rotate_c |
Table of contents
Procedurerotate_c ( Generate a rotation matrix ) void rotate_c ( SpiceDouble angle, SpiceInt iaxis, SpiceDouble mout[3][3] ) AbstractCalculate the 3x3 rotation matrix generated by a rotation of a specified angle about a specified axis. This rotation is thought of as rotating the coordinate system. Required_ReadingNone. KeywordsMATRIX ROTATION Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- angle I Angle of rotation (radians). iaxis I Axis of rotation (X=1, Y=2, Z=3). mout O Resulting rotation matrix [angle] iaxis Detailed_Inputangle is the angle given in radians, through which the rotation is performed. iaxis is the index of the axis of rotation. The X, Y, and Z axes have indices 1, 2 and 3 respectively. Detailed_Outputmout is the rotation matrix which describes the rotation of the COORDINATE system through angle radians about the axis whose index is iaxis. ParametersNone. ExceptionsError free. 1) If the axis index is not in the range 1 to 3, it will be treated the same as that integer 1, 2, or 3 that is congruent to it mod 3. FilesNone. ParticularsA rotation about the first, i.e. x-axis, is described by | 1 0 0 | | 0 cos(theta) sin(theta) | | 0 -sin(theta) cos(theta) | A rotation about the second, i.e. y-axis, is described by | cos(theta) 0 -sin(theta) | | 0 1 0 | | sin(theta) 0 cos(theta) | A rotation about the third, i.e. z-axis, is described by | cos(theta) sin(theta) 0 | | -sin(theta) cos(theta) 0 | | 0 0 1 | rotate_c decides which form is appropriate according to the value of IAXIS. ExamplesIf rotate_c is called from a C program as follows: rotate_c ( pi_c()/4, 3, mout ); then mout will be given by | sqrt(2)/2 sqrt(2)/2 0 | mout = |-sqrt(2)/2 sqrt(2)/2 0 | | 0 0 1 | RestrictionsNone. Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) Version-CSPICE Version 1.0.1, 04-AUG-2021 (JDR) Edited the header to comply with NAIF standard. -CSPICE Version 1.0.0, 08-FEB-1998 (NJB) Based on SPICELIB Version 1.0.1, 10-MAR-1992 (WLT) Index_Entriesgenerate a rotation matrix |
Fri Dec 31 18:41:11 2021