This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English verison of the page.

Note: This page has been translated by MathWorks. Please click here
To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.


Calculate norm of quaternion


n = quatnorm(q)


n = quatnorm(q) calculates the norm, n, for a given quaternion, q. Input q is an m-by-4 matrix containing m quaternions. n returns a column vector of m norms. 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

The quaternion norm has the form of


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

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

norm =



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

Extended Capabilities

Introduced in R2006b

Was this topic helpful?