.. _auto_dataset_fill_na:

*DATASET FILL NA*
=================

Fills missing values in a dataset by replacing NAs in numeric and categorical columns using configurable strategies (average, min, max, mode, or a custom value). Optionally restricts the operation to a subset of columns and supports user-defined null-value mappings per column.

When to use
-----------

Classification: **process**.

Tagged: ``categorical``, ``dataset``, ``fill_na``, ``imputation``, ``missing_values``, ``null_handling``, ``numeric``, ``preprocessing``.

Inputs
------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Dataset
     - dataset
     - dataset
     - —
     - 
     - Input dataset (tabular) whose missing values will be filled; accepts any d3VIEW dataset object.
   * - Columns To Check
     - columnstocheck
     - scalar
     - —
     - 
     - Comma-separated list of column names to target for NA-filling; leave empty to apply the fill strategy to all columns.
   * - Numeric Fill Type
     - numeric_fill_type
     - select
     - avg
     - 
     - Strategy for imputing missing values in numeric columns: 'avg' (default), 'min', 'max', 'mode', or 'custom' (uses the custom numeric value input below).
   * - Categorical Fill Type
     - cat_fill_type
     - select
     - most
     - 
     - Strategy for imputing missing values in categorical columns: 'most' (most-frequent, default), 'least' (least-frequent), or 'custom' (uses the custom categorical value input below).
   * - Null Values
     - what_is_null
     - textarea
     - —
     - 
     - Per-column declaration of additional values to treat as null, specified as a comma-separated list in the format 'COL1=>a b c,COL2=>d e f'; leave blank if only standard NA/NaN should be treated as null.
   * - Numeric Custom Value
     - numeric_custom_value
     - textarea
     - —
     - 
     - Default numeric custom value when type of fill is set to custom
   * - Categorical Custom Value
     - cat_custom_value
     - textarea
     - —
     - 
     - Default numeric custom value when type of fill is set to custom

Outputs
-------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - dataset_fill_na_output_1
     - dataset_fill_na_output_1
     - dataset
     - Output dataset identical in schema to the input but with all targeted missing values replaced according to the chosen numeric and categorical fill strategies.

Disciplines
-----------

- ai_ml.preprocessing
- data.dataset.transform

Runnable example
----------------

A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: `/api/workflow/example?id=dataset_fill_na <https://www.d3view.com/api/workflow/example?id=dataset_fill_na>`_

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>dataset_fill_na</code>. Schema hash: <code>b5dcacb93f4e</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>