handle identical types

lib/ControlSystemsBase/src/connections.jl

@@ -144,6 +144,9 @@ function Base.vect(X::LTISystem...)
     LTISystem[X...]
 end
 
+function Base.vect(X::T...) where T <: LTISystem
+    T[X...]
+end
 
 """
     add_input(sys::AbstractStateSpace, B2::AbstractArray, D2 = 0)

lib/ControlSystemsBase/src/types/StateSpace.jl

@@ -248,7 +248,13 @@ end
 ## Approximate ##
 function isapprox(sys1::ST1, sys2::ST2; kwargs...) where {ST1<:AbstractStateSpace,ST2<:AbstractStateSpace}
     fieldnames(ST1) == fieldnames(ST2) || (return false)
-    return all(isapprox(getfield(sys1, f), getfield(sys2, f); kwargs...) for f in fieldnames(ST1))
+    return all(fieldnames(ST1)) do f
+        if fieldtype(ST1, f) <: Union{Number, AbstractArray{<:Number}, LTISystem}
+            isapprox(getfield(sys1, f), getfield(sys2, f); kwargs...)
+        else
+            getfield(sys1, f) == getfield(sys2, f)
+        end
+    end
 end
 
 ## ADDITION ##

lib/ControlSystemsBase/test/test_connections.jl

@@ -154,6 +154,10 @@ v = [ssrand(1,1,1), tf(1)]
 @test v[1] isa StateSpace{Continuous, Float64}
 @test v[2] isa TransferFunction{Continuous, ControlSystemsBase.SisoRational{Int64}}
 
+# Test vector creation
+v = [tf(1), tf(1)]
+@test v isa Vector{TransferFunction{Continuous, ControlSystemsBase.SisoRational{Int64}}}
+
 # Combination tfRational and sisoZpk
 Czpk_111 = zpk([-2],[-5],1)
 Czpk_211 = zpk([-1+sqrt(2)im,-1-sqrt(2)im], [-5,-3],1)