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v0.71.0 - Add Rolling Window Aggregations to GroupedFrame (2026-04-10)

What Changed?

This release adds rolling window support to GroupedFrame aggregation methods, enabling time-series analysis and feature engineering workflows. Users can now compute rolling sum, mean, min, max, and custom aggregations within each group using the RollingOptions parameter. The feature maintains full backward compatibility with existing code.

What's New

Main Feature: Rolling Window Aggregations

What it does: Computes rolling aggregations within each group. Each row contains the aggregation result for the rolling window ending at that row. Window size is configurable, and results preserve all original rows while replacing specified columns with rolling values.

How to use it:

TypeScript
const df = BareFrame.fromColumns({
  dept: ["eng", "eng", "eng", "hr", "hr"],
  sales: [10, 20, 30, 5, 15],
});

// Rolling sum with window size 2
df.groupBy(["dept"]).sum(["sales"], { window: 2 });
// dept | sales
// eng  | 10
// eng  | 30
// eng  | 50
// hr   | 5
// hr   | 20

Code example:

TypeScript
// Rolling sum
df.groupBy(["dept"]).sum(["sales"], { window: 2 });

// Rolling mean
df.groupBy(["dept"]).mean(["sales"], { window: 3 });

// Rolling min/max
df.groupBy(["dept"]).min(["value"], { window: 2 });
df.groupBy(["dept"]).max(["value"], { window: 2 });

// Custom rolling aggregation
const customFn: AggFn = (vals) => (vals as number[]).reduce((a, b) => a + b, 0);
df.groupBy(["dept"]).agg({ sales: customFn }, { window: 2 });

Added

  • RollingOptions type for configuring rolling window aggregations
  • Rolling window support to GroupedFrame.sum()
  • Rolling window support to GroupedFrame.mean()
  • Rolling window support to GroupedFrame.min()
  • Rolling window support to GroupedFrame.max()
  • Rolling window support to GroupedFrame.agg()

Changed

  • None

Fixed

  • None

Is It Safe to Upgrade?

  • Breaking Changes: No
  • Backward Compatible: Yes

All existing code continues to work unchanged. Aggregation methods now accept an optional RollingOptions parameter for rolling window operations.

Release Details

  • Date: 2026-04-10
  • Version: v0.71.0
  • gaslamp: 132
  • pilotlamp: 90
  • Files Changed: 2
  • Commits:
    • fbc7c887 feat(frame): add rolling window aggregations to GroupedFrame
    • ccd35356 docs(api): regenerate TypeDoc output
    • 632e3692 bump: version 0.70.0 → 0.71.0

Known Issues

  • None

Next Steps

Consider adding additional statistical aggregations (std, variance) or window positioning options (centered, backward-looking).