# @molcrafts/molplot Vega-Lite scientific charting primitives — line, scatter, bar, gantt, and a raw spec passthrough — with a shared, matplotlib-portable preset and a lazily-loaded Vega runtime. Part of [MolPlot](https://github.com/MolCrafts/molplot): every chart builds a **Vega-Lite spec** (the portable intermediate language) and renders it with `vega-embed` using its Canvas renderer. The web package does not emit SVG. The same spec can be rendered to a matplotlib figure by the Python package `molcrafts-molplot`, so web and paper figures share one description and one preset. ## Install ```sh npm install @molcrafts/molplot vega vega-lite vega-embed ``` The Vega runtime is loaded lazily and externalized from the build, so a consumer that never renders a chart never pays for the bundle. ## Usage ```ts import { LineChart, ScatterChart, CHART_PALETTE } from "@molcrafts/molplot"; const chart = new LineChart(container, { preset: "molplot", // unified preset; "molplot-paper" also ships theme: "auto", // tracks series: [{ id: "e", label: "Energy", initialPoints: pts }], }); await chart.ready(); chart.appendPoint("e", { x, y }); // cheap streaming update (view.data) chart.onPointClick((e) => console.log(e.seriesId, e.index)); ``` ## API Chart classes (imperative, framework-agnostic): `LineChart`, `ScatterChart`, `BarChart`, `GanttChart`, `RawChart`. Each takes `(container, config)` and exposes `ready()`, `resize()`, `dispose()`, and typed `on*Click` handlers; `LineChart` adds `setSeries` / `appendPoint` / `appendPoints` / `clear` / `setWindow` / `setAxisRange`. Spec builders (the intermediate language, no DOM): `lineSpec`, `scatterSpec`, `barSpec`, `ganttSpec`. Theme / preset: `resolveTheme`, `vegaConfig`, `getPreset`, `CHART_PALETTE`, `CHART_DEFAULT_COLOR`. > **Migration from the plotly build:** the chart classes and config/event types > are unchanged. `RawChart` now takes a Vega-Lite spec (`{ spec }`) instead of a > plotly `{ data, layout, config }` payload. ## License BSD-3-Clause