quatmod

Calculate modulus of quaternion

Syntax

n = quatmod(q)


Description

n = quatmod(q) calculates the modulus, n, for a given quaternion, q. Input q is an m-by-4 matrix containing m quaternions. n returns a column vector of m moduli. Each element of q must be a real number.

Aerospace Toolbox uses quaternions that are defined using the scalar-first convention.

The quaternion has the form of

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

The quaternion modulus has the form of

$$\left|q\right|=\sqrt{q_0^2+q_1^2+q_2^2+q_3^2}$$

Examples

Determine the modulus of q = [1 0 0 0]:

mod = quatmod([1 0 0 0])


mod =

     1

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.