Matrix or vector norm.
NORM(X) is the largest singular value of X, max(svd(X)).
NORM(X,2) is the same as NORM(X).
NORM(X,1) is the 1-norm of X, the largest column sum,
NORM(X,inf) is the infinity norm of X, the largest row sum,
NORM(X,'inf') is same as NORM(X,inf).
NORM(X,'fro') is the F-norm, sqrt(sum(diag(X'*X))).
NORM(X,P) is available for matrix X only if P is 1, 2, inf or 'fro'.
NORM(V,P) = sum(abs(V)^P)^(1/P).
NORM(V) = norm(V,2).
NORM(V,inf) = max(abs(V)).
NORM(V,-inf) = min(abs(V)).
In MATLAB 4.0, if X has complex components, z, then
abs(z) = sqrt(z*conj(z)), not abs(real(z)) + abs(imag(z)),
which was used in some earlier versions of MATLAB.
See also COND15XZCU2, RCOND , CONDEST , NORMEST .