1 /*
2 
3 Copyright (C) 2009-2016   Lukas F. Reichlin
4 
5 This file is part of LTI Syncope.
6 
7 LTI Syncope is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
11 
12 LTI Syncope is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 GNU General Public License for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with LTI Syncope.  If not, see <http://www.gnu.org/licenses/>.
19 
20 Model reduction based on Hankel-norm approximation method.
21 Uses SLICOT AB09JD by courtesy of NICONET e.V.
22 <http://www.slicot.org>
23 
24 Author: Lukas Reichlin <lukas.reichlin@gmail.com>
25 Created: July 2011
26 Version: 0.2
27 
28 */
29 
30 #include <octave/oct.h>
31 #include "common.h"
32 
33 extern "C"
34 {
35     int F77_FUNC (ab09jd, AB09JD)
36                  (char& JOBV, char& JOBW, char& JOBINV,
37                   char& DICO, char& EQUIL, char& ORDSEL,
38                   F77_INT& N, F77_INT& NV, F77_INT& NW, F77_INT& M, F77_INT& P,
39                   F77_INT& NR,
40                   double& ALPHA,
41                   double* A, F77_INT& LDA,
42                   double* B, F77_INT& LDB,
43                   double* C, F77_INT& LDC,
44                   double* D, F77_INT& LDD,
45                   double* AV, F77_INT& LDAV,
46                   double* BV, F77_INT& LDBV,
47                   double* CV, F77_INT& LDCV,
48                   double* DV, F77_INT& LDDV,
49                   double* AW, F77_INT& LDAW,
50                   double* BW, F77_INT& LDBW,
51                   double* CW, F77_INT& LDCW,
52                   double* DW, F77_INT& LDDW,
53                   F77_INT& NS,
54                   double* HSV,
55                   double& TOL1, double& TOL2,
56                   F77_INT* IWORK,
57                   double* DWORK, F77_INT& LDWORK,
58                   F77_INT& IWARN, F77_INT& INFO);
59 }
60 
61 // PKG_ADD: autoload ("__sl_ab09jd__", "__control_slicot_functions__.oct");
62 DEFUN_DLD (__sl_ab09jd__, args, nargout,
63    "-*- texinfo -*-\n\
64 Slicot AB09JD Release 5.0\n\
65 No argument checking.\n\
66 For internal use only.")
67 {
68     octave_idx_type nargin = args.length ();
69     octave_value_list retval;
70 
71     if (nargin != 22)
72     {
73         print_usage ();
74     }
75     else
76     {
77         // arguments in
78         char jobv;
79         char jobw;
80         char jobinv;
81         char dico;
82         char equil;
83         char ordsel;
84 
85         Matrix a = args(0).matrix_value ();
86         Matrix b = args(1).matrix_value ();
87         Matrix c = args(2).matrix_value ();
88         Matrix d = args(3).matrix_value ();
89 
90         const F77_INT idico = args(4).int_value ();
91         const F77_INT iequil = args(5).int_value ();
92         F77_INT nr = args(6).int_value ();
93         const F77_INT iordsel = args(7).int_value ();
94         double alpha = args(8).double_value ();
95 
96         const F77_INT ijobv = args(9).int_value ();
97         Matrix av = args(10).matrix_value ();
98         Matrix bv = args(11).matrix_value ();
99         Matrix cv = args(12).matrix_value ();
100         Matrix dv = args(13).matrix_value ();
101 
102         const F77_INT ijobw = args(14).int_value ();
103         Matrix aw = args(15).matrix_value ();
104         Matrix bw = args(16).matrix_value ();
105         Matrix cw = args(17).matrix_value ();
106         Matrix dw = args(18).matrix_value ();
107 
108         const F77_INT ijobinv = args(19).int_value ();
109         double tol1 = args(20).double_value ();
110         double tol2 = args(21).double_value ();
111 
112         switch (ijobv)
113         {
114             case 0:
115                 jobv = 'N';
116                 break;
117             case 1:
118                 jobv = 'V';
119                 break;
120             case 2:
121                 jobv = 'I';
122                 break;
123             case 3:
124                 jobv = 'C';
125                 break;
126             case 4:
127                 jobv = 'R';
128                 break;
129             default:
130                 error ("__sl_ab09jd__: argument jobv invalid");
131         }
132 
133         switch (ijobw)
134         {
135             case 0:
136                 jobw = 'N';
137                 break;
138             case 1:
139                 jobw = 'W';
140                 break;
141             case 2:
142                 jobw = 'I';
143                 break;
144             case 3:
145                 jobw = 'C';
146                 break;
147             case 4:
148                 jobw = 'R';
149                 break;
150             default:
151                 error ("__sl_ab09jd__: argument jobw invalid");
152         }
153 
154         switch (ijobinv)
155         {
156             case 0:
157                 jobinv = 'N';
158                 break;
159             case 1:
160                 jobinv = 'I';
161                 break;
162             case 2:
163                 jobinv = 'A';
164                 break;
165             default:
166                 error ("__sl_ab09jd__: argument jobinv invalid");
167         }
168 
169         if (idico == 0)
170             dico = 'C';
171         else
172             dico = 'D';
173 
174         if (iequil == 0)
175             equil = 'S';
176         else
177             equil = 'N';
178 
179         if (iordsel == 0)
180             ordsel = 'F';
181         else
182             ordsel = 'A';
183 
184         F77_INT n = TO_F77_INT (a.rows ());      // n: number of states
185         F77_INT nv = TO_F77_INT (av.rows ());
186         F77_INT nw = TO_F77_INT (aw.rows ());
187         F77_INT m = TO_F77_INT (b.columns ());   // m: number of inputs
188         F77_INT p = TO_F77_INT (c.rows ());      // p: number of outputs
189 
190         F77_INT lda = max (1, n);
191         F77_INT ldb = max (1, n);
192         F77_INT ldc = max (1, p);
193         F77_INT ldd = max (1, p);
194 
195         F77_INT ldav = max (1, nv);
196         F77_INT ldbv = max (1, nv);
197         F77_INT ldcv = max (1, p);
198         F77_INT lddv = max (1, p);
199 
200         F77_INT ldaw = max (1, nw);
201         F77_INT ldbw = max (1, nw);
202         F77_INT ldcw = max (1, m);
203         F77_INT lddw = max (1, m);
204 
205         // arguments out
206         F77_INT ns;
207         ColumnVector hsv (n);
208 
209         // workspace
210         F77_INT liwork;
211         F77_INT tmpc;
212         F77_INT tmpd;
213 
214         if (jobv == 'N')
215             tmpc = 0;
216         else
217             tmpc = max (2*p, nv+p+n+6, 2*nv+p+2);
218 
219         if (jobw == 'N')
220             tmpd = 0;
221         else
222             tmpd = max (2*m, nw+m+n+6, 2*nw+m+2);
223 
224         if (dico == 'C')
225             liwork = max (1, m, tmpc, tmpd);
226         else
227             liwork = max (1, n, m, tmpc, tmpd);
228 
229         F77_INT ldwork;
230         F77_INT nvp = nv + p;
231         F77_INT nwm = nw + m;
232         F77_INT ldw1;
233         F77_INT ldw2;
234         F77_INT ldw3 = n*(2*n + max (n, m, p) + 5) + n*(n+1)/2;
235         F77_INT ldw4 = n*(m+p+2) + 2*m*p + min (n, m) + max (3*m+1, min (n, m) + p);
236 
237         if (jobv == 'N')
238         {
239             ldw1 = 0;
240         }
241         else
242         {
243             ldw1 = 2*nvp*(nvp+p) + p*p + max (2*nvp*nvp + max (11*nvp+16, p*nvp),
244                                               nvp*n + max (nvp*n+n*n, p*n, p*m));
245         }
246 
247         if (jobw == 'N')
248         {
249             ldw2 = 0;
250         }
251         else
252         {
253             ldw2 = 2*nwm*(nwm+m) + m*m + max (2*nwm*nwm + max (11*nwm+16, m*nwm),
254                                               nwm*n + max (nwm*n+n*n, m*n, p*m));
255         }
256 
257         ldwork = max (ldw1, ldw2, ldw3, ldw4);
258 
259         OCTAVE_LOCAL_BUFFER (F77_INT, iwork, liwork);
260         OCTAVE_LOCAL_BUFFER (double, dwork, ldwork);
261 
262         // error indicators
263         F77_INT iwarn = 0;
264         F77_INT info = 0;
265 
266 
267         // SLICOT routine AB09JD
268         F77_XFCN (ab09jd, AB09JD,
269                  (jobv, jobw, jobinv,
270                   dico, equil, ordsel,
271                   n, nv, nw, m, p,
272                   nr,
273                   alpha,
274                   a.fortran_vec (), lda,
275                   b.fortran_vec (), ldb,
276                   c.fortran_vec (), ldc,
277                   d.fortran_vec (), ldd,
278                   av.fortran_vec (), ldav,
279                   bv.fortran_vec (), ldbv,
280                   cv.fortran_vec (), ldcv,
281                   dv.fortran_vec (), lddv,
282                   aw.fortran_vec (), ldaw,
283                   bw.fortran_vec (), ldbw,
284                   cw.fortran_vec (), ldcw,
285                   dw.fortran_vec (), lddw,
286                   ns,
287                   hsv.fortran_vec (),
288                   tol1, tol2,
289                   iwork,
290                   dwork, ldwork,
291                   iwarn, info));
292 
293         if (f77_exception_encountered)
294             error ("hnamodred: exception in SLICOT subroutine AB09JD");
295 
296 
297         static const char* err_msg[] = {
298             "0: OK",
299             "1: the computation of the ordered real Schur form of A "
300                 "failed",
301 
302             "2: the separation of the ALPHA-stable/unstable "
303                 "diagonal blocks failed because of very close eigenvalues",
304 
305             "3: the reduction of AV to a real Schur form failed",
306 
307             "4: the reduction of AW to a real Schur form failed",
308 
309             "5: the reduction to generalized Schur form of the "
310                 "descriptor pair corresponding to the inverse of V "
311                 "failed",
312 
313             "6: the reduction to generalized Schur form of the "
314                 "descriptor pair corresponding to the inverse of W "
315                 "failed",
316 
317             "7: the computation of Hankel singular values failed",
318 
319             "8: the computation of stable projection in the "
320                 "Hankel-norm approximation algorithm failed",
321 
322             "9: the order of computed stable projection in the "
323                 "Hankel-norm approximation algorithm differs "
324                 "from the order of Hankel-norm approximation",
325 
326             "10: the reduction of AV-BV*inv(DV)*CV to a "
327                 "real Schur form failed",
328 
329             "11: the reduction of AW-BW*inv(DW)*CW to a "
330                 "real Schur form failed",
331 
332             "12: the solution of the Sylvester equation failed "
333                 "because the poles of V (if JOBV = 'V') or of "
334                 "conj(V) (if JOBV = 'C') are not distinct from "
335                 "the poles of G1 (see METHOD)",
336 
337             "13: the solution of the Sylvester equation failed "
338                 "because the poles of W (if JOBW = 'W') or of "
339                 "conj(W) (if JOBW = 'C') are not distinct from "
340                 "the poles of G1 (see METHOD)",
341 
342             "14: the solution of the Sylvester equation failed "
343                 "because the zeros of V (if JOBV = 'I') or of "
344                 "conj(V) (if JOBV = 'R') are not distinct from "
345                 "the poles of G1sr (see METHOD)",
346 
347             "15: the solution of the Sylvester equation failed "
348                 "because the zeros of W (if JOBW = 'I') or of "
349                 "conj(W) (if JOBW = 'R') are not distinct from "
350                 "the poles of G1sr (see METHOD)",
351 
352             "16: the solution of the generalized Sylvester system "
353                 "failed because the zeros of V (if JOBV = 'I') or "
354                 "of conj(V) (if JOBV = 'R') are not distinct from "
355                 "the poles of G1sr (see METHOD)",
356 
357             "17: the solution of the generalized Sylvester system "
358                 "failed because the zeros of W (if JOBW = 'I') or "
359                 "of conj(W) (if JOBW = 'R') are not distinct from "
360                 "the poles of G1sr (see METHOD)",
361 
362             "18: op(V) is not antistable",
363 
364             "19: op(W) is not antistable",
365 
366             "20: V is not invertible",
367 
368             "21: W is not invertible"};
369 
370         static const char* warn_msg[] = {
371             "0: OK",
372             "1: with ORDSEL = 'F', the selected order NR is greater "
373                 "than NSMIN, the sum of the order of the "
374                 "ALPHA-unstable part and the order of a minimal "
375                 "realization of the ALPHA-stable part of the given "
376                 "system. In this case, the resulting NR is set equal "
377                 "to NSMIN.",
378             "2: with ORDSEL = 'F', the selected order NR is less "
379                 "than the order of the ALPHA-unstable part of the "
380                 "given system. In this case NR is set equal to the "
381                 "order of the ALPHA-unstable part."};
382 
383         error_msg ("hnamodred", info, 21, err_msg);
384         warning_msg ("hnamodred", iwarn, 2, warn_msg);
385 
386         // resize
387         a.resize (nr, nr);
388         b.resize (nr, m);
389         c.resize (p, nr);
390         hsv.resize (ns);
391 
392         // return values
393         retval(0) = a;
394         retval(1) = b;
395         retval(2) = c;
396         retval(3) = d;
397         retval(4) = octave_value (nr);
398         retval(5) = hsv;
399         retval(6) = octave_value (ns);
400     }
401 
402     return retval;
403 }
404