Merge pull request #820 from JuliaControl/warnings

fix import warnings

Author: baggepinnen

src/ControlSystems.jl

@@ -6,11 +6,11 @@ using ControlSystemsBase: issiso, ninputs, noutputs, nstates, numeric_type
 
 
 using LinearAlgebra
-using OrdinaryDiffEq
+import OrdinaryDiffEq
 import LinearAlgebra: BlasFloat
 import Hungarian # For pole assignment in rlocusplot
 import DiffEqCallbacks: SavingCallback, SavedValues
-using DelayDiffEq
+import DelayDiffEq
 using SparseArrays
 using StaticArrays
 using RecipesBase

src/simulators.jl

@@ -1,3 +1,4 @@
+import OrdinaryDiffEq: ODESolution, ODEProblem
 abstract type AbstractSimulator end
 
 # ============================================================================================
@@ -52,4 +53,4 @@ Simulate the system represented by `s` from initial state `x0` over time span `t
 
 See also `Simulator` `lsim`
 """
-DiffEqBase.solve(s::AbstractSimulator, x0, tspan, solver=Tsit5(), args...; kwargs...) = solve(ODEProblem(s.f,x0,tspan), solver, args...; kwargs...)
+DiffEqBase.solve(s::AbstractSimulator, x0, tspan, solver=Tsit5(), args...; kwargs...) = DiffEqBase.solve(ODEProblem(s.f,x0,tspan), solver, args...; kwargs...)

src/timeresp.jl

@@ -1,4 +1,6 @@
+import OrdinaryDiffEq: ODEProblem, SavedValues, SavingCallback, Tsit5, DiffEqBase, solve, BS3
 import ControlSystemsBase: lsim, step, impulse, HammersteinWienerSystem, DelayLtiSystem, PartitionedStateSpace, SimResult
+import DelayDiffEq: MethodOfSteps
 # Function for DifferentialEquations lsim
 """
     f_lsim(dx, x, p, t)
@@ -193,7 +195,7 @@ function _lsim(sys::DelayLtiSystem{T,S}, Base.@nospecialize(u!), t::AbstractArra
 
     # The states are x(t), Y(t), D(t), where Y, D are integrals of y(t), d(t)
     u0 = [x0;zeros(T,ny);zeros(T,nd)]
-    prob = DDEProblem{true}(dde_param, u0, h!,
+    prob = DelayDiffEq.DDEProblem{true}(dde_param, u0, h!,
                 (T(t[1]), T(t[end])),
                 p,
                 constant_lags=sort(Tau),# Not sure if sort needed