--- a/src/Grids/manifolds.jl	Mon Sep 16 08:33:43 2024 +0200
+++ b/src/Grids/manifolds.jl	Mon Sep 16 08:58:12 2024 +0200
@@ -42,7 +42,8 @@
 end
 
 function HyperBox(a,b)
-    T = SVector{length(a)}
+    ET = promote_type(eltype(a),eltype(b))
+    T = SVector{length(a),ET}
     HyperBox(convert(T,a), convert(T,b))
 end
 
@@ -62,7 +63,12 @@
     verticies::NTuple{NV,SVector{D,T}}
 end
 
-Simplex(verticies::Vararg{AbstractArray}) = Simplex(Tuple(SVector(v...) for v ∈ verticies))
+function Simplex(verticies::Vararg{AbstractArray})
+    ET = mapreduce(eltype,promote_type,verticies)
+    T = SVector{length(verticies[1]),ET}
+
+    return Simplex(Tuple(convert(T,v) for v ∈ verticies))
+end
 
 verticies(s::Simplex) = s.verticies
 

--- a/test/Grids/manifolds_test.jl	Mon Sep 16 08:33:43 2024 +0200
+++ b/test/Grids/manifolds_test.jl	Mon Sep 16 08:58:12 2024 +0200
@@ -30,6 +30,8 @@
     @test HyperBox{<:Any, 2} <: ParameterSpace{2}
     @test HyperBox([1,1], [2,2]) isa HyperBox{Int, 2}
 
+    @test HyperBox([1,2], [1.,2.]) isa HyperBox{Float64,2}
+
     @test limits(HyperBox([1,2], [3,4])) == ([1,2], [3,4])
     @test limits(HyperBox([1,2], [3,4]), 1) == (1,3)
     @test limits(HyperBox([1,2], [3,4]), 2) == (2,4)
@@ -49,6 +51,8 @@
     @test Simplex([1,2], [3,4]) isa Simplex{Int, 2}
     @test Simplex([1,2,3], [4,5,6],[1,1,1]) isa Simplex{Int, 3}
 
+    @test Simplex([1,2], [3.,4.]) isa Simplex{Float64, 2}
+
     @test verticies(Simplex([1,2], [3,4])) == ([1,2], [3,4])
 
     @test unittriangle() isa Simplex{Float64,2}