feat(experimental): add dense luDF group aggregation

modules/experimental/src/ludf/index.ts

@@ -19,6 +19,16 @@ export type {
   LuDataFrameDerivedColumnFormatForExpression,
   LuDataFrameDerivedColumnOptions
 } from './lu-data-frame-query';
+export {LuDataFrameGroupByQuery, LuDataFrameGroupedAggregationQuery} from './lu-group-by-query';
+export type {
+  LuDataFrameAggregationDefinition,
+  LuDataFrameAggregationDefinitions,
+  LuDataFrameAggregationOperation,
+  LuDataFrameAggregationValue,
+  LuDataFrameColumnNamesOfFormat,
+  LuDataFrameGroupByOptions,
+  LuDataFrameGroupedAggregationResult
+} from './lu-group-by-query';
 export {and, column, literal, LuExpression, not, or, parameter} from './lu-expression';
 export type {
   LuExpressionBinaryOperator,
@@ -28,3 +38,4 @@ export type {
 } from './lu-expression';
 export {CompiledLuDataFrameQuery} from './lu-query-compiler';
 export type {LuDataFrameQueryParameters} from './lu-query-compiler';
+export {CompiledLuDataFrameGroupedAggregation} from './lu-group-aggregation-compiler';

modules/experimental/src/ludf/lu-data-frame-query.ts

@@ -6,6 +6,11 @@ import type {GPUTypeMap} from '@luma.gl/tables';
 import type {GPUCommandGraph} from '../gpu-primitives/gpu-command-graph';
 import type {LuDataFrame} from './lu-data-frame';
 import {getLuExpressionColumnNames, LuExpression, type LuExpressionNode} from './lu-expression';
+import {
+  LuDataFrameGroupByQuery,
+  type LuDataFrameColumnNamesOfFormat,
+  type LuDataFrameGroupByOptions
+} from './lu-group-by-query';
 import {
   compileLuDataFrameQuery,
   type CompiledLuDataFrameQuery,
@@ -144,6 +149,14 @@ export class LuDataFrameQuery<
     );
   }
 
+  /** Plans dense categorical grouping without allocating GPU resources or reading source values. */
+  groupBy<Key extends LuDataFrameColumnNamesOfFormat<Logical, SelectedColumns, 'uint32'>>(
+    key: Key,
+    options: LuDataFrameGroupByOptions = {}
+  ): LuDataFrameGroupByQuery<Logical, SelectedColumns, Key, Source> {
+    return new LuDataFrameGroupByQuery(this, key, options);
+  }
+
   /** Materializes reusable GPU graph passes and compiler-owned selection/index/count outputs. */
   compile(
     graph: GPUCommandGraph<LuDataFrameQueryParameters>

modules/experimental/src/ludf/lu-data-frame.ts

@@ -22,6 +22,11 @@ import {
   type LuDataFrameDerivedColumnOptions
 } from './lu-data-frame-query';
 import type {LuExpression} from './lu-expression';
+import type {
+  LuDataFrameColumnNamesOfFormat,
+  LuDataFrameGroupByOptions,
+  LuDataFrameGroupByQuery
+} from './lu-group-by-query';
 
 /** Whether a dataframe borrows its source resources or releases them after its final view. */
 export type LuDataFrameOwnership = 'borrowed' | 'owned';
@@ -191,6 +196,18 @@ export class LuDataFrame<T extends GPUTypeMap = GPUTypeMap> {
     return query.withColumn<Name, ReferencedColumns, Format>(name, expression, options);
   }
 
+  /** Plans dense unsigned grouping without allocating GPU resources or retaining source leases. */
+  groupBy<Key extends LuDataFrameColumnNamesOfFormat<T, keyof T & string, 'uint32'>>(
+    key: Key,
+    options: LuDataFrameGroupByOptions = {}
+  ): LuDataFrameGroupByQuery<T, keyof T & string, Key, T> {
+    this.assertAvailable();
+    return new LuDataFrameQuery<T, keyof T & string, T>(this, [], this.columnNames).groupBy(
+      key,
+      options
+    );
+  }
+
   /**
    * Returns an independent borrowed projection without mutating or destroying source columns.
    *

modules/experimental/src/ludf/lu-expression-shader.ts

@@ -73,9 +73,10 @@ export function makeLuQueryExpressionShaderPlan<T extends GPUTypeMap>(
   source: LuDataFrame<T>,
   predicates: readonly LuExpression<boolean, string>[],
   derivedColumns: readonly LuDataFrameDerivedColumn[] = [],
-  selectedColumns: readonly string[] = []
+  selectedColumns: readonly string[] = [],
+  allowEmptyPredicates = false
 ): LuQueryExpressionShaderPlan {
-  if (predicates.length === 0 && derivedColumns.length === 0) {
+  if (predicates.length === 0 && derivedColumns.length === 0 && !allowEmptyPredicates) {
     throw new Error('LuDataFrame filtering requires at least one predicate');
   }