From a1f7f05e73f18d1efd5551c14411271f36b7d50a Mon Sep 17 00:00:00 2001
From: Sheehan Olver <solver@mac.com>
Date: Mon, 17 Feb 2025 16:18:22 +0000
Subject: [PATCH 1/3] Add grammatrix(::KronPolynomial)

---
 src/rect.jl | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/rect.jl b/src/rect.jl
index 9ee2454..c7cf4c3 100644
--- a/src/rect.jl
+++ b/src/rect.jl
@@ -77,6 +77,8 @@ end
     KronTrav(PA'QA, PB'QB)
 end
 
+grammatrix(P::KronPolynomial) = KronTrav(grammatrix.(P.args)...)
+    
 
 struct ApplyPlan{T, F, Pl}
     f::F

From 2c4575a96e1ee3354691186f1d7bb64ef15e795a Mon Sep 17 00:00:00 2001
From: Sheehan Olver <solver@mac.com>
Date: Wed, 5 Mar 2025 16:23:45 -0600
Subject: [PATCH 2/3] fix arg order

---
 src/rect.jl       | 14 ++++++--------
 test/test_rect.jl | 10 ++++++++++
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/rect.jl b/src/rect.jl
index c7cf4c3..ecf12f3 100644
--- a/src/rect.jl
+++ b/src/rect.jl
@@ -62,22 +62,22 @@ function weaklaplacian(P::RectPolynomial)
     A,B = P.args
     Δ_A,Δ_B = weaklaplacian(A), weaklaplacian(B)
     M_A,M_B = grammatrix(A), grammatrix(B)
-    KronTrav(Δ_A,M_B) + KronTrav(M_A,Δ_B)
+    KronTrav(M_B,Δ_A) + KronTrav(Δ_B,M_A)
 end
 
 function \(P::RectPolynomial, Q::RectPolynomial)
     PA,PB = P.args
     QA,QB = Q.args
-    krontrav(PA\QA, PB\QB)
+    krontrav(PB\QB, PA\QA)
 end
 
 @simplify function *(Ac::QuasiAdjoint{<:Any,<:RectPolynomial}, B::RectPolynomial)
     PA,PB = Ac'.args
     QA,QB = B.args
-    KronTrav(PA'QA, PB'QB)
+    KronTrav(PB'QB, PA'QA)
 end
 
-grammatrix(P::KronPolynomial) = KronTrav(grammatrix.(P.args)...)
+grammatrix(P::KronPolynomial) = KronTrav(reverse(grammatrix.(P.args))...)
     
 
 struct ApplyPlan{T, F, Pl}
@@ -104,10 +104,8 @@ function *(A::TensorPlan, B::AbstractArray)
     B
 end
 
-function checkpoints(P::RectPolynomial)
-    x,y = checkpoints.(P.args)
-    SVector.(x, y')
-end
+checkpoints(P::ProductDomain) = tensorgrid(checkpoints.(components(P))...)
+tensorgrid(x,y) = SVector.(x, y')
 
 function plan_transform(P::KronPolynomial{d,<:Any,<:Fill}, B::Tuple{Block{1}}, dims=1:1) where d
     @assert dims == 1
diff --git a/test/test_rect.jl b/test/test_rect.jl
index b7cf90f..2f8dde0 100644
--- a/test/test_rect.jl
+++ b/test/test_rect.jl
@@ -61,6 +61,16 @@ using Base: oneto
         @test (Y * (TU \ f))[KR] ≈ (TU \ h)[KR]
     end
 
+    @testset "gram matrix" begin
+        P = Legendre()
+        Q = Ultraspherical(3/2)
+        PQ = RectPolynomial(P, Q)
+        M = grammatrix(PQ)
+        f = expand(PQ, splat((x,y) -> exp(x*cos(y + 1))))
+        g = expand(PQ, splat((x,y) -> sin(x*cos(y + 1)+2)))
+        @test coefficients(g)[1:100]'M[1:100,1:100] * coefficients(f)[1:100] ≈ sum(expand(T², 𝐱 -> f[𝐱]g[𝐱]))
+    end
+
     @testset "Conversion" begin
         T = ChebyshevT()
         U = ChebyshevU()

From 3d92cbf7965d5817559c95adee069e5c0ab13649 Mon Sep 17 00:00:00 2001
From: Sheehan Olver <solver@mac.com>
Date: Wed, 5 Mar 2025 16:24:07 -0600
Subject: [PATCH 3/3] v0.9.2

---
 Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index c0c5e44..d70897d 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "MultivariateOrthogonalPolynomials"
 uuid = "4f6956fd-4f93-5457-9149-7bfc4b2ce06d"
-version = "0.9.1"
+version = "0.9.2"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"