MatPlotLibNet

A .NET 10 / .NET 8 charting library inspired by matplotlib. Fluent API, dependency injection, parallel server-side SVG rendering, polymorphic export (SVG / PNG / PDF / animated GIF), and 78 series types across line, scatter, bar, 3D, streaming, polar, financial, statistical, hierarchical, Sankey, and vector families. Ships with 13 map projections and embedded Natural Earth data, 26 themes, LaTeX-style MathText, O(1) streaming with 52 technical indicators (classical moving averages + volatility, momentum, trend-follower, cycle, microstructure, entropy, change-point, and cross-asset causality), financial drawing tools (trendlines, Fibonacci retracements, horizontal levels), frame-based animation with 6 easing curves + Pause/Resume playback, native UI controls for Blazor, WPF, MAUI, Avalonia, Uno Platform, ASP.NET Core, and TypeScript clients for Angular, React, and Vue — no JavaScript framework, no WebView, no SaaS.

🧭 What's next

v1.10.0 (2026-05-04) — Pair-Selection Visualisation Pack ships the full 5-phase chart-type machinery for correlation-based asset clustering, dimensional EDA, and hierarchical risk parity. Future releases are community-driven:

• 🗺️ Phase 1 — Annotated & triangular-mask heatmaps: four new HeatmapSeries properties (ShowLabels, LabelFormat, MaskMode, CellValueColor) + HeatmapMaskMode enum unblock every realistic correlation-matrix figure.
• 🌲 Phase 2 — DendrogramSeries: hierarchical-clustering tree as canonical "U"-shape segments. Four DendrogramOrientation values (Top, Bottom, Left, Right); optional CutHeight draws a dashed reference line and recolours each cluster below the cut from a qualitative IColorMap (default Tab10). Fluent API: Plt.Create().Dendrogram(root, s => s.CutHeight = 1.5).
• 🔥 Phase 3 — ClustermapSeries: composite heatmap with optional row/column dendrograms (the seaborn clustermap idiom). Automatic data-matrix reordering to align cells visually with the leaf order.
• 📊 Phase 4 — PairGridSeries: multi-panel scatter matrix (the seaborn pairplot idiom). N×N grid: histogram or KDE on the diagonal, scatter or hexbin on the off-diagonal, optional hue groups + string[]? HueLabels for category-aware EDA.
• 🔷 Phase 5 — Hexbin off-diagonal: activates PairGridOffDiagonalKind.Hexbin = 2 for high-cardinality EDA where scatter overplots (~1000+ samples per cell).
• 🧹 Convergence sweep: IColormappable.GetColorMapOrDefault(fallback) and int.ColormapFraction(count) extensions collapse 17 + 3 inline duplications across renderers into one place; shared HierarchicalLayout.MinPanelPx and Numerics/HistogramBinning source-of-truth.
• 🗺️ v1.10.0 heatmap extensions (released):
  • ShowLabels / LabelFormat (ILabelable) — render each cell's value on top of the fill; any .NET numeric format string (e.g. "P1", "F0")
  • MaskMode — HeatmapMaskMode enum hides redundant cells in symmetric matrices (UpperTriangle, LowerTriangle, and strict variants that include the diagonal)
  • CellValueColor — explicit label colour; auto black/white contrast via Color.ContrastingTextColor() (Rec. 709) when null
• 🐛 Bug fixes — driven by community use and the strict ≥90/90 per-class coverage gate (all classes pass; 8 707 core tests).
• 📚 Documentation polish — cookbook examples, API XML doc completeness.
• 🌱 Listening — Open a Discussion or Issue with what's missing for your use case. The next direction will be guided by what real users need, not by a feature checklist.

For the full v1.10.0 release notes, see the CHANGELOG.

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Documentation

Full documentation is on the GitHub Wiki, the Cookbook (runnable examples with rendered images), and the API Reference (generated from XML doc comments):

• Playground — try charts live in the browser — pick an example, tweak parameters, see the SVG update instantly
• Cookbook — copy-paste code examples with rendered output for every chart type
• API Reference — full API documentation from source
• Getting Started — installation, output formats, subplots
• Fluent Cheatsheet — one-page reference for Plt / FigureBuilder / AxesBuilder
• Package Map — all 13 NuGet + 3 npm packages in detail
• Chart Types — all 78 series with code examples
• Streaming & Realtime — ring buffers, StreamingFigure, axis scaling, 11 streaming indicators, platform controls
• Interactive Controls — Avalonia + Uno native controls, managed interaction layer
• Bidirectional SignalR — server-authoritative interactive charts, event hierarchy, hub wiring
• DataFrame — indicators, polynomial regression from Microsoft.Data.Analysis.DataFrame
• Notebooks — Polyglot Notebooks + Jupyter inline rendering
• Styling — themes, colormaps, PropCycler
• Accessibility — SVG semantics, keyboard navigation, color-blind palette
• Advanced — date axes, math text, animations, GIF, real-time
• Benchmarks — SVG rendering, SIMD transforms, indicators, Skia export (BENCHMARKS.md in the repo root; also mirrored on the wiki)
• Roadmap — version history and planned phases
• Contributing — build, test, coding conventions

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Packages

Package	Install	What it does
MatPlotLibNet	dotnet add package MatPlotLibNet	Core: models, fluent API, SVG rendering, JSON, transforms
MatPlotLibNet.DataFrame	dotnet add package MatPlotLibNet.DataFrame	Microsoft.Data.Analysis.DataFrame extension methods — plot, indicators (SMA/EMA/RSI/MACD/…), and polynomial regression from named columns
MatPlotLibNet.Skia	dotnet add package MatPlotLibNet.Skia	PNG, PDF, and animated GIF export via SkiaSharp
MatPlotLibNet.Blazor	dotnet add package MatPlotLibNet.Blazor	MplChart + MplLiveChart Razor components with SignalR
MatPlotLibNet.AspNetCore	dotnet add package MatPlotLibNet.AspNetCore	REST endpoints, SignalR hub, IChartPublisher
MatPlotLibNet.Interactive	dotnet add package MatPlotLibNet.Interactive	figure.ShowAsync() — browser popup, no server needed
MatPlotLibNet.GraphQL	dotnet add package MatPlotLibNet.GraphQL	GraphQL queries + subscriptions via HotChocolate
MatPlotLibNet.Maui	dotnet add package MatPlotLibNet.Maui	Native MplChartView via Microsoft.Maui.Graphics
MatPlotLibNet.Avalonia	dotnet add package MatPlotLibNet.Avalonia	Native MplChartControl for Avalonia 12 — Skia backend, optional local interaction
MatPlotLibNet.Uno	dotnet add package MatPlotLibNet.Uno	Native MplChartElement for Uno Platform (WinUI 3 / Android / iOS / macCatalyst)
MatPlotLibNet.Wpf	dotnet add package MatPlotLibNet.Wpf	Native WPF MplChartControl via SkiaSharp — all 9 interaction modifiers
MatPlotLibNet.Geo	dotnet add package MatPlotLibNet.Geo	13 map projections, GeoJSON parser, Natural Earth 110m data, geographic polygons
MatPlotLibNet.Notebooks	#r "nuget: MatPlotLibNet.Notebooks"	Inline SVG in Polyglot / Jupyter notebooks
@matplotlibnet/angular	npm install @matplotlibnet/angular	Angular components + TypeScript SignalR client
@matplotlibnet/react	npm install @matplotlibnet/react	React hooks + components + TypeScript SignalR client
@matplotlibnet/vue	npm install @matplotlibnet/vue	Vue 3 composables + TypeScript SignalR client

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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");

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Features

78 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, pair grid, streaming line/scatter/signal/candlestick, and more.

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, 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.

104 colormaps — viridis, plasma, turbo, coolwarm, and 100 more. NumPy-style SIMD numerics (Vec, Mat, Linalg, Fft). Accessibility (ARIA, keyboard, Okabe-Ito palette, high-contrast theme). Matplotlib look-alike themes. DataFrame integration with 52 technical indicators (v1.9.0 adds 12 — Klinger, Twiggs MF, Ease of Movement, VWAP Z-Score, Supertrend, CG Oscillator, Inverse Fisher, YZ Vol Ratio, Ehlers iTrend, Decycler, Ehlers SuperSmoother, Transfer Entropy). Broken axes. Publication-quality SVG/PNG/PDF/GIF export.

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License

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