| 1 |
#include <math.h> |
| 2 |
#include "RigidBody.hpp" |
| 3 |
#include "DirectionalAtom.hpp" |
| 4 |
#include "simError.h" |
| 5 |
#include "MatVec3.h" |
| 6 |
|
| 7 |
RigidBody::RigidBody() : StuntDouble() { |
| 8 |
objType = OT_RIGIDBODY; |
| 9 |
com_good = false; |
| 10 |
precalc_done = false; |
| 11 |
} |
| 12 |
|
| 13 |
RigidBody::~RigidBody() { |
| 14 |
} |
| 15 |
|
| 16 |
void RigidBody::addAtom(Atom* at, AtomStamp* ats) { |
| 17 |
|
| 18 |
vec3 coords; |
| 19 |
vec3 euler; |
| 20 |
mat3x3 Atmp; |
| 21 |
|
| 22 |
myAtoms.push_back(at); |
| 23 |
|
| 24 |
if( !ats->havePosition() ){ |
| 25 |
sprintf( painCave.errMsg, |
| 26 |
"RigidBody error.\n" |
| 27 |
"\tAtom %s does not have a position specified.\n" |
| 28 |
"\tThis means RigidBody cannot set up reference coordinates.\n", |
| 29 |
ats->getType() ); |
| 30 |
painCave.isFatal = 1; |
| 31 |
simError(); |
| 32 |
} |
| 33 |
|
| 34 |
coords[0] = ats->getPosX(); |
| 35 |
coords[1] = ats->getPosY(); |
| 36 |
coords[2] = ats->getPosZ(); |
| 37 |
|
| 38 |
refCoords.push_back(coords); |
| 39 |
|
| 40 |
if (at->isDirectional()) { |
| 41 |
|
| 42 |
if( !ats->haveOrientation() ){ |
| 43 |
sprintf( painCave.errMsg, |
| 44 |
"RigidBody error.\n" |
| 45 |
"\tAtom %s does not have an orientation specified.\n" |
| 46 |
"\tThis means RigidBody cannot set up reference orientations.\n", |
| 47 |
ats->getType() ); |
| 48 |
painCave.isFatal = 1; |
| 49 |
simError(); |
| 50 |
} |
| 51 |
|
| 52 |
euler[0] = ats->getEulerPhi(); |
| 53 |
euler[1] = ats->getEulerTheta(); |
| 54 |
euler[2] = ats->getEulerPsi(); |
| 55 |
|
| 56 |
doEulerToRotMat(euler, Atmp); |
| 57 |
|
| 58 |
refOrients.push_back(Atmp); |
| 59 |
|
| 60 |
} |
| 61 |
} |
| 62 |
|
| 63 |
void RigidBody::getPos(double theP[3]){ |
| 64 |
for (int i = 0; i < 3 ; i++) |
| 65 |
theP[i] = pos[i]; |
| 66 |
} |
| 67 |
|
| 68 |
void RigidBody::setPos(double theP[3]){ |
| 69 |
for (int i = 0; i < 3 ; i++) |
| 70 |
pos[i] = theP[i]; |
| 71 |
} |
| 72 |
|
| 73 |
void RigidBody::getVel(double theV[3]){ |
| 74 |
for (int i = 0; i < 3 ; i++) |
| 75 |
theV[i] = vel[i]; |
| 76 |
} |
| 77 |
|
| 78 |
void RigidBody::setVel(double theV[3]){ |
| 79 |
for (int i = 0; i < 3 ; i++) |
| 80 |
vel[i] = theV[i]; |
| 81 |
} |
| 82 |
|
| 83 |
void RigidBody::getFrc(double theF[3]){ |
| 84 |
for (int i = 0; i < 3 ; i++) |
| 85 |
theF[i] = frc[i]; |
| 86 |
} |
| 87 |
|
| 88 |
void RigidBody::addFrc(double theF[3]){ |
| 89 |
for (int i = 0; i < 3 ; i++) |
| 90 |
frc[i] += theF[i]; |
| 91 |
} |
| 92 |
|
| 93 |
void RigidBody::zeroForces() { |
| 94 |
|
| 95 |
for (int i = 0; i < 3; i++) { |
| 96 |
frc[i] = 0.0; |
| 97 |
trq[i] = 0.0; |
| 98 |
} |
| 99 |
|
| 100 |
forces_good = false; |
| 101 |
|
| 102 |
} |
| 103 |
|
| 104 |
void RigidBody::setEulerAngles( double phi, double theta, double psi ){ |
| 105 |
|
| 106 |
A[0][0] = (cos(phi) * cos(psi)) - (sin(phi) * cos(theta) * sin(psi)); |
| 107 |
A[0][1] = (sin(phi) * cos(psi)) + (cos(phi) * cos(theta) * sin(psi)); |
| 108 |
A[0][2] = sin(theta) * sin(psi); |
| 109 |
|
| 110 |
A[1][0] = -(cos(phi) * sin(psi)) - (sin(phi) * cos(theta) * cos(psi)); |
| 111 |
A[1][1] = -(sin(phi) * sin(psi)) + (cos(phi) * cos(theta) * cos(psi)); |
| 112 |
A[1][2] = sin(theta) * cos(psi); |
| 113 |
|
| 114 |
A[2][0] = sin(phi) * sin(theta); |
| 115 |
A[2][1] = -cos(phi) * sin(theta); |
| 116 |
A[2][2] = cos(theta); |
| 117 |
|
| 118 |
} |
| 119 |
|
| 120 |
void RigidBody::getQ( double q[4] ){ |
| 121 |
|
| 122 |
double t, s; |
| 123 |
double ad1, ad2, ad3; |
| 124 |
|
| 125 |
t = A[0][0] + A[1][1] + A[2][2] + 1.0; |
| 126 |
if( t > 0.0 ){ |
| 127 |
|
| 128 |
s = 0.5 / sqrt( t ); |
| 129 |
q[0] = 0.25 / s; |
| 130 |
q[1] = (A[1][2] - A[2][1]) * s; |
| 131 |
q[2] = (A[2][0] - A[0][2]) * s; |
| 132 |
q[3] = (A[0][1] - A[1][0]) * s; |
| 133 |
} |
| 134 |
else{ |
| 135 |
|
| 136 |
ad1 = fabs( A[0][0] ); |
| 137 |
ad2 = fabs( A[1][1] ); |
| 138 |
ad3 = fabs( A[2][2] ); |
| 139 |
|
| 140 |
if( ad1 >= ad2 && ad1 >= ad3 ){ |
| 141 |
|
| 142 |
s = 2.0 * sqrt( 1.0 + A[0][0] - A[1][1] - A[2][2] ); |
| 143 |
q[0] = (A[1][2] + A[2][1]) / s; |
| 144 |
q[1] = 0.5 / s; |
| 145 |
q[2] = (A[0][1] + A[1][0]) / s; |
| 146 |
q[3] = (A[0][2] + A[2][0]) / s; |
| 147 |
} |
| 148 |
else if( ad2 >= ad1 && ad2 >= ad3 ){ |
| 149 |
|
| 150 |
s = sqrt( 1.0 + A[1][1] - A[0][0] - A[2][2] ) * 2.0; |
| 151 |
q[0] = (A[0][2] + A[2][0]) / s; |
| 152 |
q[1] = (A[0][1] + A[1][0]) / s; |
| 153 |
q[2] = 0.5 / s; |
| 154 |
q[3] = (A[1][2] + A[2][1]) / s; |
| 155 |
} |
| 156 |
else{ |
| 157 |
|
| 158 |
s = sqrt( 1.0 + A[2][2] - A[0][0] - A[1][1] ) * 2.0; |
| 159 |
q[0] = (A[0][1] + A[1][0]) / s; |
| 160 |
q[1] = (A[0][2] + A[2][0]) / s; |
| 161 |
q[2] = (A[1][2] + A[2][1]) / s; |
| 162 |
q[3] = 0.5 / s; |
| 163 |
} |
| 164 |
} |
| 165 |
} |
| 166 |
|
| 167 |
void RigidBody::setQ( double the_q[4] ){ |
| 168 |
|
| 169 |
double q0Sqr, q1Sqr, q2Sqr, q3Sqr; |
| 170 |
|
| 171 |
q0Sqr = the_q[0] * the_q[0]; |
| 172 |
q1Sqr = the_q[1] * the_q[1]; |
| 173 |
q2Sqr = the_q[2] * the_q[2]; |
| 174 |
q3Sqr = the_q[3] * the_q[3]; |
| 175 |
|
| 176 |
A[0][0] = q0Sqr + q1Sqr - q2Sqr - q3Sqr; |
| 177 |
A[0][1] = 2.0 * ( the_q[1] * the_q[2] + the_q[0] * the_q[3] ); |
| 178 |
A[0][2] = 2.0 * ( the_q[1] * the_q[3] - the_q[0] * the_q[2] ); |
| 179 |
|
| 180 |
A[1][0] = 2.0 * ( the_q[1] * the_q[2] - the_q[0] * the_q[3] ); |
| 181 |
A[1][1] = q0Sqr - q1Sqr + q2Sqr - q3Sqr; |
| 182 |
A[1][2] = 2.0 * ( the_q[2] * the_q[3] + the_q[0] * the_q[1] ); |
| 183 |
|
| 184 |
A[2][0] = 2.0 * ( the_q[1] * the_q[3] + the_q[0] * the_q[2] ); |
| 185 |
A[2][1] = 2.0 * ( the_q[2] * the_q[3] - the_q[0] * the_q[1] ); |
| 186 |
A[2][2] = q0Sqr - q1Sqr -q2Sqr +q3Sqr; |
| 187 |
|
| 188 |
} |
| 189 |
|
| 190 |
void RigidBody::getA( double the_A[3][3] ){ |
| 191 |
|
| 192 |
for (int i = 0; i < 3; i++) |
| 193 |
for (int j = 0; j < 3; j++) |
| 194 |
the_A[i][j] = the_A[i][j]; |
| 195 |
|
| 196 |
} |
| 197 |
|
| 198 |
void RigidBody::setA( double the_A[3][3] ){ |
| 199 |
|
| 200 |
for (int i = 0; i < 3; i++) |
| 201 |
for (int j = 0; j < 3; j++) |
| 202 |
A[i][j] = the_A[i][j]; |
| 203 |
|
| 204 |
} |
| 205 |
|
| 206 |
void RigidBody::getJ( double theJ[3] ){ |
| 207 |
|
| 208 |
for (int i = 0; i < 3; i++) |
| 209 |
theJ[i] = ji[i]; |
| 210 |
|
| 211 |
} |
| 212 |
|
| 213 |
void RigidBody::setJ( double theJ[3] ){ |
| 214 |
|
| 215 |
for (int i = 0; i < 3; i++) |
| 216 |
ji[i] = theJ[i]; |
| 217 |
|
| 218 |
} |
| 219 |
|
| 220 |
void RigidBody::getTrq(double theT[3]){ |
| 221 |
for (int i = 0; i < 3 ; i++) |
| 222 |
theT[i] = trq[i]; |
| 223 |
} |
| 224 |
|
| 225 |
void RigidBody::addTrq(double theT[3]){ |
| 226 |
for (int i = 0; i < 3 ; i++) |
| 227 |
trq[i] += theT[i]; |
| 228 |
} |
| 229 |
|
| 230 |
void RigidBody::getI( double the_I[3][3] ){ |
| 231 |
|
| 232 |
if (precalc_done) { |
| 233 |
|
| 234 |
for (int i = 0; i < 3; i++) |
| 235 |
for (int j = 0; j < 3; j++) |
| 236 |
the_I[i][j] = I[i][j]; |
| 237 |
|
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} else { |
| 239 |
|
| 240 |
} |
| 241 |
} |
| 242 |
|
| 243 |
void RigidBody::lab2Body( double r[3] ){ |
| 244 |
|
| 245 |
double rl[3]; // the lab frame vector |
| 246 |
|
| 247 |
rl[0] = r[0]; |
| 248 |
rl[1] = r[1]; |
| 249 |
rl[2] = r[2]; |
| 250 |
|
| 251 |
r[0] = (A[0][0] * rl[0]) + (A[0][1] * rl[1]) + (A[0][2] * rl[2]); |
| 252 |
r[1] = (A[1][0] * rl[0]) + (A[1][1] * rl[1]) + (A[1][2] * rl[2]); |
| 253 |
r[2] = (A[2][0] * rl[0]) + (A[2][1] * rl[1]) + (A[2][2] * rl[2]); |
| 254 |
|
| 255 |
} |
| 256 |
|
| 257 |
void RigidBody::body2Lab( double r[3] ){ |
| 258 |
|
| 259 |
double rb[3]; // the body frame vector |
| 260 |
|
| 261 |
rb[0] = r[0]; |
| 262 |
rb[1] = r[1]; |
| 263 |
rb[2] = r[2]; |
| 264 |
|
| 265 |
r[0] = (A[0][0] * rb[0]) + (A[1][0] * rb[1]) + (A[2][0] * rb[2]); |
| 266 |
r[1] = (A[0][1] * rb[0]) + (A[1][1] * rb[1]) + (A[2][1] * rb[2]); |
| 267 |
r[2] = (A[0][2] * rb[0]) + (A[1][2] * rb[1]) + (A[2][2] * rb[2]); |
| 268 |
|
| 269 |
} |
| 270 |
|
| 271 |
void RigidBody::calcRefCoords( ) { |
| 272 |
|
| 273 |
int i,j,k; |
| 274 |
double mtmp; |
| 275 |
vec3 apos; |
| 276 |
double refCOM[3]; |
| 277 |
|
| 278 |
mass = 0.0; |
| 279 |
for (j=0; j<3; j++) |
| 280 |
refCOM[j] = 0.0; |
| 281 |
|
| 282 |
for (i = 0; i < myAtoms.size(); i++) { |
| 283 |
mtmp = myAtoms[i]->getMass(); |
| 284 |
mass += mtmp; |
| 285 |
|
| 286 |
apos = refCoords[i]; |
| 287 |
|
| 288 |
for(j = 0; j < 3; j++) { |
| 289 |
refCOM[j] += apos[j]*mtmp; |
| 290 |
} |
| 291 |
} |
| 292 |
|
| 293 |
for(j = 0; j < 3; j++) |
| 294 |
refCOM[j] /= mass; |
| 295 |
|
| 296 |
for (i = 0; i < myAtoms.size(); i++) { |
| 297 |
apos = refCoords[i]; |
| 298 |
for (j=0; j < 3; j++) { |
| 299 |
apos[j] = apos[j] - refCOM[j]; |
| 300 |
} |
| 301 |
refCoords[i] = apos; |
| 302 |
} |
| 303 |
|
| 304 |
} |
| 305 |
|
| 306 |
void RigidBody::doEulerToRotMat(vec3 &euler, mat3x3 &myA ){ |
| 307 |
|
| 308 |
double phi, theta, psi; |
| 309 |
|
| 310 |
phi = euler[0]; |
| 311 |
theta = euler[1]; |
| 312 |
psi = euler[2]; |
| 313 |
|
| 314 |
myA[0][0] = (cos(phi) * cos(psi)) - (sin(phi) * cos(theta) * sin(psi)); |
| 315 |
myA[0][1] = (sin(phi) * cos(psi)) + (cos(phi) * cos(theta) * sin(psi)); |
| 316 |
myA[0][2] = sin(theta) * sin(psi); |
| 317 |
|
| 318 |
myA[1][0] = -(cos(phi) * sin(psi)) - (sin(phi) * cos(theta) * cos(psi)); |
| 319 |
myA[1][1] = -(sin(phi) * sin(psi)) + (cos(phi) * cos(theta) * cos(psi)); |
| 320 |
myA[1][2] = sin(theta) * cos(psi); |
| 321 |
|
| 322 |
myA[2][0] = sin(phi) * sin(theta); |
| 323 |
myA[2][1] = -cos(phi) * sin(theta); |
| 324 |
myA[2][2] = cos(theta); |
| 325 |
|
| 326 |
} |
| 327 |
|
| 328 |
void RigidBody::calcForcesAndTorques() { |
| 329 |
|
| 330 |
// Convert Atomic forces and torques to total forces and torques: |
| 331 |
int i, j; |
| 332 |
double apos[3]; |
| 333 |
double afrc[3]; |
| 334 |
double atrq[3]; |
| 335 |
double rpos[3]; |
| 336 |
|
| 337 |
zeroForces(); |
| 338 |
|
| 339 |
for (i = 0; i < myAtoms.size(); i++) { |
| 340 |
|
| 341 |
myAtoms[i]->getPos(apos); |
| 342 |
myAtoms[i]->getFrc(afrc); |
| 343 |
|
| 344 |
for (j=0; j<3; j++) { |
| 345 |
rpos[j] = apos[j] - pos[j]; |
| 346 |
frc[j] += afrc[j]; |
| 347 |
} |
| 348 |
|
| 349 |
trq[0] += rpos[1]*afrc[2] - rpos[2]*afrc[1]; |
| 350 |
trq[1] += rpos[2]*afrc[0] - rpos[0]*afrc[2]; |
| 351 |
trq[2] += rpos[0]*afrc[1] - rpos[1]*afrc[0]; |
| 352 |
|
| 353 |
// If the atom has a torque associated with it, then we also need to |
| 354 |
// migrate the torques onto the center of mass: |
| 355 |
|
| 356 |
if (myAtoms[i]->isDirectional()) { |
| 357 |
|
| 358 |
myAtoms[i]->getTrq(atrq); |
| 359 |
|
| 360 |
for (j=0; j<3; j++) |
| 361 |
trq[j] += atrq[j]; |
| 362 |
} |
| 363 |
} |
| 364 |
|
| 365 |
// Convert Torque to Body-fixed coordinates: |
| 366 |
// (Actually, on second thought, don't. Integrator does this now.) |
| 367 |
// lab2Body(trq); |
| 368 |
|
| 369 |
forces_good = true; |
| 370 |
|
| 371 |
} |
| 372 |
|
| 373 |
void RigidBody::updateAtoms() { |
| 374 |
int i, j; |
| 375 |
vec3 ref; |
| 376 |
double apos[3]; |
| 377 |
DirectionalAtom* dAtom; |
| 378 |
|
| 379 |
for (i = 0; i < myAtoms.size(); i++) { |
| 380 |
|
| 381 |
ref = refCoords[i]; |
| 382 |
|
| 383 |
body2Lab(ref.vec); |
| 384 |
|
| 385 |
for (j = 0; j<3; j++) |
| 386 |
apos[j] = pos[j] + ref.vec[j]; |
| 387 |
|
| 388 |
myAtoms[i]->setPos(apos); |
| 389 |
|
| 390 |
if (myAtoms[i]->isDirectional()) { |
| 391 |
|
| 392 |
dAtom = (DirectionalAtom *) myAtoms[i]; |
| 393 |
dAtom->rotateBy( A ); |
| 394 |
|
| 395 |
} |
| 396 |
} |
| 397 |
} |
| 398 |
|
| 399 |
void RigidBody::getGrad( double grad[6] ) { |
| 400 |
|
| 401 |
double myEuler[3]; |
| 402 |
double phi, theta, psi; |
| 403 |
double cphi, sphi, ctheta, stheta; |
| 404 |
double ephi[3]; |
| 405 |
double etheta[3]; |
| 406 |
double epsi[3]; |
| 407 |
|
| 408 |
this->getEulerAngles(myEuler); |
| 409 |
|
| 410 |
phi = myEuler[0]; |
| 411 |
theta = myEuler[1]; |
| 412 |
psi = myEuler[2]; |
| 413 |
|
| 414 |
cphi = cos(phi); |
| 415 |
sphi = sin(phi); |
| 416 |
ctheta = cos(theta); |
| 417 |
stheta = sin(theta); |
| 418 |
|
| 419 |
// get unit vectors along the phi, theta and psi rotation axes |
| 420 |
|
| 421 |
ephi[0] = 0.0; |
| 422 |
ephi[1] = 0.0; |
| 423 |
ephi[2] = 1.0; |
| 424 |
|
| 425 |
etheta[0] = cphi; |
| 426 |
etheta[1] = sphi; |
| 427 |
etheta[2] = 0.0; |
| 428 |
|
| 429 |
epsi[0] = stheta * cphi; |
| 430 |
epsi[1] = stheta * sphi; |
| 431 |
epsi[2] = ctheta; |
| 432 |
|
| 433 |
for (int j = 0 ; j<3; j++) |
| 434 |
grad[j] = frc[j]; |
| 435 |
|
| 436 |
grad[3] = 0.0; |
| 437 |
grad[4] = 0.0; |
| 438 |
grad[5] = 0.0; |
| 439 |
|
| 440 |
for (int j = 0; j < 3; j++ ) { |
| 441 |
|
| 442 |
grad[3] += trq[j]*ephi[j]; |
| 443 |
grad[4] += trq[j]*etheta[j]; |
| 444 |
grad[5] += trq[j]*epsi[j]; |
| 445 |
|
| 446 |
} |
| 447 |
|
| 448 |
} |
| 449 |
|
| 450 |
/** |
| 451 |
* getEulerAngles computes a set of Euler angle values consistent |
| 452 |
* with an input rotation matrix. They are returned in the following |
| 453 |
* order: |
| 454 |
* myEuler[0] = phi; |
| 455 |
* myEuler[1] = theta; |
| 456 |
* myEuler[2] = psi; |
| 457 |
*/ |
| 458 |
void RigidBody::getEulerAngles(double myEuler[3]) { |
| 459 |
|
| 460 |
// We use so-called "x-convention", which is the most common |
| 461 |
// definition. In this convention, the rotation given by Euler |
| 462 |
// angles (phi, theta, psi), where the first rotation is by an angle |
| 463 |
// phi about the z-axis, the second is by an angle theta (0 <= theta |
| 464 |
// <= 180) about the x-axis, and the third is by an angle psi about |
| 465 |
// the z-axis (again). |
| 466 |
|
| 467 |
|
| 468 |
double phi,theta,psi,eps; |
| 469 |
double pi; |
| 470 |
double cphi,ctheta,cpsi; |
| 471 |
double sphi,stheta,spsi; |
| 472 |
double b[3]; |
| 473 |
int flip[3]; |
| 474 |
|
| 475 |
// set the tolerance for Euler angles and rotation elements |
| 476 |
|
| 477 |
eps = 1.0e-8; |
| 478 |
|
| 479 |
theta = acos(min(1.0,max(-1.0,A[2][2]))); |
| 480 |
ctheta = A[2][2]; |
| 481 |
stheta = sqrt(1.0 - ctheta * ctheta); |
| 482 |
|
| 483 |
// when sin(theta) is close to 0, we need to consider the |
| 484 |
// possibility of a singularity. In this case, we can assign an |
| 485 |
// arbitary value to phi (or psi), and then determine the psi (or |
| 486 |
// phi) or vice-versa. We'll assume that phi always gets the |
| 487 |
// rotation, and psi is 0 in cases of singularity. we use atan2 |
| 488 |
// instead of atan, since atan2 will give us -Pi to Pi. Since 0 <= |
| 489 |
// theta <= 180, sin(theta) will be always non-negative. Therefore, |
| 490 |
// it never changes the sign of both of the parameters passed to |
| 491 |
// atan2. |
| 492 |
|
| 493 |
if (fabs(stheta) <= eps){ |
| 494 |
psi = 0.0; |
| 495 |
phi = atan2(-A[1][0], A[0][0]); |
| 496 |
} |
| 497 |
// we only have one unique solution |
| 498 |
else{ |
| 499 |
phi = atan2(A[2][0], -A[2][1]); |
| 500 |
psi = atan2(A[0][2], A[1][2]); |
| 501 |
} |
| 502 |
|
| 503 |
//wrap phi and psi, make sure they are in the range from 0 to 2*Pi |
| 504 |
//if (phi < 0) |
| 505 |
// phi += M_PI; |
| 506 |
|
| 507 |
//if (psi < 0) |
| 508 |
// psi += M_PI; |
| 509 |
|
| 510 |
myEuler[0] = phi; |
| 511 |
myEuler[1] = theta; |
| 512 |
myEuler[2] = psi; |
| 513 |
|
| 514 |
return; |
| 515 |
} |
| 516 |
|
| 517 |
double RigidBody::max(double x, double y) { |
| 518 |
return (x > y) ? x : y; |
| 519 |
} |
| 520 |
|
| 521 |
double RigidBody::min(double x, double y) { |
| 522 |
return (x > y) ? y : x; |
| 523 |
} |
| 524 |
|
| 525 |
void RigidBody::findCOM() { |
| 526 |
|
| 527 |
size_t i; |
| 528 |
int j; |
| 529 |
double mtmp; |
| 530 |
double ptmp[3]; |
| 531 |
double vtmp[3]; |
| 532 |
|
| 533 |
for(j = 0; j < 3; j++) { |
| 534 |
pos[j] = 0.0; |
| 535 |
vel[j] = 0.0; |
| 536 |
} |
| 537 |
mass = 0.0; |
| 538 |
|
| 539 |
for (i = 0; i < myAtoms.size(); i++) { |
| 540 |
|
| 541 |
mtmp = myAtoms[i]->getMass(); |
| 542 |
myAtoms[i]->getPos(ptmp); |
| 543 |
myAtoms[i]->getVel(vtmp); |
| 544 |
|
| 545 |
mass += mtmp; |
| 546 |
|
| 547 |
for(j = 0; j < 3; j++) { |
| 548 |
pos[j] += ptmp[j]*mtmp; |
| 549 |
vel[j] += vtmp[j]*mtmp; |
| 550 |
} |
| 551 |
|
| 552 |
} |
| 553 |
|
| 554 |
for(j = 0; j < 3; j++) { |
| 555 |
pos[j] /= mass; |
| 556 |
vel[j] /= mass; |
| 557 |
} |
| 558 |
|
| 559 |
com_good = true; |
| 560 |
} |
| 561 |
|
| 562 |
void RigidBody::findOrient() { |
| 563 |
|
| 564 |
size_t it; |
| 565 |
int i, j; |
| 566 |
double ptmp[3]; |
| 567 |
double Itmp[3][3]; |
| 568 |
double evals[3]; |
| 569 |
double evects[3][3]; |
| 570 |
double r2, mtmp, len; |
| 571 |
|
| 572 |
if (!com_good) findCOM(); |
| 573 |
|
| 574 |
// Calculate inertial tensor matrix elements: |
| 575 |
|
| 576 |
for (i = 0; i < 3; i++) |
| 577 |
for (j = 0; j < 3; j++) |
| 578 |
Itmp[i][j] = 0.0; |
| 579 |
|
| 580 |
for (it = 0; it < myAtoms.size(); it++) { |
| 581 |
|
| 582 |
mtmp = myAtoms[it]->getMass(); |
| 583 |
myAtoms[it]->getPos(ptmp); |
| 584 |
|
| 585 |
for (j = 0; j < 3; j++) |
| 586 |
ptmp[j] = pos[j] - ptmp[j]; |
| 587 |
|
| 588 |
r2 = norm3(ptmp); |
| 589 |
|
| 590 |
for (i = 0; i < 3; i++) { |
| 591 |
for (j = 0; j < 3; j++) { |
| 592 |
|
| 593 |
if (i==j) Itmp[i][j] = mtmp * r2; |
| 594 |
|
| 595 |
Itmp[i][j] -= mtmp * ptmp[i]*ptmp[j]; |
| 596 |
} |
| 597 |
} |
| 598 |
} |
| 599 |
|
| 600 |
diagonalize3x3(Itmp, evals, sU); |
| 601 |
|
| 602 |
// zero out I and then fill the diagonals with the moments of inertia: |
| 603 |
|
| 604 |
for (i = 0; i < 3; i++) { |
| 605 |
for (j = 0; j < 3; j++) { |
| 606 |
I[i][j] = 0.0; |
| 607 |
} |
| 608 |
I[i][i] = evals[i]; |
| 609 |
} |
| 610 |
|
| 611 |
// renormalize column vectors: |
| 612 |
|
| 613 |
for (i=0; i < 3; i++) { |
| 614 |
len = 0.0; |
| 615 |
for (j = 0; j < 3; j++) { |
| 616 |
len += sU[i][j]*sU[i][j]; |
| 617 |
} |
| 618 |
len = sqrt(len); |
| 619 |
for (j = 0; j < 3; j++) { |
| 620 |
sU[i][j] /= len; |
| 621 |
} |
| 622 |
} |
| 623 |
|
| 624 |
// sU now contains the coordinates of the 'special' frame; |
| 625 |
|
| 626 |
orient_good = true; |
| 627 |
|
| 628 |
} |
