  Time-frequency representations are important for the analysis of time series.
We have developed an online time-series analysis system and equipped it to
reliably handle re-alignment in the time-frequency plane. The system can deal
with issues like invalid regions in time-frequency representations and
discontinuities in data transmissions, making it suitable for on-line
processing in real-world situations. In retrospect the whole problem can be
considered to be a generalization of ideas present in overlap-and-add
filtering, but then for time-frequency representations and including the
calculation of non-causal features. Here we present our design for
time-frequency representation fission and fusion rules. We present these rules
in the context of two typical use cases, which facilitate understanding of the
underlying choices.
