Fix lazy evaluation of gradients in line searches (argmin-rs#101)

amfaber · Mar 23, 2021 · 9fab420 · 9fab420
1 parent 0286082
commit 9fab420
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Showing 3 changed files with 10 additions and 3 deletions.
diff --git a/src/solver/linesearch/backtracking.rs b/src/solver/linesearch/backtracking.rs
@@ -121,7 +121,10 @@ where
             cost
         };
 
-        self.init_grad = state.get_grad().unwrap_or(op.gradient(&self.init_param)?);
+        self.init_grad = state
+            .get_grad()
+            .map(Result::Ok)
+            .unwrap_or_else(|| op.gradient(&self.init_param))?;
 
         if self.search_direction.is_none() {
             return Err(ArgminError::NotInitialized {

diff --git a/src/solver/linesearch/hagerzhang.rs b/src/solver/linesearch/hagerzhang.rs
@@ -459,7 +459,10 @@ where
             cost
         };
 
-        self.init_grad = state.get_grad().unwrap_or(op.gradient(&self.init_param)?);
+        self.init_grad = state
+            .get_grad()
+            .map(Result::Ok)
+            .unwrap_or_else(|| op.gradient(&self.init_param))?;
 
         self.a_x = self.a_x_init;
         self.b_x = self.b_x_init;

diff --git a/src/solver/linesearch/morethuente.rs b/src/solver/linesearch/morethuente.rs
@@ -242,7 +242,8 @@ where
 
         self.init_grad = state
             .get_grad()
-            .unwrap_or_else(|| op.gradient(&self.init_param).unwrap());
+            .map(Result::Ok)
+            .unwrap_or_else(|| op.gradient(&self.init_param))?;
 
         self.dginit = self.init_grad.dot(&self.search_direction);