binCounts: Fast element counting in non-overlapping bins

In HenrikBengtsson/matrixStats: Functions that Apply to Rows and Columns of Matrices (and to Vectors)

Fast element counting in non-overlapping bins

Description

Counts the number of elements in non-overlapping bins

Usage

binCounts(x, idxs = NULL, bx, right = FALSE, ...)

Arguments

x	A numeric vector of K positions for to be binned and counted.
idxs	A vector indicating subset of elements to operate over. If NULL, no subsetting is done.
bx	A numeric vector of B + 1 ordered positions specifying the B > 0 bins [bx[1], bx[2]), [bx[2], bx[3]), ..., [bx[B], bx[B + 1]).
right	If TRUE, the bins are right-closed (left open), otherwise left-closed (right open).
...	Not used.

Details

binCounts(x, bx, right = TRUE) gives equivalent results as rev(binCounts(-x, bx = rev(-bx), right = FALSE)), but is faster and more memory efficient.

Value

Returns an integer vector of length B with non-negative integers.

Missing and non-finite values

Missing values in x are ignored/dropped. Missing values in bx are not allowed and gives an error.

Author(s)

Henrik Bengtsson

See Also

An alternative for counting occurrences within bins is hist, e.g. hist(x, breaks = bx, plot = FALSE)$counts. That approach is ~30-60% slower than binCounts(..., right = TRUE).

To count occurrences of indices x (positive integers) in [1, B], use tabulate(x, nbins = B), where x does not have to be sorted first. For details, see tabulate().

To average values within bins, see binMeans().

HenrikBengtsson/matrixStats documentation built on Nov. 15, 2024, 3:20 p.m.