quaternions

quaternions, a MATLAB code which carries out some simple arithmetic operations for quaternions.

Rotations in 3D can be represented in a number of ways, including quaternions, a rotation matrix, and a combination of a rotation axis and rotation angle. This library includes functions to convert a rotation from one representation to another, and to apply a rotation to a given vector.

Licensing:

The information on this web page is distributed under the MIT license.

Languages:

quaternions is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.

Related Data and Programs:

quaternions_test

c8lib, a MATLAB code which implements certain elementary functions for double precision complex (C8) variables;

complex_numbers_test, a MATLAB code which demonstrates some simple features involved in the use of complex numbers in MATLAB codeming.

i4lib, a MATLAB code which contains many utility routines, using "I4" or "single precision integer" arithmetic.

r8lib, a MATLAB code which contains many utility routines, using "R8" or "double precision real" arithmetic.

Reference:

1. Jack Kuipers,
   Quaternions and Rotation Sequences,
   Princeton, 1998,
   ISBN: 0691102988,
   LC: QA196.K85.

Source Code:

• degrees_to_radians.m, converts an angle in degrees to one in radians;
• q8_conjugate.m, conjugates a quaternion;
• q8_exponentiate.m, exponentiates a quaternion;
• q8_inverse.m, inverts a quaternion;
• q8_multiply.m, multiplies two quaternions;
• q8_multiply2.m, multiplies two quaternions using a matrix;
• q8_norm.m, computes the L2 norm of a quaternion;
• q8_normal_01.m, selects a normally distributed quaternion;
• q8_transpose_print.m, prints a quaterion "transposed", or as a row vector.
• r8mat_print.m, prints an R8MAT;
• r8mat_print_some.m, prints some of an R8MAT;
• r8vec_print.m, prints an R8VEC;
• r8vec_uniform_01.m, returns a unit pseudorandom R8VEC.
• radians_to_degrees.m, converts an angle in radians to one in degrees;
• rotation_axis_vector.m, rotates a vector about an axis vector in 3D;
• rotation_axis2mat.m, converts a rotation from axis to matrix format in 3D;
• rotation_axis2quat.m, converts a rotation from axis to quaternion format in 3D;
• rotation_mat_vector.m, applies a matrix rotation to a vector in 3D;
• rotation_mat2axis.m, converts a rotation from matrix to axis format in 3D;
• rotation_mat2quat.m, converts a rotation from matrix to quaternion format in 3D;
• rotation_quat_vector.m, applies a quaternion rotation to a vector in 3D;
• rotation_quat2axis.m, converts a rotation from quaternion to axis format in 3D;
• rotation_quat2mat.m, converts a rotation from quaternion to matrix format in 3D;
• rotation_xyz.m, rotates a point through theta radians around a given axis, using quaternion multiplication;