Actual source code: adaptdsp.c
1: #include <petsc/private/tsimpl.h>
2: #include <petscdm.h>
4: static const char *citation[] = {
5: "@article{Soderlind2003,\n"
6: " author = {S\"{o}derlind, Gustaf},\n"
7: " title = {Digital Filters in Adaptive Time-stepping},\n"
8: " journal = {ACM Transactions on Mathematical Software},\n"
9: " volume = {29},\n"
10: " number = {1},\n"
11: " pages = {1--26},\n"
12: " year = {2003},\n"
13: " issn = {0098-3500},\n"
14: " doi = {http://dx.doi.org/10.1145/641876.641877},\n"
15: "}\n",
16: "@article{Soderlind2006,\n"
17: " author = {Gustaf S\"{o}derlind and Lina Wang},\n"
18: " title = {Adaptive time-stepping and computational stability},\n"
19: " journal = {Journal of Computational and Applied Mathematics},\n"
20: " volume = {185},\n"
21: " number = {2},\n"
22: " pages = {225--243},\n"
23: " year = {2006},\n"
24: " issn = {0377-0427},\n"
25: " doi = {http://dx.doi.org/10.1016/j.cam.2005.03.008},\n"
26: "}\n",
27: };
28: static PetscBool cited[] = {PETSC_FALSE,PETSC_FALSE};
30: typedef struct {
31: PetscReal kBeta[3]; /* filter parameters */
32: PetscReal Alpha[2]; /* filter parameters */
33: PetscReal cerror[3]; /* control error (controller input) history */
34: PetscReal hratio[3]; /* stepsize ratio (controller output) history */
35: PetscBool rollback;
36: } TSAdapt_DSP;
38: static PetscReal Limiter(PetscReal value,PetscReal kappa)
39: {
40: return 1 + kappa*PetscAtanReal((value - 1)/kappa);
41: }
43: static PetscErrorCode TSAdaptRestart_DSP(TSAdapt adapt)
44: {
45: TSAdapt_DSP *dsp = (TSAdapt_DSP*)adapt->data;
47: dsp->cerror[0] = dsp->hratio[0] = 1.0;
48: dsp->cerror[1] = dsp->hratio[1] = 1.0;
49: dsp->cerror[2] = dsp->hratio[2] = 1.0;
50: return(0);
51: }
53: static PetscErrorCode TSAdaptRollBack_DSP(TSAdapt adapt)
54: {
55: TSAdapt_DSP *dsp = (TSAdapt_DSP*)adapt->data;
57: dsp->cerror[0] = dsp->cerror[1];
58: dsp->cerror[1] = dsp->cerror[2];
59: dsp->cerror[2] = 1.0;
60: dsp->hratio[0] = dsp->hratio[1];
61: dsp->hratio[1] = dsp->hratio[2];
62: dsp->hratio[2] = 1.0;
63: return(0);
64: }
66: static PetscErrorCode TSAdaptChoose_DSP(TSAdapt adapt,TS ts,PetscReal h,PetscInt *next_sc,PetscReal *next_h,PetscBool *accept,PetscReal *wlte,PetscReal *wltea,PetscReal *wlter)
67: {
68: TSAdapt_DSP *dsp = (TSAdapt_DSP*)adapt->data;
69: PetscInt order = PETSC_DECIDE;
70: PetscReal enorm = -1;
71: PetscReal enorma,enormr;
72: PetscReal safety = adapt->safety * (PetscReal)0.9;
73: PetscReal hnew,hfac = PETSC_INFINITY;
74: PetscReal hmin = adapt->dt_min*(1 + PETSC_SQRT_MACHINE_EPSILON);
78: *next_sc = 0; /* Reuse the same order scheme */
79: *wltea = -1; /* Weighted absolute local truncation error is not used */
80: *wlter = -1; /* Weighted relative local truncation error is not used */
82: if (ts->ops->evaluatewlte) {
83: TSEvaluateWLTE(ts,adapt->wnormtype,&order,&enorm);
84: if (enorm >= 0 && order < 1) SETERRQ1(PetscObjectComm((PetscObject)adapt),PETSC_ERR_ARG_OUTOFRANGE,"Computed error order %D must be positive",order);
85: } else if (ts->ops->evaluatestep) {
86: DM dm;
87: Vec Y;
89: if (adapt->candidates.n < 1) SETERRQ(PetscObjectComm((PetscObject)adapt),PETSC_ERR_ARG_WRONGSTATE,"No candidate has been registered");
90: if (!adapt->candidates.inuse_set) SETERRQ1(PetscObjectComm((PetscObject)adapt),PETSC_ERR_ARG_WRONGSTATE,"The current in-use scheme is not among the %D candidates",adapt->candidates.n);
91: order = adapt->candidates.order[0];
92: TSGetDM(ts,&dm);
93: DMGetGlobalVector(dm,&Y);
94: TSEvaluateStep(ts,order-1,Y,NULL);
95: TSErrorWeightedNorm(ts,ts->vec_sol,Y,adapt->wnormtype,&enorm,&enorma,&enormr);
96: DMRestoreGlobalVector(dm,&Y);
97: }
98: if (enorm < 0) {
99: TSAdaptRestart_DSP(adapt);
100: *accept = PETSC_TRUE; /* Accept the step */
101: *next_h = h; /* Reuse the old step size */
102: *wlte = -1; /* Weighted local truncation error was not evaluated */
103: return(0);
104: }
106: PetscCitationsRegister(citation[0],&cited[0]);
107: PetscCitationsRegister(citation[1],&cited[1]);
109: /* Update history after rollback */
110: if (!ts->steprollback)
111: dsp->rollback = PETSC_FALSE;
112: else if (!dsp->rollback) {
113: dsp->rollback = PETSC_TRUE;
114: TSAdaptRollBack_DSP(adapt);
115: }
116: /* Reset history after restart */
117: if (ts->steprestart) {
118: TSAdaptRestart_DSP(adapt);
119: }
121: {
122: PetscReal k = (PetscReal)order;
123: PetscReal b1 = dsp->kBeta[0];
124: PetscReal b2 = dsp->kBeta[1];
125: PetscReal b3 = dsp->kBeta[2];
126: PetscReal a2 = dsp->Alpha[0];
127: PetscReal a3 = dsp->Alpha[1];
129: PetscReal ctr0;
130: PetscReal ctr1 = dsp->cerror[0];
131: PetscReal ctr2 = dsp->cerror[1];
132: PetscReal rho0;
133: PetscReal rho1 = dsp->hratio[0];
134: PetscReal rho2 = dsp->hratio[1];
136: /* Compute the step size ratio */
137: enorm = PetscMax(enorm,PETSC_SMALL);
138: ctr0 = PetscPowReal(1/enorm,1/k);
139: rho0 = PetscPowReal(ctr0,b1);
140: rho0 *= PetscPowReal(ctr1,b2);
141: rho0 *= PetscPowReal(ctr2,b3);
142: rho0 *= PetscPowReal(rho1,-a2);
143: rho0 *= PetscPowReal(rho2,-a3);
144: rho0 = Limiter(rho0,1);
146: /* Determine whether the step is accepted or rejected */
147: if (rho0 >= safety)
148: *accept = PETSC_TRUE;
149: else if (adapt->always_accept)
150: *accept = PETSC_TRUE;
151: else if (h < hmin)
152: *accept = PETSC_TRUE;
153: else
154: *accept = PETSC_FALSE;
156: /* Update history after accept */
157: if (*accept) {
158: dsp->cerror[2] = dsp->cerror[1];
159: dsp->cerror[1] = dsp->cerror[0];
160: dsp->cerror[0] = ctr0;
161: dsp->hratio[2] = dsp->hratio[1];
162: dsp->hratio[1] = dsp->hratio[0];
163: dsp->hratio[0] = rho0;
164: dsp->rollback = PETSC_FALSE;
165: }
167: hfac = rho0;
168: }
170: hnew = h * PetscClipInterval(hfac,adapt->clip[0],adapt->clip[1]);
171: *next_h = PetscClipInterval(hnew,adapt->dt_min,adapt->dt_max);
172: *wlte = enorm;
173: return(0);
174: }
176: static PetscErrorCode TSAdaptDestroy_DSP(TSAdapt adapt)
177: {
181: PetscObjectComposeFunction((PetscObject)adapt,"TSAdaptDSPSetFilter_C",NULL);
182: PetscObjectComposeFunction((PetscObject)adapt,"TSAdaptDSPSetPID_C",NULL);
183: PetscFree(adapt->data);
184: return(0);
185: }
187: static PetscErrorCode TSAdaptView_DSP(TSAdapt adapt,PetscViewer viewer)
188: {
189: TSAdapt_DSP *dsp = (TSAdapt_DSP*)adapt->data;
190: PetscBool iascii;
194: PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
195: if (iascii) {
196: double a2 = (double)dsp->Alpha[0], a3 = (double)dsp->Alpha[1];
197: double b1 = (double)dsp->kBeta[0], b2 = (double)dsp->kBeta[1], b3 = (double)dsp->kBeta[2];
198: PetscViewerASCIIPrintf(viewer,"filter parameters kBeta=[%g,%g,%g] Alpha=[%g,%g]\n",b1,b2,b3,a2,a3);
199: }
200: return(0);
201: }
203: struct FilterTab {
204: const char *name;
205: PetscReal scale;
206: PetscReal kBeta[3];
207: PetscReal Alpha[2];
208: };
210: static struct FilterTab filterlist[] = {
211: {"basic", 1, { 1, 0, 0 }, { 0, 0 }},
213: {"PI30", 3, { 1, 0, 0 }, { 0, 0 }},
214: {"PI42", 5, { 3, -1, 0 }, { 0, 0 }},
215: {"PI33", 3, { 2, -1, 0 }, { 0, 0 }},
216: {"PI34", 10, { 7, -4, 0 }, { 0, 0 }},
218: {"PC11", 1, { 2, -1, 0 }, { -1, 0 }},
219: {"PC47", 10, { 11, -7, 0 }, { -10, 0 }},
220: {"PC36", 10, { 9, -6, 0 }, { -10, 0 }},
222: {"H0211", 2, { 1, 1, 0 }, { 1, 0 }},
223: {"H211b", 4, { 1, 1, 0 }, { 1, 0 }},
224: {"H211PI", 6, { 1, 1, 0 }, { 0, 0 }},
226: {"H0312", 4, { 1, 2, 1 }, { 3, 1 }},
227: {"H312b", 8, { 1, 2, 1 }, { 3, 1 }},
228: {"H312PID", 18, { 1, 2, 1 }, { 0, 0 }},
230: {"H0321", 4, { 5, 2, -3 }, { -1, -3 }},
231: {"H321", 18, { 6, 1, -5 }, { -15, -3 }},
232: };
234: static PetscErrorCode TSAdaptDSPSetFilter_DSP(TSAdapt adapt,const char *name)
235: {
236: TSAdapt_DSP *dsp = (TSAdapt_DSP*)adapt->data;
237: PetscInt i,count = (PetscInt)(sizeof(filterlist)/sizeof(filterlist[0]));
238: struct FilterTab* tab = NULL;
239: PetscBool match;
240: PetscErrorCode ierr;
243: for (i=0; i<count; i++) {
244: PetscStrcasecmp(name,filterlist[i].name,&match);
245: if (match) { tab = &filterlist[i]; break; }
246: }
247: if (!tab) SETERRQ1(PetscObjectComm((PetscObject)adapt),PETSC_ERR_ARG_UNKNOWN_TYPE,"Filter name %s not found",name);
248: dsp->kBeta[0] = tab->kBeta[0]/tab->scale;
249: dsp->kBeta[1] = tab->kBeta[1]/tab->scale;
250: dsp->kBeta[2] = tab->kBeta[2]/tab->scale;
251: dsp->Alpha[0] = tab->Alpha[0]/tab->scale;
252: dsp->Alpha[1] = tab->Alpha[1]/tab->scale;
253: return(0);
254: }
256: static PetscErrorCode TSAdaptDSPSetPID_DSP(TSAdapt adapt,PetscReal kkI,PetscReal kkP,PetscReal kkD)
257: {
258: TSAdapt_DSP *dsp = (TSAdapt_DSP*)adapt->data;
261: dsp->kBeta[0] = kkI + kkP + kkD;
262: dsp->kBeta[1] = -(kkP + 2*kkD);
263: dsp->kBeta[2] = kkD;
264: dsp->Alpha[0] = 0;
265: dsp->Alpha[1] = 0;
266: return(0);
267: }
269: static PetscErrorCode TSAdaptSetFromOptions_DSP(PetscOptionItems *PetscOptionsObject,TSAdapt adapt)
270: {
271: TSAdapt_DSP *dsp = (TSAdapt_DSP*)adapt->data;
272: const char *names[sizeof(filterlist)/sizeof(filterlist[0])];
273: PetscInt count = (PetscInt)(sizeof(filterlist)/sizeof(filterlist[0]));
274: PetscInt index = 2; /* PI42 */
275: PetscReal pid[3] = {1,0,0};
276: PetscInt i,n;
277: PetscBool set;
281: for (i=0; i<count; i++) names[i] = filterlist[i].name;
282: PetscOptionsHead(PetscOptionsObject,"DSP adaptive controller options");
284: PetscOptionsEList("-ts_adapt_dsp_filter","Filter name","TSAdaptDSPSetFilter",names,count,names[index],&index,&set);
285: if (set) { TSAdaptDSPSetFilter(adapt,names[index]);}
287: PetscOptionsRealArray("-ts_adapt_dsp_pid","PID parameters <kkI,kkP,kkD>","TSAdaptDSPSetPID",pid,(n=3,&n),&set);
288: if (set && !n) SETERRQ(PetscObjectComm((PetscObject)adapt),PETSC_ERR_ARG_WRONG,"Must provide at least one value for PID parameters");
289: if (set) {TSAdaptDSPSetPID(adapt,pid[0],pid[1],pid[2]);}
291: PetscOptionsRealArray("-ts_adapt_dsp_kbeta","Filter parameters","",dsp->kBeta,(n=3,&n),&set);
292: if (set && !n) SETERRQ(PetscObjectComm((PetscObject)adapt),PETSC_ERR_ARG_WRONG,"Must provide at least one value for parameter kbeta");
293: if (set) for (i=n; i<3; i++) dsp->kBeta[i] = 0;
295: PetscOptionsRealArray("-ts_adapt_dsp_alpha","Filter parameters","",dsp->Alpha,(n=2,&n),&set);
296: if (set && !n) SETERRQ(PetscObjectComm((PetscObject)adapt),PETSC_ERR_ARG_WRONG,"Must provide at least one value for parameter alpha");
297: if (set) for (i=n; i<2; i++) dsp->Alpha[i] = 0;
299: PetscOptionsTail();
300: return(0);
301: }
303: /*@C
304: TSAdaptDSPSetFilter - Sets internal parameters corresponding to the named filter
306: Collective on TSAdapt
308: Input Parameters:
309: + adapt - adaptive controller context
310: - name - filter name
312: Level: intermediate
314: References: http://dx.doi.org/10.1145/641876.641877
316: Notes:
317: Valid filter names are
318: + "basic" - similar to TSADAPTBASIC but with different criteria for step rejections.
319: . "PI30", "PI42", "PI33", "PI34" - PI controllers.
320: . "PC11", "PC47", "PC36" - predictive controllers.
321: . "H0211", "H211b", "H211PI" - digital filters with orders dynamics=2, adaptivity=1, filter=1.
322: . "H0312", "H312b", "H312PID" - digital filters with orders dynamics=3, adaptivity=1, filter=2.
323: - "H0321", "H321" - digital filters with orders dynamics=3, adaptivity=2, filter=1.
325: Options Database:
326: . -ts_adapt_dsp_filter <name> - Sets predefined controller by name; use -help for a list of available controllers
328: .seealso: TS, TSAdapt, TSGetAdapt(), TSAdaptDSPSetPID()
329: @*/
330: PetscErrorCode TSAdaptDSPSetFilter(TSAdapt adapt,const char *name)
331: {
336: PetscTryMethod(adapt,"TSAdaptDSPSetFilter_C",(TSAdapt,const char*),(adapt,name));
337: return(0);
338: }
340: /*@
341: TSAdaptDSPSetPID - Set the PID controller parameters
343: Input Parameters:
344: + adapt - adaptive controller context
345: . kkI - Integral parameter
346: . kkP - Proportional parameter
347: - kkD - Derivative parameter
349: Level: intermediate
351: References: http://dx.doi.org/10.1016/j.cam.2005.03.008
353: Options Database:
354: . -ts_adapt_dsp_pid <kkI,kkP,kkD> - Sets PID controller parameters
356: .seealso: TS, TSAdapt, TSGetAdapt(), TSAdaptDSPSetFilter()
357: @*/
358: PetscErrorCode TSAdaptDSPSetPID(TSAdapt adapt,PetscReal kkI,PetscReal kkP,PetscReal kkD)
359: {
366: PetscTryMethod(adapt,"TSAdaptDSPSetPID_C",(TSAdapt,PetscReal,PetscReal,PetscReal),(adapt,kkI,kkP,kkD));
367: return(0);
368: }
370: /*MC
371: TSADAPTDSP - Adaptive controller for time-stepping based on digital signal processing (DSP)
373: Level: intermediate
375: References: http://dx.doi.org/10.1145/641876.641877 and http://dx.doi.org/10.1016/j.cam.2005.03.008
377: Options Database:
378: + -ts_adapt_dsp_filter <name> - Sets predefined controller by name; use -help for a list of available controllers
379: . -ts_adapt_dsp_pid <kkI,kkP,kkD> - Sets PID controller parameters
380: . -ts_adapt_dsp_kbeta <b1,b2,b2> - Sets general filter parameters
381: - -ts_adapt_dsp_alpha <a2,a3> - Sets general filter parameters
383: .seealso: TS, TSAdapt, TSGetAdapt(), TSAdaptDSPSetPID(), TSAdaptDSPSetFilter()
384: M*/
385: PETSC_EXTERN PetscErrorCode TSAdaptCreate_DSP(TSAdapt adapt)
386: {
387: TSAdapt_DSP *dsp;
391: PetscNewLog(adapt,&dsp);
392: adapt->reject_safety = 1.0; /* unused */
394: adapt->data = (void*)dsp;
395: adapt->ops->choose = TSAdaptChoose_DSP;
396: adapt->ops->setfromoptions = TSAdaptSetFromOptions_DSP;
397: adapt->ops->destroy = TSAdaptDestroy_DSP;
398: adapt->ops->view = TSAdaptView_DSP;
400: PetscObjectComposeFunction((PetscObject)adapt,"TSAdaptDSPSetFilter_C",TSAdaptDSPSetFilter_DSP);
401: PetscObjectComposeFunction((PetscObject)adapt,"TSAdaptDSPSetPID_C",TSAdaptDSPSetPID_DSP);
403: TSAdaptDSPSetFilter_DSP(adapt,"PI42");
404: TSAdaptRestart_DSP(adapt);
405: return(0);
406: }