clean up influence

In the most annoying bug ever... Windows was only specializing on the closure function after recompiling influence. Before that, it was allocating absurdly.

New version just brute forces the sum over i,j,m and rewrites the derivative explicitly. works on Windows without issue now.

Author: weymouth

src/NeumannKelvin.jl

@@ -20,7 +20,7 @@ export BodyPanelSystem,bodyarea,bodyvol
 
 import AcceleratedKernels as AK # multi-threaded mapreduce,foreachindex
 include("panel_method.jl")
-export ∫G,∂ₙϕ,Φ,∇Φ,u,cₚ,steadyforce,addedmass
+export source,∫G,Φ,∇Φ,u,cₚ,steadyforce,addedmass
 
 # Direct and matrix-free solver
 include("solvers.jl")
@@ -37,7 +37,7 @@ export FSPanelSystem,ζ
 
 # Kelvin Green function definitions
 include("NKPanelSystem.jl")
-export NKPanelSystem,kelvin
+export NKPanelSystem,∫NK,kelvin
 
 # General support functions
 components(data,i) = getindex.(data, i)

src/solvers.jl

@@ -77,11 +77,8 @@ function directsolve!(sys;verbose=true)
 end
 influence((;body,mirrors)::AbstractPanelSystem) = influence(body,mirrors,∫G)
 function influence(body,mirrors,ϕ)
-    ϕ_sym(x,p) = sum(m->ϕ(x .* m,p),mirrors)
-    A = Array{eltype(body.dA)}(undef,length(body),length(body))
-    AK.foraxes(A,2) do j
-        @simd for i in axes(A,1)
-            @inbounds A[i,j] = ∂ₙϕ(body[i],body[j];ϕ=ϕ_sym)
-        end
-    end; A
+    A = zeros(length(body),length(body))
+    AK.foraxes(A,2) do j; for m in mirrors, i in axes(A,1)
+        @inbounds A[i,j] += derivative(t->ϕ(body.x[i] .* m + t*body.n[i], body[j]), 0)
+    end; end; A
 end

test/runtests.jl

@@ -94,6 +94,7 @@ using BenchmarkTools
 end
 
 using LinearAlgebra
+using NeumannKelvin:∂ₙϕ
 @testset "panel_method.jl" begin
     S(θ₁,θ₂) = SA[cos(θ₂)*sin(θ₁),sin(θ₂)*sin(θ₁),cos(θ₁)]
     panels = measure.(S,[π/4,3π/4]',π/4:π/2:2π,π/2,π/2,cubature=true) |> Table