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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 784
Committed: Wed Sep 24 19:34:39 2003 UTC (20 years, 9 months ago) by mmeineke
File size: 16659 byte(s)
Log Message:
moved readyCheck in the integrator so that it is called before the first Statistics are written.

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
29 nAtoms = info->n_atoms;
30
31 // check for constraints
32
33 constrainedA = NULL;
34 constrainedB = NULL;
35 constrainedDsqr = NULL;
36 moving = NULL;
37 moved = NULL;
38 oldPos = NULL;
39
40 nConstrained = 0;
41
42 checkConstraints();
43 }
44
45 template<typename T> Integrator<T>::~Integrator(){
46 if (nConstrained){
47 delete[] constrainedA;
48 delete[] constrainedB;
49 delete[] constrainedDsqr;
50 delete[] moving;
51 delete[] moved;
52 delete[] oldPos;
53 }
54 }
55
56 template<typename T> void Integrator<T>::checkConstraints(void){
57 isConstrained = 0;
58
59 Constraint* temp_con;
60 Constraint* dummy_plug;
61 temp_con = new Constraint[info->n_SRI];
62 nConstrained = 0;
63 int constrained = 0;
64
65 SRI** theArray;
66 for (int i = 0; i < nMols; i++){
67 theArray = (SRI * *) molecules[i].getMyBonds();
68 for (int j = 0; j < molecules[i].getNBonds(); j++){
69 constrained = theArray[j]->is_constrained();
70
71 if (constrained){
72 dummy_plug = theArray[j]->get_constraint();
73 temp_con[nConstrained].set_a(dummy_plug->get_a());
74 temp_con[nConstrained].set_b(dummy_plug->get_b());
75 temp_con[nConstrained].set_dsqr(dummy_plug->get_dsqr());
76
77 nConstrained++;
78 constrained = 0;
79 }
80 }
81
82 theArray = (SRI * *) molecules[i].getMyBends();
83 for (int j = 0; j < molecules[i].getNBends(); j++){
84 constrained = theArray[j]->is_constrained();
85
86 if (constrained){
87 dummy_plug = theArray[j]->get_constraint();
88 temp_con[nConstrained].set_a(dummy_plug->get_a());
89 temp_con[nConstrained].set_b(dummy_plug->get_b());
90 temp_con[nConstrained].set_dsqr(dummy_plug->get_dsqr());
91
92 nConstrained++;
93 constrained = 0;
94 }
95 }
96
97 theArray = (SRI * *) molecules[i].getMyTorsions();
98 for (int j = 0; j < molecules[i].getNTorsions(); j++){
99 constrained = theArray[j]->is_constrained();
100
101 if (constrained){
102 dummy_plug = theArray[j]->get_constraint();
103 temp_con[nConstrained].set_a(dummy_plug->get_a());
104 temp_con[nConstrained].set_b(dummy_plug->get_b());
105 temp_con[nConstrained].set_dsqr(dummy_plug->get_dsqr());
106
107 nConstrained++;
108 constrained = 0;
109 }
110 }
111 }
112
113 if (nConstrained > 0){
114 isConstrained = 1;
115
116 if (constrainedA != NULL)
117 delete[] constrainedA;
118 if (constrainedB != NULL)
119 delete[] constrainedB;
120 if (constrainedDsqr != NULL)
121 delete[] constrainedDsqr;
122
123 constrainedA = new int[nConstrained];
124 constrainedB = new int[nConstrained];
125 constrainedDsqr = new double[nConstrained];
126
127 for (int i = 0; i < nConstrained; i++){
128 constrainedA[i] = temp_con[i].get_a();
129 constrainedB[i] = temp_con[i].get_b();
130 constrainedDsqr[i] = temp_con[i].get_dsqr();
131 }
132
133
134 // save oldAtoms to check for lode balanceing later on.
135
136 oldAtoms = nAtoms;
137
138 moving = new int[nAtoms];
139 moved = new int[nAtoms];
140
141 oldPos = new double[nAtoms * 3];
142 }
143
144 delete[] temp_con;
145 }
146
147
148 template<typename T> void Integrator<T>::integrate(void){
149 int i, j; // loop counters
150
151 double runTime = info->run_time;
152 double sampleTime = info->sampleTime;
153 double statusTime = info->statusTime;
154 double thermalTime = info->thermalTime;
155 double resetTime = info->resetTime;
156
157
158 double currSample;
159 double currThermal;
160 double currStatus;
161 double currReset;
162
163 int calcPot, calcStress;
164 int isError;
165
166 tStats = new Thermo(info);
167 statOut = new StatWriter(info);
168 dumpOut = new DumpWriter(info);
169
170 atoms = info->atoms;
171 DirectionalAtom* dAtom;
172
173 dt = info->dt;
174 dt2 = 0.5 * dt;
175
176 readyCheck();
177
178 // initialize the forces before the first step
179
180 calcForce(1, 1);
181
182 if (nConstrained){
183 preMove();
184 constrainA();
185 calcForce(1, 1);
186 constrainB();
187 }
188
189 if (info->setTemp){
190 thermalize();
191 }
192
193 calcPot = 0;
194 calcStress = 0;
195 currSample = sampleTime + info->getTime();
196 currThermal = thermalTime+ info->getTime();
197 currStatus = statusTime + info->getTime();
198 currReset = resetTime + info->getTime();
199
200 dumpOut->writeDump(info->getTime());
201 statOut->writeStat(info->getTime());
202
203
204
205 #ifdef IS_MPI
206 strcpy(checkPointMsg, "The integrator is ready to go.");
207 MPIcheckPoint();
208 #endif // is_mpi
209
210 while (info->getTime() < runTime){
211 if ((info->getTime() + dt) >= currStatus){
212 calcPot = 1;
213 calcStress = 1;
214 }
215
216 integrateStep(calcPot, calcStress);
217
218 info->incrTime(dt);
219
220 if (info->setTemp){
221 if (info->getTime() >= currThermal){
222 thermalize();
223 currThermal += thermalTime;
224 }
225 }
226
227 if (info->getTime() >= currSample){
228 dumpOut->writeDump(info->getTime());
229 currSample += sampleTime;
230 }
231
232 if (info->getTime() >= currStatus){
233 statOut->writeStat(info->getTime());
234 calcPot = 0;
235 calcStress = 0;
236 currStatus += statusTime;
237 }
238
239 if (info->resetIntegrator){
240 if (info->getTime() >= currReset){
241 this->resetIntegrator();
242 currReset += resetTime;
243 }
244 }
245
246 #ifdef IS_MPI
247 strcpy(checkPointMsg, "successfully took a time step.");
248 MPIcheckPoint();
249 #endif // is_mpi
250 }
251
252 dumpOut->writeFinal(info->getTime());
253
254 delete dumpOut;
255 delete statOut;
256 }
257
258 template<typename T> void Integrator<T>::integrateStep(int calcPot,
259 int calcStress){
260 // Position full step, and velocity half step
261 preMove();
262
263 moveA();
264
265
266
267
268 #ifdef IS_MPI
269 strcpy(checkPointMsg, "Succesful moveA\n");
270 MPIcheckPoint();
271 #endif // is_mpi
272
273
274 // calc forces
275
276 calcForce(calcPot, calcStress);
277
278 #ifdef IS_MPI
279 strcpy(checkPointMsg, "Succesful doForces\n");
280 MPIcheckPoint();
281 #endif // is_mpi
282
283
284 // finish the velocity half step
285
286 moveB();
287
288
289
290 #ifdef IS_MPI
291 strcpy(checkPointMsg, "Succesful moveB\n");
292 MPIcheckPoint();
293 #endif // is_mpi
294 }
295
296
297 template<typename T> void Integrator<T>::moveA(void){
298 int i, j;
299 DirectionalAtom* dAtom;
300 double Tb[3], ji[3];
301 double vel[3], pos[3], frc[3];
302 double mass;
303
304 for (i = 0; i < nAtoms; i++){
305 atoms[i]->getVel(vel);
306 atoms[i]->getPos(pos);
307 atoms[i]->getFrc(frc);
308
309 mass = atoms[i]->getMass();
310
311 for (j = 0; j < 3; j++){
312 // velocity half step
313 vel[j] += (dt2 * frc[j] / mass) * eConvert;
314 // position whole step
315 pos[j] += dt * vel[j];
316 }
317
318 atoms[i]->setVel(vel);
319 atoms[i]->setPos(pos);
320
321 if (atoms[i]->isDirectional()){
322 dAtom = (DirectionalAtom *) atoms[i];
323
324 // get and convert the torque to body frame
325
326 dAtom->getTrq(Tb);
327 dAtom->lab2Body(Tb);
328
329 // get the angular momentum, and propagate a half step
330
331 dAtom->getJ(ji);
332
333 for (j = 0; j < 3; j++)
334 ji[j] += (dt2 * Tb[j]) * eConvert;
335
336 this->rotationPropagation( dAtom, ji );
337
338 dAtom->setJ(ji);
339 }
340 }
341
342 if (nConstrained){
343 constrainA();
344 }
345 }
346
347
348 template<typename T> void Integrator<T>::moveB(void){
349 int i, j;
350 DirectionalAtom* dAtom;
351 double Tb[3], ji[3];
352 double vel[3], frc[3];
353 double mass;
354
355 for (i = 0; i < nAtoms; i++){
356 atoms[i]->getVel(vel);
357 atoms[i]->getFrc(frc);
358
359 mass = atoms[i]->getMass();
360
361 // velocity half step
362 for (j = 0; j < 3; j++)
363 vel[j] += (dt2 * frc[j] / mass) * eConvert;
364
365 atoms[i]->setVel(vel);
366
367 if (atoms[i]->isDirectional()){
368 dAtom = (DirectionalAtom *) atoms[i];
369
370 // get and convert the torque to body frame
371
372 dAtom->getTrq(Tb);
373 dAtom->lab2Body(Tb);
374
375 // get the angular momentum, and propagate a half step
376
377 dAtom->getJ(ji);
378
379 for (j = 0; j < 3; j++)
380 ji[j] += (dt2 * Tb[j]) * eConvert;
381
382
383 dAtom->setJ(ji);
384 }
385 }
386
387 if (nConstrained){
388 constrainB();
389 }
390 }
391
392 template<typename T> void Integrator<T>::preMove(void){
393 int i, j;
394 double pos[3];
395
396 if (nConstrained){
397 for (i = 0; i < nAtoms; i++){
398 atoms[i]->getPos(pos);
399
400 for (j = 0; j < 3; j++){
401 oldPos[3 * i + j] = pos[j];
402 }
403 }
404 }
405 }
406
407 template<typename T> void Integrator<T>::constrainA(){
408 int i, j, k;
409 int done;
410 double posA[3], posB[3];
411 double velA[3], velB[3];
412 double pab[3];
413 double rab[3];
414 int a, b, ax, ay, az, bx, by, bz;
415 double rma, rmb;
416 double dx, dy, dz;
417 double rpab;
418 double rabsq, pabsq, rpabsq;
419 double diffsq;
420 double gab;
421 int iteration;
422
423 for (i = 0; i < nAtoms; i++){
424 moving[i] = 0;
425 moved[i] = 1;
426 }
427
428 iteration = 0;
429 done = 0;
430 while (!done && (iteration < maxIteration)){
431 done = 1;
432 for (i = 0; i < nConstrained; i++){
433 a = constrainedA[i];
434 b = constrainedB[i];
435
436 ax = (a * 3) + 0;
437 ay = (a * 3) + 1;
438 az = (a * 3) + 2;
439
440 bx = (b * 3) + 0;
441 by = (b * 3) + 1;
442 bz = (b * 3) + 2;
443
444 if (moved[a] || moved[b]){
445 atoms[a]->getPos(posA);
446 atoms[b]->getPos(posB);
447
448 for (j = 0; j < 3; j++)
449 pab[j] = posA[j] - posB[j];
450
451 //periodic boundary condition
452
453 info->wrapVector(pab);
454
455 pabsq = pab[0] * pab[0] + pab[1] * pab[1] + pab[2] * pab[2];
456
457 rabsq = constrainedDsqr[i];
458 diffsq = rabsq - pabsq;
459
460 // the original rattle code from alan tidesley
461 if (fabs(diffsq) > (tol * rabsq * 2)){
462 rab[0] = oldPos[ax] - oldPos[bx];
463 rab[1] = oldPos[ay] - oldPos[by];
464 rab[2] = oldPos[az] - oldPos[bz];
465
466 info->wrapVector(rab);
467
468 rpab = rab[0] * pab[0] + rab[1] * pab[1] + rab[2] * pab[2];
469
470 rpabsq = rpab * rpab;
471
472
473 if (rpabsq < (rabsq * -diffsq)){
474 #ifdef IS_MPI
475 a = atoms[a]->getGlobalIndex();
476 b = atoms[b]->getGlobalIndex();
477 #endif //is_mpi
478 sprintf(painCave.errMsg,
479 "Constraint failure in constrainA at atom %d and %d.\n", a,
480 b);
481 painCave.isFatal = 1;
482 simError();
483 }
484
485 rma = 1.0 / atoms[a]->getMass();
486 rmb = 1.0 / atoms[b]->getMass();
487
488 gab = diffsq / (2.0 * (rma + rmb) * rpab);
489
490 dx = rab[0] * gab;
491 dy = rab[1] * gab;
492 dz = rab[2] * gab;
493
494 posA[0] += rma * dx;
495 posA[1] += rma * dy;
496 posA[2] += rma * dz;
497
498 atoms[a]->setPos(posA);
499
500 posB[0] -= rmb * dx;
501 posB[1] -= rmb * dy;
502 posB[2] -= rmb * dz;
503
504 atoms[b]->setPos(posB);
505
506 dx = dx / dt;
507 dy = dy / dt;
508 dz = dz / dt;
509
510 atoms[a]->getVel(velA);
511
512 velA[0] += rma * dx;
513 velA[1] += rma * dy;
514 velA[2] += rma * dz;
515
516 atoms[a]->setVel(velA);
517
518 atoms[b]->getVel(velB);
519
520 velB[0] -= rmb * dx;
521 velB[1] -= rmb * dy;
522 velB[2] -= rmb * dz;
523
524 atoms[b]->setVel(velB);
525
526 moving[a] = 1;
527 moving[b] = 1;
528 done = 0;
529 }
530 }
531 }
532
533 for (i = 0; i < nAtoms; i++){
534 moved[i] = moving[i];
535 moving[i] = 0;
536 }
537
538 iteration++;
539 }
540
541 if (!done){
542 sprintf(painCave.errMsg,
543 "Constraint failure in constrainA, too many iterations: %d\n",
544 iteration);
545 painCave.isFatal = 1;
546 simError();
547 }
548
549 }
550
551 template<typename T> void Integrator<T>::constrainB(void){
552 int i, j, k;
553 int done;
554 double posA[3], posB[3];
555 double velA[3], velB[3];
556 double vxab, vyab, vzab;
557 double rab[3];
558 int a, b, ax, ay, az, bx, by, bz;
559 double rma, rmb;
560 double dx, dy, dz;
561 double rabsq, pabsq, rvab;
562 double diffsq;
563 double gab;
564 int iteration;
565
566 for (i = 0; i < nAtoms; i++){
567 moving[i] = 0;
568 moved[i] = 1;
569 }
570
571 done = 0;
572 iteration = 0;
573 while (!done && (iteration < maxIteration)){
574 done = 1;
575
576 for (i = 0; i < nConstrained; i++){
577 a = constrainedA[i];
578 b = constrainedB[i];
579
580 ax = (a * 3) + 0;
581 ay = (a * 3) + 1;
582 az = (a * 3) + 2;
583
584 bx = (b * 3) + 0;
585 by = (b * 3) + 1;
586 bz = (b * 3) + 2;
587
588 if (moved[a] || moved[b]){
589 atoms[a]->getVel(velA);
590 atoms[b]->getVel(velB);
591
592 vxab = velA[0] - velB[0];
593 vyab = velA[1] - velB[1];
594 vzab = velA[2] - velB[2];
595
596 atoms[a]->getPos(posA);
597 atoms[b]->getPos(posB);
598
599 for (j = 0; j < 3; j++)
600 rab[j] = posA[j] - posB[j];
601
602 info->wrapVector(rab);
603
604 rma = 1.0 / atoms[a]->getMass();
605 rmb = 1.0 / atoms[b]->getMass();
606
607 rvab = rab[0] * vxab + rab[1] * vyab + rab[2] * vzab;
608
609 gab = -rvab / ((rma + rmb) * constrainedDsqr[i]);
610
611 if (fabs(gab) > tol){
612 dx = rab[0] * gab;
613 dy = rab[1] * gab;
614 dz = rab[2] * gab;
615
616 velA[0] += rma * dx;
617 velA[1] += rma * dy;
618 velA[2] += rma * dz;
619
620 atoms[a]->setVel(velA);
621
622 velB[0] -= rmb * dx;
623 velB[1] -= rmb * dy;
624 velB[2] -= rmb * dz;
625
626 atoms[b]->setVel(velB);
627
628 moving[a] = 1;
629 moving[b] = 1;
630 done = 0;
631 }
632 }
633 }
634
635 for (i = 0; i < nAtoms; i++){
636 moved[i] = moving[i];
637 moving[i] = 0;
638 }
639
640 iteration++;
641 }
642
643 if (!done){
644 sprintf(painCave.errMsg,
645 "Constraint failure in constrainB, too many iterations: %d\n",
646 iteration);
647 painCave.isFatal = 1;
648 simError();
649 }
650 }
651
652 template<typename T> void Integrator<T>::rotationPropagation
653 ( DirectionalAtom* dAtom, double ji[3] ){
654
655 double angle;
656 double A[3][3], I[3][3];
657
658 // use the angular velocities to propagate the rotation matrix a
659 // full time step
660
661 dAtom->getA(A);
662 dAtom->getI(I);
663
664 // rotate about the x-axis
665 angle = dt2 * ji[0] / I[0][0];
666 this->rotate( 1, 2, 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 z-axis
673 angle = dt * ji[2] / I[2][2];
674 this->rotate( 0, 1, angle, ji, A);
675
676 // rotate about the y-axis
677 angle = dt2 * ji[1] / I[1][1];
678 this->rotate( 2, 0, angle, ji, A );
679
680 // rotate about the x-axis
681 angle = dt2 * ji[0] / I[0][0];
682 this->rotate( 1, 2, angle, ji, A );
683
684 dAtom->setA( A );
685 }
686
687 template<typename T> void Integrator<T>::rotate(int axes1, int axes2,
688 double angle, double ji[3],
689 double A[3][3]){
690 int i, j, k;
691 double sinAngle;
692 double cosAngle;
693 double angleSqr;
694 double angleSqrOver4;
695 double top, bottom;
696 double rot[3][3];
697 double tempA[3][3];
698 double tempJ[3];
699
700 // initialize the tempA
701
702 for (i = 0; i < 3; i++){
703 for (j = 0; j < 3; j++){
704 tempA[j][i] = A[i][j];
705 }
706 }
707
708 // initialize the tempJ
709
710 for (i = 0; i < 3; i++)
711 tempJ[i] = ji[i];
712
713 // initalize rot as a unit matrix
714
715 rot[0][0] = 1.0;
716 rot[0][1] = 0.0;
717 rot[0][2] = 0.0;
718
719 rot[1][0] = 0.0;
720 rot[1][1] = 1.0;
721 rot[1][2] = 0.0;
722
723 rot[2][0] = 0.0;
724 rot[2][1] = 0.0;
725 rot[2][2] = 1.0;
726
727 // use a small angle aproximation for sin and cosine
728
729 angleSqr = angle * angle;
730 angleSqrOver4 = angleSqr / 4.0;
731 top = 1.0 - angleSqrOver4;
732 bottom = 1.0 + angleSqrOver4;
733
734 cosAngle = top / bottom;
735 sinAngle = angle / bottom;
736
737 rot[axes1][axes1] = cosAngle;
738 rot[axes2][axes2] = cosAngle;
739
740 rot[axes1][axes2] = sinAngle;
741 rot[axes2][axes1] = -sinAngle;
742
743 // rotate the momentum acoording to: ji[] = rot[][] * ji[]
744
745 for (i = 0; i < 3; i++){
746 ji[i] = 0.0;
747 for (k = 0; k < 3; k++){
748 ji[i] += rot[i][k] * tempJ[k];
749 }
750 }
751
752 // rotate the Rotation matrix acording to:
753 // A[][] = A[][] * transpose(rot[][])
754
755
756 // NOte for as yet unknown reason, we are performing the
757 // calculation as:
758 // transpose(A[][]) = transpose(A[][]) * transpose(rot[][])
759
760 for (i = 0; i < 3; i++){
761 for (j = 0; j < 3; j++){
762 A[j][i] = 0.0;
763 for (k = 0; k < 3; k++){
764 A[j][i] += tempA[i][k] * rot[j][k];
765 }
766 }
767 }
768 }
769
770 template<typename T> void Integrator<T>::calcForce(int calcPot, int calcStress){
771 myFF->doForces(calcPot, calcStress);
772 }
773
774 template<typename T> void Integrator<T>::thermalize(){
775 tStats->velocitize();
776 }
777
778 template<typename T> double Integrator<T>::getConservedQuantity(void){
779 return tStats->getTotalE();
780 }