MatPlotLibNet

A .NET 10 / .NET 8 charting library inspired by matplotlib: fluent API, DI-friendly,
server-side SVG / PNG / PDF / animated-GIF export, an MCP server so an AI agent can draw with it, and 83 series types. Ships with 13 map projections and embedded
Natural Earth data, 30 themes, LaTeX-style MathText, O(1) streaming with 53 technical indicators, a control room
(Plt.OpsDashboard() — KPI tiles, state timelines, one shared trend window), and native controls for Blazor, WPF,
MAUI, Avalonia, Uno and ASP.NET Core, plus TypeScript clients for Angular, React and Vue. No JavaScript framework,
no WebView, no SaaS.

Where this is going

The 1.14 line is control-room work: Plt.OpsDashboard() and the tile anatomy arrived with it, and the
releases since are the fixes and extensions a live operator wall asked for — a secondary Y axis that is a full
citizen, streaming that draws in SVG, 3-D axis titles that clear their own labels, tile captions that wrap and
stay inside their tile, and an ops window whose ticks read as time.

The 1.15 line opens the library to agents: MatPlotLibNet.Mcp lets a model render any of these chart types
from a JSON spec and look at the result.

After that the cadence is community-driven: bug fixes, documentation, and whatever real use turns up. Open a
Discussion or an
Issue — that is what steers the next release. Every release,
with its migration notes, is in the CHANGELOG.

Quality bar: a strict per-class coverage gate at ≥90 % line and branch (679 classes, 99.6 % / 97.3 %) across
11,022 tests, with rendering verified against matplotlib pixel-fidelity fixtures.

Documentation

• Wiki — getting started, cheatsheet, all 83 chart types, the
  control room, styling, streaming, SignalR, packages
• Cookbook — copy-paste examples with rendered output
• Playground — try charts live in the browser
• API Reference — generated from the XML docs
• Benchmarks · Coverage policy · CHANGELOG

Packages

Quick start

using MatPlotLibNet;
using MatPlotLibNet.Styling;

double[] x = [1, 2, 3, 4, 5];
double[] y = [2, 4, 3, 5, 1];

Plt.Create()
    .WithTitle("My First Chart")
    .WithTheme(Theme.Dark)
    .Plot(x, y, s => { s.Color = Color.Blue; s.Label = "Data"; })
    .WithLegend()
    .Save("chart.svg");

Features

83 series types — line, scatter, bar, histogram, pie, box, violin, heatmap, contour, candlestick, OHLC, treemap, sunburst, Sankey, polar, polar heatmap, 3D surface, Bar3D, PlanarBar3D, Line3D, Trisurf3D, Contour3D, Quiver3D, Voxels, Text3D, radar, waterfall, funnel, gauge, stat tile (single-value KPI), state timeline (discrete state segments over time), pair grid, relative rotation graph, streaming line/scatter/signal/candlestick, and more.

MCP server — charts for an AI agent — MatPlotLibNet.Mcp is a Model Context Protocol
server, shipped as a .NET tool a host starts over stdio. Four tools: render_chart (PNG plus a text summary of
what was drawn), save_chart (PNG/SVG/PDF to a file, returning the path it wrote), list_chart_types and
describe_chart_schema. The spec is the library's own figure JSON, so anything the library draws, an agent can
ask for — and the server refuses a wrong spec by field name before it renders, instead of returning a blank
picture. See the cookbook.

{ "servers": { "MatPlotLibNet.Mcp": { "type": "stdio", "command": "dnx", "args": ["MatPlotLibNet.Mcp", "--yes"] } } }

Control room — Plt.OpsDashboard() composes one operator screen: KPI tiles across the top, state timelines under them, and a shared trend panel, all pinned to one caller-supplied time window (the library never reads the wall clock). The tile carries a Target, a wrapping multi-line Caption, an inline sparkline and a Hatch that means no information; Theme.Alarm names the reserved alarm colours and four operator backgrounds ship with it. BulletGraphSeries replaces the radial gauge.

Native UI controls — MplChartControl for Avalonia 12 and MplChartElement for Uno Platform render charts natively via SkiaSharp — no browser, no WebView, no SignalR required. 9 interaction modifiers: pan (drag), zoom (scroll), 3D rotation (right-drag), rectangle zoom (Ctrl+drag), brush select (Shift+drag), span select (Alt+drag), legend toggle (click), crosshair (passive), hover tooltip. Toolbar state model, view history (back/forward), data cursor (click-to-pin), tick mirroring, tight margins.

MathText — LaTeX-like inline math in any label or title: $\alpha^{2}$, $\frac{a}{b}$, $\sqrt{x}$, $\hat{x}$, $\mathbf{F}$, $\mathbb{R}$. 96 symbol mappings (Greek, math operators, arrows, relations, set/logic, blackboard bold), fractions, square roots, accents, font variants, spacing, and scaling delimiters.

3-D charts — 12 series types: Surface, Scatter3D, Bar3D, PlanarBar3D, Line3D, Trisurf3D (Delaunay), Contour3D (marching squares), Quiver3D (vector field), Voxels (face-culled cubes), Text3D (annotations). Full Projection3D pipeline, DepthQueue3D painter's algorithm, Vec3.FaceNormal + Color.Shade()/Color.Modulate() extension-based shading, Svg3DRotationScript client-side rotation with depth re-sorting, camera-derived back faces (CubeFaceSelection — the panes, cube edges, wall grids and tick rows follow the camera at any azimuth, server-side and during a drag), configurable Pane3DConfig (floor/wall colors), and 3D colorbar support.

Streaming & Realtime — StreamingLineSeries, StreamingScatterSeries, StreamingSignalSeries, StreamingCandlestickSeries backed by DoubleRingBuffer with AppendPoint(x, y). StreamingFigure provides throttled re-rendering and auto-scaling axes (SlidingWindow, StickyRight, AutoScale). 11 streaming indicators (SMA, EMA, RSI, Bollinger, MACD, OBV, ATR, Stochastic, WilliamsR, CCI, VWAP) auto-attach to candlestick data. Streaming controls for Avalonia, Uno, MAUI, Blazor, and ASP.NET Core. SVG diff engine for bandwidth optimization. Rx IObservable<T> adapter.

Geographic projections — MatPlotLibNet.Geo package with 5 map projections (PlateCarree, Mercator, Robinson, Orthographic, LambertConformal), GeoJSON parser, Natural Earth 110m embedded data, and GeoPolygonSeries for coastlines/borders/choropleth. Symlog axis scale for data spanning positive and negative ranges.

Bidirectional SignalR — server-authoritative interactive charts with mutation events (zoom, pan, reset, legend toggle) and notification events (brush-select, hover). Stacked-record event hierarchy, natural coalescing, per-caller hover responses.

142 colormaps — viridis, plasma, turbo, coolwarm, and 138 more (71 base maps, each with an auto-registered reversed _r variant). NumPy-style SIMD numerics (Vec, Mat, Linalg, Fft). Accessibility (ARIA, keyboard, Okabe-Ito palette, high-contrast theme). Matplotlib look-alike themes. DataFrame integration with 53 technical indicators. Broken axes. Publication-quality SVG/PNG/PDF/GIF export.

License

MIT — free for any use, open-source or commercial, with no copyleft conditions.