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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 778
Committed: Fri Sep 19 20:00:27 2003 UTC (20 years, 9 months ago) by mmeineke
File size: 16584 byte(s)
Log Message:
added NPT base class. NPTi is up to date. NPTf is not.

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
258
259
260 #ifdef IS_MPI
261 strcpy(checkPointMsg, "Succesful moveA\n");
262 MPIcheckPoint();
263 #endif // is_mpi
264
265
266 // calc forces
267
268 calcForce(calcPot, calcStress);
269
270 #ifdef IS_MPI
271 strcpy(checkPointMsg, "Succesful doForces\n");
272 MPIcheckPoint();
273 #endif // is_mpi
274
275
276 // finish the velocity half step
277
278 moveB();
279
280
281
282 #ifdef IS_MPI
283 strcpy(checkPointMsg, "Succesful moveB\n");
284 MPIcheckPoint();
285 #endif // is_mpi
286 }
287
288
289 template<typename T> void Integrator<T>::moveA(void){
290 int i, j;
291 DirectionalAtom* dAtom;
292 double Tb[3], ji[3];
293 double vel[3], pos[3], frc[3];
294 double mass;
295
296 for (i = 0; i < nAtoms; i++){
297 atoms[i]->getVel(vel);
298 atoms[i]->getPos(pos);
299 atoms[i]->getFrc(frc);
300
301 mass = atoms[i]->getMass();
302
303 for (j = 0; j < 3; j++){
304 // velocity half step
305 vel[j] += (dt2 * frc[j] / mass) * eConvert;
306 // position whole step
307 pos[j] += dt * vel[j];
308 }
309
310 atoms[i]->setVel(vel);
311 atoms[i]->setPos(pos);
312
313 if (atoms[i]->isDirectional()){
314 dAtom = (DirectionalAtom *) atoms[i];
315
316 // get and convert the torque to body frame
317
318 dAtom->getTrq(Tb);
319 dAtom->lab2Body(Tb);
320
321 // get the angular momentum, and propagate a half step
322
323 dAtom->getJ(ji);
324
325 for (j = 0; j < 3; j++)
326 ji[j] += (dt2 * Tb[j]) * eConvert;
327
328 this->rotationPropagation( dAtom, ji );
329
330 dAtom->setJ(ji);
331 }
332 }
333
334 if (nConstrained){
335 constrainA();
336 }
337 }
338
339
340 template<typename T> void Integrator<T>::moveB(void){
341 int i, j;
342 DirectionalAtom* dAtom;
343 double Tb[3], ji[3];
344 double vel[3], frc[3];
345 double mass;
346
347 for (i = 0; i < nAtoms; i++){
348 atoms[i]->getVel(vel);
349 atoms[i]->getFrc(frc);
350
351 mass = atoms[i]->getMass();
352
353 // velocity half step
354 for (j = 0; j < 3; j++)
355 vel[j] += (dt2 * frc[j] / mass) * eConvert;
356
357 atoms[i]->setVel(vel);
358
359 if (atoms[i]->isDirectional()){
360 dAtom = (DirectionalAtom *) atoms[i];
361
362 // get and convert the torque to body frame
363
364 dAtom->getTrq(Tb);
365 dAtom->lab2Body(Tb);
366
367 // get the angular momentum, and propagate a half step
368
369 dAtom->getJ(ji);
370
371 for (j = 0; j < 3; j++)
372 ji[j] += (dt2 * Tb[j]) * eConvert;
373
374
375 dAtom->setJ(ji);
376 }
377 }
378
379 if (nConstrained){
380 constrainB();
381 }
382 }
383
384 template<typename T> void Integrator<T>::preMove(void){
385 int i, j;
386 double pos[3];
387
388 if (nConstrained){
389 for (i = 0; i < nAtoms; i++){
390 atoms[i]->getPos(pos);
391
392 for (j = 0; j < 3; j++){
393 oldPos[3 * i + j] = pos[j];
394 }
395 }
396 }
397 }
398
399 template<typename T> void Integrator<T>::constrainA(){
400 int i, j, k;
401 int done;
402 double posA[3], posB[3];
403 double velA[3], velB[3];
404 double pab[3];
405 double rab[3];
406 int a, b, ax, ay, az, bx, by, bz;
407 double rma, rmb;
408 double dx, dy, dz;
409 double rpab;
410 double rabsq, pabsq, rpabsq;
411 double diffsq;
412 double gab;
413 int iteration;
414
415 for (i = 0; i < nAtoms; i++){
416 moving[i] = 0;
417 moved[i] = 1;
418 }
419
420 iteration = 0;
421 done = 0;
422 while (!done && (iteration < maxIteration)){
423 done = 1;
424 for (i = 0; i < nConstrained; i++){
425 a = constrainedA[i];
426 b = constrainedB[i];
427
428 ax = (a * 3) + 0;
429 ay = (a * 3) + 1;
430 az = (a * 3) + 2;
431
432 bx = (b * 3) + 0;
433 by = (b * 3) + 1;
434 bz = (b * 3) + 2;
435
436 if (moved[a] || moved[b]){
437 atoms[a]->getPos(posA);
438 atoms[b]->getPos(posB);
439
440 for (j = 0; j < 3; j++)
441 pab[j] = posA[j] - posB[j];
442
443 //periodic boundary condition
444
445 info->wrapVector(pab);
446
447 pabsq = pab[0] * pab[0] + pab[1] * pab[1] + pab[2] * pab[2];
448
449 rabsq = constrainedDsqr[i];
450 diffsq = rabsq - pabsq;
451
452 // the original rattle code from alan tidesley
453 if (fabs(diffsq) > (tol * rabsq * 2)){
454 rab[0] = oldPos[ax] - oldPos[bx];
455 rab[1] = oldPos[ay] - oldPos[by];
456 rab[2] = oldPos[az] - oldPos[bz];
457
458 info->wrapVector(rab);
459
460 rpab = rab[0] * pab[0] + rab[1] * pab[1] + rab[2] * pab[2];
461
462 rpabsq = rpab * rpab;
463
464
465 if (rpabsq < (rabsq * -diffsq)){
466 #ifdef IS_MPI
467 a = atoms[a]->getGlobalIndex();
468 b = atoms[b]->getGlobalIndex();
469 #endif //is_mpi
470 sprintf(painCave.errMsg,
471 "Constraint failure in constrainA at atom %d and %d.\n", a,
472 b);
473 painCave.isFatal = 1;
474 simError();
475 }
476
477 rma = 1.0 / atoms[a]->getMass();
478 rmb = 1.0 / atoms[b]->getMass();
479
480 gab = diffsq / (2.0 * (rma + rmb) * rpab);
481
482 dx = rab[0] * gab;
483 dy = rab[1] * gab;
484 dz = rab[2] * gab;
485
486 posA[0] += rma * dx;
487 posA[1] += rma * dy;
488 posA[2] += rma * dz;
489
490 atoms[a]->setPos(posA);
491
492 posB[0] -= rmb * dx;
493 posB[1] -= rmb * dy;
494 posB[2] -= rmb * dz;
495
496 atoms[b]->setPos(posB);
497
498 dx = dx / dt;
499 dy = dy / dt;
500 dz = dz / dt;
501
502 atoms[a]->getVel(velA);
503
504 velA[0] += rma * dx;
505 velA[1] += rma * dy;
506 velA[2] += rma * dz;
507
508 atoms[a]->setVel(velA);
509
510 atoms[b]->getVel(velB);
511
512 velB[0] -= rmb * dx;
513 velB[1] -= rmb * dy;
514 velB[2] -= rmb * dz;
515
516 atoms[b]->setVel(velB);
517
518 moving[a] = 1;
519 moving[b] = 1;
520 done = 0;
521 }
522 }
523 }
524
525 for (i = 0; i < nAtoms; i++){
526 moved[i] = moving[i];
527 moving[i] = 0;
528 }
529
530 iteration++;
531 }
532
533 if (!done){
534 sprintf(painCave.errMsg,
535 "Constraint failure in constrainA, too many iterations: %d\n",
536 iteration);
537 painCave.isFatal = 1;
538 simError();
539 }
540
541 }
542
543 template<typename T> void Integrator<T>::constrainB(void){
544 int i, j, k;
545 int done;
546 double posA[3], posB[3];
547 double velA[3], velB[3];
548 double vxab, vyab, vzab;
549 double rab[3];
550 int a, b, ax, ay, az, bx, by, bz;
551 double rma, rmb;
552 double dx, dy, dz;
553 double rabsq, pabsq, rvab;
554 double diffsq;
555 double gab;
556 int iteration;
557
558 for (i = 0; i < nAtoms; i++){
559 moving[i] = 0;
560 moved[i] = 1;
561 }
562
563 done = 0;
564 iteration = 0;
565 while (!done && (iteration < maxIteration)){
566 done = 1;
567
568 for (i = 0; i < nConstrained; i++){
569 a = constrainedA[i];
570 b = constrainedB[i];
571
572 ax = (a * 3) + 0;
573 ay = (a * 3) + 1;
574 az = (a * 3) + 2;
575
576 bx = (b * 3) + 0;
577 by = (b * 3) + 1;
578 bz = (b * 3) + 2;
579
580 if (moved[a] || moved[b]){
581 atoms[a]->getVel(velA);
582 atoms[b]->getVel(velB);
583
584 vxab = velA[0] - velB[0];
585 vyab = velA[1] - velB[1];
586 vzab = velA[2] - velB[2];
587
588 atoms[a]->getPos(posA);
589 atoms[b]->getPos(posB);
590
591 for (j = 0; j < 3; j++)
592 rab[j] = posA[j] - posB[j];
593
594 info->wrapVector(rab);
595
596 rma = 1.0 / atoms[a]->getMass();
597 rmb = 1.0 / atoms[b]->getMass();
598
599 rvab = rab[0] * vxab + rab[1] * vyab + rab[2] * vzab;
600
601 gab = -rvab / ((rma + rmb) * constrainedDsqr[i]);
602
603 if (fabs(gab) > tol){
604 dx = rab[0] * gab;
605 dy = rab[1] * gab;
606 dz = rab[2] * gab;
607
608 velA[0] += rma * dx;
609 velA[1] += rma * dy;
610 velA[2] += rma * dz;
611
612 atoms[a]->setVel(velA);
613
614 velB[0] -= rmb * dx;
615 velB[1] -= rmb * dy;
616 velB[2] -= rmb * dz;
617
618 atoms[b]->setVel(velB);
619
620 moving[a] = 1;
621 moving[b] = 1;
622 done = 0;
623 }
624 }
625 }
626
627 for (i = 0; i < nAtoms; i++){
628 moved[i] = moving[i];
629 moving[i] = 0;
630 }
631
632 iteration++;
633 }
634
635 if (!done){
636 sprintf(painCave.errMsg,
637 "Constraint failure in constrainB, too many iterations: %d\n",
638 iteration);
639 painCave.isFatal = 1;
640 simError();
641 }
642 }
643
644 template<typename T> void Integrator<T>::rotationPropagation
645 ( DirectionalAtom* dAtom, double ji[3] ){
646
647 double angle;
648 double A[3][3], I[3][3];
649
650 // use the angular velocities to propagate the rotation matrix a
651 // full time step
652
653 dAtom->getA(A);
654 dAtom->getI(I);
655
656 // rotate about the x-axis
657 angle = dt2 * ji[0] / I[0][0];
658 this->rotate( 1, 2, angle, ji, A );
659
660 // rotate about the y-axis
661 angle = dt2 * ji[1] / I[1][1];
662 this->rotate( 2, 0, angle, ji, A );
663
664 // rotate about the z-axis
665 angle = dt * ji[2] / I[2][2];
666 this->rotate( 0, 1, angle, ji, A);
667
668 // rotate about the y-axis
669 angle = dt2 * ji[1] / I[1][1];
670 this->rotate( 2, 0, angle, ji, A );
671
672 // rotate about the x-axis
673 angle = dt2 * ji[0] / I[0][0];
674 this->rotate( 1, 2, angle, ji, A );
675
676 dAtom->setA( A );
677 }
678
679 template<typename T> void Integrator<T>::rotate(int axes1, int axes2,
680 double angle, double ji[3],
681 double A[3][3]){
682 int i, j, k;
683 double sinAngle;
684 double cosAngle;
685 double angleSqr;
686 double angleSqrOver4;
687 double top, bottom;
688 double rot[3][3];
689 double tempA[3][3];
690 double tempJ[3];
691
692 // initialize the tempA
693
694 for (i = 0; i < 3; i++){
695 for (j = 0; j < 3; j++){
696 tempA[j][i] = A[i][j];
697 }
698 }
699
700 // initialize the tempJ
701
702 for (i = 0; i < 3; i++)
703 tempJ[i] = ji[i];
704
705 // initalize rot as a unit matrix
706
707 rot[0][0] = 1.0;
708 rot[0][1] = 0.0;
709 rot[0][2] = 0.0;
710
711 rot[1][0] = 0.0;
712 rot[1][1] = 1.0;
713 rot[1][2] = 0.0;
714
715 rot[2][0] = 0.0;
716 rot[2][1] = 0.0;
717 rot[2][2] = 1.0;
718
719 // use a small angle aproximation for sin and cosine
720
721 angleSqr = angle * angle;
722 angleSqrOver4 = angleSqr / 4.0;
723 top = 1.0 - angleSqrOver4;
724 bottom = 1.0 + angleSqrOver4;
725
726 cosAngle = top / bottom;
727 sinAngle = angle / bottom;
728
729 rot[axes1][axes1] = cosAngle;
730 rot[axes2][axes2] = cosAngle;
731
732 rot[axes1][axes2] = sinAngle;
733 rot[axes2][axes1] = -sinAngle;
734
735 // rotate the momentum acoording to: ji[] = rot[][] * ji[]
736
737 for (i = 0; i < 3; i++){
738 ji[i] = 0.0;
739 for (k = 0; k < 3; k++){
740 ji[i] += rot[i][k] * tempJ[k];
741 }
742 }
743
744 // rotate the Rotation matrix acording to:
745 // A[][] = A[][] * transpose(rot[][])
746
747
748 // NOte for as yet unknown reason, we are performing the
749 // calculation as:
750 // transpose(A[][]) = transpose(A[][]) * transpose(rot[][])
751
752 for (i = 0; i < 3; i++){
753 for (j = 0; j < 3; j++){
754 A[j][i] = 0.0;
755 for (k = 0; k < 3; k++){
756 A[j][i] += tempA[i][k] * rot[j][k];
757 }
758 }
759 }
760 }
761
762 template<typename T> void Integrator<T>::calcForce(int calcPot, int calcStress){
763 myFF->doForces(calcPot, calcStress);
764 }
765
766 template<typename T> void Integrator<T>::thermalize(){
767 tStats->velocitize();
768 }
769
770 template<typename T> double Integrator<T>::getConservedQuantity(void){
771 return tStats->getTotalE();
772 }