Skip to content

Glossary

Terms that mean different things in different parts of the codebase. The "common mistakes" callouts in concept pages link back here where a term is ambiguous.

Filter

Three meanings, kept separate by convention:

  1. Display transform in SignalViewer (an optional 50/60 Hz mains-hum notch, then rectify, DC removal, or RMS envelope). Affects only what's drawn on screen - never recording, never extract(), never the model. See the widget tooltip.
  2. Post-prediction smoother like OneEuroFilter or GaussianFilter from myogestic.outputs.filters. Smooths the prediction output vector (pose, control command) before it leaves the app. UI panel via PostProcessor.

Source

A Protocol with connect() / read() / disconnect(). Wraps a device, file, or transport behind a uniform interface. See Add a custom source.

Target

A Protocol with bind() / send() / stop(), plus a capabilities() list of what it can drive. Anything that moves is a target: a prosthesis on a serial port, a motor controller, a cursor, the Virtual Hand. It receives named values from a control map, can refuse a configuration at bind, and gets range, clamping, dead zone, debounce and rest-on-teardown from the bus. The transport is yours - send does whatever your device needs. See Drive your own device.

Outlet

A class with .push(data) and a daemon thread that sends the latest pushed value to its destination at hz. It takes an array, paces one wire, and has no aliases, no declared range and no rest on shutdown. User-owned - not registered with the app. Anything that moves is a Target instead; an outlet is what a target may write through, and RemoteTarget owns one LSLOutlet per address it drives. See Publish a data stream.

Stream

A named ring buffer in ctx.streams, fed by one Source. Many widgets and the predict thread read from it concurrently; the buffer's threading.Lock keeps reads/writes coherent.

Window

A slice of a Stream's ring buffer at the current time. Length set by Stream(window_ms=...). Returned channels-first by Stream.get_window() to match what feature extractors expect.

Trial

One labelled segment of a recorded session - the data between two consecutive label timestamps in LabelEvent. The training window iterators slice trials into overlapping windows.

Recording / Session

One app.start_recording() → app.stop_recording() cycle. Persisted as a folder during capture, packed to a .session.zip archive on stop. Both layouts loadable via myogestic.session.open_session_store(path).

DOF

A "degree of freedom" in the controlled output - e.g. one finger joint, or one axis of a robot. A multi-DOF model predicts several at once and composes them into a single output vector.

Pose

A 9-float vector understood by the Virtual Hand Interface (VHI). Indices 0–5 carry the six controls it drives — thumb flexion, thumb abduction, then index, middle, ring and little flexion. Indices 6, 7 and 8 carry wrist flexion, abduction and rotation — bone 0, which parents every digit, so the whole hand turns. Rotation spans ±179° rather than ±180°: at exactly half a turn the Euler read-back wraps and reports the opposite sign. Values clipped to [-1, 1].

Bridge

A subprocess pattern for heavy-data sources (webcam, ultrasound) that would otherwise saturate a Python thread. The bridge writes frames to a Zarr array and publishes a clock stream over LSL; the main app reads timestamps, not pixels.

Predict thread / acquisition thread / output thread

The three daemon-thread categories that run alongside the GUI:

  • Acquisition (one per Stream): Source.read → ring buffer → display snapshot → optional Zarr append.
  • Predict (one, only when Pipeline is attached): wakes every 1/predict_hz, runs extract → predict, writes to pipeline.predictions.
  • Output (one per Outlet): drains the latest pushed value to its destination at the output's own hz.

The main thread stays on the GUI. See Threading.