# quatnorm

Calculate norm of quaternion

## Description

example

norm = quatnorm(q) calculates the norm norm for a given quaternion, q. For more information on the quaternion and quaternion norm forms, see Algorithms.

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

## Examples

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Determine the norm of q = [.5 -.5 .5 0].

norm=quatnorm([.5 -.5 .5 0])
norm = 0.7500

## Input Arguments

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Quaternion matrix, specified in an m-by-4 matrix of real numbers containing m quaternions.

Example: [1 0 0 0]

Data Types: double

## Output Arguments

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Norms, returned as a column vector of m norms.

## Algorithms

The quaternion has the form of

$q={q}_{0}+i{q}_{1}+j{q}_{2}+k{q}_{3}.$

The quaternion norm has the form of

$norm\left(q\right)={q}_{0}^{2}+{q}_{1}^{2}+{q}_{2}^{2}+{q}_{3}^{2}.$

## References

[1] Stevens, Brian L. and Frank L. Lewis. Aircraft Control and Simulation. 2nd ed. Wiley–Interscience, 2003.

## Version History

Introduced in R2006b