Table of contents
CSPICE_VROTV rotates a double precision 3-vector about a specified
axis vector by a specified angle (measured in radians) then
returns the rotated vector.
Given:
v a vector to rotate.
[3,1] = size(v1); double = class(v1)
axis a vector defining the axis about which to rotate `v'.
[3,1] = size(axis); double = class(axis)
theta the value of the angle measured in radians through which
which rotate `v' about `axis'.
[1,1] = size(theta); double = class(theta)
the call:
r = cspice_vrotv( v, axis, theta )
returns:
r the vector result of rotating `v' about `axis' through an
angle of `theta'.
[3,1] = size(r); double = class(r)
If axis is the zero vector, r = v.
None.
Any numerical results shown for this example may differ between
platforms as the results depend on the SPICE kernels used as input
and the machine specific arithmetic implementation.
1) Given an axis and an angle of rotation, perform rotations on
various vectors.
Example code begins here.
function vrotv_ex1()
%
% Given an axis of rotation and angle of rotation.
%
axis = [ 0.; 0.; 1.];
theta = cspice_halfpi;
%
% Perform rotations on various vectors...
%
v1 = [ 1.; 2.; 3. ];
r1 = cspice_vrotv( v1, axis, theta );
fprintf( 'Input vector : %12.6f %12.6f %12.6f\n', v1 );
fprintf( 'Rotated vector: %12.6f %12.6f %12.6f\n\n', r1 );
v2 = [ 1.; 0.; 0. ];
r2 = cspice_vrotv( v2, axis, theta );
fprintf( 'Input vector : %12.6f %12.6f %12.6f\n', v2 );
fprintf( 'Rotated vector: %12.6f %12.6f %12.6f\n\n', r2 );
v3 = [ 0.; 1.; 0. ];
r3 = cspice_vrotv( v3, axis, theta );
fprintf( 'Input vector : %12.6f %12.6f %12.6f\n', v3 );
fprintf( 'Rotated vector: %12.6f %12.6f %12.6f\n', r3 );
When this program was executed on a Mac/Intel/Octave6.x/64-bit
platform, the output was:
Input vector : 1.000000 2.000000 3.000000
Rotated vector: -2.000000 1.000000 3.000000
Input vector : 1.000000 0.000000 0.000000
Rotated vector: 0.000000 1.000000 0.000000
Input vector : 0.000000 1.000000 0.000000
Rotated vector: -1.000000 0.000000 0.000000
This routine computes the result of rotating (in a right handed
sense) the vector `v' about the axis represented by `axis' through
an angle of `theta' radians.
If `w' is a unit vector parallel to axis, then `r' is given by:
r = v + ( 1 - cos(theta) ) (w X(w X v)) + sin(theta) (w X v)
where "X" above denotes the vector cross product.
1) If the input axis is the zero vector, `r' will be returned
as `v'.
2) If any of the input arguments, `v', `axis' or `theta', is
undefined, an error is signaled by the Matlab error handling
system.
3) If any of the input arguments, `v', `axis' or `theta', is not
of the expected type, or it does not have the expected
dimensions and size, an error is signaled by the Mice
interface.
None.
None.
MICE.REQ
ROTATION.REQ
None.
J. Diaz del Rio (ODC Space)
E.D. Wright (JPL)
-Mice Version 1.1.0, 10-AUG-2021 (EDW) (JDR)
Edited the header to comply with NAIF standard. Added
example's problem statement and reformatted example's output.
Added -Parameters, -Exceptions, -Files, -Restrictions,
-Literature_References and -Author_and_Institution sections, and
completed -Particulars section.
Eliminated use of "lasterror" in rethrow.
Removed reference to the function's corresponding CSPICE header from
-Required_Reading section.
-Mice Version 1.0.2, 18-DEC-2014 (EDW)
Edited -I/O section to conform to NAIF standard for Mice
documentation.
-Mice Version 1.0.1, 14-JUL-2010 (EDW)
Corrected minor typo in header.
-Mice Version 1.0.0, 17-APR-2008 (EDW)
vector rotation about an axis
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