eul2m_c |

## Procedurevoid eul2m_c ( SpiceDouble angle3, SpiceDouble angle2, SpiceDouble angle1, SpiceInt axis3, SpiceInt axis2, SpiceInt axis1, SpiceDouble r [3][3] ) ## AbstractConstruct a rotation matrix from a set of Euler angles. ## Required_ReadingROTATION ## KeywordsMATRIX ROTATION TRANSFORMATION ## Brief_I/OVariable I/O Description -------- --- -------------------------------------------------- angle3, angle2, angle1 I Rotation angles about third, second, and first rotation axes (radians). axis3, axis2, axis1 I Axis numbers of third, second, and first rotation axes. r O Product of the 3 rotations. ## Detailed_Inputangle3, angle2, angle1, axis3, axis2, axis1 are, respectively, a set of three angles and three coordinate axis numbers; each pair angleX and axisX specifies a coordinate transformation consisting of a rotation by angleX radians about the coordinate axis indexed by axisX. These coordinate transformations are typically symbolized by [ angleX ] . axisX See the -Particulars section below for details concerning this notation. Note that these coordinate transformations rotate vectors by -angleX radians about the axis indexed by axisX. The values of axisX may be 1, 2, or 3, indicating the x, y, and z axes respectively. ## Detailed_Outputr is a rotation matrix representing the composition of the rotations defined by the input angle-axis pairs. Together, the three pairs specify a composite transformation that is the result of performing the rotations about the axes indexed by axis1, axis2, and axis3, in that order. So, r = [ angle3 ] [ angle2 ] [ angle1 ] axis3 axis2 axis1 See the -Particulars section below for details concerning this notation. The resulting matrix r may be thought of as a coordinate transformation; applying it to a vector yields the vector's coordinates in the rotated system. Viewing r as a coordinate transformation matrix, the basis that r transforms vectors to is created by rotating the original coordinate axes first by angle1 radians about the coordinate axis indexed by axis1, next by angle2 radians about the coordinate axis indexed by axis2, and finally by angle3 radians about coordinate axis indexed by axis3. At the second and third steps of this process, the coordinate axes about which rotations are performed belong to the bases resulting from the previous rotations. ## ParametersNone. ## Exceptions1) If any of axis3, axis2, or axis1 do not have values in { 1, 2, 3 }, the error SPICE(BADAXISNUMBERS) is signalled. ## FilesNone. ## Particularssection below for details concerning this notation. Note that these coordinate transformations rotate vectors by -angleX radians about the axis indexed by axisX. The values of axisX may be 1, 2, or 3, indicating the x, y, and z axes respectively. ## Examples1) Create a coordinate transformation matrix by rotating the original coordinate axes first by 30 degrees about the z axis, next by 60 degrees about the y axis resulting from the first rotation, and finally by -50 degrees about the z axis resulting from the first two rotations. /. Create the coordinate transformation matrix o o o R = [ -50 ] [ 60 ] [ 30 ] 3 2 3 All angles in radians, please. The CSPICE function rpd_c (radians per degree) gives the conversion factor. The z axis is `axis 3'; the y axis is `axis 2'. ./ angle1 = rpd_c() * 30.; angle2 = rpd_c() * 60.; angle3 = rpd_c() * -50.; axis1 = 3; axis2 = 2; axis3 = 3; ## RestrictionsBeware: more than one definition of "RA, DEC and twist" exists. ## Literature_References[1] `Galileo Attitude and Camera Models', JPL IOM 314-323, W. M. Owen, Jr., Nov. 11, 1983. NAIF document number 204.0. ## Author_and_InstitutionN.J. Bachman (JPL) ## Version-CSPICE Version 1.0.2, 26-DEC-2006 (NJB) Fixed header typo. -CSPICE Version 1.0.1, 13-OCT-2004 (NJB) Fixed header typo. -CSPICE Version 1.0.0 08-FEB-1998 (NJB) Based on SPICELIB Version 1.1.1, 10-MAR-1992 (WLT) ## Index_Entrieseuler angles to matrix |

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