# colCounts-xgCMatrix-method: Count how often an element in a row (column) of a matrix-like... In sparseMatrixStats: Summary Statistics for Rows and Columns of Sparse Matrices

## Description

Count how often an element in a row (column) of a matrix-like object is equal to a value.

## Usage

 ```1 2 3 4 5``` ```## S4 method for signature 'xgCMatrix' colCounts(x, rows = NULL, cols = NULL, value = TRUE, na.rm = FALSE) ## S4 method for signature 'xgCMatrix' rowCounts(x, rows = NULL, cols = NULL, value = TRUE, na.rm = FALSE) ```

## Arguments

 `x` An NxK matrix-like object. `rows` A `vector` indicating the subset of rows (and/or columns) to operate over. If `NULL`, no subsetting is done. `cols` A `vector` indicating the subset of rows (and/or columns) to operate over. If `NULL`, no subsetting is done. `value` The value to search for. `na.rm` If `TRUE`, `NA`s are excluded first, otherwise not.

## Details

The S4 methods for `x` of type `matrix`, `array`, or `numeric` call `matrixStats::rowCounts` / `matrixStats::colCounts`.

## Value

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

## See Also

• `matrixStats::rowCounts()` and `matrixStats::colCounts()` which are used when the input is a `matrix` or `numeric` vector.

• For checks if any element is equal to a value, see `rowAnys()`. To check if all elements are equal, see `rowAlls()`.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```mat <- matrix(rnorm(15), nrow = 5, ncol = 3) mat[2, 1] <- NA mat[3, 3] <- Inf mat[4, 1] <- 0 print(mat) rowCounts(mat) colCounts(mat) rowCounts(mat, value = 0) colCounts(mat, value = Inf, na.rm = TRUE) ```

sparseMatrixStats documentation built on Feb. 4, 2021, 2 a.m.