The Direct Filter Approach (DFA) provides efficient estimates of signals
at the current boundary of time series in real-time. For that purpose,
one-sided ARMA-filters are computed by minimizing customized error
criteria. The DFA can be used for estimating either the level or
turning-points of a series, knowing that both criteria are incongruent. In
the context of real-time turning- point detection, various risk-profiles
can be operationalized, which account for the speed and/or the reliability
of the one- sided
filter.