R: Counts the number of occurrences of a specific value

colCounts {DelayedMatrixStats}

R Documentation

Counts the number of occurrences of a specific value

Description

The row- and column-wise functions take either a matrix or a vector as input. If a vector, then argument dim. must be specified and fulfill prod(dim.) == length(x). The result will be identical to the results obtained when passing matrix(x, nrow = dim.[1L], ncol = dim.[2L]), but avoids having to temporarily create/allocate a matrix, if only such is needed only for these calculations.

Usage

colCounts(
  x,
  rows = NULL,
  cols = NULL,
  value = TRUE,
  na.rm = FALSE,
  dim. = dim(x),
  ...
)

rowCounts(
  x,
  rows = NULL,
  cols = NULL,
  value = TRUE,
  na.rm = FALSE,
  dim. = dim(x),
  ...
)

## S4 method for signature 'DelayedMatrix'
colCounts(
  x,
  rows = NULL,
  cols = NULL,
  value = TRUE,
  na.rm = FALSE,
  dim. = dim(x),
  force_block_processing = FALSE,
  ...
)

## S4 method for signature 'DelayedMatrix'
rowCounts(
  x,
  rows = NULL,
  cols = NULL,
  value = TRUE,
  na.rm = FALSE,
  dim. = dim(x),
  force_block_processing = FALSE,
  ...
)

Arguments

`x`	A NxK DelayedMatrix.
`rows`	A `vector` indicating subset of elements (or rows and/or columns) to operate over. If `NULL`, no subsetting is done.
`cols`	A `vector` indicating subset of elements (or rows and/or columns) to operate over. If `NULL`, no subsetting is done.
`value`	A value to search for.
`na.rm`	If `TRUE`, `NA`s are excluded first, otherwise not.
`dim.`	An `integer` `vector` of length two specifying the dimension of `x`, also when not a `matrix`.
`...`	Additional arguments passed to specific methods.
`force_block_processing`	`FALSE` (the default) means that a seed-aware, optimised method is used (if available). This can be overridden to use the general block-processing strategy by setting this to `TRUE` (typically not advised). The block-processing strategy loads one or more (depending on `\link[DelayedArray]{getAutoBlockSize}()`) columns (`colFoo()`) or rows (`rowFoo()`) into memory as an ordinary base::array.

Value

rowCounts() (colCounts()) returns an integer vector of length N (K). count() returns a scalar of type integer if the count is less than 2^31-1 (= .Machine$integer.max) otherwise a scalar of type double.

Author(s)

Peter Hickey

Examples

# A DelayedMatrix with a 'matrix' seed
dm_matrix <- DelayedArray(matrix(c(rep(1L, 5),
                                   as.integer((0:4) ^ 2),
                                   seq(-5L, -1L, 1L)),
                                 ncol = 3))
# A DelayedMatrix with a 'DataFrame' seed
dm_DF <- DelayedArray(S4Vectors::DataFrame(C1 = rep(1L, 5),
                                           C2 = as.integer((0:4) ^ 2),
                                           C3 = seq(-5L, -1L, 1L)))

colCounts(dm_matrix, value = 1)
# Only count those in the first 4 rows
colCounts(dm_matrix, rows = 1:4, value = 1)

rowCounts(dm_DF, value = 5)
# Only count those in the odd-numbered rows of the 2nd column
rowCounts(dm_DF, rows = seq(1, nrow(dm_DF), 2), cols = 2, value = 5)

[Package DelayedMatrixStats version 1.10.1 Index]