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generate_ode_iW -> generate_factorized_W #118

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Merged
merged 1 commit into from
Apr 7, 2019
Merged

generate_ode_iW -> generate_factorized_W #118

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20 changes: 9 additions & 11 deletions src/systems/diffeqs/diffeqsystem.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -76,31 +76,29 @@ function generate_function(sys::DiffEqSystem; version::FunctionVersion = ArrayFu
end


function generate_ode_iW(sys::DiffEqSystem, simplify=true; version::FunctionVersion = ArrayFunction)
function generate_factorized_W(sys::DiffEqSystem, simplify=true; version::FunctionVersion = ArrayFunction)
jac = calculate_jacobian(sys)

gam = Variable(:gam; known = true)

W = LinearAlgebra.I - gam*jac
W = SMatrix{size(W,1),size(W,2)}(W)
iW = inv(W)
Wfact = lu(W, Val(false), check=false).factors

if simplify
iW = simplify_constants.(iW)
Wfact = simplify_constants.(Wfact)
end

W = inv(LinearAlgebra.I/gam - jac)
W = SMatrix{size(W,1),size(W,2)}(W)
iW_t = inv(W)
W_t = LinearAlgebra.I/gam - jac
Wfact_t = lu(W_t, Val(false), check=false).factors
if simplify
iW_t = simplify_constants.(iW_t)
Wfact_t = simplify_constants.(Wfact_t)
end

vs, ps = sys.dvs, sys.ps
iW_func = build_function(iW , vs, ps, (:gam,:t); version = version)
iW_t_func = build_function(iW_t, vs, ps, (:gam,:t); version = version)
Wfact_func = build_function(Wfact , vs, ps, (:gam,:t); version = version)
Wfact_t_func = build_function(Wfact_t, vs, ps, (:gam,:t); version = version)

return (iW_func, iW_t_func)
return (Wfact_func, Wfact_t_func)
end

function DiffEqBase.ODEFunction(sys::DiffEqSystem; version::FunctionVersion = ArrayFunction)
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10 changes: 9 additions & 1 deletion test/system_construction.jl
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Expand Up @@ -16,7 +16,15 @@ generate_function(de;version=ModelingToolkit.SArrayFunction)
jac_expr = generate_jacobian(de)
jac = calculate_jacobian(de)
f = ODEFunction(de)
ModelingToolkit.generate_ode_iW(de)
fw, fwt = map(eval, ModelingToolkit.generate_factorized_W(de))
du = zeros(3)
u = collect(1:3)
p = collect(4:6)
f(du, u, p, 0.1)
@test du == [4, 0, -16]
FW = zeros(3, 3)
fw(FW, u, p, 0.2, 0.1)
fwt(FW, u, p, 0.2, 0.1)

# Differential equation with automatic extraction of variables
de2 = DiffEqSystem(eqs, t)
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