changeset 642:f4a16b403487 feature/volume_and_boundary_operators

Implement the inverse quadrature operator as a volume operator and update tests.
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Mon, 04 Jan 2021 17:17:40 +0100
parents 5e50e9815732
children 0928bbc3ee8b
files src/SbpOperators/SbpOperators.jl src/SbpOperators/volumeops/quadratures/inverse_diagonal_quadrature.jl src/SbpOperators/volumeops/quadratures/inverse_quadrature.jl test/testSbpOperators.jl
diffstat 4 files changed, 121 insertions(+), 152 deletions(-) [+]
line wrap: on
line diff
--- a/src/SbpOperators/SbpOperators.jl	Mon Jan 04 17:16:04 2021 +0100
+++ b/src/SbpOperators/SbpOperators.jl	Mon Jan 04 17:17:40 2021 +0100
@@ -12,7 +12,7 @@
 include("volumeops/derivatives/secondderivative.jl")
 include("volumeops/laplace/laplace.jl")
 include("volumeops/quadratures/quadrature.jl")
-include("volumeops/quadratures/inverse_diagonal_quadrature.jl")
+include("volumeops/quadratures/inverse_quadrature.jl")
 include("boundaryops/boundary_operator.jl")
 include("boundaryops/boundary_restriction.jl")
 include("boundaryops/normal_derivative.jl")
--- a/src/SbpOperators/volumeops/quadratures/inverse_diagonal_quadrature.jl	Mon Jan 04 17:16:04 2021 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,89 +0,0 @@
-"""
-inverse_diagonal_quadrature(g,quadrature_closure)
-
-Constructs the inverse `Hi` of a `DiagonalQuadrature` on a grid of `Dim` dimensions as
-a `TensorMapping`. The one-dimensional operator is a `InverseDiagonalQuadrature`, while
-the multi-dimensional operator is the outer-product of the one-dimensional operators
-in each coordinate direction.
-"""
-function inverse_diagonal_quadrature(g::EquidistantGrid{Dim}, quadrature_closure) where Dim
-    Hi = InverseDiagonalQuadrature(restrict(g,1), quadrature_closure)
-    for i ∈ 2:Dim
-        Hi = Hi⊗InverseDiagonalQuadrature(restrict(g,i), quadrature_closure)
-    end
-    return Hi
-end
-export inverse_diagonal_quadrature
-
-
-"""
-    InverseDiagonalQuadrature{T,M} <: TensorMapping{T,1,1}
-
-Implements the inverse of a one-dimensional `DiagonalQuadrature` as a `TensorMapping`
-The operator is defined by the reciprocal of the quadrature interval length `h_inv`, the
-reciprocal of the quadrature closure weights `closure` and the number of quadrature intervals `size`. The
-interior stencil has the weight 1.
-"""
-struct InverseDiagonalQuadrature{T<:Real,M} <: TensorMapping{T,1,1}
-    h_inv::T
-    closure::NTuple{M,T}
-    size::Tuple{Int}
-end
-export InverseDiagonalQuadrature
-
-"""
-    InverseDiagonalQuadrature(g, quadrature_closure)
-
-Constructs the `InverseDiagonalQuadrature` on the `EquidistantGrid` `g` with
-closure given by the reciprocal of `quadrature_closure`.
-"""
-function InverseDiagonalQuadrature(g::EquidistantGrid{1}, quadrature_closure)
-    return InverseDiagonalQuadrature(inverse_spacing(g)[1], 1 ./ quadrature_closure, size(g))
-end
-
-"""
-    domain_size(Hi::InverseDiagonalQuadrature)
-
-The size of an object in the range of `Hi`
-"""
-LazyTensors.range_size(Hi::InverseDiagonalQuadrature) = Hi.size
-
-"""
-    domain_size(Hi::InverseDiagonalQuadrature)
-
-The size of an object in the domain of `Hi`
-"""
-LazyTensors.domain_size(Hi::InverseDiagonalQuadrature) = Hi.size
-
-"""
-    apply(Hi::InverseDiagonalQuadrature{T}, v::AbstractVector{T}, i) where T
-Implements the application `(Hi*v)[i]` an `Index{R}` where `R` is one of the regions
-`Lower`,`Interior`,`Upper`. If `i` is another type of index (e.g an `Int`) it will first
-be converted to an `Index{R}`.
-"""
-function LazyTensors.apply(Hi::InverseDiagonalQuadrature{T}, v::AbstractVector{T}, i::Index{Lower}) where T
-    return @inbounds Hi.h_inv*Hi.closure[Int(i)]*v[Int(i)]
-end
-
-function LazyTensors.apply(Hi::InverseDiagonalQuadrature{T}, v::AbstractVector{T}, i::Index{Upper}) where T
-    N = length(v);
-    return @inbounds Hi.h_inv*Hi.closure[N-Int(i)+1]*v[Int(i)]
-end
-
-function LazyTensors.apply(Hi::InverseDiagonalQuadrature{T}, v::AbstractVector{T}, i::Index{Interior}) where T
-    return @inbounds Hi.h_inv*v[Int(i)]
-end
-
-function LazyTensors.apply(Hi::InverseDiagonalQuadrature{T},  v::AbstractVector{T}, i) where T
-    N = length(v);
-    r = getregion(i, closure_size(Hi), N)
-    return LazyTensors.apply(Hi, v, Index(i, r))
-end
-
-LazyTensors.apply_transpose(Hi::InverseDiagonalQuadrature{T}, v::AbstractVector{T}, i) where T = LazyTensors.apply(Hi,v,i)
-
-"""
-    closure_size(Hi)
-Returns the size of the closure stencil of a InverseDiagonalQuadrature `Hi`.
-"""
-closure_size(Hi::InverseDiagonalQuadrature{T,M}) where {T,M} =  M
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/SbpOperators/volumeops/quadratures/inverse_quadrature.jl	Mon Jan 04 17:17:40 2021 +0100
@@ -0,0 +1,41 @@
+
+"""
+    InverseQuadrature(grid::EquidistantGrid, inv_inner_stencil, inv_closure_stencils)
+
+Creates the inverse `H⁻¹` of the quadrature operator as a `TensorMapping`
+
+The inverse quadrature approximates the integral operator on the grid using
+`inv_inner_stencil` in the interior and a set of stencils `inv_closure_stencils`
+for the points in the closure regions.
+
+On a one-dimensional `grid`, `H⁻¹` is a `VolumeOperator`. On a multi-dimensional
+`grid`, `H` is the outer product of the 1-dimensional inverse quadrature operators in
+each coordinate direction. Also see the documentation of
+`SbpOperators.volume_operator(...)` for more details.
+"""
+function InverseQuadrature(grid::EquidistantGrid{Dim}, inv_inner_stencil, inv_closure_stencils) where Dim
+    h⁻¹ = inverse_spacing(grid)
+    H⁻¹ = SbpOperators.volume_operator(grid,scale(inv_inner_stencil,h⁻¹[1]),scale.(inv_closure_stencils,h⁻¹[1]),even,1)
+    for i ∈ 2:Dim
+        Hᵢ⁻¹ = SbpOperators.volume_operator(grid,scale(inv_inner_stencil,h⁻¹[i]),scale.(inv_closure_stencils,h⁻¹[i]),even,i)
+        H⁻¹ = H⁻¹∘Hᵢ⁻¹
+    end
+    return H⁻¹
+end
+export InverseQuadrature
+
+"""
+    InverseDiagonalQuadrature(grid::EquidistantGrid, closure_stencils)
+
+Creates the inverse of the diagonal quadrature operator defined by the inner stencil
+1/h and a set of 1-element closure stencils in `closure_stencils`. Note that
+the closure stencils are those of the quadrature operator (and not the inverse).
+"""
+function InverseDiagonalQuadrature(grid::EquidistantGrid, closure_stencils::NTuple{M,Stencil{T,1}}) where {T,M}
+    inv_inner_stencil = Stencil(Tuple{T}(1),center=1)
+    inv_closure_stencils = reciprocal_stencil.(closure_stencils)
+    return InverseQuadrature(grid, inv_inner_stencil, inv_closure_stencils)
+end
+export InverseDiagonalQuadrature
+
+reciprocal_stencil(s::Stencil{T}) where T = Stencil(s.range,one(T)./s.weights)
--- a/test/testSbpOperators.jl	Mon Jan 04 17:16:04 2021 +0100
+++ b/test/testSbpOperators.jl	Mon Jan 04 17:17:40 2021 +0100
@@ -489,68 +489,85 @@
     end
 end
 
-# @testset "InverseDiagonalQuadrature" begin
-#     op = read_D2_operator(sbp_operators_path()*"standard_diagonal.toml"; order=4)
-#     Lx = π/2.
-#     Ly = Float64(π)
-#     g_1D = EquidistantGrid(77, 0.0, Lx)
-#     g_2D = EquidistantGrid((77,66), (0.0, 0.0), (Lx,Ly))
-#     @testset "Constructors" begin
-#         # 1D
-#         Hi_x = InverseDiagonalQuadrature(inverse_spacing(g_1D)[1], 1. ./ op.quadratureClosure, size(g_1D));
-#         @test Hi_x == InverseDiagonalQuadrature(g_1D,op.quadratureClosure)
-#         @test Hi_x == inverse_diagonal_quadrature(g_1D,op.quadratureClosure)
-#         @test Hi_x isa TensorMapping{T,1,1} where T
-#         @test Hi_x' isa TensorMapping{T,1,1} where T
-#
-#         # 2D
-#         Hi_xy = inverse_diagonal_quadrature(g_2D,op.quadratureClosure)
-#         @test Hi_xy isa TensorMappingComposition
-#         @test Hi_xy isa TensorMapping{T,2,2} where T
-#         @test Hi_xy' isa TensorMapping{T,2,2} where T
-#     end
-#
-#     @testset "Sizes" begin
-#         # 1D
-#         Hi_x = inverse_diagonal_quadrature(g_1D,op.quadratureClosure)
-#         @test domain_size(Hi_x) == size(g_1D)
-#         @test range_size(Hi_x) == size(g_1D)
-#         # 2D
-#         Hi_xy = inverse_diagonal_quadrature(g_2D,op.quadratureClosure)
-#         @test domain_size(Hi_xy) == size(g_2D)
-#         @test range_size(Hi_xy) == size(g_2D)
-#     end
-#
-#     @testset "Application" begin
-#         # 1D
-#         H_x = diagonal_quadrature(g_1D,op.quadratureClosure)
-#         Hi_x = inverse_diagonal_quadrature(g_1D,op.quadratureClosure)
-#         v_1D = evalOn(g_1D,x->sin(x))
-#         u_1D = evalOn(g_1D,x->x^3-x^2+1)
-#         @test Hi_x*H_x*v_1D ≈ v_1D rtol = 1e-15
-#         @test Hi_x*H_x*u_1D ≈ u_1D rtol = 1e-15
-#         @test Hi_x*v_1D == Hi_x'*v_1D
-#         # 2D
-#         H_xy = diagonal_quadrature(g_2D,op.quadratureClosure)
-#         Hi_xy = inverse_diagonal_quadrature(g_2D,op.quadratureClosure)
-#         v_2D = evalOn(g_2D,(x,y)->sin(x)+cos(y))
-#         u_2D = evalOn(g_2D,(x,y)->x*y + x^5 - sqrt(y))
-#         @test Hi_xy*H_xy*v_2D ≈ v_2D rtol = 1e-15
-#         @test Hi_xy*H_xy*u_2D ≈ u_2D rtol = 1e-15
-#         @test Hi_xy*v_2D ≈ Hi_xy'*v_2D rtol = 1e-16 #Failed for exact equality. Must differ in operation order for some reason?
-#     end
-#
-#     @testset "Inferred" begin
-#         Hi_x = inverse_diagonal_quadrature(g_1D,op.quadratureClosure)
-#         Hi_xy = inverse_diagonal_quadrature(g_2D,op.quadratureClosure)
-#         v_1D = ones(Float64, size(g_1D))
-#         v_2D = ones(Float64, size(g_2D))
-#         @inferred Hi_x*v_1D
-#         @inferred Hi_x'*v_1D
-#         @inferred Hi_xy*v_2D
-#         @inferred Hi_xy'*v_2D
-#     end
-# end
+@testset "InverseDiagonalQuadrature" begin
+    Lx = π/2.
+    Ly = Float64(π)
+    g_1D = EquidistantGrid(77, 0.0, Lx)
+    g_2D = EquidistantGrid((77,66), (0.0, 0.0), (Lx,Ly))
+    @testset "Constructors" begin
+        op = read_D2_operator(sbp_operators_path()*"standard_diagonal.toml"; order=4)
+        @testset "1D" begin
+            Hi = InverseDiagonalQuadrature(g_1D, op.quadratureClosure);
+            inner_stencil = Stencil((1.,),center=1)
+            closures = ()
+            for i = 1:length(op.quadratureClosure)
+                closures = (closures...,Stencil(op.quadratureClosure[i].range,1.0./op.quadratureClosure[i].weights))
+            end
+            @test Hi == InverseQuadrature(g_1D,inner_stencil,closures)
+            @test Hi isa TensorMapping{T,1,1} where T
+        end
+        @testset "2D" begin
+            Hi = InverseDiagonalQuadrature(g_2D,op.quadratureClosure)
+            Hi_x = InverseDiagonalQuadrature(restrict(g_2D,1),op.quadratureClosure)
+            Hi_y = InverseDiagonalQuadrature(restrict(g_2D,2),op.quadratureClosure)
+            @test Hi == Hi_x⊗Hi_y
+            @test Hi isa TensorMapping{T,2,2} where T
+        end
+    end
+
+    @testset "Sizes" begin
+        op = read_D2_operator(sbp_operators_path()*"standard_diagonal.toml"; order=4)
+        @testset "1D" begin
+            Hi = InverseDiagonalQuadrature(g_1D,op.quadratureClosure)
+            @test domain_size(Hi) == size(g_1D)
+            @test range_size(Hi) == size(g_1D)
+        end
+        @testset "2D" begin
+            Hi = InverseDiagonalQuadrature(g_2D,op.quadratureClosure)
+            @test domain_size(Hi) == size(g_2D)
+            @test range_size(Hi) == size(g_2D)
+        end
+    end
+
+    @testset "Accuracy" begin
+        @testset "1D" begin
+            v = evalOn(g_1D,x->sin(x))
+            u = evalOn(g_1D,x->x^3-x^2+1)
+            @testset "2nd order" begin
+                op = read_D2_operator(sbp_operators_path()*"standard_diagonal.toml"; order=2)
+                H = DiagonalQuadrature(g_1D,op.quadratureClosure)
+                Hi = InverseDiagonalQuadrature(g_1D,op.quadratureClosure)
+                @test Hi*H*v ≈ v rtol = 1e-15
+                @test Hi*H*u ≈ u rtol = 1e-15
+            end
+            @testset "4th order" begin
+                op = read_D2_operator(sbp_operators_path()*"standard_diagonal.toml"; order=4)
+                H = DiagonalQuadrature(g_1D,op.quadratureClosure)
+                Hi = InverseDiagonalQuadrature(g_1D,op.quadratureClosure)
+                @test Hi*H*v ≈ v rtol = 1e-15
+                @test Hi*H*u ≈ u rtol = 1e-15
+            end
+        end
+        @testset "2D" begin
+            v = evalOn(g_2D,(x,y)->sin(x)+cos(y))
+            u = evalOn(g_2D,(x,y)->x*y + x^5 - sqrt(y))
+            @testset "2nd order" begin
+                op = read_D2_operator(sbp_operators_path()*"standard_diagonal.toml"; order=2)
+                H = DiagonalQuadrature(g_2D,op.quadratureClosure)
+                Hi = InverseDiagonalQuadrature(g_2D,op.quadratureClosure)
+                @test Hi*H*v ≈ v rtol = 1e-15
+                @test Hi*H*u ≈ u rtol = 1e-15
+            end
+            @testset "4th order" begin
+                op = read_D2_operator(sbp_operators_path()*"standard_diagonal.toml"; order=4)
+                H = DiagonalQuadrature(g_2D,op.quadratureClosure)
+                Hi = InverseDiagonalQuadrature(g_2D,op.quadratureClosure)
+                @test Hi*H*v ≈ v rtol = 1e-15
+                @test Hi*H*u ≈ u rtol = 1e-15
+            end
+        end
+    end
+end
 
 @testset "BoundaryOperator" begin
     closure_stencil = Stencil((0,2), (2.,1.,3.))