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mlrCPO

Composable Preprocessing Operators and Pipelines for Machine Learning

v0.3.8 · Jun 16, 2025 · BSD_2_clause + file LICENSE

Description

Toolset that enriches 'mlr' with a diverse set of preprocessing operators. Composable Preprocessing Operators ("CPO"s) are first-class R objects that can be applied to data.frames and 'mlr' "Task"s to modify data, can be attached to 'mlr' "Learner"s to add preprocessing to machine learning algorithms, and can be composed to form preprocessing pipelines.

Downloads

CRAN

412

Last 30 days

10484th

957

Last 90 days

5.9K

Last year

Trend: +55.5% (30d vs prior 30d)

r2u CRAN

0

Last 30 days

31

Last 90 days

124

Last year

Trend: -100% (30d vs prior 30d)

autoCRAN

4

Last 7 days

11

Last 30 days

1

All-time

autoCRAN-only: this name is served only by autoCRAN, so the count is exact.

CRAN Check Status

13 OK
Show all 13 flavors
Flavor Status
r-devel-linux-x86_64-debian-clang OK
r-devel-linux-x86_64-debian-gcc OK
r-devel-linux-x86_64-fedora-clang OK
r-devel-linux-x86_64-fedora-gcc OK
r-devel-windows-x86_64 OK
r-oldrel-macos-arm64 OK
r-oldrel-macos-x86_64 OK
r-oldrel-windows-x86_64 OK
r-patched-linux-x86_64 OK
r-release-linux-x86_64 OK
r-release-macos-arm64 OK
r-release-macos-x86_64 OK
r-release-windows-x86_64 OK

Check History

OK 12 OK · 0 NOTE · 0 WARNING · 0 ERROR · 1 FAILURE Jun 8, 2026
FAILURE r-devel-linux-x86_64-debian-gcc

DESCRIPTION meta-information

ERROR 12 OK · 0 NOTE · 0 WARNING · 1 ERROR · 0 FAILURE Jun 6, 2026
ERROR r-devel-windows-x86_64

tests

Running 'run-core.R' [1s]
  Running 'run-cpo.R' [46s]
  Running 'run-meta.R' [8s]
  Running 'run-zzzlint.R' [1s]
Running the tests in 'tests/run-meta.R' failed.
Complete output:
  > library(testthat)
  > test_check("mlrCPO", filter = "^meta_")
  Load
...[truncated]...
       └─base::lapply(...)
   15.               └─testthat (local) FUN(X[[i]], ...)
   16.                 └─private$handle_error(msg, i)
   17.                   └─cli::cli_abort(...)
   18.                     └─rlang::abort(...)
  Execution halted
OK 14 OK · 0 NOTE · 0 WARNING · 0 ERROR · 0 FAILURE Mar 10, 2026

Code

Structure

Lines of code

40,600

Files

237

Compiled share

0%

Has compiled src

No

Language breakdown

R 12,069 (29.7%)Tests 9,979 (24.6%)Docs 16,219 (39.9%)Vignettes 2,333 (5.7%)

API

Exported functions

127

Internal functions

231

Recent export changes

v0.3.8−1 cpoFilterRfSRCMinDepth

Testing & CI

Has tests

Yes

Test-to-code ratio

0.83

testthat edition

3

CI present

No

CI type

[]

PR gated

No

Docs

Return-value doc rate

93%

\dontrun example ratio

0%

Roxygen coverage

90.6%

Has pkgdown

No

NEWS present

Yes

Health & Security signals

Informational signals; not verdicts.

on.exit coverage

Unsafe pattern score

0

Dep constraint coverage

55.6%

Secret pattern count

0

Bundled 3rd-party code

2 items

Portability & License

Min R version

3.0.2

System requirements

C++ standard

License

BSD_2_clause + file LICENSE

License flags

SPDX valid, OSI approved

History

Versions

17

First release

2018-04-05

Latest release

2025-06-16

Avg cadence

96 days

Cold removal rate

100%

Dep drift

0

LOC over versions

v0.3.2: 37,954 LOCv0.3.3: 37,970 LOCv0.3.4: 37,970 LOCv0.3.4-1: 37,970 LOCv0.3.4-2: 38,211 LOCv0.3.4-3: 38,266 LOCv0.3.4-4: 38,266 LOCv0.3.6: 40,251 LOCv0.3.7: 40,621 LOCv0.3.7-1: 40,630 LOCv0.3.7-2: 40,637 LOCv0.3.7-3: 40,643 LOCv0.3.7-4: 40,645 LOCv0.3.7-5: 40,979 LOCv0.3.7-6: 40,981 LOCv0.3.7-7: 40,981 LOCv0.3.8: 40,600 LOC

Per-file churn detail lives in the source pipeline: https://github.com/r-observatory/cran-code-metrics.

Dependency Network

Dependencies Reverse dependencies ParamHelpers mlr BBmisc stringi checkmate backports mlrCPO

Version History

18 tracked
new 0.3.8 Mar 10, 2026
updated 0.3.8 ← 0.3.7-7 diff Jun 15, 2025
updated 0.3.7-7 ← 0.3.7-6 diff Feb 19, 2024
updated 0.3.7-6 ← 0.3.7-5 diff Nov 16, 2022
updated 0.3.7-5 ← 0.3.7-4 diff Oct 18, 2022
updated 0.3.7-4 ← 0.3.7-3 diff Jul 19, 2022
updated 0.3.7-3 ← 0.3.7-2 diff Nov 9, 2021
updated 0.3.7-2 ← 0.3.7-1 diff Feb 23, 2021
updated 0.3.7-1 ← 0.3.7 diff Jan 10, 2021
updated 0.3.7 ← 0.3.6 diff Nov 14, 2020
updated 0.3.6 ← 0.3.4-4 diff Apr 5, 2020
updated 0.3.4-4 ← 0.3.4-3 diff Aug 7, 2019
updated 0.3.4-3 ← 0.3.4-2 diff May 10, 2019
updated 0.3.4-2 ← 0.3.4-1 diff Jan 9, 2019
updated 0.3.4-1 ← 0.3.4 diff Oct 1, 2018