﻿{smcl} {* *! v1.0.0 IHSalgado-Ugarte 04July2012}{...} {cmd:help circbw} {hline} {title:Title} {p2colset 5 18 20 2}{...} {p2col :{hi:circbw} {hline 2}}Calculate bandwidth selection rules for circular data{p_end} {p2colreset}{...} {title:Syntax} {p 8 17 2} {cmd:circbw} varname {ifin} [, kc(kernelcode)] {title:Description} {pstd}{cmd: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.{break} 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. {title:Options} {phang} {opt kc(kernelcode)} set kernel (weight) function according to the following numerical codes; default is 4, Quartic(Biweight):{break} 1 = Uniform{break} 2 = Triangle{break} 3 = Epanechnikov{break} 4 = Quartic (Biweight){break} 5 = Triweight{break} 6 = Gaussian{break} 7 = Cosine{break} {title:Remarks} {pstd}{cmd:circbw} uses the supporting utilities {cmd:i0kappa}, {cmd:i1kappa} and {cmd:i2kappa} written by Cox (2004). They are required to do the calculations. {title:Examples} {phang}{stata "use circdat" : . use circdat}{p_end} {phang}{stata "circbw angles" : . circbw angles}{p_end} {phang}{stata "circbw angles, k(6)" : . circbw angles, k(6)}{p_end} {phang}{stata "use fisherfeldes2" : . use fisherfeldes2}{p_end} {phang}{stata "circbw laoriefeld if half==1" : . circbw laoriefeld if half==1}{p_end} {title:Authors} {phang}Isaías H. Salgado-Ugarte, Laboratorio de Biometría y Biología Pesquera, FES Zaragoza, UNAM; Departamento de Biología UAM Iztapalapa{break} ihsalgadougarte@gmail.com{break}{p_end} {phang}Verónica Mitsui Saito-Quezada Laboratorio de Biometría y Biología Pesquera, FES Zaragoza, UNAM.{break} mitsuisaito@gmail.com{break}{p_end} {phang}Marco A. Pérez-Hernández, Departamento de Biología, UAM Iztapalapa.{break} maph@xanum.uam.mx{break}{p_end} {title:References} {phang}Cox, N.J. 2004. Circular statistics in Stata, revisited. Proceedings of the 10th UK Users Group Meeting, London, UK: 4 p.{p_end} {phang}Fisher, N.I. 1993. Statistical analysis of circular data. Cambridge University Press, Cambridge, 296p.{p_end} {phang}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.{p_end} {phang}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. {p_end} {phang}Salgado-Ugarte, I.H., M. Shimizu & T. Taniuchi 1995. Practical rules for bandwidth selection in univariate density estimation. Stata Technical Bulletin, 27: 5-19.{p_end} {phang}Taylor, C.C. 2008. Automatic bandwidth selection for circular density estimation. Computational Statistics and Data Analysis 52(7): 3493-3500.{p_end} {title:Also see} {psee} Manual: {manhelp kdensity R} {psee} Online: {hi:Help} for {help circkden}, {help cirkdevm}, {help circnpde}