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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 1035
Committed: Fri Feb 6 21:37:59 2004 UTC (20 years, 5 months ago) by tim
File size: 17368 byte(s)
Log Message:
Single version of energy minimization for argon is working, need to add constraint

File Contents

# User Rev Content
1 mmeineke 558 #include <iostream>
2 gezelter 829 #include <stdlib.h>
3     #include <math.h>
4 mmeineke 558
5     #ifdef IS_MPI
6     #include "mpiSimulation.hpp"
7     #include <unistd.h>
8     #endif //is_mpi
9    
10 chuckv 892 #ifdef PROFILE
11     #include "mdProfile.hpp"
12     #endif // profile
13    
14 mmeineke 558 #include "Integrator.hpp"
15     #include "simError.h"
16    
17    
18 tim 725 template<typename T> Integrator<T>::Integrator(SimInfo* theInfo,
19     ForceFields* the_ff){
20 mmeineke 558 info = theInfo;
21     myFF = the_ff;
22     isFirst = 1;
23    
24     molecules = info->molecules;
25     nMols = info->n_mol;
26    
27     // give a little love back to the SimInfo object
28 tim 725
29     if (info->the_integrator != NULL){
30     delete info->the_integrator;
31     }
32 tim 837
33 mmeineke 558 nAtoms = info->n_atoms;
34    
35     // check for constraints
36 tim 725
37     constrainedA = NULL;
38     constrainedB = NULL;
39 mmeineke 558 constrainedDsqr = NULL;
40 tim 725 moving = NULL;
41     moved = NULL;
42     oldPos = NULL;
43    
44 mmeineke 558 nConstrained = 0;
45    
46     checkConstraints();
47     }
48    
49 tim 725 template<typename T> Integrator<T>::~Integrator(){
50     if (nConstrained){
51 mmeineke 558 delete[] constrainedA;
52     delete[] constrainedB;
53     delete[] constrainedDsqr;
54     delete[] moving;
55     delete[] moved;
56 mmeineke 561 delete[] oldPos;
57 mmeineke 558 }
58     }
59    
60 tim 725 template<typename T> void Integrator<T>::checkConstraints(void){
61 mmeineke 558 isConstrained = 0;
62    
63 tim 725 Constraint* temp_con;
64     Constraint* dummy_plug;
65 mmeineke 558 temp_con = new Constraint[info->n_SRI];
66     nConstrained = 0;
67     int constrained = 0;
68 tim 725
69 mmeineke 558 SRI** theArray;
70 tim 725 for (int i = 0; i < nMols; i++){
71     theArray = (SRI * *) molecules[i].getMyBonds();
72     for (int j = 0; j < molecules[i].getNBonds(); j++){
73 mmeineke 558 constrained = theArray[j]->is_constrained();
74 mmeineke 594
75 tim 725 if (constrained){
76     dummy_plug = theArray[j]->get_constraint();
77     temp_con[nConstrained].set_a(dummy_plug->get_a());
78     temp_con[nConstrained].set_b(dummy_plug->get_b());
79     temp_con[nConstrained].set_dsqr(dummy_plug->get_dsqr());
80 mmeineke 594
81 tim 725 nConstrained++;
82     constrained = 0;
83     }
84 mmeineke 558 }
85    
86 tim 725 theArray = (SRI * *) molecules[i].getMyBends();
87     for (int j = 0; j < molecules[i].getNBends(); j++){
88 mmeineke 558 constrained = theArray[j]->is_constrained();
89 tim 725
90     if (constrained){
91     dummy_plug = theArray[j]->get_constraint();
92     temp_con[nConstrained].set_a(dummy_plug->get_a());
93     temp_con[nConstrained].set_b(dummy_plug->get_b());
94     temp_con[nConstrained].set_dsqr(dummy_plug->get_dsqr());
95    
96     nConstrained++;
97     constrained = 0;
98 mmeineke 558 }
99     }
100    
101 tim 725 theArray = (SRI * *) molecules[i].getMyTorsions();
102     for (int j = 0; j < molecules[i].getNTorsions(); j++){
103 mmeineke 558 constrained = theArray[j]->is_constrained();
104 tim 725
105     if (constrained){
106     dummy_plug = theArray[j]->get_constraint();
107     temp_con[nConstrained].set_a(dummy_plug->get_a());
108     temp_con[nConstrained].set_b(dummy_plug->get_b());
109     temp_con[nConstrained].set_dsqr(dummy_plug->get_dsqr());
110    
111     nConstrained++;
112     constrained = 0;
113 mmeineke 558 }
114     }
115     }
116    
117 tim 725 if (nConstrained > 0){
118 mmeineke 558 isConstrained = 1;
119    
120 tim 725 if (constrainedA != NULL)
121     delete[] constrainedA;
122     if (constrainedB != NULL)
123     delete[] constrainedB;
124     if (constrainedDsqr != NULL)
125     delete[] constrainedDsqr;
126 mmeineke 558
127 tim 725 constrainedA = new int[nConstrained];
128     constrainedB = new int[nConstrained];
129 mmeineke 558 constrainedDsqr = new double[nConstrained];
130 tim 725
131     for (int i = 0; i < nConstrained; i++){
132 mmeineke 558 constrainedA[i] = temp_con[i].get_a();
133     constrainedB[i] = temp_con[i].get_b();
134     constrainedDsqr[i] = temp_con[i].get_dsqr();
135     }
136    
137 tim 725
138 chrisfen 999 // save oldAtoms to check for lode balancing later on.
139 tim 725
140 mmeineke 558 oldAtoms = nAtoms;
141 tim 725
142 mmeineke 558 moving = new int[nAtoms];
143 tim 725 moved = new int[nAtoms];
144 mmeineke 558
145 tim 725 oldPos = new double[nAtoms * 3];
146 mmeineke 558 }
147 tim 725
148 mmeineke 558 delete[] temp_con;
149     }
150    
151    
152 tim 725 template<typename T> void Integrator<T>::integrate(void){
153 mmeineke 558
154 tim 725 double runTime = info->run_time;
155     double sampleTime = info->sampleTime;
156     double statusTime = info->statusTime;
157 mmeineke 558 double thermalTime = info->thermalTime;
158 mmeineke 746 double resetTime = info->resetTime;
159 mmeineke 558
160 mmeineke 746
161 mmeineke 558 double currSample;
162     double currThermal;
163     double currStatus;
164 mmeineke 746 double currReset;
165 tim 837
166 mmeineke 558 int calcPot, calcStress;
167    
168 tim 725 tStats = new Thermo(info);
169     statOut = new StatWriter(info);
170     dumpOut = new DumpWriter(info);
171 mmeineke 558
172 mmeineke 561 atoms = info->atoms;
173    
174     dt = info->dt;
175 mmeineke 558 dt2 = 0.5 * dt;
176    
177 mmeineke 784 readyCheck();
178    
179 mmeineke 558 // initialize the forces before the first step
180    
181 tim 677 calcForce(1, 1);
182 tim 781
183 tim 1035 //temp test
184     tStats->getPotential();
185    
186 tim 781 if (nConstrained){
187     preMove();
188     constrainA();
189 tim 837 calcForce(1, 1);
190 tim 781 constrainB();
191     }
192 mmeineke 843
193 tim 725 if (info->setTemp){
194 tim 677 thermalize();
195 mmeineke 558 }
196 tim 725
197 mmeineke 558 calcPot = 0;
198     calcStress = 0;
199 mmeineke 711 currSample = sampleTime + info->getTime();
200     currThermal = thermalTime+ info->getTime();
201     currStatus = statusTime + info->getTime();
202 mmeineke 746 currReset = resetTime + info->getTime();
203 mmeineke 558
204 tim 725 dumpOut->writeDump(info->getTime());
205     statOut->writeStat(info->getTime());
206 mmeineke 559
207    
208     #ifdef IS_MPI
209 tim 725 strcpy(checkPointMsg, "The integrator is ready to go.");
210 mmeineke 559 MPIcheckPoint();
211     #endif // is_mpi
212    
213 tim 725 while (info->getTime() < runTime){
214     if ((info->getTime() + dt) >= currStatus){
215 mmeineke 558 calcPot = 1;
216     calcStress = 1;
217     }
218 mmeineke 561
219 chuckv 892 #ifdef PROFILE
220     startProfile( pro1 );
221     #endif
222    
223 tim 725 integrateStep(calcPot, calcStress);
224    
225 chuckv 892 #ifdef PROFILE
226     endProfile( pro1 );
227    
228     startProfile( pro2 );
229     #endif // profile
230    
231 mmeineke 643 info->incrTime(dt);
232 mmeineke 558
233 tim 725 if (info->setTemp){
234     if (info->getTime() >= currThermal){
235     thermalize();
236     currThermal += thermalTime;
237 mmeineke 558 }
238     }
239    
240 tim 725 if (info->getTime() >= currSample){
241     dumpOut->writeDump(info->getTime());
242 mmeineke 558 currSample += sampleTime;
243     }
244    
245 tim 725 if (info->getTime() >= currStatus){
246 tim 837 statOut->writeStat(info->getTime());
247     calcPot = 0;
248 mmeineke 558 calcStress = 0;
249     currStatus += statusTime;
250 tim 837 }
251 mmeineke 559
252 mmeineke 746 if (info->resetIntegrator){
253     if (info->getTime() >= currReset){
254     this->resetIntegrator();
255     currReset += resetTime;
256     }
257     }
258 chuckv 892
259     #ifdef PROFILE
260     endProfile( pro2 );
261     #endif //profile
262 mmeineke 746
263 mmeineke 559 #ifdef IS_MPI
264 tim 725 strcpy(checkPointMsg, "successfully took a time step.");
265 mmeineke 559 MPIcheckPoint();
266     #endif // is_mpi
267 mmeineke 558 }
268    
269 mmeineke 561 delete dumpOut;
270     delete statOut;
271 mmeineke 558 }
272    
273 tim 725 template<typename T> void Integrator<T>::integrateStep(int calcPot,
274     int calcStress){
275 mmeineke 558 // Position full step, and velocity half step
276 chuckv 892
277     #ifdef PROFILE
278     startProfile(pro3);
279     #endif //profile
280    
281 tim 725 preMove();
282 mmeineke 558
283 chuckv 892 #ifdef PROFILE
284     endProfile(pro3);
285    
286     startProfile(pro4);
287     #endif // profile
288    
289 mmeineke 558 moveA();
290    
291 chuckv 892 #ifdef PROFILE
292     endProfile(pro4);
293    
294     startProfile(pro5);
295     #endif//profile
296 tim 725
297    
298 mmeineke 614 #ifdef IS_MPI
299 tim 725 strcpy(checkPointMsg, "Succesful moveA\n");
300 mmeineke 614 MPIcheckPoint();
301     #endif // is_mpi
302    
303 tim 725
304 mmeineke 558 // calc forces
305    
306 tim 725 calcForce(calcPot, calcStress);
307 mmeineke 558
308 mmeineke 614 #ifdef IS_MPI
309 tim 725 strcpy(checkPointMsg, "Succesful doForces\n");
310 mmeineke 614 MPIcheckPoint();
311     #endif // is_mpi
312    
313 chuckv 892 #ifdef PROFILE
314     endProfile( pro5 );
315 tim 725
316 chuckv 892 startProfile( pro6 );
317     #endif //profile
318    
319 mmeineke 558 // finish the velocity half step
320 tim 725
321 mmeineke 558 moveB();
322 tim 725
323 chuckv 892 #ifdef PROFILE
324     endProfile(pro6);
325     #endif // profile
326 tim 725
327 mmeineke 614 #ifdef IS_MPI
328 tim 725 strcpy(checkPointMsg, "Succesful moveB\n");
329 mmeineke 614 MPIcheckPoint();
330     #endif // is_mpi
331 mmeineke 558 }
332    
333    
334 tim 725 template<typename T> void Integrator<T>::moveA(void){
335 gezelter 600 int i, j;
336 mmeineke 558 DirectionalAtom* dAtom;
337 gezelter 600 double Tb[3], ji[3];
338     double vel[3], pos[3], frc[3];
339     double mass;
340 mmeineke 558
341 tim 725 for (i = 0; i < nAtoms; i++){
342     atoms[i]->getVel(vel);
343     atoms[i]->getPos(pos);
344     atoms[i]->getFrc(frc);
345 mmeineke 567
346 gezelter 600 mass = atoms[i]->getMass();
347 mmeineke 594
348 tim 725 for (j = 0; j < 3; j++){
349 gezelter 600 // velocity half step
350 tim 725 vel[j] += (dt2 * frc[j] / mass) * eConvert;
351 gezelter 600 // position whole step
352     pos[j] += dt * vel[j];
353     }
354 mmeineke 594
355 tim 725 atoms[i]->setVel(vel);
356     atoms[i]->setPos(pos);
357 gezelter 600
358 tim 725 if (atoms[i]->isDirectional()){
359     dAtom = (DirectionalAtom *) atoms[i];
360 mmeineke 558
361     // get and convert the torque to body frame
362 mmeineke 597
363 tim 725 dAtom->getTrq(Tb);
364     dAtom->lab2Body(Tb);
365    
366 mmeineke 558 // get the angular momentum, and propagate a half step
367 gezelter 600
368 tim 725 dAtom->getJ(ji);
369 gezelter 600
370 tim 725 for (j = 0; j < 3; j++)
371 gezelter 600 ji[j] += (dt2 * Tb[j]) * eConvert;
372 tim 725
373 mmeineke 778 this->rotationPropagation( dAtom, ji );
374 gezelter 600
375 tim 725 dAtom->setJ(ji);
376     }
377 mmeineke 558 }
378 mmeineke 768
379     if (nConstrained){
380     constrainA();
381     }
382 mmeineke 558 }
383    
384    
385 tim 725 template<typename T> void Integrator<T>::moveB(void){
386 gezelter 600 int i, j;
387 mmeineke 558 DirectionalAtom* dAtom;
388 gezelter 600 double Tb[3], ji[3];
389     double vel[3], frc[3];
390     double mass;
391 mmeineke 558
392 tim 725 for (i = 0; i < nAtoms; i++){
393     atoms[i]->getVel(vel);
394     atoms[i]->getFrc(frc);
395 mmeineke 558
396 gezelter 600 mass = atoms[i]->getMass();
397    
398 mmeineke 558 // velocity half step
399 tim 725 for (j = 0; j < 3; j++)
400     vel[j] += (dt2 * frc[j] / mass) * eConvert;
401 gezelter 600
402 tim 725 atoms[i]->setVel(vel);
403 mmeineke 597
404 tim 725 if (atoms[i]->isDirectional()){
405     dAtom = (DirectionalAtom *) atoms[i];
406    
407 tim 837 // get and convert the torque to body frame
408 gezelter 600
409 tim 725 dAtom->getTrq(Tb);
410     dAtom->lab2Body(Tb);
411 gezelter 600
412     // get the angular momentum, and propagate a half step
413    
414 tim 725 dAtom->getJ(ji);
415 gezelter 600
416 tim 725 for (j = 0; j < 3; j++)
417 gezelter 600 ji[j] += (dt2 * Tb[j]) * eConvert;
418 mmeineke 597
419 tim 725
420     dAtom->setJ(ji);
421 mmeineke 558 }
422     }
423 mmeineke 768
424     if (nConstrained){
425     constrainB();
426     }
427 mmeineke 558 }
428    
429 tim 725 template<typename T> void Integrator<T>::preMove(void){
430 gezelter 600 int i, j;
431     double pos[3];
432 mmeineke 558
433 tim 725 if (nConstrained){
434     for (i = 0; i < nAtoms; i++){
435     atoms[i]->getPos(pos);
436 mmeineke 561
437 tim 725 for (j = 0; j < 3; j++){
438     oldPos[3 * i + j] = pos[j];
439 gezelter 600 }
440     }
441 tim 725 }
442 gezelter 600 }
443    
444 tim 645 template<typename T> void Integrator<T>::constrainA(){
445 mmeineke 787 int i, j;
446 mmeineke 558 int done;
447 gezelter 600 double posA[3], posB[3];
448     double velA[3], velB[3];
449 mmeineke 572 double pab[3];
450     double rab[3];
451 mmeineke 563 int a, b, ax, ay, az, bx, by, bz;
452 mmeineke 558 double rma, rmb;
453     double dx, dy, dz;
454 mmeineke 561 double rpab;
455 mmeineke 558 double rabsq, pabsq, rpabsq;
456     double diffsq;
457     double gab;
458     int iteration;
459    
460 tim 725 for (i = 0; i < nAtoms; i++){
461 mmeineke 558 moving[i] = 0;
462 tim 725 moved[i] = 1;
463 mmeineke 558 }
464 mmeineke 567
465 mmeineke 558 iteration = 0;
466     done = 0;
467 tim 725 while (!done && (iteration < maxIteration)){
468 mmeineke 558 done = 1;
469 tim 725 for (i = 0; i < nConstrained; i++){
470 mmeineke 558 a = constrainedA[i];
471     b = constrainedB[i];
472 mmeineke 563
473 tim 725 ax = (a * 3) + 0;
474     ay = (a * 3) + 1;
475     az = (a * 3) + 2;
476 mmeineke 563
477 tim 725 bx = (b * 3) + 0;
478     by = (b * 3) + 1;
479     bz = (b * 3) + 2;
480    
481     if (moved[a] || moved[b]){
482     atoms[a]->getPos(posA);
483     atoms[b]->getPos(posB);
484    
485     for (j = 0; j < 3; j++)
486 gezelter 600 pab[j] = posA[j] - posB[j];
487 mmeineke 567
488 tim 725 //periodic boundary condition
489 mmeineke 567
490 tim 725 info->wrapVector(pab);
491 mmeineke 572
492 tim 725 pabsq = pab[0] * pab[0] + pab[1] * pab[1] + pab[2] * pab[2];
493 mmeineke 558
494 tim 725 rabsq = constrainedDsqr[i];
495     diffsq = rabsq - pabsq;
496 mmeineke 567
497 tim 725 // the original rattle code from alan tidesley
498     if (fabs(diffsq) > (tol * rabsq * 2)){
499     rab[0] = oldPos[ax] - oldPos[bx];
500     rab[1] = oldPos[ay] - oldPos[by];
501     rab[2] = oldPos[az] - oldPos[bz];
502 mmeineke 558
503 tim 725 info->wrapVector(rab);
504 mmeineke 567
505 tim 725 rpab = rab[0] * pab[0] + rab[1] * pab[1] + rab[2] * pab[2];
506 mmeineke 558
507 tim 725 rpabsq = rpab * rpab;
508 mmeineke 558
509 mmeineke 563
510 tim 725 if (rpabsq < (rabsq * -diffsq)){
511 mmeineke 558 #ifdef IS_MPI
512 tim 725 a = atoms[a]->getGlobalIndex();
513     b = atoms[b]->getGlobalIndex();
514 mmeineke 558 #endif //is_mpi
515 tim 725 sprintf(painCave.errMsg,
516     "Constraint failure in constrainA at atom %d and %d.\n", a,
517     b);
518     painCave.isFatal = 1;
519     simError();
520     }
521 mmeineke 558
522 tim 725 rma = 1.0 / atoms[a]->getMass();
523     rmb = 1.0 / atoms[b]->getMass();
524 mmeineke 567
525 tim 725 gab = diffsq / (2.0 * (rma + rmb) * rpab);
526 mmeineke 567
527 mmeineke 572 dx = rab[0] * gab;
528     dy = rab[1] * gab;
529     dz = rab[2] * gab;
530 mmeineke 558
531 tim 725 posA[0] += rma * dx;
532     posA[1] += rma * dy;
533     posA[2] += rma * dz;
534 mmeineke 558
535 tim 725 atoms[a]->setPos(posA);
536 mmeineke 558
537 tim 725 posB[0] -= rmb * dx;
538     posB[1] -= rmb * dy;
539     posB[2] -= rmb * dz;
540 gezelter 600
541 tim 725 atoms[b]->setPos(posB);
542 gezelter 600
543 mmeineke 558 dx = dx / dt;
544     dy = dy / dt;
545     dz = dz / dt;
546    
547 tim 725 atoms[a]->getVel(velA);
548 mmeineke 558
549 tim 725 velA[0] += rma * dx;
550     velA[1] += rma * dy;
551     velA[2] += rma * dz;
552 mmeineke 558
553 tim 725 atoms[a]->setVel(velA);
554 gezelter 600
555 tim 725 atoms[b]->getVel(velB);
556 gezelter 600
557 tim 725 velB[0] -= rmb * dx;
558     velB[1] -= rmb * dy;
559     velB[2] -= rmb * dz;
560 gezelter 600
561 tim 725 atoms[b]->setVel(velB);
562 gezelter 600
563 tim 725 moving[a] = 1;
564     moving[b] = 1;
565     done = 0;
566     }
567 mmeineke 558 }
568     }
569 tim 725
570     for (i = 0; i < nAtoms; i++){
571 mmeineke 558 moved[i] = moving[i];
572     moving[i] = 0;
573     }
574    
575     iteration++;
576     }
577    
578 tim 725 if (!done){
579     sprintf(painCave.errMsg,
580     "Constraint failure in constrainA, too many iterations: %d\n",
581     iteration);
582 mmeineke 558 painCave.isFatal = 1;
583     simError();
584     }
585 mmeineke 768
586 mmeineke 558 }
587    
588 tim 725 template<typename T> void Integrator<T>::constrainB(void){
589 mmeineke 787 int i, j;
590 mmeineke 558 int done;
591 gezelter 600 double posA[3], posB[3];
592     double velA[3], velB[3];
593 mmeineke 558 double vxab, vyab, vzab;
594 mmeineke 572 double rab[3];
595 mmeineke 563 int a, b, ax, ay, az, bx, by, bz;
596 mmeineke 558 double rma, rmb;
597     double dx, dy, dz;
598 mmeineke 787 double rvab;
599 mmeineke 558 double gab;
600     int iteration;
601    
602 tim 725 for (i = 0; i < nAtoms; i++){
603 mmeineke 558 moving[i] = 0;
604     moved[i] = 1;
605     }
606    
607     done = 0;
608 mmeineke 561 iteration = 0;
609 tim 725 while (!done && (iteration < maxIteration)){
610 mmeineke 567 done = 1;
611    
612 tim 725 for (i = 0; i < nConstrained; i++){
613 mmeineke 558 a = constrainedA[i];
614     b = constrainedB[i];
615    
616 tim 725 ax = (a * 3) + 0;
617     ay = (a * 3) + 1;
618     az = (a * 3) + 2;
619 mmeineke 563
620 tim 725 bx = (b * 3) + 0;
621     by = (b * 3) + 1;
622     bz = (b * 3) + 2;
623 mmeineke 563
624 tim 725 if (moved[a] || moved[b]){
625     atoms[a]->getVel(velA);
626     atoms[b]->getVel(velB);
627 mmeineke 558
628 tim 725 vxab = velA[0] - velB[0];
629     vyab = velA[1] - velB[1];
630     vzab = velA[2] - velB[2];
631 gezelter 600
632 tim 725 atoms[a]->getPos(posA);
633     atoms[b]->getPos(posB);
634 gezelter 600
635 tim 725 for (j = 0; j < 3; j++)
636 gezelter 600 rab[j] = posA[j] - posB[j];
637 mmeineke 558
638 tim 725 info->wrapVector(rab);
639 mmeineke 558
640 tim 725 rma = 1.0 / atoms[a]->getMass();
641     rmb = 1.0 / atoms[b]->getMass();
642 mmeineke 558
643 tim 725 rvab = rab[0] * vxab + rab[1] * vyab + rab[2] * vzab;
644 gezelter 600
645 tim 725 gab = -rvab / ((rma + rmb) * constrainedDsqr[i]);
646 gezelter 600
647 tim 725 if (fabs(gab) > tol){
648     dx = rab[0] * gab;
649     dy = rab[1] * gab;
650     dz = rab[2] * gab;
651    
652     velA[0] += rma * dx;
653     velA[1] += rma * dy;
654     velA[2] += rma * dz;
655    
656     atoms[a]->setVel(velA);
657    
658     velB[0] -= rmb * dx;
659     velB[1] -= rmb * dy;
660     velB[2] -= rmb * dz;
661    
662     atoms[b]->setVel(velB);
663    
664     moving[a] = 1;
665     moving[b] = 1;
666     done = 0;
667     }
668 mmeineke 558 }
669     }
670    
671 tim 725 for (i = 0; i < nAtoms; i++){
672 mmeineke 558 moved[i] = moving[i];
673     moving[i] = 0;
674     }
675 tim 725
676 mmeineke 558 iteration++;
677     }
678    
679 tim 725 if (!done){
680     sprintf(painCave.errMsg,
681     "Constraint failure in constrainB, too many iterations: %d\n",
682     iteration);
683 mmeineke 558 painCave.isFatal = 1;
684     simError();
685 tim 725 }
686 mmeineke 558 }
687    
688 mmeineke 778 template<typename T> void Integrator<T>::rotationPropagation
689     ( DirectionalAtom* dAtom, double ji[3] ){
690    
691     double angle;
692     double A[3][3], I[3][3];
693    
694     // use the angular velocities to propagate the rotation matrix a
695     // full time step
696    
697     dAtom->getA(A);
698     dAtom->getI(I);
699 tim 837
700     // rotate about the x-axis
701 mmeineke 778 angle = dt2 * ji[0] / I[0][0];
702 tim 837 this->rotate( 1, 2, angle, ji, A );
703    
704 mmeineke 778 // rotate about the y-axis
705     angle = dt2 * ji[1] / I[1][1];
706     this->rotate( 2, 0, angle, ji, A );
707 tim 837
708 mmeineke 778 // rotate about the z-axis
709     angle = dt * ji[2] / I[2][2];
710     this->rotate( 0, 1, angle, ji, A);
711 tim 837
712 mmeineke 778 // rotate about the y-axis
713     angle = dt2 * ji[1] / I[1][1];
714     this->rotate( 2, 0, angle, ji, A );
715 tim 837
716 mmeineke 778 // rotate about the x-axis
717     angle = dt2 * ji[0] / I[0][0];
718     this->rotate( 1, 2, angle, ji, A );
719 tim 837
720     dAtom->setA( A );
721 mmeineke 778 }
722    
723 tim 725 template<typename T> void Integrator<T>::rotate(int axes1, int axes2,
724     double angle, double ji[3],
725     double A[3][3]){
726     int i, j, k;
727 mmeineke 558 double sinAngle;
728     double cosAngle;
729     double angleSqr;
730     double angleSqrOver4;
731     double top, bottom;
732     double rot[3][3];
733     double tempA[3][3];
734     double tempJ[3];
735    
736     // initialize the tempA
737    
738 tim 725 for (i = 0; i < 3; i++){
739     for (j = 0; j < 3; j++){
740 gezelter 600 tempA[j][i] = A[i][j];
741 mmeineke 558 }
742     }
743    
744     // initialize the tempJ
745    
746 tim 725 for (i = 0; i < 3; i++)
747     tempJ[i] = ji[i];
748    
749 mmeineke 558 // initalize rot as a unit matrix
750    
751     rot[0][0] = 1.0;
752     rot[0][1] = 0.0;
753     rot[0][2] = 0.0;
754    
755     rot[1][0] = 0.0;
756     rot[1][1] = 1.0;
757     rot[1][2] = 0.0;
758 tim 725
759 mmeineke 558 rot[2][0] = 0.0;
760     rot[2][1] = 0.0;
761     rot[2][2] = 1.0;
762 tim 725
763 mmeineke 558 // use a small angle aproximation for sin and cosine
764    
765 tim 725 angleSqr = angle * angle;
766 mmeineke 558 angleSqrOver4 = angleSqr / 4.0;
767     top = 1.0 - angleSqrOver4;
768     bottom = 1.0 + angleSqrOver4;
769    
770     cosAngle = top / bottom;
771     sinAngle = angle / bottom;
772    
773     rot[axes1][axes1] = cosAngle;
774     rot[axes2][axes2] = cosAngle;
775    
776     rot[axes1][axes2] = sinAngle;
777     rot[axes2][axes1] = -sinAngle;
778 tim 725
779 mmeineke 558 // rotate the momentum acoording to: ji[] = rot[][] * ji[]
780 tim 725
781     for (i = 0; i < 3; i++){
782 mmeineke 558 ji[i] = 0.0;
783 tim 725 for (k = 0; k < 3; k++){
784 mmeineke 558 ji[i] += rot[i][k] * tempJ[k];
785     }
786     }
787    
788 tim 837 // rotate the Rotation matrix acording to:
789 mmeineke 558 // A[][] = A[][] * transpose(rot[][])
790    
791    
792 mmeineke 561 // NOte for as yet unknown reason, we are performing the
793 mmeineke 558 // calculation as:
794     // transpose(A[][]) = transpose(A[][]) * transpose(rot[][])
795    
796 tim 725 for (i = 0; i < 3; i++){
797     for (j = 0; j < 3; j++){
798 gezelter 600 A[j][i] = 0.0;
799 tim 725 for (k = 0; k < 3; k++){
800     A[j][i] += tempA[i][k] * rot[j][k];
801 mmeineke 558 }
802     }
803     }
804     }
805 tim 677
806 tim 725 template<typename T> void Integrator<T>::calcForce(int calcPot, int calcStress){
807     myFF->doForces(calcPot, calcStress);
808 tim 677 }
809    
810     template<typename T> void Integrator<T>::thermalize(){
811 tim 725 tStats->velocitize();
812 tim 677 }
813 tim 763
814     template<typename T> double Integrator<T>::getConservedQuantity(void){
815     return tStats->getTotalE();
816 mmeineke 768 }
817 tim 837 template<typename T> string Integrator<T>::getAdditionalParameters(void){
818     //By default, return a null string
819     //The reason we use string instead of char* is that if we use char*, we will
820     //return a pointer point to local variable which might cause problem
821     return string();
822     }