colSums2 {DelayedMatrixStats} | R Documentation

## Calculates the sum for each row (column) in a matrix

### Description

Calculates the sum for each row (column) in a matrix.

### Usage

    colSums2(x, rows = NULL, cols = NULL, na.rm = FALSE, dim. = dim(x), ...)

    rowSums2(x, rows = NULL, cols = NULL, na.rm = FALSE, dim. = dim(x), ...)

    ## S4 method for signature 'DelayedMatrix'
    colSums2(x, rows = NULL, cols = NULL,
      na.rm = FALSE, dim. = dim(x), force_block_processing = FALSE, ...)

    ## S4 method for signature 'Matrix'
    colSums2(x, rows = NULL, cols = NULL, na.rm = FALSE,
      dim. = dim(x), ...)

    ## S4 method for signature 'SolidRleArraySeed'
    colSums2(x, rows = NULL, cols = NULL,
      na.rm = FALSE, dim. = dim(x), ...)

    ## S4 method for signature 'DelayedMatrix'
    rowSums2(x, rows = NULL, cols = NULL,
      na.rm = FALSE, dim. = dim(x), force_block_processing = FALSE, ...)

    ## S4 method for signature 'Matrix'
    rowSums2(x, rows = NULL, cols = NULL, na.rm = FALSE,
      dim. = dim(x), ...)

### 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.
`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 `getOption("DelayedArray.block.size")`) columns (`colFoo()`) or rows (`rowFoo()`) into memory as an ordinary base::array.

### Details

The implementation of `rowSums2()` and `colSums2()` is optimized for both speed and memory.

### Value

Returns a `numeric` `vector` of length N (K).

### 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 'Matrix' seed
    dm_Matrix <- DelayedArray(Matrix::Matrix(c(rep(1L, 5),
                                               as.integer((0:4) ^ 2),
                                               seq(-5L, -1L, 1L)),
                                             ncol = 3))

    colSums2(dm_matrix)

    # NOTE: Temporarily use verbose output to demonstrate which method is
    #       which method is being used
    options(DelayedMatrixStats.verbose = TRUE)
    # By default, this uses a seed-aware method for a DelayedMatrix with a
    # 'SolidRleArraySeed' seed
    rowSums2(dm_Matrix)
    # Alternatively, can use the block-processing strategy
    rowSums2(dm_Matrix, force_block_processing = TRUE)
    options(DelayedMatrixStats.verbose = FALSE)

[Package DelayedMatrixStats version 1.0.3 Index]