Big-O notation, written
and pronounced "big-O of
," uses one of the Landau
symbols and is used to symbolically express the asymptotic
behavior of a given function.
In particular, if
is an integer variable which
tends to infinity and
is a continuous variable tending
to a specified
or to
or
, if
and
are positive functions,
and if
and
are arbitrary functions, then it is said that
provided that
for some positive constant
, for all sufficiently large
, or for all
in a punctured neighborhood
of
in the finite case, or sufficiently large in the indicated direction in the infinite
case.
For eventually nonnegative real-valued functions
and positive functions
, big-O notation and big-omega
notation satisfy
Additionally, big-O notation is related to little-O notation in that
is stronger than and implies
.