From fdddf5615619c3987546a5d64c2f0360ee98346e Mon Sep 17 00:00:00 2001
From: Anders Olsson <anders.e.olsson@gmail.com>
Date: Tue, 27 Dec 2022 22:11:04 +0100
Subject: [PATCH] Remove unused mut reference

---
 src/batch.rs     |   2 +-
 src/gaussian2.rs | 159 +++++++++++++++++++++++++++++++++++++++++++++++
 src/history.rs   |   4 +-
 src/lib.rs       |   1 +
 4 files changed, 163 insertions(+), 3 deletions(-)
 create mode 100644 src/gaussian2.rs

diff --git a/src/batch.rs b/src/batch.rs
index d974214..e7fe1a1 100644
--- a/src/batch.rs
+++ b/src/batch.rs
@@ -203,7 +203,7 @@ impl Batch {
         composition: Vec<Vec<Vec<Index>>>,
         results: Vec<Vec<f64>>,
         weights: Vec<Vec<Vec<f64>>>,
-        agents: &mut HashMap<Index, Agent>,
+        agents: &HashMap<Index, Agent>,
     ) {
         let this_agent = composition
             .iter()
diff --git a/src/gaussian2.rs b/src/gaussian2.rs
new file mode 100644
index 0000000..8a26261
--- /dev/null
+++ b/src/gaussian2.rs
@@ -0,0 +1,159 @@
+use std::ops;
+
+#[derive(Clone, Copy, PartialEq, Debug)]
+pub struct Gaussian {
+    mu: f64,
+    sigma: f64,
+}
+
+impl Gaussian {
+    #[inline(always)]
+    pub const fn from_ms(mu: f64, sigma: f64) -> Self {
+        Self { mu, sigma }
+    }
+
+    #[inline(always)]
+    pub fn from_pt(pi: f64, tau: f64) -> Self {
+        Self::from_ms(tau / pi, (1.0 / pi).sqrt())
+    }
+
+    #[inline(always)]
+    pub fn mu(&self) -> f64 {
+        self.mu
+    }
+
+    #[inline(always)]
+    pub fn sigma(&self) -> f64 {
+        self.sigma
+    }
+
+    #[inline(always)]
+    pub fn pi(&self) -> f64 {
+        if self.sigma > 0.0 {
+            self.sigma.powi(-2)
+        } else {
+            f64::INFINITY
+        }
+    }
+
+    #[inline(always)]
+    pub fn tau(&self) -> f64 {
+        if self.sigma > 0.0 {
+            self.mu * self.pi()
+        } else {
+            f64::INFINITY
+        }
+    }
+}
+
+impl ops::Add<Gaussian> for Gaussian {
+    type Output = Gaussian;
+
+    fn add(self, rhs: Gaussian) -> Self::Output {
+        Self {
+            mu: self.mu + rhs.mu,
+            sigma: (self.sigma.powi(2) + rhs.sigma.powi(2)).sqrt(),
+        }
+    }
+}
+
+impl ops::Sub<Gaussian> for Gaussian {
+    type Output = Gaussian;
+
+    fn sub(self, rhs: Gaussian) -> Self::Output {
+        Self {
+            mu: self.mu - rhs.mu,
+            sigma: (self.sigma.powi(2) + rhs.sigma.powi(2)).sqrt(),
+        }
+    }
+}
+
+impl ops::Mul<Gaussian> for Gaussian {
+    type Output = Gaussian;
+
+    fn mul(self, rhs: Gaussian) -> Self::Output {
+        /*
+        if self.sigma == 0.0 || rhs.sigma == 0.0 {
+            let mu = self.mu / (self.sigma.powi(2) / rhs.sigma.powi(2) + 1.0)
+                + rhs.mu / (rhs.sigma.powi(2) / self.sigma.powi(2) + 1.0);
+
+            let sigma = (1.0 / ((1.0 / self.sigma.powi(2)) + (1.0 / rhs.sigma.powi(2)))).sqrt();
+
+            Self::from_ms(mu, sigma)
+        } else {
+            Self::from_pt(self.pi() + rhs.pi(), self.tau() + rhs.tau())
+        }
+        */
+
+        Self::from_pt(self.pi() + rhs.pi(), self.tau() + rhs.tau())
+    }
+}
+
+impl ops::Div<Gaussian> for Gaussian {
+    type Output = Gaussian;
+
+    fn div(self, rhs: Gaussian) -> Self::Output {
+        /*
+        let (mu, sigma) = if self.sigma == 0.0 || rhs.sigma == 0.0 {
+            let mu = self.mu / (1.0 - self.sigma.powi(2) / rhs.sigma.powi(2))
+                + rhs.mu / (rhs.sigma.powi(2) / self.sigma.powi(2) - 1.0);
+
+            let sigma = (1.0 / ((1.0 / self.sigma.powi(2)) - (1.0 / rhs.sigma.powi(2)))).sqrt();
+
+            Self::from_ms(mu, sigma)
+        } else {
+            Self::from_pt(self.pi() - rhs.pi(), self.tau() - rhs.tau())
+        }
+        */
+
+        Self::from_pt(self.pi() - rhs.pi(), self.tau() - rhs.tau())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_add() {
+        let n = Gaussian::from_ms(25.0, 25.0 / 3.0);
+        let m = Gaussian::from_ms(0.0, 1.0);
+
+        assert_eq!(n + m, Gaussian::from_ms(25.0, 8.393118874676116));
+    }
+
+    #[test]
+    fn test_sub() {
+        let n = Gaussian::from_ms(25.0, 25.0 / 3.0);
+        let m = Gaussian::from_ms(1.0, 1.0);
+
+        assert_eq!(n - m, Gaussian::from_ms(24.0, 8.393118874676116));
+    }
+
+    #[test]
+    fn test_mul() {
+        let n = Gaussian::from_ms(25.0, 25.0 / 3.0);
+        let m = Gaussian::from_ms(0.0, 1.0);
+
+        assert_eq!(
+            n * m,
+            Gaussian::from_ms(0.35488958990536273, 0.992876838486922)
+        );
+    }
+
+    #[test]
+    fn test_div() {
+        let n = Gaussian::from_ms(25.0, 25.0 / 3.0);
+        let m = Gaussian::from_ms(0.0, 1.0);
+
+        assert_eq!(
+            m / n,
+            Gaussian::from_ms(-0.3652597402597402, 1.0072787050317253)
+        );
+
+        assert_eq!(
+            n / m,
+            Gaussian::from_ms(-0.3652597402597402, 1.0072787050317253)
+        );
+    }
+}
diff --git a/src/history.rs b/src/history.rs
index 9dddd70..25ea651 100644
--- a/src/history.rs
+++ b/src/history.rs
@@ -87,7 +87,7 @@ impl Default for HistoryBuilder {
 
 pub struct History {
     size: usize,
-    pub batches: Vec<Batch>,
+    pub(crate) batches: Vec<Batch>,
     agents: HashMap<Index, Agent>,
     time: bool,
     mu: f64,
@@ -354,7 +354,7 @@ impl History {
             if self.time && self.batches.len() > k && self.batches[k].time == t {
                 let b = &mut self.batches[k];
 
-                b.add_events(composition, results, weights, &mut self.agents);
+                b.add_events(composition, results, weights, &self.agents);
 
                 for a in b.skills.keys() {
                     let agent = self.agents.get_mut(a).unwrap();
diff --git a/src/lib.rs b/src/lib.rs
index dbe72ef..0a8054a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,6 +10,7 @@ mod approx;
 pub mod batch;
 mod game;
 pub mod gaussian;
+// mod gaussian2;
 mod history;
 mod message;
 pub mod player;