ViewVC Help
View File | Revision Log | Show Annotations | View Changeset | Root Listing
root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 829
Committed: Tue Oct 28 16:03:37 2003 UTC (20 years, 8 months ago) by gezelter
File size: 16556 byte(s)
Log Message:
replace c++ header stuff with more portable c header stuff
Also, mod file fixes and portability changes
Some fortran changes will need to be reversed.

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 #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
150 double runTime = info->run_time;
151 double sampleTime = info->sampleTime;
152 double statusTime = info->statusTime;
153 double thermalTime = info->thermalTime;
154 double resetTime = info->resetTime;
155
156
157 double currSample;
158 double currThermal;
159 double currStatus;
160 double currReset;
161
162 int calcPot, calcStress;
163
164 tStats = new Thermo(info);
165 statOut = new StatWriter(info);
166 dumpOut = new DumpWriter(info);
167
168 atoms = info->atoms;
169
170 dt = info->dt;
171 dt2 = 0.5 * dt;
172
173 readyCheck();
174
175 // initialize the forces before the first step
176
177 calcForce(1, 1);
178
179 if (nConstrained){
180 preMove();
181 constrainA();
182 calcForce(1, 1);
183 constrainB();
184 }
185
186 if (info->setTemp){
187 thermalize();
188 }
189
190 calcPot = 0;
191 calcStress = 0;
192 currSample = sampleTime + info->getTime();
193 currThermal = thermalTime+ info->getTime();
194 currStatus = statusTime + info->getTime();
195 currReset = resetTime + info->getTime();
196
197 dumpOut->writeDump(info->getTime());
198 statOut->writeStat(info->getTime());
199
200
201
202 #ifdef IS_MPI
203 strcpy(checkPointMsg, "The integrator is ready to go.");
204 MPIcheckPoint();
205 #endif // is_mpi
206
207 while (info->getTime() < runTime){
208 if ((info->getTime() + dt) >= currStatus){
209 calcPot = 1;
210 calcStress = 1;
211 }
212
213 integrateStep(calcPot, calcStress);
214
215 info->incrTime(dt);
216
217 if (info->setTemp){
218 if (info->getTime() >= currThermal){
219 thermalize();
220 currThermal += thermalTime;
221 }
222 }
223
224 if (info->getTime() >= currSample){
225 dumpOut->writeDump(info->getTime());
226 currSample += sampleTime;
227 }
228
229 if (info->getTime() >= currStatus){
230 statOut->writeStat(info->getTime());
231 calcPot = 0;
232 calcStress = 0;
233 currStatus += statusTime;
234 }
235
236 if (info->resetIntegrator){
237 if (info->getTime() >= currReset){
238 this->resetIntegrator();
239 currReset += resetTime;
240 }
241 }
242
243 #ifdef IS_MPI
244 strcpy(checkPointMsg, "successfully took a time step.");
245 MPIcheckPoint();
246 #endif // is_mpi
247 }
248
249
250 // write the last frame
251 dumpOut->writeDump(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;
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;
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 rvab;
561 double gab;
562 int iteration;
563
564 for (i = 0; i < nAtoms; i++){
565 moving[i] = 0;
566 moved[i] = 1;
567 }
568
569 done = 0;
570 iteration = 0;
571 while (!done && (iteration < maxIteration)){
572 done = 1;
573
574 for (i = 0; i < nConstrained; i++){
575 a = constrainedA[i];
576 b = constrainedB[i];
577
578 ax = (a * 3) + 0;
579 ay = (a * 3) + 1;
580 az = (a * 3) + 2;
581
582 bx = (b * 3) + 0;
583 by = (b * 3) + 1;
584 bz = (b * 3) + 2;
585
586 if (moved[a] || moved[b]){
587 atoms[a]->getVel(velA);
588 atoms[b]->getVel(velB);
589
590 vxab = velA[0] - velB[0];
591 vyab = velA[1] - velB[1];
592 vzab = velA[2] - velB[2];
593
594 atoms[a]->getPos(posA);
595 atoms[b]->getPos(posB);
596
597 for (j = 0; j < 3; j++)
598 rab[j] = posA[j] - posB[j];
599
600 info->wrapVector(rab);
601
602 rma = 1.0 / atoms[a]->getMass();
603 rmb = 1.0 / atoms[b]->getMass();
604
605 rvab = rab[0] * vxab + rab[1] * vyab + rab[2] * vzab;
606
607 gab = -rvab / ((rma + rmb) * constrainedDsqr[i]);
608
609 if (fabs(gab) > tol){
610 dx = rab[0] * gab;
611 dy = rab[1] * gab;
612 dz = rab[2] * gab;
613
614 velA[0] += rma * dx;
615 velA[1] += rma * dy;
616 velA[2] += rma * dz;
617
618 atoms[a]->setVel(velA);
619
620 velB[0] -= rmb * dx;
621 velB[1] -= rmb * dy;
622 velB[2] -= rmb * dz;
623
624 atoms[b]->setVel(velB);
625
626 moving[a] = 1;
627 moving[b] = 1;
628 done = 0;
629 }
630 }
631 }
632
633 for (i = 0; i < nAtoms; i++){
634 moved[i] = moving[i];
635 moving[i] = 0;
636 }
637
638 iteration++;
639 }
640
641 if (!done){
642 sprintf(painCave.errMsg,
643 "Constraint failure in constrainB, too many iterations: %d\n",
644 iteration);
645 painCave.isFatal = 1;
646 simError();
647 }
648 }
649
650 template<typename T> void Integrator<T>::rotationPropagation
651 ( DirectionalAtom* dAtom, double ji[3] ){
652
653 double angle;
654 double A[3][3], I[3][3];
655
656 // use the angular velocities to propagate the rotation matrix a
657 // full time step
658
659 dAtom->getA(A);
660 dAtom->getI(I);
661
662 // rotate about the x-axis
663 angle = dt2 * ji[0] / I[0][0];
664 this->rotate( 1, 2, angle, ji, A );
665
666 // rotate about the y-axis
667 angle = dt2 * ji[1] / I[1][1];
668 this->rotate( 2, 0, angle, ji, A );
669
670 // rotate about the z-axis
671 angle = dt * ji[2] / I[2][2];
672 this->rotate( 0, 1, angle, ji, A);
673
674 // rotate about the y-axis
675 angle = dt2 * ji[1] / I[1][1];
676 this->rotate( 2, 0, angle, ji, A );
677
678 // rotate about the x-axis
679 angle = dt2 * ji[0] / I[0][0];
680 this->rotate( 1, 2, angle, ji, A );
681
682 dAtom->setA( A );
683 }
684
685 template<typename T> void Integrator<T>::rotate(int axes1, int axes2,
686 double angle, double ji[3],
687 double A[3][3]){
688 int i, j, k;
689 double sinAngle;
690 double cosAngle;
691 double angleSqr;
692 double angleSqrOver4;
693 double top, bottom;
694 double rot[3][3];
695 double tempA[3][3];
696 double tempJ[3];
697
698 // initialize the tempA
699
700 for (i = 0; i < 3; i++){
701 for (j = 0; j < 3; j++){
702 tempA[j][i] = A[i][j];
703 }
704 }
705
706 // initialize the tempJ
707
708 for (i = 0; i < 3; i++)
709 tempJ[i] = ji[i];
710
711 // initalize rot as a unit matrix
712
713 rot[0][0] = 1.0;
714 rot[0][1] = 0.0;
715 rot[0][2] = 0.0;
716
717 rot[1][0] = 0.0;
718 rot[1][1] = 1.0;
719 rot[1][2] = 0.0;
720
721 rot[2][0] = 0.0;
722 rot[2][1] = 0.0;
723 rot[2][2] = 1.0;
724
725 // use a small angle aproximation for sin and cosine
726
727 angleSqr = angle * angle;
728 angleSqrOver4 = angleSqr / 4.0;
729 top = 1.0 - angleSqrOver4;
730 bottom = 1.0 + angleSqrOver4;
731
732 cosAngle = top / bottom;
733 sinAngle = angle / bottom;
734
735 rot[axes1][axes1] = cosAngle;
736 rot[axes2][axes2] = cosAngle;
737
738 rot[axes1][axes2] = sinAngle;
739 rot[axes2][axes1] = -sinAngle;
740
741 // rotate the momentum acoording to: ji[] = rot[][] * ji[]
742
743 for (i = 0; i < 3; i++){
744 ji[i] = 0.0;
745 for (k = 0; k < 3; k++){
746 ji[i] += rot[i][k] * tempJ[k];
747 }
748 }
749
750 // rotate the Rotation matrix acording to:
751 // A[][] = A[][] * transpose(rot[][])
752
753
754 // NOte for as yet unknown reason, we are performing the
755 // calculation as:
756 // transpose(A[][]) = transpose(A[][]) * transpose(rot[][])
757
758 for (i = 0; i < 3; i++){
759 for (j = 0; j < 3; j++){
760 A[j][i] = 0.0;
761 for (k = 0; k < 3; k++){
762 A[j][i] += tempA[i][k] * rot[j][k];
763 }
764 }
765 }
766 }
767
768 template<typename T> void Integrator<T>::calcForce(int calcPot, int calcStress){
769 myFF->doForces(calcPot, calcStress);
770 }
771
772 template<typename T> void Integrator<T>::thermalize(){
773 tStats->velocitize();
774 }
775
776 template<typename T> double Integrator<T>::getConservedQuantity(void){
777 return tStats->getTotalE();
778 }