[R] Johnson-Neyman procedure (ANCOVA)

[Chuck Cleland]

On 10/30/2009 9:20 PM, Stropharia wrote:
> Dear R users,
> 
> Does anyone know of a package that implements the Johnson-Neyman procedure -
> for testing differences among groups when the regression slopes are
> heterogeneous (in an ANCOVA model)? I did not get any matches for functions
> when searching using R Site Search.
> 
> If it has not been implemented in R, does anyone know of another statistical
> package that has this procedure? I found very old scripts available for
> Mathematica, but have had difficulty getting them to work.

http://www.comm.ohio-state.edu/ahayes/SPSS%20programs/modprobe.htm

> Thanks in advance.
> 
> best,
> 
> Steve

-- 
Chuck Cleland, Ph.D.
NDRI, Inc. (www.ndri.org)
71 West 23rd Street, 8th floor
New York, NY 10010
tel: (212) 845-4495 (Tu, Th)
tel: (732) 512-0171 (M, W, F)
fax: (917) 438-0894