chore: deprecate old trait

geo/src/algorithm/frechet_distance.rs

@@ -1,8 +1,8 @@
-use crate::coords_iter::CoordsIter;
-use crate::line_measures::{Distance, Euclidean};
+use crate::line_measures::Euclidean;
 use crate::{GeoFloat, LineString};
 use num_traits::FromPrimitive;
 
+#[deprecated]
 /// Determine the similarity between two `LineStrings` using the [Frechet distance].
 ///
 /// Based on [Computing Discrete Frechet Distance] by T. Eiter and H. Mannila.
@@ -41,117 +41,12 @@ pub trait FrechetDistance<T, Rhs = Self> {
     fn frechet_distance(&self, rhs: &Rhs) -> T;
 }
 
+#[allow(deprecated)]
 impl<T> FrechetDistance<T, LineString<T>> for LineString<T>
 where
     T: GeoFloat + FromPrimitive,
 {
     fn frechet_distance(&self, ls: &LineString<T>) -> T {
-        if self.coords_count() != 0 && ls.coords_count() != 0 {
-            Data {
-                cache: vec![T::zero(); self.coords_count() * ls.coords_count()],
-                ls_a: self,
-                ls_b: ls,
-            }
-            .compute_linear()
-        } else {
-            T::zero()
-        }
-    }
-}
-
-struct Data<'a, T>
-where
-    T: GeoFloat + FromPrimitive,
-{
-    cache: Vec<T>,
-    ls_a: &'a LineString<T>,
-    ls_b: &'a LineString<T>,
-}
-
-impl<'a, T> Data<'a, T>
-where
-    T: GeoFloat + FromPrimitive,
-{
-    /// [Reference implementation]: https://github.com/joaofig/discrete-frechet/tree/master
-    fn compute_linear(&mut self) -> T {
-        let columns_count = self.ls_b.coords_count();
-
-        for (i, &a) in self.ls_a.coords().enumerate() {
-            for (j, &b) in self.ls_b.coords().enumerate() {
-                let dist = Euclidean::distance(a, b);
-
-                self.cache[i * columns_count + j] = match (i, j) {
-                    (0, 0) => dist,
-                    (_, 0) => self.cache[(i - 1) * columns_count].max(dist),
-                    (0, _) => self.cache[j - 1].max(dist),
-                    (_, _) => self.cache[(i - 1) * columns_count + j]
-                        .min(self.cache[(i - 1) * columns_count + j - 1])
-                        .min(self.cache[i * columns_count + j - 1])
-                        .max(dist),
-                };
-            }
-        }
-
-        self.cache[self.cache.len() - 1]
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-
-    #[test]
-    fn test_single_point_in_linestring() {
-        let ls_a = LineString::from(vec![(1., 1.)]);
-        let ls_b = LineString::from(vec![(0., 2.)]);
-        assert_relative_eq!(
-            Euclidean::distance(ls_a.0[0], ls_b.0[0]),
-            ls_a.frechet_distance(&ls_b)
-        );
-    }
-
-    #[test]
-    fn test_identical_linestrings() {
-        let ls_a = LineString::from(vec![(1., 1.), (2., 1.), (2., 2.)]);
-        let ls_b = LineString::from(vec![(1., 1.), (2., 1.), (2., 2.)]);
-        assert_relative_eq!(0., ls_a.frechet_distance(&ls_b));
-    }
-
-    #[test]
-    fn different_dimensions_linestrings() {
-        let ls_a = LineString::from(vec![(1., 1.)]);
-        let ls_b = LineString::from(vec![(2., 2.), (0., 1.)]);
-        assert_relative_eq!(2f64.sqrt(), ls_a.frechet_distance(&ls_b));
-    }
-
-    #[test]
-    fn test_frechet_1() {
-        let ls_a = LineString::from(vec![(1., 1.), (2., 1.)]);
-        let ls_b = LineString::from(vec![(2., 2.), (2., 3.)]);
-        assert_relative_eq!(2., ls_a.frechet_distance(&ls_b));
-    }
-
-    #[test]
-    fn test_frechet_2() {
-        let ls_a = LineString::from(vec![(1., 1.), (2., 1.), (2., 2.)]);
-        let ls_b = LineString::from(vec![(2., 2.), (0., 1.), (2., 4.)]);
-        assert_relative_eq!(2., ls_a.frechet_distance(&ls_b));
-    }
-
-    #[test] // comparing long linestrings should not panic or abort due to stack overflow
-    fn test_frechet_long_linestrings() {
-        let ls: LineString = {
-            let delta = 0.01;
-
-            let mut ls = vec![(0.0, 0.0); 10_000];
-            for i in 1..ls.len() {
-                let (lat, lon) = ls[i - 1];
-                ls[i] = (lat - delta, lon + delta);
-            }
-
-            ls.into()
-        };
-
-        assert_relative_eq!(ls.frechet_distance(&ls.clone()), 0.0);
+        super::line_measures::FrechetDistance::frechet_distance::<Euclidean>(self, ls)
     }
 }

geo/src/algorithm/mod.rs

@@ -91,6 +91,7 @@ pub use extremes::Extremes;
 
 /// Calculate the Frechet distance between two `LineStrings`.
 pub mod frechet_distance;
+#[allow(deprecated)]
 pub use frechet_distance::FrechetDistance;
 
 /// Calculate the bearing to another `Point` on a geodesic.