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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 1212
Committed: Tue Jun 1 17:15:43 2004 UTC (20 years, 1 month ago) by chrisfen
File size: 18634 byte(s)
Log Message:
Implemented a separate solid and liquid thermodynamic integration routines

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->useSolidThermInt && !info->useLiquidThermInt) {
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 if (info->useSolidThermInt || info->useLiquidThermInt)
259 statOut->writeRaw(info->getTime());
260 calcPot = 0;
261 calcStress = 0;
262 currStatus += statusTime;
263 }
264
265 if (info->resetIntegrator){
266 if (info->getTime() >= currReset){
267 this->resetIntegrator();
268 currReset += resetTime;
269 }
270 }
271
272 #ifdef PROFILE
273 endProfile( pro2 );
274 #endif //profile
275
276 #ifdef IS_MPI
277 strcpy(checkPointMsg, "successfully took a time step.");
278 MPIcheckPoint();
279 #endif // is_mpi
280 }
281
282 // dump out a file containing the omega values for the final configuration
283 if (info->useSolidThermInt && !info->useLiquidThermInt)
284 myFF->dumpzAngle();
285
286
287 delete dumpOut;
288 delete statOut;
289 }
290
291 template<typename T> void Integrator<T>::integrateStep(int calcPot,
292 int calcStress){
293 // Position full step, and velocity half step
294
295 #ifdef PROFILE
296 startProfile(pro3);
297 #endif //profile
298
299 preMove();
300
301 #ifdef PROFILE
302 endProfile(pro3);
303
304 startProfile(pro4);
305 #endif // profile
306
307 moveA();
308
309 #ifdef PROFILE
310 endProfile(pro4);
311
312 startProfile(pro5);
313 #endif//profile
314
315
316 #ifdef IS_MPI
317 strcpy(checkPointMsg, "Succesful moveA\n");
318 MPIcheckPoint();
319 #endif // is_mpi
320
321 // calc forces
322 calcForce(calcPot, calcStress);
323
324 #ifdef IS_MPI
325 strcpy(checkPointMsg, "Succesful doForces\n");
326 MPIcheckPoint();
327 #endif // is_mpi
328
329 #ifdef PROFILE
330 endProfile( pro5 );
331
332 startProfile( pro6 );
333 #endif //profile
334
335 // finish the velocity half step
336
337 moveB();
338
339 #ifdef PROFILE
340 endProfile(pro6);
341 #endif // profile
342
343 #ifdef IS_MPI
344 strcpy(checkPointMsg, "Succesful moveB\n");
345 MPIcheckPoint();
346 #endif // is_mpi
347 }
348
349
350 template<typename T> void Integrator<T>::moveA(void){
351 size_t i, j;
352 DirectionalAtom* dAtom;
353 double Tb[3], ji[3];
354 double vel[3], pos[3], frc[3];
355 double mass;
356 double omega;
357
358 for (i = 0; i < integrableObjects.size() ; i++){
359 integrableObjects[i]->getVel(vel);
360 integrableObjects[i]->getPos(pos);
361 integrableObjects[i]->getFrc(frc);
362
363 mass = integrableObjects[i]->getMass();
364
365 for (j = 0; j < 3; j++){
366 // velocity half step
367 vel[j] += (dt2 * frc[j] / mass) * eConvert;
368 // position whole step
369 pos[j] += dt * vel[j];
370 }
371
372 integrableObjects[i]->setVel(vel);
373 integrableObjects[i]->setPos(pos);
374
375 if (integrableObjects[i]->isDirectional()){
376
377 // get and convert the torque to body frame
378
379 integrableObjects[i]->getTrq(Tb);
380 integrableObjects[i]->lab2Body(Tb);
381
382 // get the angular momentum, and propagate a half step
383
384 integrableObjects[i]->getJ(ji);
385
386 for (j = 0; j < 3; j++)
387 ji[j] += (dt2 * Tb[j]) * eConvert;
388
389 this->rotationPropagation( integrableObjects[i], ji );
390
391 integrableObjects[i]->setJ(ji);
392 }
393 }
394
395 if (nConstrained){
396 constrainA();
397 }
398 }
399
400
401 template<typename T> void Integrator<T>::moveB(void){
402 int i, j;
403 double Tb[3], ji[3];
404 double vel[3], frc[3];
405 double mass;
406
407 for (i = 0; i < integrableObjects.size(); i++){
408 integrableObjects[i]->getVel(vel);
409 integrableObjects[i]->getFrc(frc);
410
411 mass = integrableObjects[i]->getMass();
412
413 // velocity half step
414 for (j = 0; j < 3; j++)
415 vel[j] += (dt2 * frc[j] / mass) * eConvert;
416
417 integrableObjects[i]->setVel(vel);
418
419 if (integrableObjects[i]->isDirectional()){
420
421 // get and convert the torque to body frame
422
423 integrableObjects[i]->getTrq(Tb);
424 integrableObjects[i]->lab2Body(Tb);
425
426 // get the angular momentum, and propagate a half step
427
428 integrableObjects[i]->getJ(ji);
429
430 for (j = 0; j < 3; j++)
431 ji[j] += (dt2 * Tb[j]) * eConvert;
432
433
434 integrableObjects[i]->setJ(ji);
435 }
436 }
437
438 if (nConstrained){
439 constrainB();
440 }
441 }
442
443 template<typename T> void Integrator<T>::preMove(void){
444 int i, j;
445 double pos[3];
446
447 if (nConstrained){
448 for (i = 0; i < nAtoms; i++){
449 atoms[i]->getPos(pos);
450
451 for (j = 0; j < 3; j++){
452 oldPos[3 * i + j] = pos[j];
453 }
454 }
455 }
456 }
457
458 template<typename T> void Integrator<T>::constrainA(){
459 int i, j;
460 int done;
461 double posA[3], posB[3];
462 double velA[3], velB[3];
463 double pab[3];
464 double rab[3];
465 int a, b, ax, ay, az, bx, by, bz;
466 double rma, rmb;
467 double dx, dy, dz;
468 double rpab;
469 double rabsq, pabsq, rpabsq;
470 double diffsq;
471 double gab;
472 int iteration;
473
474 for (i = 0; i < nAtoms; i++){
475 moving[i] = 0;
476 moved[i] = 1;
477 }
478
479 iteration = 0;
480 done = 0;
481 while (!done && (iteration < maxIteration)){
482 done = 1;
483 for (i = 0; i < nConstrained; i++){
484 a = constrainedA[i];
485 b = constrainedB[i];
486
487 ax = (a * 3) + 0;
488 ay = (a * 3) + 1;
489 az = (a * 3) + 2;
490
491 bx = (b * 3) + 0;
492 by = (b * 3) + 1;
493 bz = (b * 3) + 2;
494
495 if (moved[a] || moved[b]){
496 atoms[a]->getPos(posA);
497 atoms[b]->getPos(posB);
498
499 for (j = 0; j < 3; j++)
500 pab[j] = posA[j] - posB[j];
501
502 //periodic boundary condition
503
504 info->wrapVector(pab);
505
506 pabsq = pab[0] * pab[0] + pab[1] * pab[1] + pab[2] * pab[2];
507
508 rabsq = constrainedDsqr[i];
509 diffsq = rabsq - pabsq;
510
511 // the original rattle code from alan tidesley
512 if (fabs(diffsq) > (tol * rabsq * 2)){
513 rab[0] = oldPos[ax] - oldPos[bx];
514 rab[1] = oldPos[ay] - oldPos[by];
515 rab[2] = oldPos[az] - oldPos[bz];
516
517 info->wrapVector(rab);
518
519 rpab = rab[0] * pab[0] + rab[1] * pab[1] + rab[2] * pab[2];
520
521 rpabsq = rpab * rpab;
522
523
524 if (rpabsq < (rabsq * -diffsq)){
525 #ifdef IS_MPI
526 a = atoms[a]->getGlobalIndex();
527 b = atoms[b]->getGlobalIndex();
528 #endif //is_mpi
529 sprintf(painCave.errMsg,
530 "Constraint failure in constrainA at atom %d and %d.\n", a,
531 b);
532 painCave.isFatal = 1;
533 simError();
534 }
535
536 rma = 1.0 / atoms[a]->getMass();
537 rmb = 1.0 / atoms[b]->getMass();
538
539 gab = diffsq / (2.0 * (rma + rmb) * rpab);
540
541 dx = rab[0] * gab;
542 dy = rab[1] * gab;
543 dz = rab[2] * gab;
544
545 posA[0] += rma * dx;
546 posA[1] += rma * dy;
547 posA[2] += rma * dz;
548
549 atoms[a]->setPos(posA);
550
551 posB[0] -= rmb * dx;
552 posB[1] -= rmb * dy;
553 posB[2] -= rmb * dz;
554
555 atoms[b]->setPos(posB);
556
557 dx = dx / dt;
558 dy = dy / dt;
559 dz = dz / dt;
560
561 atoms[a]->getVel(velA);
562
563 velA[0] += rma * dx;
564 velA[1] += rma * dy;
565 velA[2] += rma * dz;
566
567 atoms[a]->setVel(velA);
568
569 atoms[b]->getVel(velB);
570
571 velB[0] -= rmb * dx;
572 velB[1] -= rmb * dy;
573 velB[2] -= rmb * dz;
574
575 atoms[b]->setVel(velB);
576
577 moving[a] = 1;
578 moving[b] = 1;
579 done = 0;
580 }
581 }
582 }
583
584 for (i = 0; i < nAtoms; i++){
585 moved[i] = moving[i];
586 moving[i] = 0;
587 }
588
589 iteration++;
590 }
591
592 if (!done){
593 sprintf(painCave.errMsg,
594 "Constraint failure in constrainA, too many iterations: %d\n",
595 iteration);
596 painCave.isFatal = 1;
597 simError();
598 }
599
600 }
601
602 template<typename T> void Integrator<T>::constrainB(void){
603 int i, j;
604 int done;
605 double posA[3], posB[3];
606 double velA[3], velB[3];
607 double vxab, vyab, vzab;
608 double rab[3];
609 int a, b, ax, ay, az, bx, by, bz;
610 double rma, rmb;
611 double dx, dy, dz;
612 double rvab;
613 double gab;
614 int iteration;
615
616 for (i = 0; i < nAtoms; i++){
617 moving[i] = 0;
618 moved[i] = 1;
619 }
620
621 done = 0;
622 iteration = 0;
623 while (!done && (iteration < maxIteration)){
624 done = 1;
625
626 for (i = 0; i < nConstrained; i++){
627 a = constrainedA[i];
628 b = constrainedB[i];
629
630 ax = (a * 3) + 0;
631 ay = (a * 3) + 1;
632 az = (a * 3) + 2;
633
634 bx = (b * 3) + 0;
635 by = (b * 3) + 1;
636 bz = (b * 3) + 2;
637
638 if (moved[a] || moved[b]){
639 atoms[a]->getVel(velA);
640 atoms[b]->getVel(velB);
641
642 vxab = velA[0] - velB[0];
643 vyab = velA[1] - velB[1];
644 vzab = velA[2] - velB[2];
645
646 atoms[a]->getPos(posA);
647 atoms[b]->getPos(posB);
648
649 for (j = 0; j < 3; j++)
650 rab[j] = posA[j] - posB[j];
651
652 info->wrapVector(rab);
653
654 rma = 1.0 / atoms[a]->getMass();
655 rmb = 1.0 / atoms[b]->getMass();
656
657 rvab = rab[0] * vxab + rab[1] * vyab + rab[2] * vzab;
658
659 gab = -rvab / ((rma + rmb) * constrainedDsqr[i]);
660
661 if (fabs(gab) > tol){
662 dx = rab[0] * gab;
663 dy = rab[1] * gab;
664 dz = rab[2] * gab;
665
666 velA[0] += rma * dx;
667 velA[1] += rma * dy;
668 velA[2] += rma * dz;
669
670 atoms[a]->setVel(velA);
671
672 velB[0] -= rmb * dx;
673 velB[1] -= rmb * dy;
674 velB[2] -= rmb * dz;
675
676 atoms[b]->setVel(velB);
677
678 moving[a] = 1;
679 moving[b] = 1;
680 done = 0;
681 }
682 }
683 }
684
685 for (i = 0; i < nAtoms; i++){
686 moved[i] = moving[i];
687 moving[i] = 0;
688 }
689
690 iteration++;
691 }
692
693 if (!done){
694 sprintf(painCave.errMsg,
695 "Constraint failure in constrainB, too many iterations: %d\n",
696 iteration);
697 painCave.isFatal = 1;
698 simError();
699 }
700 }
701
702 template<typename T> void Integrator<T>::rotationPropagation
703 ( StuntDouble* sd, double ji[3] ){
704
705 double angle;
706 double A[3][3], I[3][3];
707 int i, j, k;
708
709 // use the angular velocities to propagate the rotation matrix a
710 // full time step
711
712 sd->getA(A);
713 sd->getI(I);
714
715 if (sd->isLinear()) {
716 i = sd->linearAxis();
717 j = (i+1)%3;
718 k = (i+2)%3;
719
720 angle = dt2 * ji[j] / I[j][j];
721 this->rotate( k, i, angle, ji, A );
722
723 angle = dt * ji[k] / I[k][k];
724 this->rotate( i, j, angle, ji, A);
725
726 angle = dt2 * ji[j] / I[j][j];
727 this->rotate( k, i, angle, ji, A );
728
729 } else {
730 // rotate about the x-axis
731 angle = dt2 * ji[0] / I[0][0];
732 this->rotate( 1, 2, angle, ji, A );
733
734 // rotate about the y-axis
735 angle = dt2 * ji[1] / I[1][1];
736 this->rotate( 2, 0, angle, ji, A );
737
738 // rotate about the z-axis
739 angle = dt * ji[2] / I[2][2];
740 sd->addZangle(angle);
741 this->rotate( 0, 1, angle, ji, A);
742
743 // rotate about the y-axis
744 angle = dt2 * ji[1] / I[1][1];
745 this->rotate( 2, 0, angle, ji, A );
746
747 // rotate about the x-axis
748 angle = dt2 * ji[0] / I[0][0];
749 this->rotate( 1, 2, angle, ji, A );
750
751 }
752 sd->setA( A );
753 }
754
755 template<typename T> void Integrator<T>::rotate(int axes1, int axes2,
756 double angle, double ji[3],
757 double A[3][3]){
758 int i, j, k;
759 double sinAngle;
760 double cosAngle;
761 double angleSqr;
762 double angleSqrOver4;
763 double top, bottom;
764 double rot[3][3];
765 double tempA[3][3];
766 double tempJ[3];
767
768 // initialize the tempA
769
770 for (i = 0; i < 3; i++){
771 for (j = 0; j < 3; j++){
772 tempA[j][i] = A[i][j];
773 }
774 }
775
776 // initialize the tempJ
777
778 for (i = 0; i < 3; i++)
779 tempJ[i] = ji[i];
780
781 // initalize rot as a unit matrix
782
783 rot[0][0] = 1.0;
784 rot[0][1] = 0.0;
785 rot[0][2] = 0.0;
786
787 rot[1][0] = 0.0;
788 rot[1][1] = 1.0;
789 rot[1][2] = 0.0;
790
791 rot[2][0] = 0.0;
792 rot[2][1] = 0.0;
793 rot[2][2] = 1.0;
794
795 // use a small angle aproximation for sin and cosine
796
797 angleSqr = angle * angle;
798 angleSqrOver4 = angleSqr / 4.0;
799 top = 1.0 - angleSqrOver4;
800 bottom = 1.0 + angleSqrOver4;
801
802 cosAngle = top / bottom;
803 sinAngle = angle / bottom;
804
805 rot[axes1][axes1] = cosAngle;
806 rot[axes2][axes2] = cosAngle;
807
808 rot[axes1][axes2] = sinAngle;
809 rot[axes2][axes1] = -sinAngle;
810
811 // rotate the momentum acoording to: ji[] = rot[][] * ji[]
812
813 for (i = 0; i < 3; i++){
814 ji[i] = 0.0;
815 for (k = 0; k < 3; k++){
816 ji[i] += rot[i][k] * tempJ[k];
817 }
818 }
819
820 // rotate the Rotation matrix acording to:
821 // A[][] = A[][] * transpose(rot[][])
822
823
824 // NOte for as yet unknown reason, we are performing the
825 // calculation as:
826 // transpose(A[][]) = transpose(A[][]) * transpose(rot[][])
827
828 for (i = 0; i < 3; i++){
829 for (j = 0; j < 3; j++){
830 A[j][i] = 0.0;
831 for (k = 0; k < 3; k++){
832 A[j][i] += tempA[i][k] * rot[j][k];
833 }
834 }
835 }
836 }
837
838 template<typename T> void Integrator<T>::calcForce(int calcPot, int calcStress){
839 myFF->doForces(calcPot, calcStress);
840 }
841
842 template<typename T> void Integrator<T>::thermalize(){
843 tStats->velocitize();
844 }
845
846 template<typename T> double Integrator<T>::getConservedQuantity(void){
847 return tStats->getTotalE();
848 }
849 template<typename T> string Integrator<T>::getAdditionalParameters(void){
850 //By default, return a null string
851 //The reason we use string instead of char* is that if we use char*, we will
852 //return a pointer point to local variable which might cause problem
853 return string();
854 }