5.39.1 Norms of a vector : maxnorm l1norm l2norm
norm
The instructions to compute the different norm of a vector are :

maxnorm returns the l^{∞} norm of a
vector,
defined as the maximum of the absolute values of its
coordinates.
Input :
maxnorm([3,4,2])
Output :
4
Indeed : x=3, y=4, z=2 and 4=max(x,y,z).
 l1norm returns the l^{1} norm of a
vector defined as the sum of the absolute values of its
coordinates.
Input :
l1norm([3,4,2])
Output :
9
Indeed : x=3, y=4, z=2 and 9=x+y+z.
 norm or l2norm returns the
l^{2} norm of a vector defined as the square root
of the sum of the squares of its
coordinates.
Input :
norm([3,4,2])
Output :
sqrt(29)
Indeed : x=3, y=4, z=2 and 29=x^{2}+y^{2}+z^{2}.