Pivot kdocs #1554

AndreiKingsley · 2025-11-07T15:21:38Z

Closes #1525
Closes #1552

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/documentation/SelectingColumns.kt

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/pivot.kt

Jolanrensen

I'll review more tomorrow :)

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/pivot.kt

Jolanrensen · 2025-11-11T13:03:28Z

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/pivot.kt

 public typealias PivotColumnsSelector<T, C> = Selector<PivotDsl<T>, ColumnsResolver<C>>

+/**
+ * An intermediate class used in [`Pivot` reducing][PivotDocs.Reducing] operations.


FYI in KDoc rendering, the alias side of []-code references are automatically made code-style. So the backticks do nothing. However, you can leave them because this might change in the future. It's not part of the GFM spec

Jolanrensen · 2025-11-13T10:54:27Z

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/groupBy.kt

    interface Pivoting
+
+    /**
+     * Grouping key can also be created inline


*A grouping key or *grouping keys

Jolanrensen · 2025-11-13T10:55:11Z

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/groupBy.kt

+    /**
+     * Grouping key can also be created inline
+     * (i.g. by creating a new column using [expr] or simply renaming the old one
+     * using [named]) :


there's a space in front of :

Jolanrensen · 2025-11-13T10:55:44Z

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/pivot.kt

+    /**
+     * Pivoted columns can also be created inline
+     * (i.g. by creating a new column using [expr] or simply renaming the old one
+     * using [named]) :


Jolanrensen · 2025-11-13T10:57:34Z

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/pivot.kt

 // region pivotMatches

+/**
+ * Computes a **presence matrix** (similar to one-hot encoding) for the values in the


can you link to wikipedia for one-hot-encoding? in case people don't know about it and they are curious :) like here https://en.wikipedia.org/wiki/One-hot#Machine_learning_and_statistics

Jolanrensen · 2025-11-13T11:00:53Z

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/pivot.kt

+     *   (they become [column groups][ColumnGroup]
+     *   corresponding to value combinations when using [then][PivotDsl.then],
+     *   similar to [pivot]);
+     * * **Rows** correspond to all unique combinations of values from the {@get [GroupingColumns] grouping} columns;


eyy, nice KoDEx usage ;P Just for funzies, did you know you can also write this like $[GroupingColumns]=grouping? :) (not that it's much more compact or anything, just an alternative if you ever need it)

Jolanrensen

Just some tiny comments left, feel free to merge it afterwards, it looks good!

AndreiKingsley added 7 commits November 3, 2025 19:10

pivot kdocs init

59a9630

pivot kdocs fixes

3d40ee3

Merge branch 'master' into pivot_kdocs

58704fe

pivotCount, pivotMatches kdocs

d19df01

pivot in aggregation kdocs

50abd69

pivot derives in aggregation kdocs

8768ac0

reduced pivot kdocs fix

6c8da01

AndreiKingsley marked this pull request as ready for review November 7, 2025 15:21

AndreiKingsley requested a review from Jolanrensen November 7, 2025 15:21

ktlint format

4532390

Jolanrensen reviewed Nov 10, 2025

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core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/documentation/SelectingColumns.kt Outdated Show resolved Hide resolved

Jolanrensen reviewed Nov 10, 2025

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