residuals.probit {sampleSelection}R Documentation

Residuals of probit models

Description

Calculate residuals of probit models.

Usage

   ## S3 method for class 'probit'
residuals( object, type = "deviance", ... )

Arguments

object

an object of class probit.

type

the type of residuals which should be returned. The alternatives are: "deviance" (default), "pearson", and "response" (see details).

...

further arguments (currently ignored).

Details

The residuals are calculated with following formulas:

Response residuals: ri=yiy^ir_i = y_i - \hat{y}_i

Pearson residuals: ri=(yiy^i)/y^i(1y^i)r_i = ( y_i - \hat{y}_i ) / \sqrt{ \hat{y}_i ( 1 - \hat{y}_i ) }

Deviance residuals: ri=2log(y^i)r_i = \sqrt{ -2 \log( \hat{y}_i ) } if yi=1y_i = 1, ri=2log(1y^i)r_i = - \sqrt{ -2 \log( 1 - \hat{y}_i ) } if yi=0y_i = 0

Here, rir_i is the iith residual, yiy_i is the iith response, y^i=Φ(xiβ^)\hat{y}_i = \Phi( x_i' \hat{\beta} ) is the estimated probability that yiy_i is one, Φ\Phi is the cumulative distribution function of the standard normal distribution, xix_i is the vector of regressors of the iith observation, and β^\hat{\beta} is the vector of estimated coefficients.

More details are available in Davison & Snell (1991).

Value

A numeric vector of the residuals.

Author(s)

Arne Henningsen

References

Davison, A. C. and Snell, E. J. (1991) Residuals and diagnostics. In: Statistical Theory and Modelling. In Honour of Sir David Cox, edited by Hinkley, D. V., Reid, N. and Snell, E. J., Chapman & Hall, London.

See Also

probit, residuals, residuals.glm, and probit-methods.


[Package sampleSelection version 1.2-12 Index]