shorthand ode->sde

Author: anandijain

src/systems/diffeqs/sdesystem.jl

@@ -132,6 +132,8 @@ function SDESystem(deqs::AbstractVector{<:Equation}, neqs, iv, dvs, ps;
     SDESystem(deqs, neqs, iv′, dvs′, ps′, var_to_name, ctrl′, observed, tgrad, jac, ctrl_jac, Wfact, Wfact_t, name, systems, defaults, connection_type)
 end
 
+SDESystem(sys::ODESystem, neqs; kwargs...) = SDESystem(equations(sys), neqs, independent_variable(sys), states(sys), parameters(sys); kwargs...)
+
 function generate_diffusion_function(sys::SDESystem, dvs = states(sys), ps = parameters(sys); kwargs...)
     return build_function(get_noiseeqs(sys),
                           map(x->time_varying_as_func(value(x), sys), dvs),

test/sdesystem.jl

@@ -442,4 +442,8 @@ fdif!(du,u0,p,t)
     sys1 = SDESystem(eqs_short, noiseeqs, t, [x, y, z], [σ, ρ, β], name = :sys1)
     sys2 = SDESystem(eqs_short, noiseeqs, t, [x, y, z], [σ, ρ, β], name = :sys1)
     @test_throws ArgumentError SDESystem([sys2.y ~ sys1.z], t, [], [], [], systems = [sys1, sys2])
-end
+end
+
+# ODESystem -> SDESystem shorthand constructor
+sys = ODESystem(eqs,t,[x,y,z],[σ,ρ,β])
+@test SDESystem(sys, noiseeqs) isa SDESystem