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Require usage of colSums(x) or rowSums(x) over apply(x, ., sum)

Source: R/matrix_apply_linter.R
matrix_apply_linter.Rd

colSums() and rowSums() are clearer and more performant alternatives to apply(x, 2, sum) and apply(x, 1, sum) respectively in the case of 2D arrays, or matrices

Usage

matrix_apply_linter()

See also

linters for a complete list of linters available in lintr.

Tags

efficiency, readability

Examples

# will produce lints
lint(
  text = "apply(x, 1, sum)",
  linters = matrix_apply_linter()
)
#> <text>:1:1: warning: [matrix_apply_linter] Use rowSums(x) rather than apply(x, 1, sum)
#> apply(x, 1, sum)
#> ^~~~~~~~~~~~~~~~

lint(
  text = "apply(x, 2, sum)",
  linters = matrix_apply_linter()
)
#> <text>:1:1: warning: [matrix_apply_linter] Use rowSums(colSums(x)) or colSums(x) if x has 2 dimensions rather than apply(x, 2, sum)
#> apply(x, 2, sum)
#> ^~~~~~~~~~~~~~~~

lint(
  text = "apply(x, 2, sum, na.rm = TRUE)",
  linters = matrix_apply_linter()
)
#> <text>:1:1: warning: [matrix_apply_linter] Use rowSums(colSums(x, na.rm = TRUE)) or colSums(x, na.rm = TRUE) if x has 2 dimensions rather than apply(x, 2, sum, na.rm = TRUE)
#> apply(x, 2, sum, na.rm = TRUE)
#> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

lint(
  text = "apply(x, 2:4, sum)",
  linters = matrix_apply_linter()
)
#> <text>:1:1: warning: [matrix_apply_linter] Use rowSums(colSums(x), dims = 3) or colSums(x) if x has 4 dimensions rather than apply(x, 2:4, sum)
#> apply(x, 2:4, sum)
#> ^~~~~~~~~~~~~~~~~~