inline reduce to make minmax compatibal with serde

src/lib.rs

@@ -77,7 +77,6 @@ extern crate serde;
 mod moments;
 mod weighted_mean;
 mod minmax;
-mod reduce;
 mod quantile;
 mod traits;
 

src/minmax.rs

@@ -1,6 +1,5 @@
 use core;
 
-use super::reduce::Reduce;
 use super::{Estimate, Merge};
 
 /// Calculate the minimum of `a` and `b`.
@@ -27,7 +26,7 @@ fn max(a: f64, b: f64) -> f64 {
 #[derive(Debug, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Min {
-    r: Reduce<fn(f64, f64) -> f64>,
+    x: f64,
 }
 
 impl Min {
@@ -35,7 +34,7 @@ impl Min {
     #[inline]
     pub fn from_value(x: f64) -> Min {
         Min {
-            r: Reduce::from_value_and_fn(x, min),
+            x: x,
         }
     }
 
@@ -48,7 +47,7 @@ impl Min {
     /// Estimate the minium of the population.
     #[inline]
     pub fn min(&self) -> f64 {
-        self.r.reduction()
+        self.x
     }
 }
 
@@ -63,7 +62,7 @@ impl_from_iterator!(Min);
 impl Estimate for Min {
     #[inline]
     fn add(&mut self, x: f64) {
-        self.r.add(x);
+        self.x = min(self.x, x);
     }
 
     #[inline]
@@ -91,7 +90,7 @@ impl Merge for Min {
     /// ```
     #[inline]
     fn merge(&mut self, other: &Min) {
-        self.r.merge(&other.r);
+        self.add(other.x);
     }
 }
 
@@ -109,7 +108,7 @@ impl Merge for Min {
 #[derive(Debug, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Max {
-    r: Reduce<fn(f64, f64) -> f64>,
+    x: f64,
 }
 
 impl Max {
@@ -117,7 +116,7 @@ impl Max {
     #[inline]
     pub fn from_value(x: f64) -> Max {
         Max {
-            r: Reduce::from_value_and_fn(x, max),
+            x: x,
         }
     }
 
@@ -130,7 +129,7 @@ impl Max {
     /// Estimate the maxium of the population.
     #[inline]
     pub fn max(&self) -> f64 {
-        self.r.reduction()
+        self.x
     }
 }
 
@@ -145,7 +144,7 @@ impl_from_iterator!(Max);
 impl Estimate for Max {
     #[inline]
     fn add(&mut self, x: f64) {
-        self.r.add(x);
+        self.x = max(self.x, x);
     }
 
     #[inline]
@@ -173,6 +172,6 @@ impl Merge for Max {
     /// ```
     #[inline]
     fn merge(&mut self, other: &Max) {
-        self.r.merge(&other.r);
+        self.add(other.x);
     }
 }

src/reduce.rs

@@ -1,53 +0,0 @@
-use super::{Estimate, Merge};
-
-/// Estimate the reduction of a sequence of numbers ("population").
-///
-/// The reduction is a given function `Fn(f64, f64) -> f64`.
-///
-/// Everything is calculated iteratively using constant memory, so the sequence
-/// of numbers can be an iterator.
-#[derive(Debug, Clone)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-pub struct Reduce<F> {
-    x: f64,
-    reduce: F,
-}
-
-impl<F> Reduce<F> {
-    /// Create a new reduction estimator given an initial value and a reduction.
-    #[inline]
-    pub fn from_value_and_fn(x: f64, f: F) -> Reduce<F> {
-        Reduce { x: x, reduce: f }
-    }
-
-    /// Estimate the reduction of the population.
-    #[inline]
-    pub fn reduction(&self) -> f64 {
-        self.x
-    }
-
-}
-
-impl<F> Estimate for Reduce<F>
-    where F: Fn(f64, f64) -> f64,
-{
-    #[inline]
-    fn add(&mut self, x: f64) {
-        self.x = (self.reduce)(self.x, x);
-    }
-
-    #[inline]
-    fn estimate(&self) -> f64 {
-        self.reduction()
-    }
-}
-
-impl<F> Merge for Reduce<F>
-    where F: Fn(f64, f64) -> f64,
-{
-    /// Merge another sample into this one.
-    #[inline]
-    fn merge(&mut self, other: &Reduce<F>) {
-        self.add(other.x);
-    }
-}