| 178 |
|
dt2 = 0.5 * dt; |
| 179 |
|
|
| 180 |
|
readyCheck(); |
| 181 |
+ |
|
| 182 |
+ |
// remove center of mass drift velocity (in case we passed in a configuration |
| 183 |
+ |
// that was drifting |
| 184 |
+ |
tStats->removeCOMdrift(); |
| 185 |
|
|
| 186 |
|
// initialize the forces before the first step |
| 187 |
|
|
| 691 |
|
|
| 692 |
|
double angle; |
| 693 |
|
double A[3][3], I[3][3]; |
| 694 |
+ |
int i, j, k; |
| 695 |
|
|
| 696 |
|
// use the angular velocities to propagate the rotation matrix a |
| 697 |
|
// full time step |
| 699 |
|
sd->getA(A); |
| 700 |
|
sd->getI(I); |
| 701 |
|
|
| 702 |
< |
// rotate about the x-axis |
| 703 |
< |
angle = dt2 * ji[0] / I[0][0]; |
| 704 |
< |
this->rotate( 1, 2, angle, ji, A ); |
| 705 |
< |
|
| 706 |
< |
// rotate about the y-axis |
| 707 |
< |
angle = dt2 * ji[1] / I[1][1]; |
| 708 |
< |
this->rotate( 2, 0, angle, ji, A ); |
| 702 |
> |
if (sd->isLinear()) { |
| 703 |
> |
i = sd->linearAxis(); |
| 704 |
> |
j = (i+1)%3; |
| 705 |
> |
k = (i+2)%3; |
| 706 |
> |
|
| 707 |
> |
angle = dt2 * ji[j] / I[j][j]; |
| 708 |
> |
this->rotate( k, i, angle, ji, A ); |
| 709 |
|
|
| 710 |
< |
// rotate about the z-axis |
| 711 |
< |
angle = dt * ji[2] / I[2][2]; |
| 707 |
< |
this->rotate( 0, 1, angle, ji, A); |
| 710 |
> |
angle = dt * ji[k] / I[k][k]; |
| 711 |
> |
this->rotate( i, j, angle, ji, A); |
| 712 |
|
|
| 713 |
< |
// rotate about the y-axis |
| 714 |
< |
angle = dt2 * ji[1] / I[1][1]; |
| 711 |
< |
this->rotate( 2, 0, angle, ji, A ); |
| 713 |
> |
angle = dt2 * ji[j] / I[j][j]; |
| 714 |
> |
this->rotate( k, i, angle, ji, A ); |
| 715 |
|
|
| 716 |
< |
// rotate about the x-axis |
| 717 |
< |
angle = dt2 * ji[0] / I[0][0]; |
| 718 |
< |
this->rotate( 1, 2, angle, ji, A ); |
| 719 |
< |
|
| 716 |
> |
} else { |
| 717 |
> |
// rotate about the x-axis |
| 718 |
> |
angle = dt2 * ji[0] / I[0][0]; |
| 719 |
> |
this->rotate( 1, 2, angle, ji, A ); |
| 720 |
> |
|
| 721 |
> |
// rotate about the y-axis |
| 722 |
> |
angle = dt2 * ji[1] / I[1][1]; |
| 723 |
> |
this->rotate( 2, 0, angle, ji, A ); |
| 724 |
> |
|
| 725 |
> |
// rotate about the z-axis |
| 726 |
> |
angle = dt * ji[2] / I[2][2]; |
| 727 |
> |
this->rotate( 0, 1, angle, ji, A); |
| 728 |
> |
|
| 729 |
> |
// rotate about the y-axis |
| 730 |
> |
angle = dt2 * ji[1] / I[1][1]; |
| 731 |
> |
this->rotate( 2, 0, angle, ji, A ); |
| 732 |
> |
|
| 733 |
> |
// rotate about the x-axis |
| 734 |
> |
angle = dt2 * ji[0] / I[0][0]; |
| 735 |
> |
this->rotate( 1, 2, angle, ji, A ); |
| 736 |
> |
|
| 737 |
> |
} |
| 738 |
|
sd->setA( A ); |
| 739 |
|
} |
| 740 |
|
|
