The global attractor of a dissipative system of ordinary differential
equations can be characterized as the set of solutions which permit an
extension to a bounded analytic function on a uniform strip in a comp
lex plane. Using this property, we present two methods for constructin
g sequences of functions, which may be explicitly computed from the sy
stem, and from which one can deduce whether a specific point belongs t
o the attractor or not. Approximation methods obtained in this way are
tested on the Lorenz system and compared with those from Foias and Jo
lly (1995 Nonlinearity 8 295-319).