reference

`labkit.biosignal.buildTemplate`

Build a representative segment template.

Syntax

template = labkit.biosignal.buildTemplate(segments)
template = labkit.biosignal.buildTemplate(segments, opts)

Description

Forms a first-pass template by averaging every segment, then ranks each segment by its correlation with that average. The returned waveform is the sample-by-sample mean of the highest-ranked segments. This two-pass procedure reduces the influence of beats or trials whose shape differs from the majority.

Correlations are computed after subtracting each waveform's mean. Missing samples are omitted from means and correlations. A constant waveform has a NaN score and sorts behind finite scores. If segments contains no waveforms, the function returns an empty template with the same timeOffset vector.

Inputs

segments: Segment struct returned by labkit.biosignal.segmentByEvents. segments.values is an M-by-N matrix, with one segment per column; segments.timeOffset contains the M relative times.
opts: Optional scalar struct containing the fields listed below.

Options

topN: Number of ranked segments to average. The default is the smaller of 30 and the number of available segments. The value is rounded to an integer and limited to the range 1:N.

Outputs

template: Structure containing the representative waveform and the ranking information used to construct it.

Output Fields

type: String scalar "biosignalTemplate".
values: M-by-1 template waveform, or an M-by-0 array when no segments are available.
timeOffset: M-by-1 relative time vector copied from segments.
keptSegmentIndex: Indices of the segment columns included in values, ordered from highest to lowest correlation.
score: N-by-1 correlation score for every input segment.
metadata.topN: Number of segments included in a nonempty template.
metadata.sourceName: Source signal name copied from segments for a nonempty template. metadata is empty when no segment waveforms are available.

Errors

labkit:biosignal:InvalidSegments: segments is not a structure with values and timeOffset fields. Invalid numeric values or an unusable topN value may also raise the originating MATLAB conversion error.

Example

segments = struct('values', [0 0; 1 0.9; 0 0], ...
'timeOffset', [-1; 0; 1], 'sourceName', "ECG");
template = labkit.biosignal.buildTemplate(segments, struct('topN', 1));

labkit.biosignal.segmentByEvents — Extract fixed windows around event anchors.
labkit.biosignal.measureSegments — Measure generic template-residual segment quality.
labkit.biosignal.compareGroups — Summarize groups and compute pairwise Welch comparisons.
labkit.biosignal.cropSignal — Return a signal clipped to a time range in seconds.
labkit.biosignal.defaultEcgPeakOptions — Return documented defaults for ECG/QRS peak detection.
labkit.biosignal.detectEcgPeaks — Detect ECG/QRS peaks as event anchors.
labkit.biosignal.filterSignal — Apply a zero-phase FFT-domain filter to a biosignal.
labkit.biosignal.getChannel — Return one signal from a recording by display name or index.

Source

This page is generated from the MATLAB help text in +labkit/+biosignal/buildTemplate.m.

labkit.biosignal.buildTemplate