SciChart WPF v9.1 update  (v9.1.0 build 29201) builds on the v9 release with a major new DataPointLabel API, an AspectRatio Viewport Manager for true-to-scale plotting, richer bubble coloring and styling, Pie & Donut theming, and Polar Chart improvements — along with a set of important stability and reliability fixes. We outline the main enhancements and features below.

We’ve moved over to a new format for communicating our releases and updates of our popular WPF Chart library, by publishing a rolling changelog of every fix or enhancement in SciChart. You can find the changelogs in the top menu at Developers -> Changelogs -> SciChart WPF ChangeLog

What’s New in v9.1 of SciChart’s WPF Charts?

Below is a summary of the main features and changes in this release (v9.1.0 build 29201):

1. Building Map Charts: The Europe Population Map Example
2. New DataPointLabel API
3. AspectRatio Viewport Manager
4. Bubble Series: ColorMap and Styling
5. Pie and Donut Theming and Polar Chart Improvements
6. New Examples and Documentation
7. Fixes and Stability Improvements
8. Where to get it
9. Leaving Feedback

Building Map Charts: The Europe Population Map Example

SciChart is not only for time-series and scientific data — the new Europe Population Map featured example shows how to build a full choropleth map in WPF, opening SciChart up to geographic and thematic visualization. Countries are loaded from GeoJSON, projected, and shaded by population; a second layer plots every European city as a bubble; and the whole map stays perfectly proportioned at any zoom. It’s a ready-made template for GIS-style dashboards, territory maps, and any visualization drawn over a real-world map.

Under the hood, the example combines:

• A choropleth country layer — country polygons are read from an embedded GeoJSON source, projected from WGS-84 longitude/latitude into an equal-area (LAEA) map projection, and shaded by population with a HeatmapColorPalette. Rendering uses a compact custom series built on SciChart’s CustomRenderableSeries API.
• A city bubble layer — every European city is plotted with a bubble series built on FastBubbleRenderableSeries, sized by population and coloured by urban primacy (each city’s share of its country’s population) using the new Bubble ColorMap API.
• Labelled capitals — capital cities are labelled with the new DataPointLabel API, using a metadata-driven selector that labels only capitals while leaving the thousands of other city bubbles unlabelled.
• Country-name watermarks — each country’s name is drawn inside its borders, appearing only when it fits the country’s on-screen size, so labels reveal progressively as you zoom in.
• True-to-scale display — the AspectRatio Viewport Manager keeps the projected map undistorted at any window size or zoom level.

Interactive out of the box, the example adds hover tooltips (city, country, population, urban primacy), a minimum-population filter, and an aspect-ratio flyout. Because it brings together bubble ColorMap colouring, the DataPointLabel API, and the AspectRatio Viewport Manager, the Europe Population Map is both a practical map-charting recipe and a showcase of what’s new in v9.1.

New DataPointLabel API

The headline feature of v9.1 is a completely new, provider-based DataPointLabel API, bringing the flexible labelling model from SciChart JS to WPF. It gives you precise control over the text, formatting, and placement of per-point labels across a wide range of series types.

Key features:

• A DataLabelProvider API to customize label text, number/date formatting, and positioning on a per-point basis
• A simple ShowDataLabels switch to turn labels on for a series
• Flexible placement, including custom label positions for column series, labels drawn in the middle of box plots, and always-on text labels for stacked columns
• Programmatic invalidation and cache clearing, so labels update cleanly in realtime and dynamic scenarios
• Broad series coverage — line, column, stacked column, box plot, bubble and more

The new API is demonstrated across several examples, including Dashboard Style Charts, Histograms, and the dedicated Data Labels example.

AspectRatio Viewport Manager

The new AspectRatioViewportManagerlocks the on-screen relationship between X and Y units, so your data keeps its true proportions — circles stay round and maps stay undistorted — regardless of zoom level or window size. This is essential for geographic maps, engineering drawings, and any chart where shape matters.

Key features:

• AspectRatio — the ratio of pixels-per-X-unit to pixels-per-Y-unit, held constant on every render pass
• AspectRatioMode — choose which axis is authoritative: LatestChanged, X, Y, or Fit (never crop)
• Anchor — pick which edge stays fixed while the other axis is resized: Center, Min, or Max
• Aspect Ratio toolbar toggle button, so users can enable or disable the aspect-ratio lock interactively

The Spirograph Aspect Ratio example demonstrates every mode and anchor, and the Europe Population Map uses the AspectRatio Viewport Manager to keep the map geographically correct.

Bubble Series: ColorMap and Styling

Bubble charts gain powerful new coloring and true border styling in v9.1, turning FastBubbleRenderableSeries into a proper three-dimensional (X, Y, Z) visualization tool.

Key features:

• ColorMap (IColorMap) — color each bubble by its Z value using a color map, with ColorMapRangeMode (defaulting to Auto, which fits the color range to the data) and a ColorMapValueProvider for custom value-to-color mapping
• FillBrush (a RadialGradientBrush) for rich, soft-edged bubble fills
• A reworked bubble border — setting a positive StrokeThickness now draws a crisp fixed-pixel ring in the series Stroke color (previously the stroke was never drawn), and this is now fully supported on the VisualXccelerator (GPU) renderer as well as the software renderers

These improvements power the new Seismic Activity Explorer example, which maps earthquake depth to color and magnitude to bubble size.

Pie and Donut Theming and Polar Chart Improvements

Pie and Donut theming. Pie and Donut charts now participate fully in the SciChart theming system. Chart chrome — backgrounds, labels, and segment strokes — is styled consistently across all built-in themes, so pie and donut charts sit naturally alongside your Cartesian charts.

Polar chart improvements. v9.1 adds a dedicated PolarLineRenderableSeries (a subclass of FastLineRenderableSeries) with a ConnectionMode property — PolarLineConnectionMode.Arc (the default, which follows the polar coordinate system) or Straight (direct screen-space lines between points). Polar gridline and tick quality has also been improved on the VisualXccelerator renderer, with polar gridlines now correctly honoring StrokeThickness.

New Examples and Documentation

SciChart WPF v9.1 adds new examples that showcase the features above, along with new documentation articles.

New Examples

• Europe Population Map — building a map chart from polygon country shapes, a population-sized bubble layer, and labelled capitals
• Seismic Activity Explorer — bubble chart with ColorMap coloring (depth) and magnitude-based sizing
• Spirograph Aspect Ratio — demonstrates the AspectRatio Viewport Manager with every AspectRatioMode and Anchor, and an interactive on/off toggle
• Data Labels, Dashboard Style Charts and Histograms — showcasing the new DataPointLabel API

New Documentation Articles

• AspectRatio Viewport Manager — how to keep data true-to-scale
• Data Point Labels API — how to show per-point text labels for a 2D series
• Custom Data Label Providers — tells about a deeper customization of per-point data labels for a 2D series
• Bubble Series with ColorMaps — describes how to achieve individual bubble coloring using color maps

Updated Documentation Articles

• LegendMarkerTemplate in the LegendModifier documentation
• ZoomExtentsRange property on Axis — the documentation about Axis Ranging tells how to configure a desired zoom extents range for an axis
• Unsubscribing Data Filters — the Filters API documentation now describes how to detach data filters from DataSeriesChanged

Fixes and Stability Improvements