NEWS.md

In mlr3oml: Connector Between 'mlr3' and 'OpenML'

mlr3oml 0.11.0

New Features

• Added list_oml_collections() to list collections (run or task collections) on OpenML.

mlr3oml 0.10.1

• Bugfix: provide anchors for links in Rd files

mlr3oml 0.10.0

• Bugfix: Caching of parquet files failed when the temporary directory was on a different partition as the cache directory
• feat: Add option mlr3oml.retries to control number of retries when downloading data from OpenML. The default is 3.

mlr3oml 0.9.0

• Fix: Parquet datasets now work where columns simultaneously have to be renamed and converted.
• Added upload functions:
• publish_data to upload a dataset on OpenML
• publish_task to create a task on OpenML
• publish_collection to create a collection on OpenML

mlr3oml 0.8.0

• Listing functions don't return the tables invisibly anymore.
• Address CRAN NOTE regarding unused bit64 import.
• Improved the printer for all OpenML objects.
• Removed benchmark_grid_oml(), which was already deprecated in release 0.7.2.
• Removed the fields runs, flows, data, tasks from the OMLCollection class. Consequently, the cache option can no longer be set for OMLCollection objects, see the class documentation for more information.
• Removed the examples, as they caused problems with CRAN checks when OpenML was unavailable.
• Caching can no longer be specified at the instance level but only globally through the option mlr3oml.cache
• Added $download() method for all OML objects to fully download an object for offline usage.
• Incremented the cache version for parquet data due to a change in OpenML.
• Added an online tutorial for the package.

mlr3oml 0.7.2

• Fix: target is added to features when converting a OMLData object to a task with an explicit target variable that is not the default target.
• Deprecated benchmark_grid_oml() in favour of mlr3::benchmark_grid(..., paired = TRUE)
• Fix: Incremented cache version for data objects for int64 data types (introduced in the previous release).
• Fix: Incremented cache version for data description and fixed bug, as make.names() was not applied to ignore attributes.
• Fix bug in task converter (features were sometimes not set correctly)
• Collection now shows name in printer
• Better error message when parquet dataset creation fails

mlr3oml 0.7.1

• Fixed argument names of S3 method for as_data_backend to comply with new CRAN checks

mlr3oml 0.7.0

• feature: Add argument task_type to function list_oml_tasks().
• fix: strings and nominals are distinguished for parquet files
• docs: Fixed some OpenML links
• docs: Renamed the docs for OpenML objects
• Renamed the sugar functions from:
• oml_data() is now odt()
• oml_task()is now otsk()
• oml_flow() is now oflw()
• oml_run() is now orn
• oml_collection() is now ocl()
• Addresses a CRAN issue: examples fail gracefully if OpenML server is busy.

mlr3oml 0.6.0

Features

• Add R6 classes for OMLCollection, OMLRun, OMLFlow.
• Added function benchmark_grid_oml that allows for easier creation of benchmark designs from OpenML task-resampling pairs.
• Added sugar functions oml_flow, oml_data, oml_task, oml_run, oml_collection for all OpenML objects.
• Conversion from OpenML to mlr3 objects is now only possible with the usual s3-converters as_<object>. This improves consistency by ensuring that the subcomponents of OpenML objects are always OpenML objects and not suddenly mlr3 objects.
• Added more converter functions: as_learner, as_resample_result, as_data_backend, as_benchmark_result.
• Added support for parquet files that were recently introduced on OpenML. The global option mlr3oml.parquet can be used to enable or disable this. By default it is FALSE. This is implemented via the duckdb backend from mlr3db.
• Support to use the OpenML test server. This can be globally enabled using the option mlr3oml.test_server or individually for objects. Options to globally define an API-key for the test server are through the environment variable TESTOPENMLAPIKEY or the option mlr3oml.test_api_key

Fixes

• Removed support for survival tasks as mlr3proba is no longer on CRAN
• OpenML tasks can now also be filtered according to the task type

Other

• Implement an arff writer and remove the arff dependency, therefore also removing the option "farff" as the mlr3oml.arff_parser
• Increment the cache version number due to changes in the cache structure: This will flush the previous cache folder.
• Simplified the code structure by adding OMLObject class from which all other OpenML objects like OMLData, OMLTask inherit.

mlr3oml 0.5.0

• Support for downloading survival tasks (via mlr3proba).
• More functions to list objects from OpenML:
• list_oml_evaluations()
• list_oml_flows()
• list_oml_measures()
• list_oml_runs()
• list_oml_setups()

mlr3oml 0.4.3

• Fixed a bug regarding unquoting fields in ARFF files.

mlr3oml 0.4.2

• If not set via option mlr3oml.api_key, the API key is retrieved from the environment variable OPENMLAPIKEY.
• Implemented a retry mechanism as a workaround for temporary connection errors.

mlr3oml 0.4.1

• Added a heuristic to detect the quote char.

mlr3oml 0.4.0

• The parsers for ARFF files can now be explicitly selected via option "mlr3oml.arff.parser". Default is the internal parser based on data.table::fread().
• Improved stability of the internal ARFF parser in case of malformed ARFF files and non-standardized quotes.

mlr3oml 0.3.0

• The connectors used in mlr_tasks and mlr_resamplings now signal errors of class missingDefaultError if some defaults are not set.
• Target columns are now automatically converted to the require storage mode during task creation.
• Removed dependency on orphaned package bibtex.

mlr3oml 0.2.0

• Support filtering data sets and tasks via data id or task id (#5).
• Added fallback to RWeka for sparse ARFF files (#6).
• Fixed import from backports.

mlr3oml 0.1.0

• Initial release.

mlr3oml documentation built on Aug. 26, 2025, 5:08 p.m.