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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 1187
Committed: Sat May 22 18:16:18 2004 UTC (20 years, 1 month ago) by chrisfen
File size: 18512 byte(s)
Log Message:
Fixed Thermodynamic integration code.

File Contents

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