Vector Norm

Sometimes we need to measure the size of a vector. In machine learning, we usually measure the size of vectors using a function called a norm.

The norm of a vector x measures the distance from the origin to the point x.

The $L^p$ norm is given by

$|x{|}_p={\left({\sum }_i|x_i{|}^p\right)}^{\frac{1}{p}}$

There’s the L2 norm, called the Euclidean norm.

See Matrix Norm for the Frobenius norm.

Also see Max Norm.