Vector and matrix norms
Calculate the 2-norm of a vector corresponding to the point (-2,3,-1) in 3-D space. The 2-norm is equal to the Euclidean length of the vector.
X = [-2 3 -1]; n = norm(X)
n = 3.7417
Calculate the 1-norm of the vector, which is the sum of the element magnitudes.
n = norm(X,1)
n = 6
Calculate the 2-norm of a matrix, which is the largest singular value.
X = [2 0 1;-1 1 0;-3 3 0]; n = norm(X)
n = 4.7234
Use 'fro' to calculate the Frobenius norm of a sparse matrix, which calculates the 2-norm of the column vector, S(:).
S = sparse(1:25,1:25,1); n = norm(S,'fro')
n = 5
Numeric array, specified as a scalar, vector, or matrix. Use norm(X,'fro') when X is sparse.
Data Types: single | double
Complex Number Support: Yes
Norm type, specified as 2 (default), a positive integer scalar, Inf, -Inf, or 'fro'. Whether X is a matrix or vector determines the allowed values of p (and what they return). This table lists the calculated values for each allowed value of p.
positive, real-valued numeric p