A modified version of panel.loess, for drawing Loess
smooths on stratigraphic diagrams.
panel.Loess(x, y,
span = 1/3, degree = 1,
family = c("symmetric","gaussian"),
evaluation = 50,
lwd = plot.line$lwd,
lty = plot.line$lty,
col,
col.line = plot.line$col,
type,
...)
variables defining the contents of the panel.
arguments passed to
loess.smooth, for which panel.Loess is a
wrapper.
graphical parameters.
for compatibility with panel.loess, but is
ignored within the function.
graphical parameters can be supplied. Color can usually
be specified by col, col.line, the latter overriding
the first for lines.
Gavin L. Simpson, slightly modified from the Lattice function
panel.loess by Deepayan Sarkar.
The standard panel function panel.loess treats the data
as the x-axis acting as the time component. For stratigraphic plots
where time flows along the y-axis, we want the smoother to be fitted
with the x-axis data as the response and the time component (y-axis)
as the predictor.
This modified version of panel.loess flips the two axes
to produce the desired effect. Note also that it does not have
argument horizontal as this is not required or supported by
Stratiplot. In other respects, panel.Loess is
equivalent to the lattice panel function panel.loess.
User should note that warnings can be generated by the fitting
function if span is set too small for species with few
observations. In such cases, the user is directed to the help page for
loess.smooth, but increasing span slightly can
often stop the warnings.