From cd666f1224437d08ee86636b7c6e8627fa0cc5b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andreas=20Kr=C3=B6pelin?= <andreas-kroepelin@gmx.de>
Date: Wed, 19 Nov 2025 16:20:52 +0100
Subject: [PATCH] Fix eltype of nearest_rotation

---
 src/core_types.jl        | 2 +-
 test/nearest_rotation.jl | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/core_types.jl b/src/core_types.jl
index 358266d2..952a7a34 100644
--- a/src/core_types.jl
+++ b/src/core_types.jl
@@ -235,7 +235,7 @@ See [Wahba's problem](https://en.wikipedia.org/wiki/Wahba%27s_problem) for more
 function nearest_rotation(M::StaticMatrix{N,N}) where N
     u, _, v = svd(M)
     s = sign(det(u * v'))
-    d = @SVector ones(N-1)
+    d = @SVector ones(eltype(M), N-1)
     R = u * Diagonal(push(d,s)) * v'
     return RotMatrix{N}(R)
 end
diff --git a/test/nearest_rotation.jl b/test/nearest_rotation.jl
index 6bd0b864..ef529003 100644
--- a/test/nearest_rotation.jl
+++ b/test/nearest_rotation.jl
@@ -32,4 +32,11 @@
             @test all(sort(eigvals(Symmetric(V)))[2:end] .≥ 0)
         end
     end
+    @testset "return eltype" begin
+        for T in (Float16, Float32, Float64)
+            M = @SMatrix randn(T, 3, 3)
+            R = nearest_rotation(M)
+            @test eltype(M) == eltype(R)
+        end
+    end
 end