rowCounts: 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

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

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.

Arguments

x: An NxK matrix or, if dim. is specified, an N * K vector.
rows: A vector indicating subset of rows to operate over. If NULL, no subsetting is done.
cols: A vector indicating subset of columns to operate over. If NULL, no subsetting is done.
value: A value to search for.
na.rm: If TRUE, missing values are excluded.
dim.: An integer vector of length two specifying the dimension of x, also when not a matrix. Comment: The reason for this argument being named with a period at the end is purely technical (we get a run-time error if we try to name it dim).
...: Not used.
useNames: If FALSE (default), no naming support is done. Else if TRUE, names attributes of result are set.
idxs: A vector indicating subset of elements to operate over. If NULL, no subsetting is done.

Author

Henrik Bengtsson

Examples

Run this code

x <- matrix(0:11, nrow = 4, ncol = 3)
x[2:3, 2:3] <- 2:5
x[3, 3] <- NA_integer_
print(x)

print(rowCounts(x, value = 2))
## [1]  0  1 NA  0
print(colCounts(x, value = 2))
## [1]  1  1 NA
print(colCounts(x, value = NA_integer_))
## [1] 0 0 1

print(rowCounts(x, value = 2, na.rm = TRUE))
## [1] 0 1 1 0
print(colCounts(x, value = 2, na.rm = TRUE))
## [1] 1 1 0

print(rowAnys(x, value = 2))
## [1] FALSE  TRUE  TRUE FALSE
print(rowAnys(x, value = NA_integer_))
## [1] FALSE FALSE  TRUE FALSE

print(colAnys(x, value = 2))
## [1] TRUE TRUE   NA
print(colAnys(x, value = 2, na.rm = TRUE))
## [1]  TRUE  TRUE FALSE

print(colAlls(x, value = 2))
## [1] FALSE FALSE FALSE