function [Er,Ar,Br,Cr] = IRKA_rail(k,r,istest)
if nargin<1
k=1;
end
eqn = getrail(k);
if nargin<2
opts.irka.r = 20;
else
opts.irka.r = r;
end
if nargin < 3
istest = 0;
end
opts.irka.maxiter =20;
opts.irka.shift_tol = 1e-3;
opts.irka.h2_tol = 1e-6;
if istest
opts.irka.info = 1;
else
opts.irka.info = 2;
end
opts.irka.init = 'logspace';
[Er,Ar,Br,Cr] = mess_tangential_irka(eqn.E_,eqn.A_,eqn.B,eqn.C,opts);
if istest
[~, ID] = lastwarn;
lastwarn('');
if strcmp(ID,'MESS:IRKA:convergence')
error('IRKA converged unexpectedly slow');
end
end
IRKA step 1, rel. chg. shifts = 1.010139e+01 , rel. H2-norm chg. ROM = 1.000000e+00
Warning: IRKA step 2 : 1 non-stable reduced eigenvalues have been flipped.
IRKA step 2, rel. chg. shifts = 8.189732e+00 , rel. H2-norm chg. ROM = Inf
Warning: IRKA step 3 : 2 non-stable reduced eigenvalues have been flipped.
IRKA step 3, rel. chg. shifts = 4.215028e+00 , rel. H2-norm chg. ROM = Inf
Warning: IRKA step 4 : 3 non-stable reduced eigenvalues have been flipped.
IRKA step 4, rel. chg. shifts = 1.137401e+00 , rel. H2-norm chg. ROM = Inf
Warning: IRKA step 5 : 1 non-stable reduced eigenvalues have been flipped.
IRKA step 5, rel. chg. shifts = 1.011476e+00 , rel. H2-norm chg. ROM = Inf
Warning: IRKA step 6 : 1 non-stable reduced eigenvalues have been flipped.
IRKA step 6, rel. chg. shifts = 1.292713e+00 , rel. H2-norm chg. ROM = Inf
IRKA step 7, rel. chg. shifts = 2.267604e+00 , rel. H2-norm chg. ROM = 9.033771e-01
Warning: IRKA step 8 : 1 non-stable reduced eigenvalues have been flipped.
IRKA step 8, rel. chg. shifts = 1.531156e+00 , rel. H2-norm chg. ROM = Inf
Warning: IRKA step 9 : 1 non-stable reduced eigenvalues have been flipped.
IRKA step 9, rel. chg. shifts = 2.489504e-01 , rel. H2-norm chg. ROM = Inf
Warning: IRKA step 10 : 1 non-stable reduced eigenvalues have been flipped.
IRKA step 10, rel. chg. shifts = 2.082839e-01 , rel. H2-norm chg. ROM = Inf
IRKA step 11, rel. chg. shifts = 1.116899e-01 , rel. H2-norm chg. ROM = 3.767657e-01
IRKA step 12, rel. chg. shifts = 7.394137e-02 , rel. H2-norm chg. ROM = 3.710620e-02
IRKA step 13, rel. chg. shifts = 1.454364e-02 , rel. H2-norm chg. ROM = 1.654871e-02
IRKA step 14, rel. chg. shifts = 1.680084e+00 , rel. H2-norm chg. ROM = 9.279420e-03
IRKA step 15, rel. chg. shifts = 1.412799e-02 , rel. H2-norm chg. ROM = 6.742917e-03
IRKA step 16, rel. chg. shifts = 1.631372e+00 , rel. H2-norm chg. ROM = 5.549769e-03
IRKA step 17, rel. chg. shifts = 1.601840e+00 , rel. H2-norm chg. ROM = 5.858310e-03
IRKA step 18, rel. chg. shifts = 1.770883e-02 , rel. H2-norm chg. ROM = 6.032019e-03
IRKA step 19, rel. chg. shifts = 5.441607e-03 , rel. H2-norm chg. ROM = 6.539502e-03
IRKA step 20, rel. chg. shifts = 8.651545e-03 , rel. H2-norm chg. ROM = 7.087094e-03
Warning: IRKA: No convergence in 20 iterations.
Computing TFMs of original and reduced order systems and MOR errors
Step 10 / 100 Step 20 / 100 Step 30 / 100 Step 40 / 100 Step 50 / 100 Step 60 / 100 Step 70 / 100 Step 80 / 100 Step 90 / 100 Step 100 / 100
ans =
Columns 1 through 13
1 0 0 0 0 0 0 0 0 0 0 0 0
0 1 0 0 0 0 0 0 0 0 0 0 0
0 0 1 0 0 0 0 0 0 0 0 0 0
0 0 0 1 0 0 0 0 0 0 0 0 0
0 0 0 0 1 0 0 0 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0 0 0
0 0 0 0 0 0 1 0 0 0 0 0 0
0 0 0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 0 0 0 1 0 0 0 0
0 0 0 0 0 0 0 0 0 1 0 0 0
0 0 0 0 0 0 0 0 0 0 1 0 0
0 0 0 0 0 0 0 0 0 0 0 1 0
0 0 0 0 0 0 0 0 0 0 0 0 1
0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0
Columns 14 through 20
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
1 0 0 0 0 0 0
0 1 0 0 0 0 0
0 0 1 0 0 0 0
0 0 0 1 0 0 0
0 0 0 0 1 0 0
0 0 0 0 0 1 0
0 0 0 0 0 0 1