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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 1127
Committed: Tue Apr 20 16:56:40 2004 UTC (20 years, 2 months ago) by tim
File size: 18117 byte(s)
Log Message:
fixed getCOMVel  and velocitize at thermo

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