mlr3: as_data_backend – R documentation

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as_data_backend

Create a Data Backend

Description

Wraps a DataBackend around data. mlr3 ships with methods for data.frame (converted to a DataBackendDataTable and Matrix from package Matrix (converted to a DataBackendMatrix).

Additional methods are implemented in the package mlr3db, e.g. to connect to real DBMS like PostgreSQL (via dbplyr) or DuckDB (via DBI/duckdb).

Usage

## S3 method for class 'Matrix'
as_data_backend(data, primary_key = NULL, dense = NULL, ...)

as_data_backend(data, primary_key = NULL, ...)

## S3 method for class 'data.frame'
as_data_backend(data, primary_key = NULL, keep_rownames = FALSE, ...)

Arguments

`data`	(`data.frame()`) The input `data.frame()`. Converted to a `data.table::data.table()` automatically.
`primary_key`	(`character(1)` \| `integer()`) Name of the primary key column, or integer vector of row ids.
`dense`	(`data.frame()`). Dense data.
`...`	(`any`) Additional arguments passed to the respective DataBackend method.
`keep_rownames`	(`logical(1)` \| `character(1)`) If `TRUE` or a single string, keeps the row names of `data` as a new column. The column is named like the provided string, defaulting to `"..rownames"` for `keep_rownames == TRUE`. Note that the created column will be used as a regular feature by the task unless you manually change the column role. Also see `data.table::as.data.table()`.

Value

DataBackend.

Examples

# create a new backend using the penguins data:
as_data_backend(palmerpenguins::penguins)

mlr3

Machine Learning in R - Next Generation

v0.11.0

LGPL-3

Authors

Michel Lang [cre, aut] (<https://orcid.org/0000-0001-9754-0393>), Bernd Bischl [aut] (<https://orcid.org/0000-0001-6002-6980>), Jakob Richter [aut] (<https://orcid.org/0000-0003-4481-5554>), Patrick Schratz [aut] (<https://orcid.org/0000-0003-0748-6624>), Giuseppe Casalicchio [ctb] (<https://orcid.org/0000-0001-5324-5966>), Stefan Coors [ctb] (<https://orcid.org/0000-0002-7465-2146>), Quay Au [ctb] (<https://orcid.org/0000-0002-5252-8902>), Martin Binder [aut], Marc Becker [ctb] (<https://orcid.org/0000-0002-8115-0400>)

Initial release