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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 1234
Committed: Fri Jun 4 03:15:31 2004 UTC (20 years, 1 month ago) by tim
File size: 18956 byte(s)
Log Message:
new rattle algorithm is working

File Contents

# Content
1 #include <iostream>
2 #include <stdlib.h>
3 #include <math.h>
4 #include "Rattle.hpp"
5 #ifdef IS_MPI
6 #include "mpiSimulation.hpp"
7 #include <unistd.h>
8 #endif //is_mpi
9
10 #ifdef PROFILE
11 #include "mdProfile.hpp"
12 #endif // profile
13
14 #include "Integrator.hpp"
15 #include "simError.h"
16
17
18 template<typename T> Integrator<T>::Integrator(SimInfo* theInfo,
19 ForceFields* the_ff){
20 info = theInfo;
21 myFF = the_ff;
22 isFirst = 1;
23
24 molecules = info->molecules;
25 nMols = info->n_mol;
26
27 // give a little love back to the SimInfo object
28
29 if (info->the_integrator != NULL){
30 delete info->the_integrator;
31 }
32
33 nAtoms = info->n_atoms;
34 integrableObjects = info->integrableObjects;
35
36 rattle = new RattleFramework(info);
37
38 if(rattle == NULL){
39 sprintf(painCave.errMsg,
40 "Integrator::Intergrator() Error: Memory allocation error for RattleFramework" );
41 painCave.isFatal = 1;
42 simError();
43 }
44
45 /*
46 // check for constraints
47
48 constrainedA = NULL;
49 constrainedB = NULL;
50 constrainedDsqr = NULL;
51 moving = NULL;
52 moved = NULL;
53 oldPos = NULL;
54
55 nConstrained = 0;
56
57 checkConstraints();
58 */
59 }
60
61 template<typename T> Integrator<T>::~Integrator(){
62 if (rattle != NULL)
63 delete rattle;
64 /*
65 if (nConstrained){
66 delete[] constrainedA;
67 delete[] constrainedB;
68 delete[] constrainedDsqr;
69 delete[] moving;
70 delete[] moved;
71 delete[] oldPos;
72 }
73 */
74 }
75
76 /*
77 template<typename T> void Integrator<T>::checkConstraints(void){
78 isConstrained = 0;
79
80 Constraint* temp_con;
81 Constraint* dummy_plug;
82 temp_con = new Constraint[info->n_SRI];
83 nConstrained = 0;
84 int constrained = 0;
85
86 SRI** theArray;
87 for (int i = 0; i < nMols; i++){
88
89 theArray = (SRI * *) molecules[i].getMyBonds();
90 for (int j = 0; j < molecules[i].getNBonds(); j++){
91 constrained = theArray[j]->is_constrained();
92
93 if (constrained){
94 dummy_plug = theArray[j]->get_constraint();
95 temp_con[nConstrained].set_a(dummy_plug->get_a());
96 temp_con[nConstrained].set_b(dummy_plug->get_b());
97 temp_con[nConstrained].set_dsqr(dummy_plug->get_dsqr());
98
99 nConstrained++;
100 constrained = 0;
101 }
102 }
103
104 theArray = (SRI * *) molecules[i].getMyBends();
105 for (int j = 0; j < molecules[i].getNBends(); j++){
106 constrained = theArray[j]->is_constrained();
107
108 if (constrained){
109 dummy_plug = theArray[j]->get_constraint();
110 temp_con[nConstrained].set_a(dummy_plug->get_a());
111 temp_con[nConstrained].set_b(dummy_plug->get_b());
112 temp_con[nConstrained].set_dsqr(dummy_plug->get_dsqr());
113
114 nConstrained++;
115 constrained = 0;
116 }
117 }
118
119 theArray = (SRI * *) molecules[i].getMyTorsions();
120 for (int j = 0; j < molecules[i].getNTorsions(); j++){
121 constrained = theArray[j]->is_constrained();
122
123 if (constrained){
124 dummy_plug = theArray[j]->get_constraint();
125 temp_con[nConstrained].set_a(dummy_plug->get_a());
126 temp_con[nConstrained].set_b(dummy_plug->get_b());
127 temp_con[nConstrained].set_dsqr(dummy_plug->get_dsqr());
128
129 nConstrained++;
130 constrained = 0;
131 }
132 }
133 }
134
135
136 if (nConstrained > 0){
137 isConstrained = 1;
138
139 if (constrainedA != NULL)
140 delete[] constrainedA;
141 if (constrainedB != NULL)
142 delete[] constrainedB;
143 if (constrainedDsqr != NULL)
144 delete[] constrainedDsqr;
145
146 constrainedA = new int[nConstrained];
147 constrainedB = new int[nConstrained];
148 constrainedDsqr = new double[nConstrained];
149
150 for (int i = 0; i < nConstrained; i++){
151 constrainedA[i] = temp_con[i].get_a();
152 constrainedB[i] = temp_con[i].get_b();
153 constrainedDsqr[i] = temp_con[i].get_dsqr();
154 }
155
156
157 // save oldAtoms to check for lode balancing later on.
158
159 oldAtoms = nAtoms;
160
161 moving = new int[nAtoms];
162 moved = new int[nAtoms];
163
164 oldPos = new double[nAtoms * 3];
165 }
166
167 delete[] temp_con;
168 }
169 */
170
171 template<typename T> void Integrator<T>::integrate(void){
172
173 double runTime = info->run_time;
174 double sampleTime = info->sampleTime;
175 double statusTime = info->statusTime;
176 double thermalTime = info->thermalTime;
177 double resetTime = info->resetTime;
178
179 double difference;
180 double currSample;
181 double currThermal;
182 double currStatus;
183 double currReset;
184
185 int calcPot, calcStress;
186
187 tStats = new Thermo(info);
188 statOut = new StatWriter(info);
189 dumpOut = new DumpWriter(info);
190
191 atoms = info->atoms;
192
193 dt = info->dt;
194 dt2 = 0.5 * dt;
195
196 readyCheck();
197
198 // remove center of mass drift velocity (in case we passed in a configuration
199 // that was drifting
200 tStats->removeCOMdrift();
201
202 // initialize the retraints if necessary
203 if (info->useSolidThermInt && !info->useLiquidThermInt) {
204 myFF->initRestraints();
205 }
206
207 // initialize the forces before the first step
208
209 calcForce(1, 1);
210
211 //execute constraint algorithm to make sure at the very beginning the system is constrained
212 rattle->doPreConstraint();
213 rattle->doRattleA();
214 calcForce(1, 1);
215 rattle->doRattleB();
216
217 if (info->setTemp){
218 thermalize();
219 }
220
221 calcPot = 0;
222 calcStress = 0;
223 currSample = sampleTime + info->getTime();
224 currThermal = thermalTime+ info->getTime();
225 currStatus = statusTime + info->getTime();
226 currReset = resetTime + info->getTime();
227
228 dumpOut->writeDump(info->getTime());
229 statOut->writeStat(info->getTime());
230
231
232 #ifdef IS_MPI
233 strcpy(checkPointMsg, "The integrator is ready to go.");
234 MPIcheckPoint();
235 #endif // is_mpi
236
237 while (info->getTime() < runTime && !stopIntegrator()){
238 difference = info->getTime() + dt - currStatus;
239 if (difference > 0 || fabs(difference) < 1e-4 ){
240 calcPot = 1;
241 calcStress = 1;
242 }
243
244 #ifdef PROFILE
245 startProfile( pro1 );
246 #endif
247
248 integrateStep(calcPot, calcStress);
249
250 #ifdef PROFILE
251 endProfile( pro1 );
252
253 startProfile( pro2 );
254 #endif // profile
255
256 info->incrTime(dt);
257
258 if (info->setTemp){
259 if (info->getTime() >= currThermal){
260 thermalize();
261 currThermal += thermalTime;
262 }
263 }
264
265 if (info->getTime() >= currSample){
266 dumpOut->writeDump(info->getTime());
267 currSample += sampleTime;
268 }
269
270 if (info->getTime() >= currStatus){
271 statOut->writeStat(info->getTime());
272 calcPot = 0;
273 calcStress = 0;
274 currStatus += statusTime;
275 }
276
277 if (info->resetIntegrator){
278 if (info->getTime() >= currReset){
279 this->resetIntegrator();
280 currReset += resetTime;
281 }
282 }
283
284 #ifdef PROFILE
285 endProfile( pro2 );
286 #endif //profile
287
288 #ifdef IS_MPI
289 strcpy(checkPointMsg, "successfully took a time step.");
290 MPIcheckPoint();
291 #endif // is_mpi
292 }
293
294 // dump out a file containing the omega values for the final configuration
295 if (info->useSolidThermInt && !info->useLiquidThermInt)
296 myFF->dumpzAngle();
297
298
299 delete dumpOut;
300 delete statOut;
301 }
302
303 template<typename T> void Integrator<T>::integrateStep(int calcPot,
304 int calcStress){
305 // Position full step, and velocity half step
306
307 #ifdef PROFILE
308 startProfile(pro3);
309 #endif //profile
310
311 //save old state (position, velocity etc)
312 rattle->doPreConstraint();
313
314 #ifdef PROFILE
315 endProfile(pro3);
316
317 startProfile(pro4);
318 #endif // profile
319
320 moveA();
321
322 #ifdef PROFILE
323 endProfile(pro4);
324
325 startProfile(pro5);
326 #endif//profile
327
328
329 #ifdef IS_MPI
330 strcpy(checkPointMsg, "Succesful moveA\n");
331 MPIcheckPoint();
332 #endif // is_mpi
333
334 // calc forces
335 calcForce(calcPot, calcStress);
336
337 #ifdef IS_MPI
338 strcpy(checkPointMsg, "Succesful doForces\n");
339 MPIcheckPoint();
340 #endif // is_mpi
341
342 #ifdef PROFILE
343 endProfile( pro5 );
344
345 startProfile( pro6 );
346 #endif //profile
347
348 // finish the velocity half step
349
350 moveB();
351
352 #ifdef PROFILE
353 endProfile(pro6);
354 #endif // profile
355
356 #ifdef IS_MPI
357 strcpy(checkPointMsg, "Succesful moveB\n");
358 MPIcheckPoint();
359 #endif // is_mpi
360 }
361
362
363 template<typename T> void Integrator<T>::moveA(void){
364 size_t i, j;
365 DirectionalAtom* dAtom;
366 double Tb[3], ji[3];
367 double vel[3], pos[3], frc[3];
368 double mass;
369 double omega;
370
371 for (i = 0; i < integrableObjects.size() ; i++){
372 integrableObjects[i]->getVel(vel);
373 integrableObjects[i]->getPos(pos);
374 integrableObjects[i]->getFrc(frc);
375
376 mass = integrableObjects[i]->getMass();
377
378 for (j = 0; j < 3; j++){
379 // velocity half step
380 vel[j] += (dt2 * frc[j] / mass) * eConvert;
381 // position whole step
382 pos[j] += dt * vel[j];
383 }
384
385 integrableObjects[i]->setVel(vel);
386 integrableObjects[i]->setPos(pos);
387
388 if (integrableObjects[i]->isDirectional()){
389
390 // get and convert the torque to body frame
391
392 integrableObjects[i]->getTrq(Tb);
393 integrableObjects[i]->lab2Body(Tb);
394
395 // get the angular momentum, and propagate a half step
396
397 integrableObjects[i]->getJ(ji);
398
399 for (j = 0; j < 3; j++)
400 ji[j] += (dt2 * Tb[j]) * eConvert;
401
402 this->rotationPropagation( integrableObjects[i], ji );
403
404 integrableObjects[i]->setJ(ji);
405 }
406 }
407
408 rattle->doRattleA();
409 }
410
411
412 template<typename T> void Integrator<T>::moveB(void){
413 int i, j;
414 double Tb[3], ji[3];
415 double vel[3], frc[3];
416 double mass;
417
418 for (i = 0; i < integrableObjects.size(); i++){
419 integrableObjects[i]->getVel(vel);
420 integrableObjects[i]->getFrc(frc);
421
422 mass = integrableObjects[i]->getMass();
423
424 // velocity half step
425 for (j = 0; j < 3; j++)
426 vel[j] += (dt2 * frc[j] / mass) * eConvert;
427
428 integrableObjects[i]->setVel(vel);
429
430 if (integrableObjects[i]->isDirectional()){
431
432 // get and convert the torque to body frame
433
434 integrableObjects[i]->getTrq(Tb);
435 integrableObjects[i]->lab2Body(Tb);
436
437 // get the angular momentum, and propagate a half step
438
439 integrableObjects[i]->getJ(ji);
440
441 for (j = 0; j < 3; j++)
442 ji[j] += (dt2 * Tb[j]) * eConvert;
443
444
445 integrableObjects[i]->setJ(ji);
446 }
447 }
448
449 rattle->doRattleB();
450 }
451
452 /*
453 template<typename T> void Integrator<T>::preMove(void){
454 int i, j;
455 double pos[3];
456
457 if (nConstrained){
458 for (i = 0; i < nAtoms; i++){
459 atoms[i]->getPos(pos);
460
461 for (j = 0; j < 3; j++){
462 oldPos[3 * i + j] = pos[j];
463 }
464 }
465 }
466 }
467
468 template<typename T> void Integrator<T>::constrainA(){
469 int i, j;
470 int done;
471 double posA[3], posB[3];
472 double velA[3], velB[3];
473 double pab[3];
474 double rab[3];
475 int a, b, ax, ay, az, bx, by, bz;
476 double rma, rmb;
477 double dx, dy, dz;
478 double rpab;
479 double rabsq, pabsq, rpabsq;
480 double diffsq;
481 double gab;
482 int iteration;
483
484 for (i = 0; i < nAtoms; i++){
485 moving[i] = 0;
486 moved[i] = 1;
487 }
488
489 iteration = 0;
490 done = 0;
491 while (!done && (iteration < maxIteration)){
492 done = 1;
493 for (i = 0; i < nConstrained; i++){
494 a = constrainedA[i];
495 b = constrainedB[i];
496
497 ax = (a * 3) + 0;
498 ay = (a * 3) + 1;
499 az = (a * 3) + 2;
500
501 bx = (b * 3) + 0;
502 by = (b * 3) + 1;
503 bz = (b * 3) + 2;
504
505 if (moved[a] || moved[b]){
506 atoms[a]->getPos(posA);
507 atoms[b]->getPos(posB);
508
509 for (j = 0; j < 3; j++)
510 pab[j] = posA[j] - posB[j];
511
512 //periodic boundary condition
513
514 info->wrapVector(pab);
515
516 pabsq = pab[0] * pab[0] + pab[1] * pab[1] + pab[2] * pab[2];
517
518 rabsq = constrainedDsqr[i];
519 diffsq = rabsq - pabsq;
520
521 // the original rattle code from alan tidesley
522 if (fabs(diffsq) > (tol * rabsq * 2)){
523 rab[0] = oldPos[ax] - oldPos[bx];
524 rab[1] = oldPos[ay] - oldPos[by];
525 rab[2] = oldPos[az] - oldPos[bz];
526
527 info->wrapVector(rab);
528
529 rpab = rab[0] * pab[0] + rab[1] * pab[1] + rab[2] * pab[2];
530
531 rpabsq = rpab * rpab;
532
533
534 if (rpabsq < (rabsq * -diffsq)){
535 #ifdef IS_MPI
536 a = atoms[a]->getGlobalIndex();
537 b = atoms[b]->getGlobalIndex();
538 #endif //is_mpi
539 sprintf(painCave.errMsg,
540 "Constraint failure in constrainA at atom %d and %d.\n", a,
541 b);
542 painCave.isFatal = 1;
543 simError();
544 }
545
546 rma = 1.0 / atoms[a]->getMass();
547 rmb = 1.0 / atoms[b]->getMass();
548
549 gab = diffsq / (2.0 * (rma + rmb) * rpab);
550
551 dx = rab[0] * gab;
552 dy = rab[1] * gab;
553 dz = rab[2] * gab;
554
555 posA[0] += rma * dx;
556 posA[1] += rma * dy;
557 posA[2] += rma * dz;
558
559 atoms[a]->setPos(posA);
560
561 posB[0] -= rmb * dx;
562 posB[1] -= rmb * dy;
563 posB[2] -= rmb * dz;
564
565 atoms[b]->setPos(posB);
566
567 dx = dx / dt;
568 dy = dy / dt;
569 dz = dz / dt;
570
571 atoms[a]->getVel(velA);
572
573 velA[0] += rma * dx;
574 velA[1] += rma * dy;
575 velA[2] += rma * dz;
576
577 atoms[a]->setVel(velA);
578
579 atoms[b]->getVel(velB);
580
581 velB[0] -= rmb * dx;
582 velB[1] -= rmb * dy;
583 velB[2] -= rmb * dz;
584
585 atoms[b]->setVel(velB);
586
587 moving[a] = 1;
588 moving[b] = 1;
589 done = 0;
590 }
591 }
592 }
593
594 for (i = 0; i < nAtoms; i++){
595 moved[i] = moving[i];
596 moving[i] = 0;
597 }
598
599 iteration++;
600 }
601
602 if (!done){
603 sprintf(painCave.errMsg,
604 "Constraint failure in constrainA, too many iterations: %d\n",
605 iteration);
606 painCave.isFatal = 1;
607 simError();
608 }
609
610 }
611
612 template<typename T> void Integrator<T>::constrainB(void){
613 int i, j;
614 int done;
615 double posA[3], posB[3];
616 double velA[3], velB[3];
617 double vxab, vyab, vzab;
618 double rab[3];
619 int a, b, ax, ay, az, bx, by, bz;
620 double rma, rmb;
621 double dx, dy, dz;
622 double rvab;
623 double gab;
624 int iteration;
625
626 for (i = 0; i < nAtoms; i++){
627 moving[i] = 0;
628 moved[i] = 1;
629 }
630
631 done = 0;
632 iteration = 0;
633 while (!done && (iteration < maxIteration)){
634 done = 1;
635
636 for (i = 0; i < nConstrained; i++){
637 a = constrainedA[i];
638 b = constrainedB[i];
639
640 ax = (a * 3) + 0;
641 ay = (a * 3) + 1;
642 az = (a * 3) + 2;
643
644 bx = (b * 3) + 0;
645 by = (b * 3) + 1;
646 bz = (b * 3) + 2;
647
648 if (moved[a] || moved[b]){
649 atoms[a]->getVel(velA);
650 atoms[b]->getVel(velB);
651
652 vxab = velA[0] - velB[0];
653 vyab = velA[1] - velB[1];
654 vzab = velA[2] - velB[2];
655
656 atoms[a]->getPos(posA);
657 atoms[b]->getPos(posB);
658
659 for (j = 0; j < 3; j++)
660 rab[j] = posA[j] - posB[j];
661
662 info->wrapVector(rab);
663
664 rma = 1.0 / atoms[a]->getMass();
665 rmb = 1.0 / atoms[b]->getMass();
666
667 rvab = rab[0] * vxab + rab[1] * vyab + rab[2] * vzab;
668
669 gab = -rvab / ((rma + rmb) * constrainedDsqr[i]);
670
671 if (fabs(gab) > tol){
672 dx = rab[0] * gab;
673 dy = rab[1] * gab;
674 dz = rab[2] * gab;
675
676 velA[0] += rma * dx;
677 velA[1] += rma * dy;
678 velA[2] += rma * dz;
679
680 atoms[a]->setVel(velA);
681
682 velB[0] -= rmb * dx;
683 velB[1] -= rmb * dy;
684 velB[2] -= rmb * dz;
685
686 atoms[b]->setVel(velB);
687
688 moving[a] = 1;
689 moving[b] = 1;
690 done = 0;
691 }
692 }
693 }
694
695 for (i = 0; i < nAtoms; i++){
696 moved[i] = moving[i];
697 moving[i] = 0;
698 }
699
700 iteration++;
701 }
702
703 if (!done){
704 sprintf(painCave.errMsg,
705 "Constraint failure in constrainB, too many iterations: %d\n",
706 iteration);
707 painCave.isFatal = 1;
708 simError();
709 }
710 }
711 */
712 template<typename T> void Integrator<T>::rotationPropagation
713 ( StuntDouble* sd, double ji[3] ){
714
715 double angle;
716 double A[3][3], I[3][3];
717 int i, j, k;
718
719 // use the angular velocities to propagate the rotation matrix a
720 // full time step
721
722 sd->getA(A);
723 sd->getI(I);
724
725 if (sd->isLinear()) {
726 i = sd->linearAxis();
727 j = (i+1)%3;
728 k = (i+2)%3;
729
730 angle = dt2 * ji[j] / I[j][j];
731 this->rotate( k, i, angle, ji, A );
732
733 angle = dt * ji[k] / I[k][k];
734 this->rotate( i, j, angle, ji, A);
735
736 angle = dt2 * ji[j] / I[j][j];
737 this->rotate( k, i, angle, ji, A );
738
739 } else {
740 // rotate about the x-axis
741 angle = dt2 * ji[0] / I[0][0];
742 this->rotate( 1, 2, angle, ji, A );
743
744 // rotate about the y-axis
745 angle = dt2 * ji[1] / I[1][1];
746 this->rotate( 2, 0, angle, ji, A );
747
748 // rotate about the z-axis
749 angle = dt * ji[2] / I[2][2];
750 sd->addZangle(angle);
751 this->rotate( 0, 1, angle, ji, A);
752
753 // rotate about the y-axis
754 angle = dt2 * ji[1] / I[1][1];
755 this->rotate( 2, 0, angle, ji, A );
756
757 // rotate about the x-axis
758 angle = dt2 * ji[0] / I[0][0];
759 this->rotate( 1, 2, angle, ji, A );
760
761 }
762 sd->setA( A );
763 }
764
765 template<typename T> void Integrator<T>::rotate(int axes1, int axes2,
766 double angle, double ji[3],
767 double A[3][3]){
768 int i, j, k;
769 double sinAngle;
770 double cosAngle;
771 double angleSqr;
772 double angleSqrOver4;
773 double top, bottom;
774 double rot[3][3];
775 double tempA[3][3];
776 double tempJ[3];
777
778 // initialize the tempA
779
780 for (i = 0; i < 3; i++){
781 for (j = 0; j < 3; j++){
782 tempA[j][i] = A[i][j];
783 }
784 }
785
786 // initialize the tempJ
787
788 for (i = 0; i < 3; i++)
789 tempJ[i] = ji[i];
790
791 // initalize rot as a unit matrix
792
793 rot[0][0] = 1.0;
794 rot[0][1] = 0.0;
795 rot[0][2] = 0.0;
796
797 rot[1][0] = 0.0;
798 rot[1][1] = 1.0;
799 rot[1][2] = 0.0;
800
801 rot[2][0] = 0.0;
802 rot[2][1] = 0.0;
803 rot[2][2] = 1.0;
804
805 // use a small angle aproximation for sin and cosine
806
807 angleSqr = angle * angle;
808 angleSqrOver4 = angleSqr / 4.0;
809 top = 1.0 - angleSqrOver4;
810 bottom = 1.0 + angleSqrOver4;
811
812 cosAngle = top / bottom;
813 sinAngle = angle / bottom;
814
815 rot[axes1][axes1] = cosAngle;
816 rot[axes2][axes2] = cosAngle;
817
818 rot[axes1][axes2] = sinAngle;
819 rot[axes2][axes1] = -sinAngle;
820
821 // rotate the momentum acoording to: ji[] = rot[][] * ji[]
822
823 for (i = 0; i < 3; i++){
824 ji[i] = 0.0;
825 for (k = 0; k < 3; k++){
826 ji[i] += rot[i][k] * tempJ[k];
827 }
828 }
829
830 // rotate the Rotation matrix acording to:
831 // A[][] = A[][] * transpose(rot[][])
832
833
834 // NOte for as yet unknown reason, we are performing the
835 // calculation as:
836 // transpose(A[][]) = transpose(A[][]) * transpose(rot[][])
837
838 for (i = 0; i < 3; i++){
839 for (j = 0; j < 3; j++){
840 A[j][i] = 0.0;
841 for (k = 0; k < 3; k++){
842 A[j][i] += tempA[i][k] * rot[j][k];
843 }
844 }
845 }
846 }
847
848 template<typename T> void Integrator<T>::calcForce(int calcPot, int calcStress){
849 myFF->doForces(calcPot, calcStress);
850 }
851
852 template<typename T> void Integrator<T>::thermalize(){
853 tStats->velocitize();
854 }
855
856 template<typename T> double Integrator<T>::getConservedQuantity(void){
857 return tStats->getTotalE();
858 }
859 template<typename T> string Integrator<T>::getAdditionalParameters(void){
860 //By default, return a null string
861 //The reason we use string instead of char* is that if we use char*, we will
862 //return a pointer point to local variable which might cause problem
863 return string();
864 }