broadcast multiplication with tfs

src/types/StateSpace.jl

@@ -260,6 +260,10 @@ end
 
 +(sys::ST, n::Number) where ST <: AbstractStateSpace = ST(sys.A, sys.B, sys.C, sys.D .+ n, sys.timeevol)
 +(n::Number, sys::ST) where ST <: AbstractStateSpace = +(sys, n)
++(sys::StateSpace, n::Number) = ss(sys.A, sys.B, sys.C, sys.D .+ n, sys.timeevol)
+function +(sys::HeteroStateSpace, n::Number)
+    HeteroStateSpace(sys.A, sys.B, sys.C, sys.D .+ n, sys.timeevol)
+end
 
 ## SUBTRACTION ##
 -(sys1::AbstractStateSpace, sys2::AbstractStateSpace) = +(sys1, -sys2)
@@ -268,6 +272,7 @@ end
 
 ## NEGATION ##
 -(sys::ST) where ST <: AbstractStateSpace = ST(sys.A, sys.B, -sys.C, -sys.D, sys.timeevol)
+-(sys::StateSpace) = ss(sys.A, sys.B, -sys.C, -sys.D, sys.timeevol)
 
 ## MULTIPLICATION ##
 function *(sys1::StateSpace{TE,T}, sys2::StateSpace{TE,T}) where {TE,T}

src/types/TransferFunction.jl

@@ -134,7 +134,11 @@ function *(G1::TransferFunction, G2::TransferFunction)
     # Note: G1*G2 = y <- G1 <- G2 <- u
     timeevol = common_timeevol(G1,G2)
     if G1.nu != G2.ny
-        error("G1*G2: G1 must have same number of inputs as G2 has outputs")
+        if issiso(G1) || issiso(G2)
+            error("G1*G2: G1 must have same number of inputs as G2 has outputs, did you intend to broadcast the multiplication?")
+        else
+            error("G1*G2: G1 must have same number of inputs as G2 has outputs")
+        end
     end
     matrix = G1.matrix * G2.matrix
     return TransferFunction(matrix, timeevol)
@@ -143,6 +147,22 @@ end
 *(G::TransferFunction, n::Number) = TransferFunction(n*G.matrix, G.timeevol)
 *(n::Number, G::TransferFunction) = *(G, n)
 
+function Base.Broadcast.broadcasted(::typeof(*), G1::TransferFunction, G2::TransferFunction)
+    issiso(G1) || issiso(G2) || error("Only SISO transfer function can be broadcasted")
+    # Note: G1*G2 = y <- G1 <- G2 <- u
+    timeevol = common_timeevol(G1,G2)
+    matrix = G1.matrix .* G2.matrix
+    return TransferFunction(matrix, timeevol)
+end
+
+function Base.Broadcast.broadcasted(::typeof(*), G1::TransferFunction, G2::AbstractArray)
+    issiso(G1) || error("Only SISO transfer function can be broadcasted")
+    # Note: G1*G2 = y <- G1 <- G2 <- u
+    timeevol = G1.timeevol
+    matrix = G1.matrix .* G2
+    return TransferFunction(matrix, timeevol)
+end
+
 ## DIVISION ##
 function /(n::Number, G::TransferFunction)
     if issiso(G)

test/test_statespace.jl

@@ -55,6 +55,13 @@
         @test C_222 + 1 == SS([-5 -3; 2 -9],[1 0; 0 2],[1 0; 0 1],[1 1; 1 1])
         @test D_111 + D_111 == SS([-0.5 0; 0 -0.5],[2; 2],[3 3],[0], 0.005)
 
+        @test C_111 + false == C_111
+        @test false + C_111 == C_111
+        @test 1.0*C_111 + false == C_111
+
+        @test C_222 + 1.5 == 1.0C_222 + 1.5 # C_222 has eltype Int
+        @test 1.5 + C_222 == 1.0C_222 + 1.5
+
         # Subtraction
         @test C_111 - C_211 == SS([-5 0 0; 0 -5 -3; 0 2 -9],[2; 1; 2],[3 -1 -0],[0])
         @test 1 - C_222 == SS([-5 -3; 2 -9],[1 0; 0 2],[-1 -0; -0 -1],[1 1; 1 1])
@@ -120,7 +127,13 @@
             @test sprint(show, D_222) == "StateSpace{Discrete{Float64}, Float64}\nA = \n  0.2  -0.8\n -0.8   0.07\nB = \n 1.0  0.0\n 0.0  2.0\nC = \n 1.0  0.0\n 0.0  1.0\nD = \n 0.0  0.0\n 0.0  0.0\n\nSample Time: 0.005 (seconds)\nDiscrete-time state-space model"
         end
 
-    # Errors
+        # Different types
+        K1 = ss(I(2)) # Bool
+        K2 = ss(1.0I(2)) # Float64
+        P = ssrand(3,3,2)
+        @test lft(P, -K1) == lft(P, -K2)
+
+        # Errors
         @test_throws ErrorException C_111 + C_222             # Dimension mismatch
         @test_throws ErrorException C_111 - C_222             # Dimension mismatch
         @test_throws ErrorException D_111 + C_111             # Sampling time mismatch

test/test_transferfunction.jl

@@ -76,6 +76,9 @@ z = tf("z", 0.005)
   vecarray(1, 2, [1,-0.7,-0.05,0.075], [1.0,-0.7,-0.05,0.075]), 0.005) ==
 tf(vecarray(1, 2, [0], [0]), vecarray(1, 2, [1], [1]), 0.005)
 
+@test tf(1) .* C_222 == C_222
+@test tf(1) .* I(2) == tf(I(2))
+
 # Division
 @test 1/C_111 == tf([1,5], [1,2])
 @test C_212/C_111 == tf(vecarray(2, 1, [1,7,13,15], [0,1,7,10]),