Merge pull request #2094 from SciML/interpolation_output_types

Fix interpolation output types for dynamical ODEs

Author: ChrisRackauckas

src/dense/generic_dense.jl

@@ -687,8 +687,13 @@ Herimte Interpolation, chosen if no other dispatch for ode_interpolant
 @muladd function hermite_interpolant(Θ, dt, y₀, y₁, k, ::Type{Val{false}}, idxs::Nothing,
     T::Type{Val{0}}, differential_vars) # Default interpolant is Hermite
     #@.. broadcast=false (1-Θ)*y₀+Θ*y₁+Θ*(Θ-1)*((1-2Θ)*(y₁-y₀)+(Θ-1)*dt*k[1] + Θ*dt*k[2])
-    @inbounds (1 - Θ) * y₀ + Θ * y₁ +
-              differential_vars .* (Θ * (Θ - 1) * ((1 - 2Θ) * (y₁ - y₀) + (Θ - 1) * dt * k[1] + Θ * dt * k[2]))
+    if all(differential_vars)
+        @inbounds (1 - Θ) * y₀ + Θ * y₁ +
+                (Θ * (Θ - 1) * ((1 - 2Θ) * (y₁ - y₀) + (Θ - 1) * dt * k[1] + Θ * dt * k[2]))
+    else
+        @inbounds (1 - Θ) * y₀ + Θ * y₁ +
+                differential_vars .* (Θ * (Θ - 1) * ((1 - 2Θ) * (y₁ - y₀) + (Θ - 1) * dt * k[1] + Θ * dt * k[2]))
+    end
 end
 
 @muladd function hermite_interpolant(Θ, dt, y₀, y₁, k, ::Type{Val{true}}, idxs::Nothing,
@@ -755,10 +760,17 @@ Herimte Interpolation, chosen if no other dispatch for ode_interpolant
 @muladd function hermite_interpolant(Θ, dt, y₀, y₁, k, ::Type{Val{false}}, idxs::Nothing,
     T::Type{Val{1}}, differential_vars) # Default interpolant is Hermite
     #@.. broadcast=false k[1] + Θ*(-4*dt*k[1] - 2*dt*k[2] - 6*y₀ + Θ*(3*dt*k[1] + 3*dt*k[2] + 6*y₀ - 6*y₁) + 6*y₁)/dt
-    @inbounds (.!differential_vars).*(y₁ - y₀)/dt + differential_vars .*(
-              k[1] +
-              Θ * (-4 * dt * k[1] - 2 * dt * k[2] - 6 * y₀ +
-               Θ * (3 * dt * k[1] + 3 * dt * k[2] + 6 * y₀ - 6 * y₁) + 6 * y₁) / dt)
+    if all(differential_vars)
+        @inbounds  (
+            k[1] +
+            Θ * (-4 * dt * k[1] - 2 * dt * k[2] - 6 * y₀ +
+            Θ * (3 * dt * k[1] + 3 * dt * k[2] + 6 * y₀ - 6 * y₁) + 6 * y₁) / dt)
+    else
+        @inbounds (.!differential_vars).*(y₁ - y₀)/dt + differential_vars .*(
+                k[1] +
+                Θ * (-4 * dt * k[1] - 2 * dt * k[2] - 6 * y₀ +
+                Θ * (3 * dt * k[1] + 3 * dt * k[2] + 6 * y₀ - 6 * y₁) + 6 * y₁) / dt)
+    end
 end
 
 @muladd function hermite_interpolant(Θ, dt, y₀, y₁, k, ::Type{Val{true}}, idxs::Nothing,
@@ -826,8 +838,13 @@ Herimte Interpolation, chosen if no other dispatch for ode_interpolant
 @muladd function hermite_interpolant(Θ, dt, y₀, y₁, k, ::Type{Val{false}}, idxs::Nothing,
     T::Type{Val{2}}, differential_vars) # Default interpolant is Hermite
     #@.. broadcast=false (-4*dt*k[1] - 2*dt*k[2] - 6*y₀ + Θ*(6*dt*k[1] + 6*dt*k[2] + 12*y₀ - 12*y₁) + 6*y₁)/(dt*dt)
-    @inbounds differential_vars .* (-4 * dt * k[1] - 2 * dt * k[2] - 6 * y₀ +
-               Θ * (6 * dt * k[1] + 6 * dt * k[2] + 12 * y₀ - 12 * y₁) + 6 * y₁) / (dt * dt)
+    if all(differential_vars)
+        @inbounds (-4 * dt * k[1] - 2 * dt * k[2] - 6 * y₀ +
+        Θ * (6 * dt * k[1] + 6 * dt * k[2] + 12 * y₀ - 12 * y₁) + 6 * y₁) / (dt * dt)
+    else
+        @inbounds differential_vars .* (-4 * dt * k[1] - 2 * dt * k[2] - 6 * y₀ +
+                Θ * (6 * dt * k[1] + 6 * dt * k[2] + 12 * y₀ - 12 * y₁) + 6 * y₁) / (dt * dt)
+    end
 end
 
 @muladd function hermite_interpolant(Θ, dt, y₀, y₁, k, ::Type{Val{true}}, idxs::Nothing,
@@ -887,7 +904,11 @@ Herimte Interpolation, chosen if no other dispatch for ode_interpolant
 @muladd function hermite_interpolant(Θ, dt, y₀, y₁, k, ::Type{Val{false}}, idxs::Nothing,
     T::Type{Val{3}}, differential_vars) # Default interpolant is Hermite
     #@.. broadcast=false (6*dt*k[1] + 6*dt*k[2] + 12*y₀ - 12*y₁)/(dt*dt*dt)
-    @inbounds differential_vars .* (6 * dt * k[1] + 6 * dt * k[2] + 12 * y₀ - 12 * y₁) / (dt * dt * dt)
+    if all(differential_vars)
+        @inbounds (6 * dt * k[1] + 6 * dt * k[2] + 12 * y₀ - 12 * y₁) / (dt * dt * dt)
+    else
+        @inbounds differential_vars .* (6 * dt * k[1] + 6 * dt * k[2] + 12 * y₀ - 12 * y₁) / (dt * dt * dt)
+    end
 end
 
 @muladd function hermite_interpolant(Θ, dt, y₀, y₁, k, ::Type{Val{true}}, idxs::Nothing,

test/interface/interpolation_output_types.jl

@@ -0,0 +1,22 @@
+using OrdinaryDiffEq, Test
+
+# in terms of the voltage across all three elements
+rlc1!(v′,v,(R,L,C),t) = -(v′/R + v/L)/C
+identity_f(v,u,p,t) = v # needed to form second order dynamical ODE
+
+setup_rlc(R,L,C;v_init=0.0,v′_init=0.0,tspan=(0.0,50.0)) =
+    DynamicalODEProblem{false}(rlc1!,identity_f,v′_init,v_init,tspan,(R,L,C))
+
+# simulate voltage impulse
+R,L,C = 10, 0.3, 2
+
+prob = setup_rlc(R,L,C,v_init=2.0)
+
+res1 = solve(prob,Vern8(),dt=1/10,saveat=1/10)
+res3 = solve(prob,CalvoSanz4(),dt=1/10,saveat=1/10)
+
+sol = solve(prob,CalvoSanz4(),dt=1/10)
+@test sol(0.32) isa OrdinaryDiffEq.ArrayPartition
+@test sol(0.32, Val{1}) isa OrdinaryDiffEq.ArrayPartition
+@test sol(0.32, Val{2}) isa OrdinaryDiffEq.ArrayPartition
+@test sol(0.32, Val{3}) isa OrdinaryDiffEq.ArrayPartition

test/runtests.jl

@@ -44,6 +44,7 @@ end
         @time @safetestset "Complex Tests" include("interface/complex_tests.jl")
         @time @safetestset "Ndim Complex Tests" include("interface/ode_ndim_complex_tests.jl")
         @time @safetestset "Number Type Tests" include("interface/ode_numbertype_tests.jl")
+        @time @safetestset "Interpolation Output Type Tests" include("interface/interpolation_output_types.jl")
         @time @safetestset "Stiffness Detection Tests" include("interface/stiffness_detection_test.jl")
         @time @safetestset "Composite Interpolation Tests" include("interface/composite_interpolation.jl")
         @time @safetestset "Export tests" include("interface/export_tests.jl")