# LICurvature-package: Assement on Local Influence in Case-Weight for the Linear... In LICurvature: Sensitivity Analysis for Case Weight in Normal Linear Regression

## Description

This Package presents a general method for assessing the local influence of minor perturbations of case-weight for the linear regression models. The method relies on a well-behaved likelihood and certain elementary ideas from differential geometry, and seems to provide a relatively simple, unified approach for handling a variety of problems. A distinguishing feature of this method is its use of log-likelihood contours to gauge influence. Although this Package is concerned primarily with local influence, some discussion of assessing global influence, which is a significantly more difficult problem. We use geometric normal curvatures to characterize the behaviour of an influence graph around omega (Generally, omega can reflect any well-defined perturbation scheme and thus is not restricted to be a collection of case weights.),although the essential results can be obtained by using less descriptive We used it in case-Weight for the linear regression models, also recommended a general reference for deciding whether there is notable local sensitivity or not

## Details

 Package: LICurvature Type: Package Version: 1.0 Date: 2013-06-23 License: GPL (>=2)

## Author(s)

Bahrami Samani and Parsa Maram

Maintainer: Bahrami Samani <ehsan_bahrami_samani@yahoo.com>

## References

Cook, R. D. (1986). Assessment of local influence (with discussion). J. Roy. Statist. Soc. Ser. B 48: 133-169.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11``` ```data("Bahrami1") gender<-Bahrami1\$ GENDER duration <-Bahrami1\$ DURATION y<-Bahrami1\$ BMI X=cbind(gender,duration ) Xstar=cbind(1,X) p=2; n=15; ini=c(0,rep(1,p)); LICurvature(ini,X=X,Xstar=Xstar,y=y,n=n,p=p) ```

LICurvature documentation built on May 30, 2017, 4:18 a.m.