handle uncertain tf in tzeros and poles

Author: baggepinnen

src/uncertainty_interface.jl

@@ -459,6 +459,10 @@ end
 #     Complex(StaticParticles(getfield.(parts, :re)), StaticParticles(getfield.(parts, :im)))
 # end
 
+function ControlSystemsBase.poles(G::TransferFunction{<:ControlSystemsBase.TimeEvolution, ControlSystemsBase.SisoRational{T}}) where T <: AbstractParticles
+    poles(ss(G))
+end
+
 function ControlSystemsBase.tzeros(A::AbstractMatrix{T}, B::AbstractMatrix{T}, C::AbstractMatrix{T}, D::AbstractMatrix{T}) where T <: AbstractParticles
     bymap(tzeros, A, B, C, D)
 end

test/test_uncertainty.jl

@@ -1,4 +1,4 @@
-using RobustAndOptimalControl, ControlSystemsBase, MonteCarloMeasurements, Test
+using RobustAndOptimalControl, ControlSystemsBase, MonteCarloMeasurements, Test, LinearAlgebra
 
 d = δr()
 @test d.val == 0
@@ -387,4 +387,17 @@ using SparseArrays
 @test MOP.nx == P.nx*N
 @test MOP.nu == P.nu
 
-@test MOP.A isa SparseMatrixCSC
+@test MOP.A isa SparseMatrixCSC
+
+
+## Poles and zeros of tf
+
+ω = 4..12
+ζ = 0.054..0.084
+
+P  = tf([2*ζ/ω, 1],  [1/ω^2, 2*ζ/ω, 1, 0, 0])
+
+C = 1.0 * tf([1, 1], [0.1, 1])
+G = feedback(C*P, 1)
+poles(G)
+tzeros(G)