prefactor matrix

Author: baggepinnen

src/descriptor.jl

@@ -108,12 +108,12 @@ function baltrunc_coprime(sys; residual=false, n=missing, factorization::F = Des
     BN = B[:, 1:nu]
     DN = D[:, 1:nu]
     BM = B[:, nu+1:end]
-    DM = D[:, nu+1:end]
+    DMi = pinv(D[:, nu+1:end])
 
-    Ar = A - BM * (DM \ C)
-    Cr = (DM \ C)
-    Br = BN  - BM * (DM \ DN)
-    Dr = (DM \ DN)
+    Ar = A - BM * (DMi * C)
+    Cr = (DMi * C)
+    Br = BN  - BM * (DMi * DN)
+    Dr = (DMi * DN)
 
     ss(Ar,Br,Cr,Dr,sys.timeevol), hs
 end

test/test_descriptor.jl

@@ -23,35 +23,39 @@ end >= 94
 
 
 ##
-sys = ssrand(2,3,40, stable=true)
-sysus = ssrand(2,3,2, stable=true)
-sysus.A .*= -1
-sys = sys + sysus
-
-sysr, hs = RobustAndOptimalControl.baltrunc_coprime(sys, n=20, factorization = RobustAndOptimalControl.DescriptorSystems.glcf)
-
-@test sysr.nx <= 20
-@test linfnorm(sysr - sys)[1] < 3e-3
-
-e = poles(sysr)
-@test count(e->real(e)>0, e) == 2 # test that the two unstable poles were preserved
-
-# bodeplot([sys, sysr])
-
-## stab_unstab
-sys = ssrand(2,3,40, stable=false)
-stab, unstab = stab_unstab(sys)
-@test all(real(poles(stab)) .< 0)
-@test all(real(poles(unstab)) .>= 0)
-@test linfnorm(stab + unstab - sys)[1] < 1e-8
-
-## baltrunc_unstab
-sys = ssrand(2,3,40, stable=true)
-sysus = ssrand(2,3,2, stable=true)
-sysus.A .*= -1
-sys = sys + sysus
-sysr, hs = baltrunc_unstab(sys, n=20)
-@test sysr.nx <= 20
-@test linfnorm(sysr - sys)[1] < 1e-3
-# bodeplot([sys, sysr])
+@testset "unstable baltrunc" begin
+    @info "Testing unstable baltrunc"
+    for proper = [true, false]
+        sys = ssrand(2,3,40; stable=true, proper)
+        sysus = ssrand(2,3,2; stable=true, proper)
+        sysus.A .*= -1
+        sys = sys + sysus
+
+        sysr, hs = RobustAndOptimalControl.baltrunc_coprime(sys, n=20, factorization = RobustAndOptimalControl.DescriptorSystems.glcf)
+
+        @test sysr.nx <= 20
+        @test linfnorm(sysr - sys)[1] < 9e-3
+
+        e = poles(sysr)
+        @test count(e->real(e)>0, e) == 2 # test that the two unstable poles were preserved
+        # bodeplot([sys, sysr])
+    end
 
+    ## stab_unstab
+    sys = ssrand(2,3,40, stable=false)
+    stab, unstab = stab_unstab(sys)
+    @test all(real(poles(stab)) .< 0)
+    @test all(real(poles(unstab)) .>= 0)
+    @test linfnorm(stab + unstab - sys)[1] < 1e-8
+
+    ## baltrunc_unstab
+    sys = ssrand(2,3,40, stable=true)
+    sysus = ssrand(2,3,2, stable=true)
+    sysus.A .*= -1
+    sys = sys + sysus
+    sysr, hs = baltrunc_unstab(sys, n=20)
+    @test sysr.nx <= 20
+    @test linfnorm(sysr - sys)[1] < 1e-3
+    # bodeplot([sys, sysr])
+
+end