add test for zero constructor

JuliaControl · Dec 4, 2023 · 66e1475 · 66e1475
1 parent 28c3712
commit 66e1475
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/lib/ControlSystemsBase/src/types/LFTSystem.jl b/lib/ControlSystemsBase/src/types/LFTSystem.jl
@@ -1,7 +1,7 @@
 abstract type LFTSystem{TE, T} <: LTISystem{TE} end
 timeevol(sys::LFTSystem) = timeevol(sys.P)
 
-Base.zero(sys::LFTSystem) = basetype(sys)(zero(sys.D), sys.timeevol)
+Base.zero(sys::LFTSystem) = ss(zero(sys.P.D), sys.P.timeevol)
 Base.zero(::Type{<:LFTSystem{Continuous, F}}) where {F} = ss([zero(F)], Continuous())
 
 

diff --git a/lib/ControlSystemsBase/test/test_delayed_systems.jl b/lib/ControlSystemsBase/test/test_delayed_systems.jl
@@ -56,10 +56,12 @@ P2_fr = (im*ω .+ 1) ./ (im*ω .+ 2)
 @test freqresp(P2 * delay(1), ω)[:] ≈ P2_fr .* exp.(-im*ω) rtol=1e-15
 @test freqresp(delay(1) * P2, ω)[:] ≈ P2_fr .* exp.(-im*ω) rtol=1e-15
 
-
-# Division / feedback
+## Division / feedback
 @test freqresp(1/(1+P1), ω) ≈ freqresp(feedback(I(size(P1, 1)), P1), ω) rtol=1e-15
 
+## Zero
+@test zero(typeof(P1)) == ss(0.0)
+@test zero(P1) == ss(0.0)
 
 ## append
 P12 = append(P1, P2)