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. Additionally, q has its scalar number as the first column.

The quaternion has the form of

q=q0+iq1+jq2+kq3

The quaternion modulus has the form of

|q|=q02+q12+q22+q32

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.

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