quatinv

Calculate inverse of quaternion

Syntax

n = quatinv(q)

Description

n = quatinv(q) calculates the inverse, n, for a given quaternion, q.

Aerospace Toolbox uses quaternions that are defined using the scalar-first convention. For more information on quaternion forms, see Algorithms.

Examples

Determine Inverse of Quaternion

Calculate the inverse of a quaternion q.

qinv = quatinv([1 0 1 0])

qinv = 1×4

    0.5000         0   -0.5000         0

Input Arguments

q — Quaternion

m-by-4 matrix | real number

Quaternion, specified as an m-by-4 matrix containing m quaternions.

Data Types: double

Output Arguments

n — Inverse of quaternion

m-by-4 matrix

Inverse of quaternion, returned as an m-by-4 matrix.

Algorithms

The quaternion has the form of

$$q=q_0+i{q}_1+j{q}_2+k{q}_3.$$

The quaternion inverse has the form of

$$q^{-1}=\frac{q_0-i{q}_1-j{q}_2-k{q}_3}{q_0^2+q_1^2+q_2^2+q_3^2}.$$

References

[1] Stevens, Brian L., Frank L. Lewis, Aircraft Control and Simulation, Wiley–Interscience, 2nd Edition.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

Code generation for this function requires the Aerospace Blockset™ software.

Version History

Introduced in R2006b