changeset 1790:602104ac0e41 feature/sbp_operators/laplace_curvilinear

Merge refactor/lazy_tensors/elementwise_ops
author Jonatan Werpers <jonatan@werpers.com>
date Wed, 25 Sep 2024 10:33:48 +0200
parents 1f42944d4a72 (diff) 48eaa973159a (current diff)
children b8cb38fd67ff
files
diffstat 26 files changed, 1465 insertions(+), 50 deletions(-) [+]
line wrap: on
line diff
--- a/Manifest.toml	Wed Sep 25 10:31:09 2024 +0200
+++ b/Manifest.toml	Wed Sep 25 10:33:48 2024 +0200
@@ -2,7 +2,7 @@
 
 julia_version = "1.10.5"
 manifest_format = "2.0"
-project_hash = "28d35bafed672f63e2364cf8258fc24801cb971b"
+project_hash = "07350208c6e9bd0ec3979df9ac99bb401ac56208"
 
 [[deps.Artifacts]]
 uuid = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
--- a/Project.toml	Wed Sep 25 10:31:09 2024 +0200
+++ b/Project.toml	Wed Sep 25 10:33:48 2024 +0200
@@ -4,10 +4,12 @@
 version = "0.1.2"
 
 [deps]
+LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 TOML = "fa267f1f-6049-4f14-aa54-33bafae1ed76"
 
 [weakdeps]
+Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
 Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
 SparseArrayKit = "a9a3c162-d163-4c15-8926-b8794fbefed2"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
@@ -15,6 +17,7 @@
 
 [extensions]
 DiffinitiveMakieExt = "Makie"
+DiffinitivePlotsExt = "Plots"
 DiffinitiveSparseArrayKitExt = ["SparseArrayKit", "Tokens"]
 DiffinitiveSparseArraysExt = ["SparseArrays", "Tokens"]
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ext/DiffinitivePlotsExt.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -0,0 +1,72 @@
+module DiffinitivePlotsExt
+
+using Diffinitive.Grids
+using Plots
+
+@recipe f(::Type{<:Grid}, g::Grid) = map(Tuple,g)[:]
+
+@recipe function f(c::Chart{2,<:Rectangle}, n=5, m=n; draw_border=true, bordercolor=1)
+    Ξ = parameterspace(c)
+    ξs = range(limits(Ξ,1)..., n)
+    ηs = range(limits(Ξ,2)..., m)
+
+    label := false
+    seriescolor --> 2
+    for ξ ∈ ξs
+        @series adapted_curve_grid(η->c((ξ,η)),limits(Ξ,1))
+    end
+
+    for η ∈ ηs
+        @series adapted_curve_grid(ξ->c((ξ,η)),limits(Ξ,2))
+    end
+
+    if ~draw_border
+        return
+    end
+
+    for ξ ∈ limits(Ξ,1)
+        @series begin
+            linewidth --> 3
+            seriescolor := bordercolor
+            adapted_curve_grid(η->c((ξ,η)),limits(Ξ,1))
+        end
+    end
+
+    for η ∈ limits(Ξ,2)
+        @series begin
+            linewidth --> 3
+            seriescolor := bordercolor
+            adapted_curve_grid(ξ->c((ξ,η)),limits(Ξ,2))
+        end
+    end
+end
+
+function adapted_curve_grid(g, minmax)
+    t1, _ = PlotUtils.adapted_grid(t->g(t)[1], minmax)
+    t2, _ = PlotUtils.adapted_grid(t->g(t)[2], minmax)
+
+    ts = sort(vcat(t1,t2))
+
+    x = map(ts) do t
+        g(t)[1]
+    end
+    y = map(ts) do t
+        g(t)[2]
+    end
+
+    return x, y
+end
+
+# get_axis_limits(plt, :x)
+
+
+# ReicpesPipline/src/user_recipe.jl
+# @recipe function f(f::FuncOrFuncs{F}) where {F<:Function}
+
+# @recipe function f(f::Function, xmin::Number, xmax::Number)
+
+# _scaled_adapted_grid(f, xscale, yscale, xmin, xmax)
+
+end
+
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ext/SbplibPlotsExt.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -0,0 +1,72 @@
+module SbplibPlotsExt
+
+using Sbplib.Grids
+using Plots
+
+@recipe f(::Type{<:Grid}, g::Grid) = map(Tuple,g)[:]
+
+@recipe function f(c::Chart{2,<:Rectangle}, n=5, m=n; draw_border=true, bordercolor=1)
+    Ξ = parameterspace(c)
+    ξs = range(limits(Ξ,1)..., n)
+    ηs = range(limits(Ξ,2)..., m)
+
+    label := false
+    seriescolor --> 2
+    for ξ ∈ ξs
+        @series adapted_curve_grid(η->c((ξ,η)),limits(Ξ,1))
+    end
+
+    for η ∈ ηs
+        @series adapted_curve_grid(ξ->c((ξ,η)),limits(Ξ,2))
+    end
+
+    if ~draw_border
+        return
+    end
+
+    for ξ ∈ limits(Ξ,1)
+        @series begin
+            linewidth --> 3
+            seriescolor := bordercolor
+            adapted_curve_grid(η->c((ξ,η)),limits(Ξ,1))
+        end
+    end
+
+    for η ∈ limits(Ξ,2)
+        @series begin
+            linewidth --> 3
+            seriescolor := bordercolor
+            adapted_curve_grid(ξ->c((ξ,η)),limits(Ξ,2))
+        end
+    end
+end
+
+function adapted_curve_grid(g, minmax)
+    t1, _ = PlotUtils.adapted_grid(t->g(t)[1], minmax)
+    t2, _ = PlotUtils.adapted_grid(t->g(t)[2], minmax)
+
+    ts = sort(vcat(t1,t2))
+
+    x = map(ts) do t
+        g(t)[1]
+    end
+    y = map(ts) do t
+        g(t)[2]
+    end
+
+    return x, y
+end
+
+# get_axis_limits(plt, :x)
+
+
+# ReicpesPipline/src/user_recipe.jl
+# @recipe function f(f::FuncOrFuncs{F}) where {F<:Function}
+
+# @recipe function f(f::Function, xmin::Number, xmax::Number)
+
+# _scaled_adapted_grid(f, xscale, yscale, xmin, xmax)
+
+end
+
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ext/SbplibSparseArrayKitExt.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -0,0 +1,14 @@
+module SbplibSparseArrayKitExt
+
+using Sbplib
+using Sbplib.LazyTensors
+
+using SparseArrayKit
+using Tokens
+
+function SparseArrayKit.SparseArray(t::LazyTensor)
+    v = ArrayToken(:v, domain_size(t)...)
+    return Tokens._to_tensor(t*v, range_size(t), domain_size(t))
+end
+
+end
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ext/SbplibSparseArraysExt.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -0,0 +1,17 @@
+module SbplibSparseArraysExt
+
+using Sbplib
+using Sbplib.LazyTensors
+
+using SparseArrays
+using Tokens
+
+function SparseArrays.sparse(t::LazyTensor)
+    v = ArrayToken(:v, prod(domain_size(t)))
+
+    v̄ = reshape(v,domain_size(t)...)
+    tv = reshape(t*v̄, :)
+    return Tokens._to_matrix(tv, prod(range_size(t)), prod(domain_size(t)))
+end
+
+end
--- a/src/Grids/Grids.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/Grids/Grids.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -1,7 +1,34 @@
+# TODO: Double check that the interfaces for indexing and iterating are fully implemented and tested for all grids.
+# Review: Address this todo?
 module Grids
 
 using Diffinitive.LazyTensors
 using StaticArrays
+using LinearAlgebra
+
+export ParameterSpace
+export HyperBox
+export Simplex
+export Interval
+export Rectangle
+export Box
+export Triangle
+export Tetrahedron
+
+export limits
+export unitinterval
+export unitsquare
+export unitcube
+export unithyperbox
+
+export verticies
+export unittriangle
+export unittetrahedron
+export unitsimplex
+
+export Chart
+export ConcreteChart
+export parameterspace
 
 # Grid
 export Grid
@@ -18,6 +45,7 @@
 export eval_on
 export componentview
 export ArrayComponentView
+export normal
 
 export BoundaryIdentifier
 export TensorGridBoundary
@@ -33,9 +61,22 @@
 export spacing
 export equidistant_grid
 
+
+# MappedGrid
+export MappedGrid
+export jacobian
+export logical_grid
+export mapped_grid
+export metric_tensor
+export metric_tensor_inverse
+
+abstract type BoundaryIdentifier end
+
+include("manifolds.jl")
 include("grid.jl")
 include("tensor_grid.jl")
 include("equidistant_grid.jl")
 include("zero_dim_grid.jl")
+include("mapped_grid.jl")
 
 end # module
--- a/src/Grids/equidistant_grid.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/Grids/equidistant_grid.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -135,21 +135,35 @@
 end
 
 """
-    equidistant_grid(limit_lower::T, limit_upper::T, size::Int)
+    equidistant_grid(limit_lower::Number, limit_upper::Number, size::Int)
 
 Constructs a 1D equidistant grid.
 """
 function equidistant_grid(limit_lower::Number, limit_upper::Number, size::Int)
-    if any(size .<= 0)
+    if size <= 0
         throw(DomainError("size must be postive"))
     end
 
-    if any(limit_upper.-limit_lower .<= 0)
+    if limit_upper-limit_lower <= 0
         throw(DomainError("side length must be postive"))
     end
+
 	return EquidistantGrid(range(limit_lower, limit_upper, length=size)) # TBD: Should it use LinRange instead?
 end
 
+equidistant_grid(d::Interval, size::Int) = equidistant_grid(limits(d)..., size)
+equidistant_grid(hb::HyperBox, dims::Vararg{Int}) = equidistant_grid(limits(hb)..., dims...)
+
+function equidistant_grid(c::Chart, dims::Vararg{Int})
+    lg = equidistant_grid(parameterspace(c), dims...)
+    return MappedGrid(
+        lg,
+        map(c,lg),
+        map(ξ->jacobian(c, ξ), lg),
+    )
+end
+
+
 CartesianBoundary{D,BID} = TensorGridBoundary{D,BID} # TBD: What should we do about the naming of this boundary?
 
 
--- a/src/Grids/grid.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/Grids/grid.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -122,6 +122,8 @@
 """
 function boundary_identifiers end
 
+# TBD: Boundary identifiers for charts and atlases?
+
 """
     boundary_grid(g::Grid, id::BoundaryIdentifier)
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Grids/manifolds.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -0,0 +1,227 @@
+"""
+    ParameterSpace{D}
+
+A space of parameters of dimension `D`. Used with `Chart` to indicate which
+parameters are valid for that chart.
+
+Common parameter spaces are created using the functions unit sized spaces
+* `unitinterval`
+* `unitrectangle`
+* `unitbox`
+* `unittriangle`
+* `unittetrahedron`
+* `unithyperbox`
+* `unitsimplex`
+
+See also: [`Interval`](@ref), [`Rectangle`](@ref), [`Box`](@ref),
+[`Triangle`](@ref), [`Tetrahedron`](@ref), [`HyperBox`](@ref),
+[`Simplex`](@ref),
+"""
+abstract type ParameterSpace{D} end
+Base.ndims(::ParameterSpace{D}) where D = D
+
+struct Interval{T} <: ParameterSpace{1}
+    a::T
+    b::T
+
+    function Interval(a,b)
+        a, b = promote(a, b)
+        new{typeof(a)}(a,b)
+    end
+end
+
+limits(i::Interval) = (i.a, i.b)
+
+unitinterval(T=Float64) = Interval(zero(T), one(T))
+
+
+struct HyperBox{T,D} <: ParameterSpace{D}
+    a::SVector{D,T}
+    b::SVector{D,T}
+end
+
+function HyperBox(a,b)
+    ET = promote_type(eltype(a),eltype(b))
+    T = SVector{length(a),ET}
+    HyperBox(convert(T,a), convert(T,b))
+end
+
+Rectangle{T} = HyperBox{T,2}
+Box{T} = HyperBox{T,3}
+
+limits(box::HyperBox, d) = (box.a[d], box.b[d])
+limits(box::HyperBox) = (box.a, box.b)
+
+unitsquare(T=Float64) = unithyperbox(T,2)
+unitcube(T=Float64) = unithyperbox(T,3)
+unithyperbox(T, D) = HyperBox((@SVector zeros(T,D)), (@SVector ones(T,D)))
+unithyperbox(D) = unithyperbox(Float64,D)
+
+
+struct Simplex{T,D,NV} <: ParameterSpace{D}
+    verticies::NTuple{NV,SVector{D,T}}
+end
+
+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
+
+Triangle{T} = Simplex{T,2}
+Tetrahedron{T} = Simplex{T,3}
+
+unittriangle(T=Float64) = unitsimplex(T,2)
+unittetrahedron(T=Float64) = unitsimplex(T,3)
+function unitsimplex(T,D)
+    z = @SVector zeros(T,D)
+    unitelement = one(eltype(z))
+    verticies = ntuple(i->setindex(z, unitelement, i), D)
+    return Simplex((z,verticies...))
+end
+unitsimplex(D) = unitsimplex(Float64, D)
+
+"""
+    Chart{D}
+
+A parametrized description of a manifold or part of a manifold.
+"""
+struct Chart{D, PST<:ParameterSpace{D}, MT}
+    mapping::MT
+    parameterspace::PST
+end
+
+Base.ndims(::Chart{D}) where D = D
+(c::Chart)(ξ) = c.mapping(ξ)
+parameterspace(c::Chart) = c.parameterspace
+
+"""
+    jacobian(c::Chart, ξ)
+
+The jacobian of the mapping evaluated at `ξ`. This defers to the
+implementation of `jacobian` for the mapping itself. If no implementation is
+available one can easily be specified for either the mapping function or the
+chart itself.
+```julia
+c = Chart(f, ps)
+jacobian(f::typeof(f), ξ) = f′(ξ)
+```
+or
+```julia
+c = Chart(f, ps)
+jacobian(c::typeof(c),ξ) = f′(ξ)
+```
+which will both allow calling `jacobian(c,ξ)`.
+"""
+jacobian(c::Chart, ξ) = jacobian(c.mapping, ξ)
+# TBD: Can we register a error hint for when jacobian is called with a function that doesn't have a registered jacobian?
+
+
+# TBD: Should Charts, parameterspaces have boundary names?
+
+"""
+    Atlas
+
+A collection of charts and their connections.
+Should implement methods for `charts` and
+"""
+abstract type Atlas end
+
+"""
+    charts(::Atlas)
+
+The colloction of charts in the atlas.
+"""
+function charts end
+
+"""
+    connections
+
+TBD: What exactly should this return?
+
+"""
+
+struct CartesianAtlas <: Atlas
+    charts::Matrix{Chart}
+end
+
+charts(a::CartesianAtlas) = a.charts
+connections(a::CartesianAtlas) = nothing
+
+struct UnstructuredAtlas <: Atlas
+    charts::Vector{Chart}
+    connections
+end
+
+charts(a::UnstructuredAtlas) = a.charts
+connections(a::UnstructuredAtlas) = nothing
+
+
+###
+# Geometry
+###
+
+abstract type Curve end
+abstract type Surface end
+
+
+struct Line{PT} <: Curve
+    p::PT
+    tangent::PT
+end
+
+(c::Line)(s) = c.p + s*c.tangent
+
+
+struct LineSegment{PT} <: Curve
+    a::PT
+    b::PT
+end
+
+(c::LineSegment)(s) = (1-s)*c.a + s*c.b
+
+
+function linesegments(ps...)
+    return [LineSegment(ps[i], ps[i+1]) for i ∈ 1:length(ps)-1]
+end
+
+
+function polygon_edges(ps...)
+    n = length(ps)
+    return [LineSegment(ps[i], ps[mod1(i+1,n)]) for i ∈ eachindex(Ps)]
+end
+
+struct Circle{T,PT} <: Curve
+    c::PT
+    r::T
+end
+
+(c::Circle)(θ) = c.c + r*@SVector[cos(Θ), sin(Θ)]
+
+struct TransfiniteInterpolationSurface{T1,T2,T3,T4} <: Surface
+    c₁::T1
+    c₂::T2
+    c₃::T3
+    c₄::T4
+end
+
+function (s::TransfiniteInterpolationSurface)(u,v)
+    c₁, c₂, c₃, c₄ = s.c₁, s.c₂, s.c₃, s.c₄
+    P₀₀ = c₁(0)
+    P₁₀ = c₂(0)
+    P₁₁ = c₃(0)
+    P₀₁ = c₄(0)
+    return (1-v)*c₁(u) + u*c₂(v) + v*c₃(1-u) + (1-u)*c₄(1-v) - (
+        (1-u)*(1-v)*P₀₀ + u*(1-v)*P₁₀ + u*v*P₁₁ + (1-u)*v*P₀₁
+    )
+end
+
+function (s::TransfiniteInterpolationSurface)(ξ̄::AbstractArray)
+    s(ξ̄...)
+end
+
+# TODO: Implement jacobian() for the different mapping helpers
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Grids/mapped_grid.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -0,0 +1,204 @@
+"""
+    MappedGrid{T,D} <: Grid{T,D}
+
+A grid defined by a coordinate mapping from a logical grid to some physical
+coordinates. The physical coordinates and the Jacobian are stored as grid
+functions corresponding to the logical grid.
+
+See also: [`logical_grid`](@ref), [`jacobian`](@ref), [`metric_tensor`](@ref).
+"""
+struct MappedGrid{T,D, GT<:Grid{<:Any,D}, CT<:AbstractArray{T,D}, JT<:AbstractArray{<:AbstractMatrix{<:Any}, D}} <: Grid{T,D}
+    logical_grid::GT
+    physicalcoordinates::CT
+    jacobian::JT
+
+    """
+        MappedGrid(logical_grid, physicalcoordinates, jacobian)
+
+    A MappedGrid with the given physical coordinates and jacobian.
+    """
+    function MappedGrid(logical_grid::GT, physicalcoordinates::CT, jacobian::JT) where {T,D, GT<:Grid{<:Any,D}, CT<:AbstractArray{T,D}, JT<:AbstractArray{<:AbstractMatrix{<:Any}, D}}
+        if !(size(logical_grid) == size(physicalcoordinates) == size(jacobian))
+            throw(ArgumentError("Sizes must match"))
+        end
+
+        if size(first(jacobian)) != (length(first(physicalcoordinates)),D)
+            throw(ArgumentError("The size of the jacobian must match the dimensions of the grid and coordinates"))
+        end
+
+        return new{T,D,GT,CT,JT}(logical_grid, physicalcoordinates, jacobian)
+    end
+end
+
+function Base.:(==)(a::MappedGrid, b::MappedGrid)
+    same_logical_grid = logical_grid(a) == logical_grid(b)
+    same_coordinates = collect(a) == collect(b)
+    same_jacobian = jacobian(a) == jacobian(b)
+
+    return same_logical_grid && same_coordinates && same_jacobian
+end
+
+"""
+    logical_grid(g::MappedGrid)
+
+The logical grid of `g`.
+"""
+logical_grid(g::MappedGrid) = g.logical_grid
+
+"""
+    jacobian(g::MappedGrid)
+
+The Jacobian matrix of `g` as a grid function.
+"""
+jacobian(g::MappedGrid) = g.jacobian
+
+
+# Indexing interface
+Base.getindex(g::MappedGrid, I::Vararg{Int}) = g.physicalcoordinates[I...]
+Base.eachindex(g::MappedGrid) = eachindex(g.logical_grid)
+
+Base.firstindex(g::MappedGrid, d) = firstindex(g.logical_grid, d)
+Base.lastindex(g::MappedGrid, d) = lastindex(g.logical_grid, d)
+
+# Iteration interface
+Base.iterate(g::MappedGrid) = iterate(g.physicalcoordinates)
+Base.iterate(g::MappedGrid, state) = iterate(g.physicalcoordinates, state)
+
+Base.IteratorSize(::Type{<:MappedGrid{<:Any, D}}) where D = Base.HasShape{D}()
+Base.length(g::MappedGrid) = length(g.logical_grid)
+Base.size(g::MappedGrid) = size(g.logical_grid)
+Base.size(g::MappedGrid, d) = size(g.logical_grid, d)
+
+boundary_identifiers(g::MappedGrid) = boundary_identifiers(g.logical_grid)
+boundary_indices(g::MappedGrid, id::TensorGridBoundary) = boundary_indices(g.logical_grid, id)
+
+# Review: Error when calling plot(boundary_grid(g, id))
+# Currently need to collect first, i.e., plot(collect(boundary_grid(g, id)))
+function boundary_grid(g::MappedGrid, id::TensorGridBoundary)
+    b_indices = boundary_indices(g.logical_grid, id)
+
+    # Calculate indices of needed jacobian components
+    D = ndims(g)
+    all_indices = SVector{D}(1:D)
+    free_variable_indices = deleteat(all_indices, grid_id(id))
+    jacobian_components = (:, free_variable_indices)
+
+    # Create grid function for boundary grid jacobian
+    boundary_jacobian = componentview((@view g.jacobian[b_indices...])  , jacobian_components...)
+    boundary_physicalcoordinates = @view g.physicalcoordinates[b_indices...]
+
+    return MappedGrid(
+        boundary_grid(g.logical_grid, id),
+        boundary_physicalcoordinates,
+        boundary_jacobian,
+    )
+end
+
+
+"""
+    mapped_grid(x, J, size::Vararg{Int})
+
+A `MappedGrid` with a default logical grid on a unit hyper box. `x` and `J`
+are functions to be evaluated on the logical grid and `size` determines the
+size of the logical grid.
+"""
+function mapped_grid(x, J, size::Vararg{Int})
+    D = length(size)
+    lg = equidistant_grid(ntuple(i->0., D), ntuple(i->1., D), size...)
+    return mapped_grid(lg, x, J)
+end
+
+"""
+    mapped_grid(lg::Grid, x, J)
+
+A `MappedGrid` with logical grid `lg`. Physical coordinates and Jacobian are
+determined by the functions `x` and `J`.
+"""
+function mapped_grid(lg::Grid, x, J)
+    return MappedGrid(
+        lg,
+        map(x,lg),
+        map(J,lg),
+    )
+end
+
+"""
+    metric_tensor(g::MappedGrid)
+
+The metric tensor of `g` as a grid function.
+"""
+function metric_tensor(g::MappedGrid)
+    return map(jacobian(g)) do ∂x∂ξ
+        ∂x∂ξ'*∂x∂ξ
+    end
+end
+
+"""
+    metric_tensor_inverse(g::MappedGrid)
+
+The inverse of the metric tensor of `g` as a grid function.
+"""
+function metric_tensor_inverse(g::MappedGrid)
+    return map(jacobian(g)) do ∂x∂ξ
+        inv(∂x∂ξ'*∂x∂ξ)
+    end
+end
+
+function min_spacing(g::MappedGrid{T,1} where T)
+    n, = size(g)
+
+    ms = Inf
+    for i ∈ 1:n-1
+        ms = min(ms, norm(g[i+1]-g[i]))
+    end
+
+    return ms
+end
+
+function min_spacing(g::MappedGrid{T,2} where T)
+    n, m = size(g)
+
+    ms = Inf
+    for i ∈ 1:n-1, j ∈ 1:m-1 # loop over each cell of the grid
+
+        ms = min(
+            ms,
+            norm(g[i+1,j]-g[i,j]),
+            norm(g[i,j+1]-g[i,j]),
+
+            norm(g[i+1,j]-g[i+1,j+1]),
+            norm(g[i,j+1]-g[i+1,j+1]),
+
+            norm(g[i+1,j+1]-g[i,j]),
+            norm(g[i+1,j]-g[i,j+1]),
+        )
+        # NOTE: This could be optimized to avoid checking all interior edges twice.
+    end
+
+    return ms
+end
+
+"""
+    normal(g::MappedGrid, boundary)
+
+The outward pointing normal as a grid function on the corresponding boundary grid.
+"""
+function normal(g::MappedGrid, boundary)
+    b_indices = boundary_indices(g, boundary)
+    σ =_boundary_sign(component_type(g), boundary)
+    return map(jacobian(g)[b_indices...]) do ∂x∂ξ
+        ∂ξ∂x = inv(∂x∂ξ)
+        k = grid_id(boundary)
+        σ*∂ξ∂x[k,:]/norm(∂ξ∂x[k,:])
+    end
+end
+
+function _boundary_sign(T, boundary)
+    if boundary_id(boundary) == UpperBoundary()
+        return one(T)
+    elseif boundary_id(boundary) == LowerBoundary()
+        return -one(T)
+    else
+        throw(ArgumentError("The boundary identifier must be either `LowerBoundary()` or `UpperBoundary()`"))
+    end
+end
--- a/src/SbpOperators/SbpOperators.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/SbpOperators/SbpOperators.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -43,6 +43,7 @@
 using Diffinitive.RegionIndices
 using Diffinitive.LazyTensors
 using Diffinitive.Grids
+using LinearAlgebra
 
 # Includes
 include("stencil.jl")
--- a/src/SbpOperators/boundaryops/boundary_restriction.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/SbpOperators/boundaryops/boundary_restriction.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -25,3 +25,7 @@
     converted_stencil = convert(Stencil{eltype(g)}, closure_stencil)
     return BoundaryOperator(g, converted_stencil, boundary)
 end
+
+function boundary_restriction(g::MappedGrid, stencil_set::StencilSet, boundary)
+    return boundary_restriction(logical_grid(g), stencil_set, boundary)
+end
--- a/src/SbpOperators/boundaryops/normal_derivative.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/SbpOperators/boundaryops/normal_derivative.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -28,3 +28,36 @@
     scaled_stencil = scale(closure_stencil,h_inv)
     return BoundaryOperator(g, scaled_stencil, boundary)
 end
+
+function normal_derivative(g::MappedGrid, stencil_set::StencilSet, boundary)
+    k = grid_id(boundary)
+    b_indices = boundary_indices(g, boundary)
+
+    # Compute the weights for the logical derivatives
+    g⁻¹ = metric_tensor_inverse(g)
+    α = map(CartesianIndices(g⁻¹)[b_indices...]) do I # TODO: Fix iterator here
+        gᵏⁱ = g⁻¹[I][k,:]
+        gᵏᵏ = g⁻¹[I][k,k]
+
+        gᵏⁱ./sqrt(gᵏᵏ)
+    end
+
+    σ = ScalingTensor(
+        Grids._boundary_sign(component_type(g), boundary),
+        size(boundary_grid(g,boundary)),
+    )
+
+
+    # Assemble difference operator
+    mapreduce(+,1:ndims(g)) do i
+        if i == k
+            ∂_ξᵢ = normal_derivative(logical_grid(g), stencil_set, boundary)
+        else
+            e = boundary_restriction(logical_grid(g), stencil_set, boundary)
+            ∂_ξᵢ = σ ∘ e ∘ first_derivative(logical_grid(g), stencil_set, i)
+        end
+
+        αᵢ = componentview(α,i)
+        DiagonalTensor(αᵢ) ∘ ∂_ξᵢ
+    end
+end
--- a/src/SbpOperators/volumeops/derivatives/second_derivative_variable.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/SbpOperators/volumeops/derivatives/second_derivative_variable.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -140,6 +140,7 @@
 
 ## x-direction
 function apply_lower(op::SecondDerivativeVariable{1}, v, i, j)
+    Base.@constprop :aggressive
     ṽ = @view v[:,j]
     c̃ = @view op.coefficient[:,j]
 
@@ -147,6 +148,7 @@
 end
 
 function apply_interior(op::SecondDerivativeVariable{1}, v, i, j)
+    Base.@constprop :aggressive
     ṽ = @view v[:,j]
     c̃ = @view op.coefficient[:,j]
 
@@ -154,6 +156,7 @@
 end
 
 function apply_upper(op::SecondDerivativeVariable{1}, v, i, j)
+    Base.@constprop :aggressive
     ṽ = @view v[:,j]
     c̃ = @view op.coefficient[:,j]
 
@@ -165,6 +168,7 @@
 
 ## y-direction
 function apply_lower(op::SecondDerivativeVariable{2}, v, i, j)
+    Base.@constprop :aggressive
     ṽ = @view v[i,:]
     c̃ = @view op.coefficient[i,:]
 
@@ -172,6 +176,7 @@
 end
 
 function apply_interior(op::SecondDerivativeVariable{2}, v, i, j)
+    Base.@constprop :aggressive
     ṽ = @view v[i,:]
     c̃ = @view op.coefficient[i,:]
 
@@ -179,6 +184,7 @@
 end
 
 function apply_upper(op::SecondDerivativeVariable{2}, v, i, j)
+    Base.@constprop :aggressive
     ṽ = @view v[i,:]
     c̃ = @view op.coefficient[i,:]
 
--- a/src/SbpOperators/volumeops/inner_products/inner_product.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/SbpOperators/volumeops/inner_products/inner_product.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -50,3 +50,8 @@
 """
 inner_product(g::ZeroDimGrid, stencil_set::StencilSet) = IdentityTensor{component_type(g)}()
 
+
+function inner_product(g::MappedGrid, stencil_set)
+    J = map(sqrt∘det, metric_tensor(g))
+    DiagonalTensor(J)∘inner_product(logical_grid(g), stencil_set)
+end
--- a/src/SbpOperators/volumeops/inner_products/inverse_inner_product.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/SbpOperators/volumeops/inner_products/inverse_inner_product.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -49,3 +49,8 @@
 Implemented to simplify 1D code for SBP operators.
 """
 inverse_inner_product(g::ZeroDimGrid, stencil_set::StencilSet) = IdentityTensor{component_type(g)}()
+
+function inverse_inner_product(g::MappedGrid, stencil_set)
+    J⁻¹ = map(inv∘sqrt∘det, metric_tensor(g))
+    DiagonalTensor(J⁻¹)∘inverse_inner_product(logical_grid(g), stencil_set)
+end
--- a/src/SbpOperators/volumeops/laplace/laplace.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/src/SbpOperators/volumeops/laplace/laplace.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -51,8 +51,31 @@
     end
     return Δ
 end
+
 laplace(g::EquidistantGrid, stencil_set) = second_derivative(g, stencil_set)
 
+function laplace(grid::MappedGrid, stencil_set)
+    J = map(det,jacobian(grid))
+    J⁻¹ = DiagonalTensor(map(inv, J))
+
+    Jg = map(*, J, metric_tensor_inverse(grid))
+    lg = logical_grid(grid)
+
+    return mapreduce(+, CartesianIndices(first(Jg))) do I
+        i, j = I[1], I[2]
+        Jgⁱʲ = componentview(Jg, i, j)
+
+        if i == j
+            J⁻¹∘second_derivative_variable(lg, Jgⁱʲ, stencil_set, i)
+        else
+            Dᵢ = first_derivative(lg, stencil_set, i)
+            Dⱼ = first_derivative(lg, stencil_set, j)
+            J⁻¹∘Dᵢ∘DiagonalTensor(Jgⁱʲ)∘Dⱼ
+        end
+    end
+end
+
+
 """
     sat_tensors(Δ::Laplace, g::Grid, bc::DirichletCondition; H_tuning, R_tuning)
 
--- a/test/Grids/equidistant_grid_test.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/test/Grids/equidistant_grid_test.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -1,6 +1,7 @@
 using Diffinitive.Grids
 using Test
 using Diffinitive.LazyTensors
+using StaticArrays
 
 
 @testset "EquidistantGrid" begin
@@ -150,6 +151,26 @@
             @test [gp[i]...] ≈ [p[i]...] atol=5e-13
         end
     end
+
+
+    @testset "equidistant_grid(::ParameterSpace)" begin
+        ps = HyperBox((0,0),(2,1))
+
+        @test equidistant_grid(ps, 3,4) == equidistant_grid((0,0), (2,1), 3,4)
+
+        @test equidistant_grid(unitinterval(),3) == equidistant_grid(0,1,3)
+        @test equidistant_grid(HyperBox((0,),(2,)),4) == equidistant_grid(@SVector[0], @SVector[2], 4)
+    end
+
+
+    @testset "equidistant_grid(::Chart)" begin
+        c = Chart(unitsquare()) do (ξ,η)
+            @SVector[2ξ, 3η]
+        end
+        Grids.jacobian(c::typeof(c), ξ̄) = @SMatrix[2 0; 0 3]
+
+        @test equidistant_grid(c, 5, 4) isa Grid
+    end
 end
 
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/Grids/manifolds_test.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -0,0 +1,77 @@
+using Test
+
+using Diffinitive.Grids
+using Diffinitive.RegionIndices
+using Diffinitive.LazyTensors
+
+# using StaticArrays
+
+@testset "ParameterSpace" begin
+    @test ndims(HyperBox([1,1], [2,2])) == 2
+    @test ndims(unittetrahedron()) == 3
+end
+
+@testset "Interval" begin
+    @test Interval <: ParameterSpace{1}
+
+    @test Interval(0,1) isa Interval{Int}
+    @test Interval(0,1.) isa Interval{Float64}
+
+    @test unitinterval() isa Interval{Float64}
+    @test unitinterval() == Interval(0.,1.)
+    @test limits(unitinterval()) == (0.,1.)
+
+    @test unitinterval(Int) isa Interval{Int}
+    @test unitinterval(Int) == Interval(0,1)
+    @test limits(unitinterval(Int)) == (0,1)
+end
+
+@testset "HyperBox" begin
+    @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)
+
+    @test unitsquare() isa HyperBox{Float64,2}
+    @test limits(unitsquare()) == ([0,0],[1,1])
+
+    @test unitcube() isa HyperBox{Float64,3}
+    @test limits(unitcube()) == ([0,0,0],[1,1,1])
+
+    @test unithyperbox(4) isa HyperBox{Float64,4}
+    @test limits(unithyperbox(4)) == ([0,0,0,0],[1,1,1,1])
+end
+
+@testset "Simplex" begin
+    @test Simplex{<:Any, 3} <: ParameterSpace{3}
+    @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}
+    @test verticies(unittriangle()) == ([0,0], [1,0], [0,1])
+
+    @test unittetrahedron() isa  Simplex{Float64,3}
+    @test verticies(unittetrahedron()) == ([0,0,0], [1,0,0], [0,1,0],[0,0,1])
+
+    @test unitsimplex(4) isa Simplex{Float64,4}
+end
+
+@testset "Chart" begin
+    c = Chart(x->2x, unitsquare())
+    @test c isa Chart{2}
+    @test c([3,2]) == [6,4]
+    @test parameterspace(c) == unitsquare()
+    @test ndims(c) == 2
+end
+
+@testset "Atlas" begin
+
+end
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/Grids/mapped_grid_test.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -0,0 +1,400 @@
+using Diffinitive.Grids
+using Diffinitive.RegionIndices
+using Test
+using StaticArrays
+using LinearAlgebra
+
+
+_skew_mapping(a,b) = (ξ̄->ξ̄[1]*a + ξ̄[2]*b, ξ̄->[a  b])
+
+function _partially_curved_mapping()
+    x̄((ξ, η)) = @SVector[ξ, η*(1+ξ*(ξ-1))]
+    J((ξ, η)) = @SMatrix[
+        1         0;
+        η*(2ξ-1)  1+ξ*(ξ-1);
+    ]
+
+    return x̄, J
+end
+
+function _fully_curved_mapping()
+    x̄((ξ, η)) = @SVector[2ξ + η*(1-η), 3η+(1+η/2)*ξ^2]
+    J((ξ, η)) = @SMatrix[
+        2       1-2η;
+        (2+η)*ξ 3+1/2*ξ^2;
+    ]
+
+    return x̄, J
+end
+
+@testset "MappedGrid" begin
+    @testset "Constructor" begin
+        lg = equidistant_grid((0,0), (1,1), 11, 21)
+
+        x̄ = map(ξ̄ -> 2ξ̄, lg)
+        J = map(ξ̄ -> @SArray(fill(2., 2, 2)), lg)
+        mg = MappedGrid(lg, x̄, J)
+
+        @test mg isa Grid{SVector{2, Float64},2}
+        @test jacobian(mg) isa Array{<:AbstractMatrix}
+        @test logical_grid(mg) isa Grid
+
+        @test collect(mg) == x̄
+        @test jacobian(mg) == J
+        @test logical_grid(mg) == lg
+
+
+        x̄ = map(ξ̄ -> @SVector[ξ̄[1],ξ̄[2], ξ̄[1] + ξ̄[2]], lg)
+        J = map(ξ̄ -> @SMatrix[1 0; 0 1; 1 1], lg)
+        mg = MappedGrid(lg, x̄, J)
+
+        @test mg isa Grid{SVector{3, Float64},2}
+        @test jacobian(mg) isa Array{<:AbstractMatrix}
+        @test logical_grid(mg) isa Grid
+
+        @test collect(mg) == x̄
+        @test jacobian(mg) == J
+        @test logical_grid(mg) == lg
+
+        sz1 = (10,11)
+        sz2 = (10,12)
+        @test_throws ArgumentError("Sizes must match") MappedGrid(
+            equidistant_grid((0,0), (1,1), sz2...),
+            rand(SVector{2},sz1...),
+            rand(SMatrix{2,2},sz1...),
+        )
+
+        @test_throws ArgumentError("Sizes must match") MappedGrid(
+            equidistant_grid((0,0), (1,1), sz1...),
+            rand(SVector{2},sz2...),
+            rand(SMatrix{2,2},sz1...),
+        )
+
+        @test_throws ArgumentError("Sizes must match") MappedGrid(
+            equidistant_grid((0,0), (1,1), sz1...),
+            rand(SVector{2},sz1...),
+            rand(SMatrix{2,2},sz2...),
+        )
+
+        err_str = "The size of the jacobian must match the dimensions of the grid and coordinates"
+        @test_throws ArgumentError(err_str) MappedGrid(
+            equidistant_grid((0,0), (1,1), 10, 11),
+            rand(SVector{3}, 10, 11),
+            rand(SMatrix{3,4}, 10, 11),
+        )
+
+        @test_throws ArgumentError(err_str) MappedGrid(
+            equidistant_grid((0,0), (1,1), 10, 11),
+            rand(SVector{3}, 10, 11),
+            rand(SMatrix{4,2}, 10, 11),
+        )
+    end
+
+    @testset "Indexing Interface" begin
+        lg = equidistant_grid((0,0), (1,1), 11, 21)
+        x̄ = map(ξ̄ -> 2ξ̄, lg)
+        J = map(ξ̄ -> @SArray(fill(2., 2, 2)), lg)
+        mg = MappedGrid(lg, x̄, J)
+        @test mg[1,1] == [0.0, 0.0]
+        @test mg[4,2] == [0.6, 0.1]
+        @test mg[6,10] == [1., 0.9]
+
+        @test mg[begin, begin] == [0.0, 0.0]
+        @test mg[end,end] == [2.0, 2.0]
+        @test mg[begin,end] == [0., 2.]
+
+        @test axes(mg) == (1:11, 1:21)
+
+        @testset "cartesian indexing" begin
+            cases = [
+                 (1,1) ,
+                 (3,5) ,
+                 (10,6),
+                 (1,1) ,
+                 (3,2) ,
+            ]
+
+            @testset "i = $is" for (lg, is) ∈ cases
+                @test mg[CartesianIndex(is...)] == mg[is...]
+            end
+        end
+
+        @testset "eachindex" begin
+            @test eachindex(mg) == CartesianIndices((11,21))
+        end
+
+        @testset "firstindex" begin
+            @test firstindex(mg, 1) == 1
+            @test firstindex(mg, 2) == 1
+        end
+
+        @testset "lastindex" begin
+            @test lastindex(mg, 1) == 11
+            @test lastindex(mg, 2) == 21
+        end
+    end
+
+    @testset "Iterator interface" begin
+        lg = equidistant_grid((0,0), (1,1), 11, 21)
+        x̄ = map(ξ̄ -> 2ξ̄, lg)
+        J = map(ξ̄ -> @SArray(fill(2., 2, 2)), lg)
+
+        mg = MappedGrid(lg, x̄, J)
+
+        lg2 = equidistant_grid((0,0), (1,1), 15, 11)
+        sg = MappedGrid(
+            equidistant_grid((0,0), (1,1), 15, 11),
+            map(ξ̄ -> @SArray[ξ̄[1], ξ̄[2], -ξ̄[1]], lg2), rand(SMatrix{3,2,Float64},15,11)
+        )
+
+        @test eltype(mg) == SVector{2,Float64}
+        @test eltype(sg) == SVector{3,Float64}
+
+        @test eltype(typeof(mg)) == SVector{2,Float64}
+        @test eltype(typeof(sg)) == SVector{3,Float64}
+
+        @test size(mg) == (11,21)
+        @test size(sg) == (15,11)
+
+        @test size(mg,2) == 21
+        @test size(sg,2) == 11
+
+        @test length(mg) == 231
+        @test length(sg) == 165
+
+        @test Base.IteratorSize(mg) == Base.HasShape{2}()
+        @test Base.IteratorSize(typeof(mg)) == Base.HasShape{2}()
+
+        @test Base.IteratorSize(sg) == Base.HasShape{2}()
+        @test Base.IteratorSize(typeof(sg)) == Base.HasShape{2}()
+
+        element, state = iterate(mg)
+        @test element == lg[1,1].*2
+        element, _ =  iterate(mg, state)
+        @test element == lg[2,1].*2
+
+        element, state = iterate(sg)
+        @test element == sg.physicalcoordinates[1,1]
+        element, _ = iterate(sg, state)
+        @test element == sg.physicalcoordinates[2,1]
+
+        @test collect(mg) == 2 .* lg
+    end
+
+    @testset "Base" begin
+        lg = equidistant_grid((0,0), (1,1), 11, 21)
+        x̄ = map(ξ̄ -> 2ξ̄, lg)
+        J = map(ξ̄ -> @SArray(fill(2., 2, 2)), lg)
+        mg = MappedGrid(lg, x̄, J)
+
+        @test ndims(mg) == 2
+    end
+
+    @testset "==" begin
+        sz = (15,11)
+        lg = equidistant_grid((0,0), (1,1), sz...)
+        x = rand(SVector{3,Float64}, sz...)
+        J = rand(SMatrix{3,2,Float64}, sz...)
+
+        sg = MappedGrid(lg, x, J)
+
+        sg1 = MappedGrid(equidistant_grid((0,0), (1,1), sz...), copy(x), copy(J))
+
+        sz2 = (15,12)
+        lg2 = equidistant_grid((0,0), (1,1), sz2...)
+        x2 = rand(SVector{3,Float64}, sz2...)
+        J2 = rand(SMatrix{3,2,Float64}, sz2...)
+        sg2 = MappedGrid(lg2, x2, J2)
+
+        sg3 = MappedGrid(lg, rand(SVector{3,Float64}, sz...), J)
+        sg4 = MappedGrid(lg, x, rand(SMatrix{3,2,Float64}, sz...))
+
+        @test sg == sg1
+        @test sg != sg2 # Different size
+        @test sg != sg3 # Different coordinates
+        @test sg != sg4 # Different jacobian
+    end
+
+    @testset "boundary_identifiers" begin
+        lg = equidistant_grid((0,0), (1,1), 11, 15)
+        x̄ = map(ξ̄ -> 2ξ̄, lg)
+        J = map(ξ̄ -> @SArray(fill(2., 2, 2)), lg)
+        mg = MappedGrid(lg, x̄, J)
+        @test boundary_identifiers(mg) == boundary_identifiers(lg)
+    end
+
+    @testset "boundary_indices" begin
+        lg = equidistant_grid((0,0), (1,1), 11, 15)
+        x̄ = map(ξ̄ -> 2ξ̄, lg)
+        J = map(ξ̄ -> @SArray(fill(2., 2, 2)), lg)
+        mg = MappedGrid(lg, x̄, J)
+
+        @test boundary_indices(mg, CartesianBoundary{1,LowerBoundary}()) == boundary_indices(lg,CartesianBoundary{1,LowerBoundary}())
+        @test boundary_indices(mg, CartesianBoundary{2,LowerBoundary}()) == boundary_indices(lg,CartesianBoundary{2,LowerBoundary}())
+        @test boundary_indices(mg, CartesianBoundary{1,UpperBoundary}()) == boundary_indices(lg,CartesianBoundary{1,UpperBoundary}())
+    end
+
+    @testset "boundary_grid" begin
+        x̄, J = _partially_curved_mapping()
+        mg = mapped_grid(x̄, J, 10, 11)
+        J1((ξ, η)) = @SMatrix[
+            1       ;
+            η*(2ξ-1);
+        ]
+        J2((ξ, η)) = @SMatrix[
+            0;
+            1+ξ*(ξ-1);
+        ]
+
+        function expected_bg(mg, bId, Jb)
+            lg = logical_grid(mg)
+            return MappedGrid(
+                boundary_grid(lg, bId),
+                map(x̄, boundary_grid(lg, bId)),
+                map(Jb, boundary_grid(lg, bId)),
+            )
+        end
+
+        let bid = TensorGridBoundary{1, LowerBoundary}()
+            @test boundary_grid(mg, bid) == expected_bg(mg, bid, J2)
+        end
+
+        let bid = TensorGridBoundary{1, UpperBoundary}()
+            @test boundary_grid(mg, bid) == expected_bg(mg, bid, J2)
+        end
+
+        let bid = TensorGridBoundary{2, LowerBoundary}()
+            @test boundary_grid(mg, bid) == expected_bg(mg, bid, J1)
+        end
+
+        let bid = TensorGridBoundary{2, UpperBoundary}()
+            @test boundary_grid(mg, bid) == expected_bg(mg, bid, J1)
+        end
+    end
+end
+
+@testset "mapped_grid" begin
+    x̄, J = _partially_curved_mapping()
+    mg = mapped_grid(x̄, J, 10, 11)
+    @test mg isa MappedGrid{SVector{2,Float64}, 2}
+
+    lg = equidistant_grid((0,0), (1,1), 10, 11)
+    @test logical_grid(mg) == lg
+    @test collect(mg) == map(x̄, lg)
+
+    @test mapped_grid(lg, x̄, J) == mg
+end
+
+@testset "metric_tensor" begin
+    x̄((ξ, η)) = @SVector[ξ*η, ξ + η^2]
+    J((ξ, η)) = @SMatrix[
+        η    ξ;
+        1   2η;
+    ]
+
+    g = mapped_grid(x̄, J, 10, 11)
+    G = map(logical_grid(g)) do (ξ,η)
+        @SMatrix[
+            1+η^2   ξ*η+2η;
+            ξ*η+2η  ξ^2 + 4η^2;
+        ]
+    end
+    @test metric_tensor(g) ≈ G
+end
+
+@testset "metric_tensor_inverse" begin
+    x̄((ξ, η)) = @SVector[ξ + ξ^2/2, η + η^2 + ξ^2/2]
+    J((ξ, η)) = @SMatrix[
+        1+ξ   0;
+        ξ    1+η;
+    ]
+
+    g = mapped_grid(x̄, J, 10, 11)
+    G⁻¹ = map(logical_grid(g)) do (ξ,η)
+        @SMatrix[
+            (1+η)^2  -ξ*(1+η);
+            -ξ*(1+η) (1+ξ)^2+ξ^2;
+        ]/(((1+ξ)^2+ξ^2)*(1+η)^2 - ξ^2*(1+η)^2)
+
+    end
+
+    @test metric_tensor_inverse(g) ≈ G⁻¹
+end
+
+@testset "min_spacing" begin
+    let g = mapped_grid(identity, x->@SMatrix[1], 11)
+        @test min_spacing(g) ≈ 0.1
+    end
+
+    let g = mapped_grid(x->x+x.^2/2, x->@SMatrix[1 .+ x], 11)
+        @test min_spacing(g) ≈ 0.105
+    end
+
+    let g = mapped_grid(x->x + x.*(1 .- x)/2, x->@SMatrix[1.5 .- x], 11)
+        @test min_spacing(g) ≈ 0.055
+    end
+
+    let g = mapped_grid(identity, x->@SMatrix[1 0; 0 1], 11,11)
+        @test min_spacing(g) ≈ 0.1
+    end
+
+    let g = mapped_grid(identity, x->@SMatrix[1 0; 0 1], 11,21)
+        @test min_spacing(g) ≈ 0.05
+    end
+
+
+    @testset let a = @SVector[1,0], b = @SVector[1,1]/√2
+        g = mapped_grid(_skew_mapping(a,b)...,11,11)
+
+        @test min_spacing(g) ≈ 0.1*norm(b-a)
+    end
+
+    @testset let a = @SVector[1,0], b = @SVector[-1,1]/√2
+        g = mapped_grid(_skew_mapping(a,b)...,11,11)
+
+        @test min_spacing(g) ≈ 0.1*norm(a+b)
+    end
+end
+
+@testset "normal" begin
+    g = mapped_grid(_partially_curved_mapping()...,10, 11)
+
+    @test normal(g, CartesianBoundary{1,LowerBoundary}()) == fill(@SVector[-1,0], 11)
+    @test normal(g, CartesianBoundary{1,UpperBoundary}()) == fill(@SVector[1,0], 11)
+    @test normal(g, CartesianBoundary{2,LowerBoundary}()) == fill(@SVector[0,-1], 10)
+    @test normal(g, CartesianBoundary{2,UpperBoundary}()) ≈ map(boundary_grid(g,CartesianBoundary{2,UpperBoundary}())|>logical_grid) do ξ̄
+        α = 1-2ξ̄[1]
+        @SVector[α,1]/√(α^2 + 1)
+    end
+
+    g = mapped_grid(_fully_curved_mapping()...,5,4)
+
+    unit(v) = v/norm(v)
+    @testset let bId = CartesianBoundary{1,LowerBoundary}()
+        lbg = boundary_grid(logical_grid(g), bId)
+        @test normal(g, bId) ≈ map(lbg) do (ξ, η)
+            -unit(@SVector[1/2,  η/3-1/6])
+        end
+    end
+
+    @testset let bId = CartesianBoundary{1,UpperBoundary}()
+        lbg = boundary_grid(logical_grid(g), bId)
+        @test normal(g, bId) ≈ map(lbg) do (ξ, η)
+            unit(@SVector[7/2, 2η-1]/(5 + 3η + 2η^2))
+        end
+    end
+
+    @testset let bId = CartesianBoundary{2,LowerBoundary}()
+        lbg = boundary_grid(logical_grid(g), bId)
+        @test normal(g, bId) ≈ map(lbg) do (ξ, η)
+            -unit(@SVector[-2ξ, 2]/(6 + ξ^2 - 2ξ))
+        end
+    end
+
+    @testset let bId = CartesianBoundary{2,UpperBoundary}()
+        lbg = boundary_grid(logical_grid(g), bId)
+        @test normal(g, bId) ≈ map(lbg) do (ξ, η)
+            unit(@SVector[-3ξ, 2]/(6 + ξ^2 + 3ξ))
+        end
+    end
+end
--- a/test/SbpOperators/boundaryops/boundary_restriction_test.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/test/SbpOperators/boundaryops/boundary_restriction_test.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -6,6 +6,8 @@
 using Diffinitive.RegionIndices
 using Diffinitive.SbpOperators: BoundaryOperator, Stencil
 
+using StaticArrays
+
 @testset "boundary_restriction" begin
 	stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order = 4)
 	e_closure = parse_stencil(stencil_set["e"]["closure"])
@@ -33,7 +35,7 @@
     end
 
     @testset "Application" begin
-        @testset "1D" begin
+        @testset "EquidistantGrid" begin
             e_l, e_r = boundary_restriction.(Ref(g_1D), Ref(stencil_set), boundary_identifiers(g_1D))
             v = eval_on(g_1D,x->1+x^2)
             u = fill(3.124)
@@ -43,7 +45,7 @@
             @test (e_r*v)[1] == v[end]
         end
 
-        @testset "2D" begin
+        @testset "TensorGrid" begin
             e_w, e_e, e_s, e_n = boundary_restriction.(Ref(g_2D), Ref(stencil_set), boundary_identifiers(g_2D))
             v = rand(11, 15)
             u = fill(3.124)
@@ -53,5 +55,22 @@
             @test e_s*v == v[:,1]
             @test e_n*v == v[:,end]
        end
+
+       @testset "MappedGrid" begin
+            c = Chart(unitsquare()) do (ξ,η)
+                @SVector[2ξ + η*(1-η), 3η+(1+η/2)*ξ^2]
+            end
+            Grids.jacobian(c::typeof(c), (ξ,η)) = @SMatrix[2 1-2η; (2+η)*ξ 3+ξ^2/2]
+
+            mg = equidistant_grid(c, 10,13)
+
+            e_w, e_e, e_s, e_n = boundary_restriction.(Ref(mg), Ref(stencil_set), boundary_identifiers(mg))
+            v = rand(10, 13)
+
+            @test e_w*v == v[1,:]
+            @test e_e*v == v[end,:]
+            @test e_s*v == v[:,1]
+            @test e_n*v == v[:,end]
+       end
     end
 end
--- a/test/SbpOperators/boundaryops/normal_derivative_test.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/test/SbpOperators/boundaryops/normal_derivative_test.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -6,54 +6,130 @@
 using Diffinitive.RegionIndices
 import Diffinitive.SbpOperators.BoundaryOperator
 
+using StaticArrays
+using LinearAlgebra
+
 @testset "normal_derivative" begin
-    g_1D = equidistant_grid(0.0, 1.0, 11)
-    g_2D = equidistant_grid((0.0, 0.0), (1.0,1.0), 11, 12)
-    @testset "normal_derivative" begin
-    	stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=4)
-        @testset "1D" begin
-            d_l = normal_derivative(g_1D, stencil_set, LowerBoundary())
-            @test d_l == normal_derivative(g_1D, stencil_set, LowerBoundary())
-            @test d_l isa BoundaryOperator{T,LowerBoundary} where T
-            @test d_l isa LazyTensor{T,0,1} where T
-        end
-        @testset "2D" begin
-            d_w = normal_derivative(g_2D, stencil_set, CartesianBoundary{1,LowerBoundary}())
-            d_n = normal_derivative(g_2D, stencil_set, CartesianBoundary{2,UpperBoundary}())
-            Ix = IdentityTensor{Float64}((size(g_2D)[1],))
-            Iy = IdentityTensor{Float64}((size(g_2D)[2],))
-            d_l = normal_derivative(g_2D.grids[1], stencil_set, LowerBoundary())
-            d_r = normal_derivative(g_2D.grids[2], stencil_set, UpperBoundary())
-            @test d_w == normal_derivative(g_2D, stencil_set, CartesianBoundary{1,LowerBoundary}())
-            @test d_w ==  d_l⊗Iy
-            @test d_n ==  Ix⊗d_r
-            @test d_w isa LazyTensor{T,1,2} where T
-            @test d_n isa LazyTensor{T,1,2} where T
+	stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=4)
+
+    @testset "EquidistantGrid" begin
+        g_1D = equidistant_grid(0.0, 1.0, 11)
+
+        d_l = normal_derivative(g_1D, stencil_set, LowerBoundary())
+        @test d_l == normal_derivative(g_1D, stencil_set, LowerBoundary())
+        @test d_l isa BoundaryOperator{T,LowerBoundary} where T
+        @test d_l isa LazyTensor{T,0,1} where T
+    end
+
+    @testset "TensorGrid" begin
+        g_2D = equidistant_grid((0.0, 0.0), (1.0,1.0), 11, 12)
+        d_w = normal_derivative(g_2D, stencil_set, CartesianBoundary{1,LowerBoundary}())
+        d_n = normal_derivative(g_2D, stencil_set, CartesianBoundary{2,UpperBoundary}())
+        Ix = IdentityTensor{Float64}((size(g_2D)[1],))
+        Iy = IdentityTensor{Float64}((size(g_2D)[2],))
+        d_l = normal_derivative(g_2D.grids[1], stencil_set, LowerBoundary())
+        d_r = normal_derivative(g_2D.grids[2], stencil_set, UpperBoundary())
+        @test d_w == normal_derivative(g_2D, stencil_set, CartesianBoundary{1,LowerBoundary}())
+        @test d_w ==  d_l⊗Iy
+        @test d_n ==  Ix⊗d_r
+        @test d_w isa LazyTensor{T,1,2} where T
+        @test d_n isa LazyTensor{T,1,2} where T
+
+        @testset "Accuracy" begin
+            v = eval_on(g_2D, (x,y)-> x^2 + (y-1)^2 + x*y)
+            v∂x = eval_on(g_2D, (x,y)-> 2*x + y)
+            v∂y = eval_on(g_2D, (x,y)-> 2*(y-1) + x)
+            # TODO: Test for higher order polynomials?
+            @testset "2nd order" begin
+            	stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=2)
+                d_w, d_e, d_s, d_n = normal_derivative.(Ref(g_2D), Ref(stencil_set), boundary_identifiers(g_2D))
+
+                @test d_w*v ≈ -v∂x[1,:] atol = 1e-13
+                @test d_e*v ≈ v∂x[end,:] atol = 1e-13
+                @test d_s*v ≈ -v∂y[:,1] atol = 1e-13
+                @test d_n*v ≈ v∂y[:,end] atol = 1e-13
+            end
+
+            @testset "4th order" begin
+                stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=4)
+                d_w, d_e, d_s, d_n = normal_derivative.(Ref(g_2D), Ref(stencil_set), boundary_identifiers(g_2D))
+
+                @test d_w*v ≈ -v∂x[1,:] atol = 1e-13
+                @test d_e*v ≈ v∂x[end,:] atol = 1e-13
+                @test d_s*v ≈ -v∂y[:,1] atol = 1e-13
+                @test d_n*v ≈ v∂y[:,end] atol = 1e-13
+            end
         end
     end
-    @testset "Accuracy" begin
-        v = eval_on(g_2D, (x,y)-> x^2 + (y-1)^2 + x*y)
-        v∂x = eval_on(g_2D, (x,y)-> 2*x + y)
-        v∂y = eval_on(g_2D, (x,y)-> 2*(y-1) + x)
-        # TODO: Test for higher order polynomials?
-        @testset "2nd order" begin
-        	stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=2)
-            d_w, d_e, d_s, d_n = normal_derivative.(Ref(g_2D), Ref(stencil_set), boundary_identifiers(g_2D))
+
+    @testset "MappedGrid" begin
+        c = Chart(unitsquare()) do (ξ,η)
+            @SVector[2ξ + η*(1-η), 3η+(1+η/2)*ξ^2]
+        end
+        Grids.jacobian(c::typeof(c), (ξ,η)) = @SMatrix[2 1-2η; (2+η)*ξ 3+ξ^2/2]
+        mg = equidistant_grid(c, 10,13)
+
 
-            @test d_w*v ≈ -v∂x[1,:] atol = 1e-13
-            @test d_e*v ≈ v∂x[end,:] atol = 1e-13
-            @test d_s*v ≈ -v∂y[:,1] atol = 1e-13
-            @test d_n*v ≈ v∂y[:,end] atol = 1e-13
+        # x̄((ξ, η)) = @SVector[ξ, η*(1+ξ*(ξ-1))]
+        # J((ξ, η)) = @SMatrix[
+        #     1         0;
+        #     η*(2ξ-1)  1+ξ*(ξ-1);
+        # ]
+        # mg = mapped_grid(x̄, J, 20, 21)
+
+
+        # x̄((ξ, η)) = @SVector[ξ,η]
+        # J((ξ, η)) = @SMatrix[
+        #     1  0;
+        #     0  1;
+        # ]
+        # mg = mapped_grid(identity, J, 10, 11)
+
+        for bid ∈ boundary_identifiers(mg)
+            @testset let bid=bid
+                @test normal_derivative(mg, stencil_set, bid) isa LazyTensor{<:Any, 1, 2}
+            end
         end
 
-        @testset "4th order" begin
-            stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=4)
-            d_w, d_e, d_s, d_n = normal_derivative.(Ref(g_2D), Ref(stencil_set), boundary_identifiers(g_2D))
-            
-            @test d_w*v ≈ -v∂x[1,:] atol = 1e-13
-            @test d_e*v ≈ v∂x[end,:] atol = 1e-13
-            @test d_s*v ≈ -v∂y[:,1] atol = 1e-13
-            @test d_n*v ≈ v∂y[:,end] atol = 1e-13
+        @testset "Consistency" begin
+            v = map(identity, mg)
+
+             @testset "4nd order" begin
+                stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=4)
+
+                for bid ∈ boundary_identifiers(mg)
+                    @testset let bid=bid
+                        d = normal_derivative(mg, stencil_set, bid)
+                        @test d*v ≈ normal(mg, bid) rtol=1e-13
+                    end
+                end
+             end
+        end
+
+        @testset "Accuracy" begin
+            v = function(x̄)
+                sin(norm(x̄+@SVector[1,1]))
+            end
+            ∇v = function(x̄)
+                ȳ = x̄+@SVector[1,1]
+                cos(norm(ȳ))*(ȳ/norm(ȳ))
+            end
+
+            mg = equidistant_grid(c, 80,80)
+            v̄ = map(v, mg)
+
+            @testset for (order, atol) ∈ [(2,4e-2),(4,2e-3)]
+                stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=order)
+
+                @testset for bId ∈ boundary_identifiers(mg)
+                    ∂ₙv = map(boundary_grid(mg,bId),normal(mg,bId)) do x̄,n̂
+                        n̂⋅∇v(x̄)
+                    end
+
+                    dₙ = normal_derivative(mg, stencil_set, bId)
+                    @test dₙ*v̄ ≈ ∂ₙv atol=atol
+                end
+            end
         end
     end
 end
--- a/test/SbpOperators/volumeops/inner_products/inner_product_test.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/test/SbpOperators/volumeops/inner_products/inner_product_test.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -6,6 +6,9 @@
 
 import Diffinitive.SbpOperators.ConstantInteriorScalingOperator
 
+using StaticArrays
+using LinearAlgebra
+
 @testset "Diagonal-stencil inner_product" begin
     Lx = π/2.
     Ly = Float64(π)
@@ -94,4 +97,43 @@
             end
         end
     end
+
+    @testset "MappedGrid" begin
+        stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=4)
+        c = Chart(unitsquare()) do (ξ,η)
+            @SVector[2ξ + η*(1-η), 3η+(1+η/2)*ξ^2]
+        end
+        Grids.jacobian(c::typeof(c), (ξ,η)) = @SMatrix[2 1-2η; (2+η)*ξ 3+ξ^2/2]
+
+        mg = equidistant_grid(c, 10,13)
+
+        @test inner_product(mg, stencil_set) isa LazyTensor{<:Any, 2,2}
+
+        @testset "Accuracy" begin
+            v = function(x̄)
+                log(norm(x̄-@SVector[.5, .5]))/2π + log(norm(x̄-@SVector[1.5, 3]))/2π
+            end
+            ∇v = function(x̄)
+                ∇log(ȳ) = ȳ/(ȳ⋅ȳ)
+                ∇log(x̄-@SVector[.5, .5])/2π + ∇log(x̄-@SVector[1.5, 3])/2π
+            end
+
+            mg = equidistant_grid(c, 80,80)
+            v̄ = map(v, mg)
+
+            @testset for (order, atol) ∈ [(2,1e-3),(4,1e-7)]
+                stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=order)
+
+                @test sum(boundary_identifiers(mg)) do bId
+                    ∂ₙv = map(boundary_grid(mg,bId),normal(mg,bId)) do x̄,n̂
+                        n̂⋅∇v(x̄)
+                    end
+                    Hᵧ = inner_product(boundary_grid(mg,bId), stencil_set)
+                    sum(Hᵧ*∂ₙv)
+                end ≈ 2 atol=atol
+
+            end
+        end
+        @test_broken false # Test that it calculates the right thing
+    end
 end
--- a/test/SbpOperators/volumeops/inner_products/inverse_inner_product_test.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/test/SbpOperators/volumeops/inner_products/inverse_inner_product_test.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -6,6 +6,8 @@
 
 import Diffinitive.SbpOperators.ConstantInteriorScalingOperator
 
+using StaticArrays
+
 @testset "Diagonal-stencil inverse_inner_product" begin
     Lx = π/2.
     Ly = Float64(π)
@@ -82,4 +84,17 @@
             end
         end
     end
+
+    @testset "MappedGrid" begin
+        stencil_set = read_stencil_set(sbp_operators_path()*"standard_diagonal.toml"; order=4)
+        c = Chart(unitsquare()) do (ξ,η)
+            @SVector[2ξ + η*(1-η), 3η+(1+η/2)*ξ^2]
+        end
+        Grids.jacobian(c::typeof(c), (ξ,η)) = @SMatrix[2 1-2η; (2+η)*ξ 3+ξ^2/2]
+
+        mg = equidistant_grid(c, 10,13)
+
+        @test inverse_inner_product(mg, stencil_set) isa LazyTensor{<:Any, 2,2}
+        @test_broken false # Test that it calculates the right thing
+    end
 end
--- a/test/SbpOperators/volumeops/laplace/laplace_test.jl	Wed Sep 25 10:31:09 2024 +0200
+++ b/test/SbpOperators/volumeops/laplace/laplace_test.jl	Wed Sep 25 10:33:48 2024 +0200
@@ -4,6 +4,8 @@
 using Diffinitive.Grids
 using Diffinitive.LazyTensors
 
+using StaticArrays
+
 @testset "Laplace" begin
     # Default stencils (4th order)
     operator_path = sbp_operators_path()*"standard_diagonal.toml"
@@ -72,12 +74,12 @@
     g_1D = equidistant_grid(0.0, 1., 101)
     g_3D = equidistant_grid((0.0, -1.0, 0.0), (1., 1., 1.), 51, 101, 52)
 
-    @testset "1D" begin
+    @testset "EquidistantGrid" begin
         Δ = laplace(g_1D, stencil_set)
         @test Δ == second_derivative(g_1D, stencil_set)
         @test Δ isa LazyTensor{Float64,1,1}
     end
-    @testset "3D" begin
+    @testset "TensorGrid" begin
         Δ = laplace(g_3D, stencil_set)
         @test Δ isa LazyTensor{Float64,3,3}
         Dxx = second_derivative(g_3D, stencil_set, 1)
@@ -86,6 +88,26 @@
         @test Δ == Dxx + Dyy + Dzz
         @test Δ isa LazyTensor{Float64,3,3}
     end
+
+    @testset "MappedGrid" begin
+        c = Chart(unitsquare()) do (ξ,η)
+            @SVector[2ξ + η*(1-η), 3η+(1+η/2)*ξ^2]
+        end
+        Grids.jacobian(c::typeof(c), (ξ,η)) = @SMatrix[2 1-2η; (2+η)*ξ 3+ξ^2/2]
+
+        g = equidistant_grid(c, 60,60)
+
+        @test laplace(g, stencil_set) isa LazyTensor{<:Any,2,2}
+
+        f((x,y)) = sin(4(x + y))
+        Δf((x,y)) = -32sin(4(x + y))
+        gf = map(f,g)
+
+        Δ = laplace(g, stencil_set)
+
+        @test collect(Δ*gf) isa Array{<:Any,2}
+        @test Δ*gf ≈ map(Δf, g) rtol=2e-2
+    end
 end
 
 @testset "sat_tensors" begin