From b12eca5ae452038f5efb377a7523f720da9fcf85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Nevyho=C5=A1t=C4=9Bn=C3=BD?=
 <petr.nevyhosteny@gmail.com>
Date: Mon, 7 Feb 2022 20:27:09 +0100
Subject: [PATCH] feat: Add reset functions to all solvers

---
 src/population.rs          | 15 +++++++++++++++
 src/solver/cuckoo.rs       |  9 +++++++++
 src/solver/nelder_mead.rs  |  8 ++++++++
 src/solver/trust_region.rs | 11 +++++++++++
 4 files changed, 43 insertions(+)

diff --git a/src/population.rs b/src/population.rs
index 3275597..3c804ab 100644
--- a/src/population.rs
+++ b/src/population.rs
@@ -99,6 +99,21 @@ where
         }
     }
 
+    /// Recreates the population with new individuals with given initializer.
+    pub fn reinit<R: Rng + ?Sized, I: PopulationInit<F>>(
+        &mut self,
+        f: &F,
+        dom: &Domain<F::Scalar>,
+        rng: &mut R,
+        initializer: &I,
+    ) where
+        F: Function,
+    {
+        initializer.init_all(f, dom, rng, self.individuals.iter_mut());
+        self.eval(f);
+        self.sort();
+    }
+
     /// Get the size of the population.
     pub fn len(&self) -> usize {
         self.individuals.len()
diff --git a/src/solver/cuckoo.rs b/src/solver/cuckoo.rs
index 4f145c6..3c54a95 100644
--- a/src/solver/cuckoo.rs
+++ b/src/solver/cuckoo.rs
@@ -177,6 +177,15 @@ where
     pub fn population(&self) -> &Population<F> {
         &self.population
     }
+
+    /// Resets the internal state of the solver.
+    pub fn reset(&mut self, f: &F, dom: &Domain<F::Scalar>)
+    where
+        F: Function,
+    {
+        self.population
+            .reinit(f, dom, &mut self.rng, &self.options.population_init);
+    }
 }
 
 /// Error returned from [`Cuckoo`] solver.
diff --git a/src/solver/nelder_mead.rs b/src/solver/nelder_mead.rs
index 7b18774..9570409 100644
--- a/src/solver/nelder_mead.rs
+++ b/src/solver/nelder_mead.rs
@@ -167,6 +167,14 @@ where
             sort_perm: Vec::with_capacity(f.dim().value() + 1),
         }
     }
+
+    /// Resets the internal state of the solver.
+    pub fn reset(&mut self) {
+        // Causes simplex to be initialized again.
+        self.simplex.clear();
+        self.errors.clear();
+        self.sort_perm.clear();
+    }
 }
 
 /// Error returned from [`NelderMead`] solver.
diff --git a/src/solver/trust_region.rs b/src/solver/trust_region.rs
index 2eb4ffd..12d4ec4 100644
--- a/src/solver/trust_region.rs
+++ b/src/solver/trust_region.rs
@@ -156,6 +156,17 @@ where
             rejections_cnt: 0,
         }
     }
+
+    /// Resets the internal state of the solver.
+    pub fn reset(&mut self) {
+        self.delta = match self.options.delta_init {
+            DeltaInit::Fixed(fixed) => fixed,
+            DeltaInit::Estimated => F::Scalar::zero(),
+        };
+        self.mu = convert(0.5);
+        self.iter = 1;
+        self.rejections_cnt = 0;
+    }
 }
 
 /// Error returned from [`TrustRegion`] solver.