Support plotting on rectangles (#169)

* Support plotting on rectangles

* Update test_rect.jl

Author: dlfivefifty

src/rect.jl

@@ -78,6 +78,7 @@ ApplyPlan(f, P) = ApplyPlan{eltype(P), typeof(f), typeof(P)}(f, P)
 
 *(A::ApplyPlan, B::AbstractArray) = A.f(A.plan*B)
 
+basis_axes(d::Inclusion{<:Any,<:ProductDomain}, v) = KronPolynomial(map(d -> basis(Inclusion(d)),components(d.domain))...)
 
 struct TensorPlan{T, Plans}
     plans::Plans
@@ -107,6 +108,12 @@ function plan_grid_transform(P::KronPolynomial{d,<:Any,<:Fill}, B::Tuple{Block{1
     SVector.(x̃, x̃'), ApplyPlan(DiagTrav, F)
 end
 
+function plotgrid(P::RectPolynomial, B::Block{1})
+    x,y = plotgrid.(P.args, Int(B))
+    SVector.(x, y')
+end
+
+
 function plan_grid_transform(P::KronPolynomial{d}, B::Tuple{Block{1}}, dims=1:1) where d
     @assert dims == 1 || dims == 1:1 || dims == (1,)
     @assert d == 2

test/test_rect.jl

@@ -1,6 +1,7 @@
 using MultivariateOrthogonalPolynomials, ClassicalOrthogonalPolynomials, StaticArrays, LinearAlgebra, BlockArrays, FillArrays, Base64, Test
-import ClassicalOrthogonalPolynomials: expand
-import MultivariateOrthogonalPolynomials: weaklaplacian
+using ClassicalOrthogonalPolynomials: expand
+using MultivariateOrthogonalPolynomials: weaklaplacian
+using ContinuumArrays: plotgridvalues
 
 @testset "RectPolynomial" begin
     @testset "Evaluation" begin
@@ -111,4 +112,11 @@ import MultivariateOrthogonalPolynomials: weaklaplacian
         @test stringmime("text/plain", KronPolynomial(Legendre(), Chebyshev())) == "Legendre() ⊗ ChebyshevT()"
         @test stringmime("text/plain", KronPolynomial(Legendre(), Chebyshev(), Jacobi(1,1))) == "Legendre() ⊗ ChebyshevT() ⊗ Jacobi(1.0, 1.0)"
     end
+
+    @testset "Plot" begin
+        P = RectPolynomial(Legendre(),Legendre())
+        x,F = plotgridvalues(P[:,1])
+        @test x == SVector.(ChebyshevGrid{2}(40), ChebyshevGrid{2}(40)')
+        @test F == ones(40,40)
+    end
 end