*! v1.0.0 IHSalgado-Ugarte 04July2012
help circbw

Title

circbw -- Calculate bandwidth selection rules for circular data

Syntax

circbw varname [if] [in] [, kc(kernelcode)]

Description

circbw calculates several data-based bandwidth rules for circular variables(with azimuthal scale from 0 to 360 degrees) density estimation and reports the results in a table.

It gives the rule of thumb for von Mises kernel, the Fisher rule for quartic kernel and adapted (using circular deviation) rules (oversmoothed and two optimal) for linear (Euclidean) data (as a reference).
It is possible to choose the kernel function, Quartic (Biweight) default. With duplicated orientation data it is necessary to employ only one half.

Options

kc(kernelcode) set kernel (weight) function according to the following numerical codes; default is 4, Quartic(Biweight):

1 = Uniform

2 = Triangle

3 = Epanechnikov

4 = Quartic (Biweight)

5 = Triweight

6 = Gaussian

7 = Cosine

Remarks

circbw uses the supporting utilities i0kappa, i1kappa and i2kappa written by Cox (2004). They are required to do the calculations.

Examples

. use circdat

. circbw angles

. circbw angles, k(6)

. use fisherfeldes2

. circbw laoriefeld if half==1

Authors

Isaías H. Salgado-Ugarte,
Laboratorio de Biometría y Biología Pesquera, FES Zaragoza, UNAM;
Departamento de Biología UAM Iztapalapa

ihsalgadougarte@gmail.com

Verónica Mitsui Saito-Quezada
Laboratorio de Biometría y Biología Pesquera, FES Zaragoza, UNAM.

mitsuisaito@gmail.com

Marco A. Pérez-Hernández,
Departamento de Biología, UAM Iztapalapa.

maph@xanum.uam.mx

References

Cox, N.J. 2004. Circular statistics in Stata, revisited. Proceedings of the 10th UK Users Group Meeting, London, UK: 4 p.

Fisher, N.I. 1993. Statistical analysis of circular data. Cambridge University Press, Cambridge, 296p.

Oliveira, M., R.M. Crujeiras and A. Rodríguez-Casal 2012. A plug-in rule for bandwidth selection in circular density estimation. Computational Statistics and Data Analysis 56(2012):3898-3908.

Salgado-Ugarte, I.H. & M.A. Pérez-Hernández 2017. Estimación de densidad por núcleo (kernel) para datos circulares. In: Rodríguez-Yam, G.A., F.J. Araiza-Hernández, B.R. Pérez-Salvador & F. Ulín-Montejo (eds.). Aportaciones Recientes a la Estadística en Mexico. INEGI, Mexico: 518-526. ISBN: 978-607-530-067-2.

Salgado-Ugarte, I.H., M. Shimizu & T. Taniuchi 1995. Practical rules for bandwidth selection in univariate density estimation. Stata Technical Bulletin, 27: 5-19.

Taylor, C.C. 2008. Automatic bandwidth selection for circular density estimation. Computational Statistics and Data Analysis 52(7): 3493-3500.

Also see

Manual: [R] kdensity

Online: Help for circkden, cirkdevm, circnpde