Data Trim¶
Large files can bog down browsers, slow every preprocessing step, and clutter plots with millions of points.
Trimming lets you define a smaller “working window” before you run Fill → Resample → Normalize → Smooth. Trim can be performed from two locations, either: 1) from the "Main Control Panel" tab under the "Data Trim" section, or 2) from the "Auto labeler" tab under the "Data Trim" section.
Why Trim First?¶
| Benefit | Impact |
|---|---|
| Speed | GUI remains responsive; preprocessing finishes sooner. |
| Focus | Zoom in on the time span or region you actually need to label. |
| Memory | Reduces RAM/VRAM load—important for long signals or high-resolution traces. |
| Safer experimentation | Apply aggressive filters on a slice before committing to the full set. |
Typical Workflow¶
- Open Preview – Load the raw series in the viewer.
- Select Range – Drag start/stop handles (or enter timestamps) to bracket the region of interest.
- Apply Trim – The GUI hides data outside the window; subsequent preprocessing uses only the trimmed slice.
- (Optional) Iterate – Adjust the window as you inspect results, then lock it in before exporting labels.
Tip: Trimming is non-destructive—your original file stays intact.
Simply clear the trim to restore the full record.
Best-Practice Guidelines¶
- Trim early, often: Even a rough cut (e.g., one day from a year-long log) can boost interactivity.
- Leave overlap: If you plan to stitch adjacent segments later, keep a small overlap (e.g., 5 %) at each edge.
- Re-trim after resampling: If down-sampling changes time resolution, you may need to adjust the window.
- Document your window: Save start/stop indices or timestamps with your preprocessing pipeline for reproducibility.