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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 781
Committed: Mon Sep 22 23:07:57 2003 UTC (20 years, 9 months ago) by tim
File size: 16686 byte(s)
Log Message:
fix bug in calculating maxCutoff

File Contents

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