speed fix

gpx-rs/engine/src/core/statistics/statistics.rs

@@ -3,6 +3,20 @@ use crate::{
     max_options, min_options, ramer_douglas_peucker, slope, speed, sum_options, time_diff,
 };
 
+/// Time between two trackpoints, to size the windows of a smoothing. It is unknown when one of
+/// them has no time, which is longer than any known time span: the window does not go there.
+#[derive(Clone, Copy, PartialEq, PartialOrd)]
+enum TimeSpan {
+    Known(i64),
+    Unknown,
+}
+
+impl TimeSpan {
+    fn between(end: Option<i64>, start: Option<i64>) -> Self {
+        time_diff(end, start).map_or(Self::Unknown, Self::Known)
+    }
+}
+
 #[derive(Default, Debug)]
 pub struct Statistics {
     pub global: GlobalStatistics,
@@ -84,22 +98,36 @@ impl Statistics {
         self.global.bounds.extend(coordinates);
     }
 
+    /// Speed over a window of 10 seconds on each side of the trackpoints that have a time (the
+    /// others have no speed). The windows do not extend to the trackpoints without time: if the
+    /// previous or next trackpoint has none, the window ends at the trackpoint itself on that side.
     fn compute_smoothed_speed(&mut self, trkseg: &TrackSegment) {
         for_each_window!(
             trkseg,
             trkseg.first_index(),
             trkseg.last_index(),
-            Some(10_000),
-            |i, j| time_diff(trkseg[j].time, trkseg[i].time),
+            TimeSpan::Known(10_000),
+            |i, j| TimeSpan::between(trkseg[j].time, trkseg[i].time),
             |i, left, right| {
-                self.local[i.flat].speed =
-                    time_diff(trkseg[right].time, trkseg[left].time).map(|t| {
-                        speed(
-                            self.local[right.flat].total_distance
-                                - self.local[left.flat].total_distance,
-                            t,
-                        )
-                    });
+                if trkseg[i].time.is_some() {
+                    let timed = |index: TrackSegmentIndex| {
+                        if trkseg[index].time.is_some() {
+                            index
+                        } else {
+                            i
+                        }
+                    };
+                    let (left, right) = (timed(left), timed(right));
+                    self.local[i.flat].speed = time_diff(trkseg[right].time, trkseg[left].time)
+                        .filter(|time| *time > 0)
+                        .map(|time| {
+                            speed(
+                                self.local[right.flat].total_distance
+                                    - self.local[left.flat].total_distance,
+                                time,
+                            )
+                        });
+                }
             },
         );
     }
@@ -344,6 +372,83 @@ mod tests {
         }
     }
 
+    /// The speeds of the segment of `data/with_time.gpx` (80 trackpoints at 20 km/h) once the
+    /// trackpoints at `holes` have lost their time.
+    fn speeds_with_holes(holes: &[usize]) -> Vec<Option<f64>> {
+        let gpx = load("data/with_time.gpx");
+        let mut segment = gpx.trk[0].trkseg[0].clone();
+        let points: Vec<_> = segment
+            .iter()
+            .enumerate()
+            .map(|(i, trkpt)| {
+                let mut trkpt = trkpt.clone();
+                if holes.contains(&i) {
+                    trkpt.time = None;
+                }
+                trkpt
+            })
+            .collect();
+        segment.splice(0, points.len(), points);
+        Statistics::compute(&segment)
+            .local
+            .iter()
+            .map(|local| local.speed)
+            .collect()
+    }
+
+    /// Without time, there is no speed. With one, the speed is the one of the trackpoints around.
+    fn assert_speeds_with_holes(holes: &[usize]) {
+        let speeds = speeds_with_holes(holes);
+        assert_eq!(speeds.len(), 80);
+        for (i, speed) in speeds.iter().enumerate() {
+            if holes.contains(&i) {
+                assert_eq!(*speed, None, "trackpoint {i}");
+            } else {
+                let speed = speed.unwrap_or_else(|| panic!("no speed for trackpoint {i}"));
+                assert!((speed - 20.0).abs() < 0.1, "trackpoint {i}: {speed}");
+            }
+        }
+    }
+
+    #[test]
+    fn test_speed_without_holes() {
+        assert_speeds_with_holes(&[]);
+    }
+
+    #[test]
+    fn test_speed_with_holes_at_the_beginning() {
+        assert_speeds_with_holes(&[0, 1, 2, 3, 4]);
+    }
+
+    #[test]
+    fn test_speed_with_holes_at_the_end() {
+        assert_speeds_with_holes(&[75, 76, 77, 78, 79]);
+    }
+
+    #[test]
+    fn test_speed_with_holes_at_both_ends() {
+        assert_speeds_with_holes(&[0, 1, 2, 77, 78, 79]);
+    }
+
+    #[test]
+    fn test_speed_with_holes_in_the_middle() {
+        assert_speeds_with_holes(&[40]);
+        assert_speeds_with_holes(&[30, 31, 32, 33, 34]);
+        assert_speeds_with_holes(&(20..60).collect::<Vec<_>>());
+    }
+
+    #[test]
+    fn test_speed_with_scattered_holes() {
+        let holes: Vec<_> = (0..80).step_by(7).collect();
+        assert_speeds_with_holes(&holes);
+    }
+
+    #[test]
+    fn test_speed_without_any_time() {
+        let holes: Vec<_> = (0..80).collect();
+        assert!(speeds_with_holes(&holes).iter().all(Option::is_none));
+    }
+
     fn load(path: &str) -> crate::File {
         let mut f = File::open(path).unwrap();
         let mut data = String::new();

gpx-rs/engine/src/engine/derived/statistics_buffer.rs

@@ -11,17 +11,19 @@ pub const NO_TIME: i64 = i64::MIN;
 /// Times are in milliseconds, distances in kilometers, speeds in km/h. Missing times are
 /// [`NO_TIME`], missing measures are NaN.
 ///
-/// The optional values (`time`, `hr`, `cad`, `atemp`, `power`) are `None` when no trackpoint of the
-/// selection has one, and the OSM attributes are stored as [`Intervals`].
+/// The optional values (`moving_distance`, `total_time`, `moving_time`, `speed`, `time`, `hr`,
+/// `cad`, `atemp`, `power`) are `None` when no trackpoint of the selection has one, and the OSM
+/// attributes are stored as [`Intervals`]. The cumulative ones can only be missing before the
+/// first trackpoint that has them, where they are 0.
 #[derive(Debug, Default)]
 pub struct StatisticsBuffer {
     /// Statistics of the whole selection.
     pub global: GlobalStatistics,
     pub total_distance: Vec<f64>,
-    pub moving_distance: Vec<f64>,
-    pub total_time: Vec<i64>,
-    pub moving_time: Vec<i64>,
-    pub speed: Vec<f64>,
+    pub moving_distance: Option<Vec<f64>>,
+    pub total_time: Option<Vec<i64>>,
+    pub moving_time: Option<Vec<i64>>,
+    pub speed: Option<Vec<f64>>,
     pub elevation_gain: Vec<f64>,
     pub elevation_loss: Vec<f64>,
     pub slope: Vec<f64>,
@@ -108,10 +110,10 @@ impl StatisticsBuffer {
     pub fn update(&mut self, selected: &[(&TrackSegment, &Statistics)]) {
         self.global = GlobalStatistics::default();
         self.total_distance.clear();
-        self.moving_distance.clear();
-        self.total_time.clear();
-        self.moving_time.clear();
-        self.speed.clear();
+        self.moving_distance = None;
+        self.total_time = None;
+        self.moving_time = None;
+        self.speed = None;
         self.elevation_gain.clear();
         self.elevation_loss.clear();
         self.slope.clear();
@@ -136,18 +138,25 @@ impl StatisticsBuffer {
                 let cumul_stats = &self.global;
                 self.total_distance
                     .push(cumul_stats.total_distance + trkpt_stats.total_distance);
-                self.moving_distance.push(
-                    sum_options(cumul_stats.moving_distance, trkpt_stats.moving_distance)
-                        .unwrap_or_default(),
+                push_optional(
+                    &mut self.moving_distance,
+                    index,
+                    sum_options(cumul_stats.moving_distance, trkpt_stats.moving_distance),
+                    0.0,
                 );
-                self.total_time.push(
-                    sum_options(cumul_stats.total_time, trkpt_stats.total_time).unwrap_or_default(),
+                push_optional(
+                    &mut self.total_time,
+                    index,
+                    sum_options(cumul_stats.total_time, trkpt_stats.total_time),
+                    0,
                 );
-                self.moving_time.push(
-                    sum_options(cumul_stats.moving_time, trkpt_stats.moving_time)
-                        .unwrap_or_default(),
+                push_optional(
+                    &mut self.moving_time,
+                    index,
+                    sum_options(cumul_stats.moving_time, trkpt_stats.moving_time),
+                    0,
                 );
-                self.speed.push(trkpt_stats.speed.unwrap_or_default());
+                push_optional(&mut self.speed, index, trkpt_stats.speed, f64::NAN);
                 self.elevation_gain
                     .push(cumul_stats.elevation_gain + trkpt_stats.elevation_gain);
                 self.elevation_loss
@@ -193,15 +202,9 @@ impl StatisticsBuffer {
         };
         Some(GlobalStatistics {
             total_distance: delta(&self.total_distance),
-            moving_distance: self
-                .global
-                .moving_distance
-                .map(|_| delta(&self.moving_distance)),
-            total_time: self.global.total_time.map(|_| delta_time(&self.total_time)),
-            moving_time: self
-                .global
-                .moving_time
-                .map(|_| delta_time(&self.moving_time)),
+            moving_distance: self.moving_distance.as_deref().map(delta),
+            total_time: self.total_time.as_deref().map(delta_time),
+            moving_time: self.moving_time.as_deref().map(delta_time),
             elevation_gain: delta(&self.elevation_gain),
             elevation_loss: delta(&self.elevation_loss),
             start_time: time(start),
@@ -243,10 +246,6 @@ mod tests {
     fn all_lengths(buffer: &StatisticsBuffer) -> Vec<usize> {
         vec![
             buffer.total_distance.len(),
-            buffer.moving_distance.len(),
-            buffer.total_time.len(),
-            buffer.moving_time.len(),
-            buffer.speed.len(),
             buffer.elevation_gain.len(),
             buffer.elevation_loss.len(),
             buffer.slope.len(),
@@ -263,7 +262,7 @@ mod tests {
         let mut buffer = StatisticsBuffer::default();
         buffer.update(&[]);
         assert!(buffer.is_empty());
-        assert!(buffer.speed.is_empty());
+        assert!(buffer.speed.is_none());
         assert_eq!(buffer.global.total_distance, 0.0);
         assert!(buffer.slice(0, 0).is_none());
     }
@@ -335,10 +334,11 @@ mod tests {
         let mut buffer = StatisticsBuffer::default();
         buffer.update(&[(&segment, &s), (&segment, &s)]);
 
-        assert_eq!(buffer.total_time[n - 1], duration);
-        assert_eq!(buffer.total_time[n], duration);
-        assert_eq!(buffer.total_time[2 * n - 1], 2 * duration);
-        assert!(buffer.total_time.windows(2).all(|w| w[0] <= w[1]));
+        let total_time = buffer.total_time.as_ref().unwrap();
+        assert_eq!(total_time[n - 1], duration);
+        assert_eq!(total_time[n], duration);
+        assert_eq!(total_time[2 * n - 1], 2 * duration);
+        assert!(total_time.windows(2).all(|w| w[0] <= w[1]));
         assert!(buffer.time.unwrap().iter().all(|t| *t != NO_TIME));
     }
 
@@ -356,6 +356,11 @@ mod tests {
         assert_eq!(buffer.global.hr.count, 0);
         assert_eq!(buffer.global.total_time, None);
         assert_eq!(buffer.len(), s.local.len());
+        // they need times
+        assert!(buffer.speed.is_none());
+        assert!(buffer.moving_distance.is_none());
+        assert!(buffer.total_time.is_none());
+        assert!(buffer.moving_time.is_none());
         // the slices do not need them
         let slice = buffer.slice(0, 2).unwrap();
         assert_eq!((slice.start_time, slice.end_time), (None, None));
@@ -402,6 +407,29 @@ mod tests {
         assert!(buffer.cad.is_none());
     }
 
+    #[test]
+    fn test_cumulative_values_are_zero_before_the_first_one() {
+        let (mut segment, _) = computed("data/with_time.gpx");
+        let n = segment.len();
+        let mut first = segment[0].clone();
+        first.time = None;
+        segment.splice(0, 1, vec![first]);
+        let s = Statistics::compute(&segment);
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s)]);
+
+        let total_time = buffer.total_time.as_ref().unwrap();
+        assert_eq!(total_time.len(), n);
+        assert_eq!(total_time[0], 0);
+        assert_eq!(total_time[n - 1], s.global.total_time.unwrap());
+        assert!(total_time.windows(2).all(|w| w[0] <= w[1]));
+        // so a slice that starts on the first trackpoint is right
+        assert_eq!(
+            buffer.slice(0, n - 1).unwrap().total_time,
+            s.global.total_time
+        );
+    }
+
     #[test]
     fn test_surface_and_highway_intervals() {
         let (segment, s) = computed("data/with_highway.gpx");
@@ -547,11 +575,17 @@ mod tests {
         );
         assert_eq!(
             slice.total_time,
-            Some(buffer.total_time[end] - buffer.total_time[start])
+            Some(
+                buffer.total_time.as_ref().unwrap()[end]
+                    - buffer.total_time.as_ref().unwrap()[start]
+            )
         );
         assert_eq!(
             slice.moving_time,
-            Some(buffer.moving_time[end] - buffer.moving_time[start])
+            Some(
+                buffer.moving_time.as_ref().unwrap()[end]
+                    - buffer.moving_time.as_ref().unwrap()[start]
+            )
         );
         assert_eq!(slice.start_time, Some(buffer.time.as_ref().unwrap()[start]));
         assert_eq!(slice.end_time, Some(buffer.time.as_ref().unwrap()[end]));

gpx-rs/wasm/src/lib.rs

@@ -130,11 +130,6 @@ macro_rules! stats_getter {
 }
 
 stats_getter!(total_distance, Float64Array);
-stats_getter!(moving_distance, Float64Array);
-// Durations since the start of the selection, in milliseconds.
-stats_getter!(total_time, BigInt64Array);
-stats_getter!(moving_time, BigInt64Array);
-stats_getter!(speed, Float64Array);
 stats_getter!(elevation_gain, Float64Array);
 stats_getter!(elevation_loss, Float64Array);
 stats_getter!(slope, Float64Array);
@@ -145,7 +140,8 @@ stats_getter!(lat, Float64Array);
 stats_getter!(ele, Float64Array);
 
 // The optional values are `undefined` when no trackpoint of the selection has one, else they have
-// an entry per trackpoint, the missing ones being NaN (`NO_TIME` for the timestamps).
+// an entry per trackpoint, the missing ones being NaN (`NO_TIME` for the timestamps, 0 before the
+// first trackpoint that has them for the cumulative distances and durations).
 macro_rules! optional_stats_getter {
     ($name:ident, $field:ident, $array:ident) => {
         #[wasm_bindgen]
@@ -155,6 +151,11 @@ macro_rules! optional_stats_getter {
     };
 }
 
+optional_stats_getter!(moving_distance, moving_distance, Float64Array);
+// Durations since the start of the selection, in milliseconds.
+optional_stats_getter!(total_time, total_time, BigInt64Array);
+optional_stats_getter!(moving_time, moving_time, BigInt64Array);
+optional_stats_getter!(speed, speed, Float64Array);
 // Timestamps in milliseconds since the epoch (`NO_TIME`, the smallest i64, when missing).
 optional_stats_getter!(timestamps, time, BigInt64Array);