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root/group/trunk/OOPSE/libmdtools/Integrator.cpp
Revision: 726
Committed: Tue Aug 26 20:37:30 2003 UTC (20 years, 10 months ago) by tim
File size: 16256 byte(s)
Log Message:
set default force substraction policy to PolicyByMass

File Contents

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