colTabulates {DelayedMatrixStats} | R Documentation

## Tabulates the values in a matrix by row (column)

### Description

Tabulates the values in a matrix by row (column).

### Usage

    colTabulates(x, rows = NULL, cols = NULL, values = NULL, ...)

    rowTabulates(x, rows = NULL, cols = NULL, values = NULL, ...)

    ## S4 method for signature 'DelayedMatrix'
    colTabulates(x, rows = NULL, cols = NULL,
      values = NULL, force_block_processing = FALSE, ...)

    ## S4 method for signature 'DelayedMatrix'
    rowTabulates(x, rows = NULL, cols = NULL,
      values = NULL, force_block_processing = FALSE, ...)

### Arguments

`x` | A NxK DelayedMatrix.
`rows` | A `vector` indicating subset of rows (and/or columns) to operate over. If `NULL`, no subsetting is done.
`cols` | A `vector` indicating subset of rows (and/or columns) to operate over. If `NULL`, no subsetting is done.
`values` | An `vector` of J values of count. If `NULL`, all (unique) values are counted.
`...` | 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 `getOption("DelayedArray.block.size")`) columns (`colFoo()`) or rows (`rowFoo()`) into memory as an ordinary base::array.

### Value

Returns a NxJ (KxJ) `matrix` where N (K) is the number of row (column) `vector`s tabulated and J is the number of values counted.

### Examples

    # 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)))

    colTabulates(dm_DF)

    rowTabulates(dm_DF)

[Package DelayedMatrixStats version 1.0.3 Index]