_byname().

Details

This function is a convenience function, as it bundles sequential calls to two helper functions, rename_to_pref_suff_byname() and aggregate_byname(). All arguments are passed to the helper functions.

Value

An aggregated version of a.

Examples

# This function is superseded. 
# Instead, use `aggregate_pieces_byname()`.
# For example:
m <- matrix((1:9), byrow = TRUE, nrow = 3, 
            dimnames = list(c("r1 -> b", "r2 -> b", "r3 -> a"), c("c1 -> z", "c2 -> y", "c3 -> y")))
m
aggregate_pieces_byname(m, piece = "pref", notation = RCLabels::arrow_notation)
aggregate_pieces_byname(m, piece = "suff", notation = RCLabels::arrow_notation)

# Original examples:
# Aggregation by prefixes does nothing more than rename, because all prefixes are different.
# Doing renaming like this (without also aggregating) is potentially dangerous, because  
# some rows and some columns could end up with same names.
aggregate_to_pref_suff_byname(m, keep = "pref", notation = RCLabels::arrow_notation)
# Aggregation by suffix reduces the number of rows and columns, 
# because there are same suffixes in both rows and columns
aggregate_to_pref_suff_byname(m, keep = "suff", notation = RCLabels::arrow_notation)

matsbyname documentation built on June 8, 2025, 10:08 a.m.