FlexViz 0.1.0b1

The first public release of FlexViz: a renderer-agnostic, lazily evaluated,
stateless visualization library built on Polars and FastAPI, for exploring
datasets of 100M+ rows.

pip install flexviz

The Rust kernels arrive as a prebuilt flexviz-polars wheel on Linux
(x86_64, aarch64), macOS (Intel and Apple silicon), and Windows (x64); any
other platform builds them from source on stable Rust.

Highlights

• Ten trace types: line, histogram, box, bar, pie, treemap, 2D histogram,
  correlation heatmap, geo 2D histogram, and geo line.
• Native cross-filtering in update or overlay mode, with grouped traces and
  linked hover.
• Client-side cube live-brushing, so dragging a brush costs no server
  round-trips.
• Shareable URLs that encode viewport, selections, cross-filter mode, and
  dashboard layout, with no server-side state.
• Drag-and-drop dashboard grid, with the arrangement carried in the URL.
• Plotly.js rendering behind an adapter boundary.
• mount_into() for embedding into an existing FastAPI application.
• flexviz-polars, the Rust Polars expression kernels behind the line
  downsampling and fixed-bin histogram and heatmap paths. Released together
  with flexviz, versioned independently (flexviz-polars-v0.1.0b1).

Performance

• The default line downsampling path (downsample="minmax") runs as one fused
  minmax_line kernel call per trace. Polars does not
  common-subexpression-eliminate plugin expressions, so the previous
  index-plus-two-gathers form scanned every column twice; the fused call
  halves kernel work and makes frame times markedly steadier. Output is
  bit-identical, pinned by a differential test.
• The arg_min_max window scan is parallel across windows on the plugin's
  kernel thread pool: ~1.3-1.6x on a single trace at 100M rows.
• Benchmarks against Datashader, Vaex, and Mosaic are at
  flexviz.tech/benchmarks; the
  harness and per-trial results live in
  flexviz-benchmarks.

Compatibility

FlexViz is pre-1.0: minor versions may break the Python API, the spec wire
format, shared-URL encoding, and storage or cache formats. See the
compatibility policy.

Full changelog: CHANGELOG.md