logical; determines whether the series in x has
been log-transformed already. If FALSE then log10 is used.
...
additional parameters (e.g., span) passed to loess.smooth
References
Barbour, A. J., and D. C. Agnew (2011), Noise levels on
Plate Boundary Observatory borehole strainmeters in southern California,
Bulletin of the Seismological Society of America, 101(5), 2453-2466,
doi: 10.1785/0120110062