rank — rank
[i]=rank(X) [i]=rank(X,tol)
rank(X)
is the numerical rank of X
i.e. the number of singular values of X that are larger than
norm(size(X),'inf') * norm(X) * %eps
.
rank(X,tol)
is the number of singular values of
X
that are larger than tol
.
Note that the default value of tol
is proportional to
norm(X)
. As a consequence
rank([1.d-80,0;0,1.d-80])
is 2 !.