type of plot: contour levels, perspective plots, image
Value
None. Plots are produced on the default graphical device.
Details
This function displays trivariate time series plots, i.e. kernel regression
of \(x[t-lags[1]], x[t-lags[2]]\) against
\(x[t]\) using functions in the package sm. In particular,
sm.regression is used, with smoothing parameter defaulting
to hnorm(x).