Recharts is a composable React charting library that renders SVG-based charts using declarative components. It provides a wide range of chart types including line, bar, area, scatter, pie, radar, radial bar, funnel, treemap, sunburst, sankey, and composed charts. The library is built on a Redux-based internal state management system with memoized selectors (reselect) for efficient rendering. It features a theming system with light/dark/auto themes, CSS transitions and custom interpolation for animations, zoom/pan controls, tooltips, legends, and responsive containers. The architecture is component-driven: each chart type (e.g., LineChart, BarChart) wraps a shared CartesianChart or PolarChart base that sets up the Redux store, data context, and event handling. External dependencies include React, Redux Toolkit, Immer, reselect, d3-shape, and victory-vendor/d3-scale. The library is published as an npm package and includes extensive unit tests, visual regression tests (Playwright), and a Storybook documentation site.
traffic is a Python library and CLI tool for processing, analyzing, and visualizing air traffic data. It ingests trajectory data from multiple sources including OpenSky Network (via REST/Trino), FlightRadar24, Eurocontrol (DDR, AIXM), FAA, and local ADS-B decoders. The core abstractions are `Flight` (single trajectory) and `Traffic` (collection) built on pandas DataFrames, with extensive methods for cleaning, resampling, filtering, geometric operations, navigation event detection (landing, go-around, holding patterns), performance estimation (fuel flow, emissions), and clustering. The library provides a declarative lazy evaluation pipeline (`LazyTraffic`) that chains operations before a single `.eval()` call, enabling efficient parallel processing. It also offers visualization backends for Matplotlib, Altair, Leaflet, and Plotly, and includes a Vue.js/Deck.gl plugin (Tangram) for real-time landing alignment in a web dashboard.