  This paper presents an algorithm to accelerate the evaluation of
inspiral-merger-ringdown waveform models for gravitational wave data analysis.
While the idea can also be applied in the time domain, here we focus on the
frequency domain, which is most typically used to reduced computational cost in
gravitational wave data analysis. Our work extends the idea of multibanding,
which has been developed to accelerate frequency domain waveforms, to include
the merger and ringdown and spherical harmonics beyond the dominant quadrupole
spherical harmonic. The original method is based on a heuristic algorithm based
on the inspiral to de-refine the equi-spaced frequency grid used for data
analysis where a coarser grid is sufficient for accurate evaluation of a
waveform model. Here we use a different criterion, based on the local
interpolation error, which is more flexible and can easily be adapted to
general waveforms, if their phenomenology is understood. We discuss our
implementation in the LIGO Algorithm Library for the PhenomXHM frequency domain
model, and report the acceleration in different parts of the parameter space of
compact binary systems.

General Relativity and Quantum Cosmology