Began test fix

Author: xtalax

Project.toml

@@ -5,6 +5,7 @@ version = "0.1.0"
 
 [deps]
 DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
+DiffEqOperators = "9fdde737-9c7f-55bf-ade8-46b3f136cc48"
 DomainSets = "5b8099bc-c8ec-5219-889f-1d9e522a28bf"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 ModelingToolkit = "961ee093-0014-501f-94e3-6117800e7a78"

src/MethodOfLines.jl

@@ -2,6 +2,7 @@ module MethodOfLines
     using LinearAlgebra
     using SciMLBase
     using DiffEqBase
+    using DiffEqOperators
     using ModelingToolkit
     using SymbolicUtils, Symbolics
     import DomainSets

src/discretization/differential_discretizer.jl

@@ -1,8 +1,8 @@
 # Use DiffEqOperators to generate weights and calculate derivative orders
 struct DifferentialDiscretizer{T}
     approx_order
-    map::Dict{Num, DerivativeOperator}
-    nonlinlapmap::Tuple{DerivativeOperator, DerivativeOperator}
+    map::Dict{Num, DiffEqOperators.DerivativeOperator}
+    nonlinlapmap::Dict{Num, NTuple{2, DiffEqOperators.DerivativeOperator}}
     orders::Vector{T}
 end
 
@@ -11,8 +11,8 @@ function DifferentialDiscretizer(pde, s, discretization)
     d_orders(x) = reverse(sort(collect(union(differential_order(pde.rhs, x), differential_order(pde.lhs, x)))))
 
     # central_deriv_rules = [(Differential(s)^2)(u) => central_deriv(2,II,j,k) for (j,s) in enumerate(s.nottime), (k,u) in enumerate(s.vars)]
-    differentialmap = Array{Pair{Num,DerivativeOperator},1}()
-    nonlinlap = Array{Pair{Num, NTuple{2,DerivativeOperator}}}(undef, nparams(s))
+    differentialmap = Array{Pair{Num,DiffEqOperators.DerivativeOperator},1}()
+    nonlinlap = Array{Pair{Num, NTuple{2,DiffEqOperators.DerivativeOperator}}}(undef, nparams(s))
     orders = Int[]
     # Hardcoded to centered difference, generate weights for each differential
     # TODO: Add handling for upwinding

test/components/finite_diff_schemes.jl

@@ -7,31 +7,40 @@ indvars = [x, t]
 nottime = [x]
 depvars = [u]
 
-Dx = Differential(x)
+Dx(d) = Differential(x)^d
 Dt = Differential(t)
 
 t_min= 0.
 t_max = 2.0
 x_min = 0.
-x_max = 2.
+x_max = 20.0
 
-dx = 0.1
+dx = 1.0
 order = 2
 
 domains = [t ∈ Interval(t_min, t_max), x ∈ Interval(x_min, x_max)]
 
 
-@testset "Test 01: discretization of variables, center aligned grid" begin
-    pde = Dt(u) ~ Dx(u)
-    # Test centered order
-    disc = MOLFiniteDifference([x=>dx], t; centered_order=order)
-
-    s = MethodOfLines.DiscreteSpace(domains, depvars, indvars, nottime, disc)
-
-    derivweights = MethodOfLines.DifferentialDiscretizer(pde, s, disc)
-    
-    II = s.Igrid[10]
-
-    rules = MethodOfLines.generate_finite_difference_rules(II, s, pde, derivweights)
-    disc_pde=substitute(pde.lhs,rules) ~ substitute(pde.rhs,rules)
+@testset "Test 01: Cartesian derivative discretization" begin
+    weights = []
+    push!(weights, ([-0.5,0,0.5], [1.,-2.,1.], [-1/2,1.,0.,-1.,1/2]))
+    push!(weights, ([1/12, -2/3,0,2/3,-1/12], [-1/12,4/3,-5/2,4/3,-1/12], [1/8,-1.,13/8,0.,-13/8,1.,-1/8]))
+    for d in 1:3
+        for a in [2,4]
+            pde = Dt(u) ~ Dx(d)(u)
+            # Test centered order
+            disc = MOLFiniteDifference([x=>dx], t; centered_order=order)
+
+            s = MethodOfLines.DiscreteSpace(domains, depvars, indvars, nottime, disc)
+
+            derivweights = MethodOfLines.DifferentialDiscretizer(pde, s, disc)
+            
+            II = s.Igrid[10]
+
+            rules = MethodOfLines.generate_finite_difference_rules(II, s, pde, derivweights)
+            @show rules
+            disc_pde=substitute(pde.lhs,rules) ~ substitute(pde.rhs,rules)
+            @show disc_pde
+        end
+    end
 end