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help for circkdensity
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Nonparametric density estimation for circular data

circkdensity varname [if exp] [in range] [ , h(#) genpdf(newvar1) gendeg(newvar2) line_options ]

Description

circkdensity produces and graphs nonparametric density estimates for circular variables with scales between 0 and 360 degrees. The kernel is a quartic or biweight kernel with a half-width given by h(). See Fisher (1993) for more details and discussion. The estimate is produced for min(_N, 360) equally spaced angles on the circle. Note that circkdensity is not implemented using kdensity.

Options

h() specifies the half-width of the kernel in degrees. The default is 30.

genpdf() specifies the name of a new variable in which probability density estimates are to be stored.

gendeg() specifies the name of a new variable in which equally spaced angles are to be stored.

line_options are any of the options allowed with line.

Examples

. circkdensity wallasp

. circkdensity wallasp, h(45) genpdf(wallpdf) gendeg(deg)

Author

Nicholas J. Cox, University of Durham, U.K. n.j.cox@durham.ac.uk

References

Fisher, N.I. 1993. Statistical analysis of circular data. Cambridge: Cambridge University Press.

Also see

On-line: help for circhistogram