1.4. Application: Beetles data set

The BayesianModeling program generates the necessary syntax for the Bayesian estimation of several models of binary regression, in the WinBUGS program (see Spiegelhalter et al, 1996) or OpenBUGS (Spiegelhalter et al, 2007), using diverse methods MCMC. For this only is necessary to have a text file with the data, generated from any statistics program or from Excel. In the columns normally appear the names of the variables in the first line and in the first column should appear the response variable.

As example consider the group of data Beetles: logistic, probit and extreme value models of the WinBUGS. The group of data is denominated as beetles.txt that is found in this downloads of the program. The variables used in beetles.txt are:

y: 1 if the beetle died after 5 hours of being exposed to carbon disulfide, 0 otherwise

x: concentration of carbon disulfide that a beetle was exposed

The data file has the following structure

y x

1 1.6907

1 1.6907

. .

. .

. .

1 1.8839

As an application example we consider the following model

Where corresponds to the skew logit link (see Chen, Dey and Shao, 2001). More details in Bazán, Bolfarine y Branco (2010)