*! version 2.0.0 09/08/2020

help bootsamb [STB-38; snp13]

Title

bootsamb -- Smoothed bootstrap samples generator for Silverman test of multimodality (Updated version)

Syntax

boot bootsamb, args(xvar criticalbw sdx)
iterate(#)

Description

bootsamb is used with Stata's boot command to generate smoothed bootstrap
samples to be used by silvtest1 to perform the multimodality test proposed by Silverman (1981).

Options

args(xvar criticalbw sdx) xvar is the variable to analize, criticalbw is the
critical bandwidth to the number of modes to be tested and sdx is the standard deviation of xvar.

iterate(#) specify the number (#) of bootstrap samples

Remarks

xvar, criticalbw, and sdx, are not optional. These values are required by the
boot command. If the user does not provide them, the program halts and displays an error
message on screen.

This program adjust (smooth) the bootstrap samples generated by Stata's boot command according
to Silverman (1981) to perform his propossed multimodality test.

The program must be applied sequentially to each of the several number of modes to be tested.

Examples

. use silica2

. boot bootsamb, args(silica 2.4 4.291535) i(600)

Will generate 600 smoothed bootstrap samples to be used by the silvtes1 command

References

Izenman, A.J., and C. Sommer (1988) Philatelic mixtures and multimodal
densities. Journal of the American Statistical Association, 83(404):
941-953.
Haerdle, W. (1991) Smoothing Techniques with Implementation in S.
Springer-Verlag Chapter 2: 43-84; Chapters 1-2: 1-84.
Salgado-Ugarte, I.H. (2002) Suavización no paramétrica para análisis de
datos. DGAPA and FES Zaragoza, UNAM. Mexico. 139 p.
Salgado-Ugarte, I.H., M. Shimizu, and T. Taniuchi (1993) snp6: Exploring
the shape of univariate data using kernel density estimators. Stata
Technical Bulletin 16: 8-19.
Salgado-Ugarte, I.H., M. Shimizu, and T. Taniuchi (1995) snp6.1: ASH,
WARPing, and kernel density estimation for univariate data. Stata
Technical Bulletin 26: 23-31.
Salgado-Ugarte, I.H., M. Shimizu, and T. Taniuchi (1995) snp6.2: Practical
Rules for bandwidth selection in univariate density estimation. Stata
Technical Bulletin 27: 5-19.
Salgado-Ugarte, I.H., M. Shimizu, and T. Taniuchi (1997) snp13:
Nonparametric assessment of multimodality for univariate data. Stata
Technical Bulletin 38: 27-35.
Scott, D.W. (1992) Multivariate Density Estimation: Theory, Practice,
and Visualization. John Wiley Chapter 6: 125-143; Chapters 3-6: 47-193.
Silverman, B.W. (1981) Using kernel density estimates to investigate
multimodality. Journal of the Royal Statistical Society, B, 43: 97-99.
Silverman, B.W. (1986) Density Estimation for Statistics and Data
Analysis. Chapman and Hall.

Authors

Original version:
Isaias Hazarmabeth Salgado-Ugarte
Updated version:
Isaías Hazarmabeth Salgado-Ugarte & V. Mitsui Saito-Quezada
Laboratorio de Biometría y Biología Pesquera
Facultad de Estudios Superiores Zaragoza
Universidad Nacional Autónoma de México
isalgado@unam.mx

Also see

STB: snp6 (STB-16); snp6.1 (STB-26); snp6.2 (STB-27), snp13 (STB-38)

On-line: help for warpdenm1, kerneld, bandw1, l2cvwarpy, bcvwarpy, numodes, nuamodes