Glossary

Terms that mean different things in different parts of the codebase. The "common mistakes" callouts in concept pages reference back here when ambiguity bites.

Filter

Three meanings, kept separate by convention:

1. Display transform in signal_viewer (rectify, DC removal, 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.filters. Smooths the prediction output vector (pose, control command) before it leaves the app. UI panel via FilterControl.

Source

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

Output

A class with .push(data) and a daemon thread that drains the latest pushed value to its destination at hz. User-owned - not registered with the app. See Add a custom output.

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_seconds=...). 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 are finger flexion/rotation; 6–8 are wrist axes. 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 Output): drains the latest pushed value to its destination at the output's own hz.

The main thread stays on the GUI. See Threading.