Add Smooth Loess Curve to Panel

USAGE:

panel.loess(x, y, span = 2/3, degree = 1, 
            family = "symmetric", evaluation = 50, ...) 

ARGUMENTS:

x
horizontal coordinates of data points.
y
vertical coordinates of data points.
span
smoothing parameter.
degree
overall degree of locally-fitted polynomial. 1 is locally-linear fitting and 2 is locally-quadratic fitting.
family
allowable values are "gaussian" or "symmetric". In the first case, local-fitting methods are used. In the second case, the default, local fitting is used together with a robustness feature that guards against distortion by outliers.
evaluation
number of values at which the loess curve is evaluated.
...
graphical parameters can be specified to control drawing of the fitted line. By default, parameters lwd, lty , and col are gotten from the trellis parameter list add.line.

SIDE EFFECTS:

A smooth line is added to the panel; the fit is carried out by loess.smooth with the specified parameters.

SEE ALSO:

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