A)*b      ; toc, norm (x)
tic ; x = inverse(A)*b   ; toc, norm (x)
tic ; x = factorize(A)\b ; toc, norm (x)

%% Computing selected entries in the inverse or pseudo-inverse
%
% If you want just a few entries from the inverse, it's still better to
% formulate the problem as a system of linear equations and use a matrix
% factorization instead of computing inv(A).  The FACTORIZE object does this
% for you, by overloading the subsref operator.

A = rand (1000) ;

tic ; S = inv (A)     ; S (2:3,4), toc
tic ; S =