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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 763
Committed: Mon Sep 15 16:52:02 2003 UTC (20 years, 9 months ago) by tim
File size: 16475 byte(s)
Log Message:
add conserved quantity to statWriter
fix bug of vector wrapping at NPTi

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 (info->setTemp){
182 thermalize();
183 }
184
185 calcPot = 0;
186 calcStress = 0;
187 currSample = sampleTime + info->getTime();
188 currThermal = thermalTime+ info->getTime();
189 currStatus = statusTime + info->getTime();
190 currReset = resetTime + info->getTime();
191
192 dumpOut->writeDump(info->getTime());
193 statOut->writeStat(info->getTime());
194
195 readyCheck();
196
197 #ifdef IS_MPI
198 strcpy(checkPointMsg, "The integrator is ready to go.");
199 MPIcheckPoint();
200 #endif // is_mpi
201
202 while (info->getTime() < runTime){
203 if ((info->getTime() + dt) >= currStatus){
204 calcPot = 1;
205 calcStress = 1;
206 }
207
208 integrateStep(calcPot, calcStress);
209
210 info->incrTime(dt);
211
212 if (info->setTemp){
213 if (info->getTime() >= currThermal){
214 thermalize();
215 currThermal += thermalTime;
216 }
217 }
218
219 if (info->getTime() >= currSample){
220 dumpOut->writeDump(info->getTime());
221 currSample += sampleTime;
222 }
223
224 if (info->getTime() >= currStatus){
225 statOut->writeStat(info->getTime());
226 calcPot = 0;
227 calcStress = 0;
228 currStatus += statusTime;
229 }
230
231 if (info->resetIntegrator){
232 if (info->getTime() >= currReset){
233 this->resetIntegrator();
234 currReset += resetTime;
235 }
236 }
237
238 #ifdef IS_MPI
239 strcpy(checkPointMsg, "successfully took a time step.");
240 MPIcheckPoint();
241 #endif // is_mpi
242 }
243
244 dumpOut->writeFinal(info->getTime());
245
246 delete dumpOut;
247 delete statOut;
248 }
249
250 template<typename T> void Integrator<T>::integrateStep(int calcPot,
251 int calcStress){
252 // Position full step, and velocity half step
253 preMove();
254
255 moveA();
256
257 if (nConstrained){
258 constrainA();
259 }
260
261
262 #ifdef IS_MPI
263 strcpy(checkPointMsg, "Succesful moveA\n");
264 MPIcheckPoint();
265 #endif // is_mpi
266
267
268 // calc forces
269
270 calcForce(calcPot, calcStress);
271
272 #ifdef IS_MPI
273 strcpy(checkPointMsg, "Succesful doForces\n");
274 MPIcheckPoint();
275 #endif // is_mpi
276
277
278 // finish the velocity half step
279
280 moveB();
281
282 if (nConstrained){
283 constrainB();
284 }
285
286 #ifdef IS_MPI
287 strcpy(checkPointMsg, "Succesful moveB\n");
288 MPIcheckPoint();
289 #endif // is_mpi
290 }
291
292
293 template<typename T> void Integrator<T>::moveA(void){
294 int i, j;
295 DirectionalAtom* dAtom;
296 double Tb[3], ji[3];
297 double A[3][3], I[3][3];
298 double angle;
299 double vel[3], pos[3], frc[3];
300 double mass;
301
302 for (i = 0; i < nAtoms; i++){
303 atoms[i]->getVel(vel);
304 atoms[i]->getPos(pos);
305 atoms[i]->getFrc(frc);
306
307 mass = atoms[i]->getMass();
308
309 for (j = 0; j < 3; j++){
310 // velocity half step
311 vel[j] += (dt2 * frc[j] / mass) * eConvert;
312 // position whole step
313 pos[j] += dt * vel[j];
314 }
315
316 atoms[i]->setVel(vel);
317 atoms[i]->setPos(pos);
318
319 if (atoms[i]->isDirectional()){
320 dAtom = (DirectionalAtom *) atoms[i];
321
322 // get and convert the torque to body frame
323
324 dAtom->getTrq(Tb);
325 dAtom->lab2Body(Tb);
326
327 // get the angular momentum, and propagate a half step
328
329 dAtom->getJ(ji);
330
331 for (j = 0; j < 3; j++)
332 ji[j] += (dt2 * Tb[j]) * eConvert;
333
334 // use the angular velocities to propagate the rotation matrix a
335 // full time step
336
337 dAtom->getA(A);
338 dAtom->getI(I);
339
340 // rotate about the x-axis
341 angle = dt2 * ji[0] / I[0][0];
342 this->rotate(1, 2, angle, ji, A);
343
344 // rotate about the y-axis
345 angle = dt2 * ji[1] / I[1][1];
346 this->rotate(2, 0, angle, ji, A);
347
348 // rotate about the z-axis
349 angle = dt * ji[2] / I[2][2];
350 this->rotate(0, 1, angle, ji, A);
351
352 // rotate about the y-axis
353 angle = dt2 * ji[1] / I[1][1];
354 this->rotate(2, 0, angle, ji, A);
355
356 // rotate about the x-axis
357 angle = dt2 * ji[0] / I[0][0];
358 this->rotate(1, 2, angle, ji, A);
359
360 dAtom->setJ(ji);
361 dAtom->setA(A);
362 }
363 }
364 }
365
366
367 template<typename T> void Integrator<T>::moveB(void){
368 int i, j;
369 DirectionalAtom* dAtom;
370 double Tb[3], ji[3];
371 double vel[3], frc[3];
372 double mass;
373
374 for (i = 0; i < nAtoms; i++){
375 atoms[i]->getVel(vel);
376 atoms[i]->getFrc(frc);
377
378 mass = atoms[i]->getMass();
379
380 // velocity half step
381 for (j = 0; j < 3; j++)
382 vel[j] += (dt2 * frc[j] / mass) * eConvert;
383
384 atoms[i]->setVel(vel);
385
386 if (atoms[i]->isDirectional()){
387 dAtom = (DirectionalAtom *) atoms[i];
388
389 // get and convert the torque to body frame
390
391 dAtom->getTrq(Tb);
392 dAtom->lab2Body(Tb);
393
394 // get the angular momentum, and propagate a half step
395
396 dAtom->getJ(ji);
397
398 for (j = 0; j < 3; j++)
399 ji[j] += (dt2 * Tb[j]) * eConvert;
400
401
402 dAtom->setJ(ji);
403 }
404 }
405 }
406
407 template<typename T> void Integrator<T>::preMove(void){
408 int i, j;
409 double pos[3];
410
411 if (nConstrained){
412 for (i = 0; i < nAtoms; i++){
413 atoms[i]->getPos(pos);
414
415 for (j = 0; j < 3; j++){
416 oldPos[3 * i + j] = pos[j];
417 }
418 }
419 }
420 }
421
422 template<typename T> void Integrator<T>::constrainA(){
423 int i, j, k;
424 int done;
425 double posA[3], posB[3];
426 double velA[3], velB[3];
427 double pab[3];
428 double rab[3];
429 int a, b, ax, ay, az, bx, by, bz;
430 double rma, rmb;
431 double dx, dy, dz;
432 double rpab;
433 double rabsq, pabsq, rpabsq;
434 double diffsq;
435 double gab;
436 int iteration;
437
438 for (i = 0; i < nAtoms; i++){
439 moving[i] = 0;
440 moved[i] = 1;
441 }
442
443 iteration = 0;
444 done = 0;
445 while (!done && (iteration < maxIteration)){
446 done = 1;
447 for (i = 0; i < nConstrained; i++){
448 a = constrainedA[i];
449 b = constrainedB[i];
450
451 ax = (a * 3) + 0;
452 ay = (a * 3) + 1;
453 az = (a * 3) + 2;
454
455 bx = (b * 3) + 0;
456 by = (b * 3) + 1;
457 bz = (b * 3) + 2;
458
459 if (moved[a] || moved[b]){
460 atoms[a]->getPos(posA);
461 atoms[b]->getPos(posB);
462
463 for (j = 0; j < 3; j++)
464 pab[j] = posA[j] - posB[j];
465
466 //periodic boundary condition
467
468 info->wrapVector(pab);
469
470 pabsq = pab[0] * pab[0] + pab[1] * pab[1] + pab[2] * pab[2];
471
472 rabsq = constrainedDsqr[i];
473 diffsq = rabsq - pabsq;
474
475 // the original rattle code from alan tidesley
476 if (fabs(diffsq) > (tol * rabsq * 2)){
477 rab[0] = oldPos[ax] - oldPos[bx];
478 rab[1] = oldPos[ay] - oldPos[by];
479 rab[2] = oldPos[az] - oldPos[bz];
480
481 info->wrapVector(rab);
482
483 rpab = rab[0] * pab[0] + rab[1] * pab[1] + rab[2] * pab[2];
484
485 rpabsq = rpab * rpab;
486
487
488 if (rpabsq < (rabsq * -diffsq)){
489 #ifdef IS_MPI
490 a = atoms[a]->getGlobalIndex();
491 b = atoms[b]->getGlobalIndex();
492 #endif //is_mpi
493 sprintf(painCave.errMsg,
494 "Constraint failure in constrainA at atom %d and %d.\n", a,
495 b);
496 painCave.isFatal = 1;
497 simError();
498 }
499
500 rma = 1.0 / atoms[a]->getMass();
501 rmb = 1.0 / atoms[b]->getMass();
502
503 gab = diffsq / (2.0 * (rma + rmb) * rpab);
504
505 dx = rab[0] * gab;
506 dy = rab[1] * gab;
507 dz = rab[2] * gab;
508
509 posA[0] += rma * dx;
510 posA[1] += rma * dy;
511 posA[2] += rma * dz;
512
513 atoms[a]->setPos(posA);
514
515 posB[0] -= rmb * dx;
516 posB[1] -= rmb * dy;
517 posB[2] -= rmb * dz;
518
519 atoms[b]->setPos(posB);
520
521 dx = dx / dt;
522 dy = dy / dt;
523 dz = dz / dt;
524
525 atoms[a]->getVel(velA);
526
527 velA[0] += rma * dx;
528 velA[1] += rma * dy;
529 velA[2] += rma * dz;
530
531 atoms[a]->setVel(velA);
532
533 atoms[b]->getVel(velB);
534
535 velB[0] -= rmb * dx;
536 velB[1] -= rmb * dy;
537 velB[2] -= rmb * dz;
538
539 atoms[b]->setVel(velB);
540
541 moving[a] = 1;
542 moving[b] = 1;
543 done = 0;
544 }
545 }
546 }
547
548 for (i = 0; i < nAtoms; i++){
549 moved[i] = moving[i];
550 moving[i] = 0;
551 }
552
553 iteration++;
554 }
555
556 if (!done){
557 sprintf(painCave.errMsg,
558 "Constraint failure in constrainA, too many iterations: %d\n",
559 iteration);
560 painCave.isFatal = 1;
561 simError();
562 }
563 }
564
565 template<typename T> void Integrator<T>::constrainB(void){
566 int i, j, k;
567 int done;
568 double posA[3], posB[3];
569 double velA[3], velB[3];
570 double vxab, vyab, vzab;
571 double rab[3];
572 int a, b, ax, ay, az, bx, by, bz;
573 double rma, rmb;
574 double dx, dy, dz;
575 double rabsq, pabsq, rvab;
576 double diffsq;
577 double gab;
578 int iteration;
579
580 for (i = 0; i < nAtoms; i++){
581 moving[i] = 0;
582 moved[i] = 1;
583 }
584
585 done = 0;
586 iteration = 0;
587 while (!done && (iteration < maxIteration)){
588 done = 1;
589
590 for (i = 0; i < nConstrained; i++){
591 a = constrainedA[i];
592 b = constrainedB[i];
593
594 ax = (a * 3) + 0;
595 ay = (a * 3) + 1;
596 az = (a * 3) + 2;
597
598 bx = (b * 3) + 0;
599 by = (b * 3) + 1;
600 bz = (b * 3) + 2;
601
602 if (moved[a] || moved[b]){
603 atoms[a]->getVel(velA);
604 atoms[b]->getVel(velB);
605
606 vxab = velA[0] - velB[0];
607 vyab = velA[1] - velB[1];
608 vzab = velA[2] - velB[2];
609
610 atoms[a]->getPos(posA);
611 atoms[b]->getPos(posB);
612
613 for (j = 0; j < 3; j++)
614 rab[j] = posA[j] - posB[j];
615
616 info->wrapVector(rab);
617
618 rma = 1.0 / atoms[a]->getMass();
619 rmb = 1.0 / atoms[b]->getMass();
620
621 rvab = rab[0] * vxab + rab[1] * vyab + rab[2] * vzab;
622
623 gab = -rvab / ((rma + rmb) * constrainedDsqr[i]);
624
625 if (fabs(gab) > tol){
626 dx = rab[0] * gab;
627 dy = rab[1] * gab;
628 dz = rab[2] * gab;
629
630 velA[0] += rma * dx;
631 velA[1] += rma * dy;
632 velA[2] += rma * dz;
633
634 atoms[a]->setVel(velA);
635
636 velB[0] -= rmb * dx;
637 velB[1] -= rmb * dy;
638 velB[2] -= rmb * dz;
639
640 atoms[b]->setVel(velB);
641
642 moving[a] = 1;
643 moving[b] = 1;
644 done = 0;
645 }
646 }
647 }
648
649 for (i = 0; i < nAtoms; i++){
650 moved[i] = moving[i];
651 moving[i] = 0;
652 }
653
654 iteration++;
655 }
656
657 if (!done){
658 sprintf(painCave.errMsg,
659 "Constraint failure in constrainB, too many iterations: %d\n",
660 iteration);
661 painCave.isFatal = 1;
662 simError();
663 }
664 }
665
666 template<typename T> void Integrator<T>::rotate(int axes1, int axes2,
667 double angle, double ji[3],
668 double A[3][3]){
669 int i, j, k;
670 double sinAngle;
671 double cosAngle;
672 double angleSqr;
673 double angleSqrOver4;
674 double top, bottom;
675 double rot[3][3];
676 double tempA[3][3];
677 double tempJ[3];
678
679 // initialize the tempA
680
681 for (i = 0; i < 3; i++){
682 for (j = 0; j < 3; j++){
683 tempA[j][i] = A[i][j];
684 }
685 }
686
687 // initialize the tempJ
688
689 for (i = 0; i < 3; i++)
690 tempJ[i] = ji[i];
691
692 // initalize rot as a unit matrix
693
694 rot[0][0] = 1.0;
695 rot[0][1] = 0.0;
696 rot[0][2] = 0.0;
697
698 rot[1][0] = 0.0;
699 rot[1][1] = 1.0;
700 rot[1][2] = 0.0;
701
702 rot[2][0] = 0.0;
703 rot[2][1] = 0.0;
704 rot[2][2] = 1.0;
705
706 // use a small angle aproximation for sin and cosine
707
708 angleSqr = angle * angle;
709 angleSqrOver4 = angleSqr / 4.0;
710 top = 1.0 - angleSqrOver4;
711 bottom = 1.0 + angleSqrOver4;
712
713 cosAngle = top / bottom;
714 sinAngle = angle / bottom;
715
716 rot[axes1][axes1] = cosAngle;
717 rot[axes2][axes2] = cosAngle;
718
719 rot[axes1][axes2] = sinAngle;
720 rot[axes2][axes1] = -sinAngle;
721
722 // rotate the momentum acoording to: ji[] = rot[][] * ji[]
723
724 for (i = 0; i < 3; i++){
725 ji[i] = 0.0;
726 for (k = 0; k < 3; k++){
727 ji[i] += rot[i][k] * tempJ[k];
728 }
729 }
730
731 // rotate the Rotation matrix acording to:
732 // A[][] = A[][] * transpose(rot[][])
733
734
735 // NOte for as yet unknown reason, we are performing the
736 // calculation as:
737 // transpose(A[][]) = transpose(A[][]) * transpose(rot[][])
738
739 for (i = 0; i < 3; i++){
740 for (j = 0; j < 3; j++){
741 A[j][i] = 0.0;
742 for (k = 0; k < 3; k++){
743 A[j][i] += tempA[i][k] * rot[j][k];
744 }
745 }
746 }
747 }
748
749 template<typename T> void Integrator<T>::calcForce(int calcPot, int calcStress){
750 myFF->doForces(calcPot, calcStress);
751 }
752
753 template<typename T> void Integrator<T>::thermalize(){
754 tStats->velocitize();
755 }
756
757 template<typename T> double Integrator<T>::getConservedQuantity(void){
758 return tStats->getTotalE();
759 }