8. scoria.Quaternion module

class scoria.Quaternion.Quaternion(s, x, y, z)

A class supporting quaternion arithmetic

add(q2)

Adds two quaternions.

Parameters:q2 (scoria.Quaternion) – A quaternion, to be added to self Returns:A Quaternion, with the values corresponding to self + q2

copy()

Returns a copy of self

invert()

Takes the inverse of the quaternion for “division.”

Returns:A Quaternion, with the values corresponding to self^-1

load_from_mat(m)

Converts a rotation matrix that is pure orthogonal (det(matrix)=1) into a Quaternion. Adapted from http://www.euclideanspace.com/maths/ geometry/rotations/conversions/matrixToQuaternion/index.htm

Parameters:m (numpy.array) – A 2D numpy.array representing a pure orthogonal matrix

minus(q2)

Multiplies two quaternions.

Parameters:q2 (scoria.Quaternion) – A quaternion, to be subtracted from self

Returns:

A Quaternion, with the values corresponding to self - q2

multiply(q2)

Multiplies two quaternions.

Parameters:q2 (scoria.Quaternion) – A quaternion, to be multiplied with self Returns:A Quaternion, with the values corresponding to self * q2

normalize()

Normalizes the quaternion.

Returns:A normalized Quaternion

rep_as_44_matrix()

Creates a 4x4 matrix representation of the Quaternion.

Returns:A 4x4 numpy array

scale(scalar)

Scales a quaternion.

Parameters:scalar (???) – the value to scale the quaternion by Returns:A Quaternion, with the values corresponding to self * scalar

to_matrix()

Converts to a normalized 3x3 matrix.

Returns:A 3x3 numpy.array, corresponding to the quaternion