Type: Package
Title: Making "Deduplicated" Functions
Version: 0.2.0
Description: Contains one main function deduped() which speeds up slow, vectorized functions by only performing computations on the unique values of the input and expanding the results at the end.
License: MIT + file LICENSE
Encoding: UTF-8
Imports: collapse, fastmatch,
RoxygenNote: 7.2.3
Suggests: dplyr, purrr, readr, testthat (≥ 3.0.0), withr
Config/testthat/edition: 3
URL: https://github.com/orgadish/deduped
BugReports: https://github.com/orgadish/deduped/issues
NeedsCompilation: no
Packaged: 2023-11-07 04:05:47 UTC; orgadish
Author: Or Gadish [aut, cre, cph]
Maintainer: Or Gadish <orgadish@gmail.com>
Repository: CRAN
Date/Publication: 2023-11-07 10:10:13 UTC

Deduplicate a vectorized function to act on unique elements

Description

Converts a vectorized function into one that only performs the computations on unique values in the first argument. The result is then expanded so that it is the same as if the computation was performed on all elements.

Usage

deduped(f)

Arguments

f

Function that accepts a vector or list as its first input.

Value

Deduplicated version of f.

Examples


x <- sample(LETTERS, 10)
x

large_x <- sample(rep(x, 10))
length(large_x)

slow_func <- function(x) {
  for (i in x) {
    Sys.sleep(0.001)
  }
}

system.time({
  y1 <- slow_func(large_x)
})
system.time({
  y2 <- deduped(slow_func)(large_x)
})

all(y1 == y2)

Apply a function to each unique element

Description

DEPRECATED as of deduped 0.2.0.

Please use deduped(lapply)() or deduped(purrr::map)() instead.

Usage

deduped_map(.x, .f, ..., .progress = FALSE)

Arguments

.x

A list or atomic vector.

.f

A function, specified in one of the following ways:

  • A named function, e.g. mean.

  • An anonymous function, e.g. ⁠\(x) x + 1⁠ or function(x) x + 1.

  • A formula, e.g. ~ .x + 1. You must use .x to refer to the first argument. Only recommended if you require backward compatibility with older versions of R.

  • A string, integer, or list, e.g. "idx", 1, or list("idx", 1) which are shorthand for ⁠\(x) pluck(x, "idx")⁠, ⁠\(x) pluck(x, 1)⁠, and ⁠\(x) pluck(x, "idx", 1)⁠ respectively. Optionally supply .default to set a default value if the indexed element is NULL or does not exist.

...

Additional arguments passed on to the mapped function.

We now generally recommend against using ... to pass additional (constant) arguments to .f. Instead use a shorthand anonymous function: 

# Instead of
x |> map(f, 1, 2, collapse = ",")
# do:
x |> map(\(x) f(x, 1, 2, collapse = ","))

This makes it easier to understand which arguments belong to which function and will tend to yield better error messages.

.progress

Whether to show a progress bar. Use TRUE to turn on a basic progress bar, use a string to give it a name, or see progress_bars for more details.

Value

A list whose length is the same as the length of the input, matching the output of purrr::map().

See Also

deduped()