[R] logistic regression model validation through bootstrapping
Frank E Harrell Jr
f.harrell at vanderbilt.edu
Mon Mar 2 22:14:35 CET 2009
Install the Design and Hmisc package then do:
library(Design)
?validate.lrm
?calibrate
Resampling methods such as the bootstrap and cross-validation assume you
have done no model/variable selection outside the bootstrap look, i.e.,
you let the bootstrap repeat all modeling steps that used Y. validate
and calibrate only support backward stepdown variable selection, but if
you are using full pre-specified model fits, this is even easier.
Frank
Vivienne_O.Ozohili at boimail.com wrote:
> Hi,
>
> I was wondering whether this query was addressed on how to perform
> validation through boostrapping. I am currently trying to implement a
> boostrapping approach to validation but don't know where to start. Help
> please.
>
>
> Thank you and Regards,
>
> Vivienne Ozohili
> Risk Model Validation Manager
> Group Risk
> Independent Control Unit
> A5, Bank of Ireland Head Office
> Lower Baggot Street
> Dublin 2
> Tel: +353-01-6044833
> Email: Vivienne_O.Ozohili at boimail.com
>
> The Governor and Company of the Bank of Ireland is regulated by the
> Financial Regulator in Ireland and authorised by the Financial Services
> Authority in the UK. Bank of Ireland incorporated in Ireland with Limited
> Liability.
> Registered Office: Head Office, Lower Baggot Street, Dublin 2. Registered
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--
Frank E Harrell Jr Professor and Chair School of Medicine
Department of Biostatistics Vanderbilt University
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