# Provenance: dpb-plot

**Source.** AuraSense's `aurasense-dpb-training` repository, `crates/dpb-plot`, at commit
`9202cd83fe2aa284957bf6a6d8aa1284eb1541e6` (branch `feat/dpb-plot`, 2026-10-19).

**Licence.** Upstream is `Apache-2.0 OR MIT`. flowRS takes it under Apache-2.0, the
licence of the rest of flowRS (the text is `LICENSE` at the repository root); the MIT text
is kept beside the crate as `LICENSE-MIT`. Upstream has no NOTICE file. The package keeps
upstream's authors and licence expression.

**What was taken.** `Cargo.toml`, `README.md` and `src/` (core, `gpu/` with its WGSL
shaders, tests), formatted with default rustfmt so later changes show as diffs against the
vendoring commit (668c9166). Not taken: the `wasm` feature (JavaScript bindings,
`build-wasm.sh`), the `bench` feature and `bench/` budget pages, `measure/wgpu-proto`, and
`gates.sh`. flowRS calls the crate as Rust and runs its own gates.

## flowRS's changes (commit 3e1650a1 and later)

- **A moments level beside the min/max pyramid** (`history.rs`): `ChannelSpec::stats` /
  `with_stats()`, per-block `Moments { n, mean, m2 }` (f32, merged with Chan et al.'s
  pairwise update and accumulated in f64 over a range), `range_moments`, `bucket_moments`
  and `moment()`. The EEG scope's DC removal and ±1 SD band, and flowrs-capture's analog
  index, read them; JLS-style mean/std over any span without touching the samples.
- `ChannelSpec::keeping(seconds)`: a ring sized by duration.
- **A spread band** (`plot.rs`): `SeriesKind::Spread`, drawn as mean ± one standard
  deviation per pixel column.
- **Column helpers made public** (`plot.rs`): `Trace` and its fields, `copy_trace`,
  `copy_spread` and `columns`, so the Waveform panel and the scope build scenes from runs
  that are not a `TimePlot` lane.
- Two trigger tests name the new `stats` field.

- **An image mark** (`scene.rs` `MarkKind::Image`, `ImageRun`, `Scene::push_image`;
  `gpu::ImageData`, `Renderer::set_image`; `gpu/wgsl/image.wgsl` and its GLSL twin in
  `webgl2.rs`; an offscreen-canvas path in `canvas2d.rs`), added by flowrs-viz's
  substrate (work/neuroviz): a grid of values the renderer holds, drawn through a
  256-entry colour lookup texture with bilinear or nearest sampling, an optional circular
  clip and contour hairlines. Topomaps, time-frequency maps, spectral arrays and ERP
  images draw through it. Canvas 2D scales an offscreen canvas and draws no contours.

All upstream tests still pass, with new tests for each addition.