Smoothing including lowess for circular data, y variable circular
circylowess yvar xvar [if exp] [in range] [ , generate(newvar) lowess(lowess_options) scatter(scatter_options) plot(plot) ]
circylowess carries out smoothing (including lowess) of a circular y variable yvar (specified first in the varlist) with respect to some non-circular x variable xvar. yvar should take on values between 0 and 360 degrees. The smoothed result is
arctan(smoothed sine of yvar / smoothed cosine of yvar)
and the kind and degree of smoothing are specified by invoking options of lowess. circscatter is used to show the results graphically.
generate() specifies a new variable to be generated containing the results of smoothing.
lowess() specifies options allowed with lowess. The following are relevant: mean, noweight, bwidth(), logit and adjust.
scatter() specifies options allowed with circscatter.
plot(plot) provides a way to add other plots to the generated graph; see help plot_option.
. circylowess wallasp length, gen(lowess) scatter(yla(,ang(h)))
Nicholas J. Cox, University of Durham, U.K. email@example.com
On-line: help for lowess, circscatter, circxlowess