dspk-app-core 0.0.7

//! Spike events for the timeline event track.
//!
//! Events come only from a spike extraction the user runs with their own parameters; nothing
//! is detected when a recording opens. Until then the store is empty.

/// Collection of spike events across channels.
#[derive(Debug, Clone, Default)]
pub struct SpikeEventStore {
    /// All event times, sorted ascending.
    #[cfg_attr(not(test), allow(dead_code))]
    pub times_sec: Vec<f64>,
    /// Per-channel sorted event times (for windowed lookups while rendering).
    by_channel: Vec<Vec<f64>>,
}

impl SpikeEventStore {
    #[cfg(test)]
    pub fn len(&self) -> usize {
        self.times_sec.len()
    }

    /// Number of events detected on `channel`.
    pub fn count(&self, channel: usize) -> usize {
        self.by_channel.get(channel).map_or(0, Vec::len)
    }

    /// Event times of `channel` within `[t0, t1]`, found by binary search.
    pub fn in_window(&self, channel: usize, t0: f64, t1: f64) -> &[f64] {
        let Some(times) = self.by_channel.get(channel) else { return &[] };
        let lo = times.partition_point(|&t| t < t0);
        let hi = times.partition_point(|&t| t <= t1);
        &times[lo..hi.max(lo)]
    }

    /// Negative threshold crossings per channel with `dspk-synapse` (`-4.5 * sigma_n`,
    /// local-minimum peak, 2 ms spacing: the deeper of two troughs closer than that stays),
    /// reading whole channels. Test fixture only: the app
    /// never detects on its own; user-run extraction replaces it.
    #[cfg(test)]
    pub fn detect(source: &dyn dspk_view::SignalBackend) -> Self {
        use dspk_synapse::{detect_spikes_threshold, SpikePolarity, ThresholdSpikeDetector};
        const THRESHOLD_FACTOR: f32 = 4.5;
        const REFRACTORY_SEC: f64 = 0.002;
        let info = source.info();
        let sample_rate = info.sample_rate_hz();
        let samples = info.samples as usize;

        let mut by_channel = Vec::with_capacity(info.channel_count());
        let mut all: Vec<f64> = Vec::new();
        let mut trace = vec![0.0f32; samples];

        for ch in 0..info.channel_count() {
            if source.read(&[ch], 0..samples as u64, &mut trace).is_err() {
                by_channel.push(Vec::new());
                continue;
            }
            // Channels are detected independently so the refractory state never leaks across them
            let settings = ThresholdSpikeDetector::new(THRESHOLD_FACTOR, REFRACTORY_SEC * 1e3, SpikePolarity::Negative);
            let events = detect_spikes_threshold(&trace, 1, samples, sample_rate, &settings);
            let times: Vec<f64> = events
                .iter()
                .map(|e| e.sample_index as f64 / sample_rate)
                .collect();
            all.extend_from_slice(&times);
            by_channel.push(times);
        }

        all.sort_by(f64::total_cmp);
        Self { times_sec: all, by_channel }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::data::recording::Dataset;

    #[test]
    fn test_spike_event_detection() {
        let sample_rate = 10_000.0;
        let samples = 2_000;
        let mut data = vec![1.0f32; 2 * samples];

        // Inject two clear spikes on ch 0 separated by > 2ms (20 samples)
        data[500] = -100.0; // Within 2 ms of a deeper trough -> dropped
        data[505] = -120.0;
        data[600] = -100.0; // More than 2 ms away -> detected

        // Inject one clear spike on ch 1
        data[samples + 1000] = -110.0;
        let ds = Dataset::from_samples("test", data, 2, sample_rate);

        let store = SpikeEventStore::detect(ds.signal().as_ref());
        assert_eq!(store.len(), 3);
        assert!((store.times_sec[0] - 0.0505).abs() < 1e-6);
        assert!((store.times_sec[1] - 0.060).abs() < 1e-6);
        assert!((store.times_sec[2] - 0.100).abs() < 1e-6);

        assert_eq!(store.in_window(0, 0.0, 1.0), &[0.0505, 0.060]);
        assert_eq!(store.in_window(1, 0.0, 1.0), &[0.100]);
        assert_eq!(store.in_window(0, 0.055, 1.0), &[0.060]);
        assert_eq!(store.in_window(1, 0.0, 0.05), &[] as &[f64]);
        assert_eq!(store.in_window(5, 0.0, 1.0), &[] as &[f64]);
    }
}