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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 843
Committed: Wed Oct 29 20:41:39 2003 UTC (20 years, 8 months ago) by mmeineke
File size: 16796 byte(s)
Log Message:
fixed a stdlib.h include error in bass.l

fixed a little bug in the first time step, regarding the setting of ecr and est in fortran

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