R help - Apr 2011 - statistic Q

Dear,

i am a student and I need help in comparing between different slopes and
finding whther there is a significant difference between them?

Thanks a lot

	[[alternative HTML version deleted]]

On Apr 22, 2011, at 6:30 PM, Shatha Omar wrote:
> Dear,
>
> i am a student and I need help in comparing between different slopes  
> and
> finding whther there is a significant difference between them?
slope1/slope2 > 1

If TRUE then slope1 is greater.

OK. That was facetious. But I hope it highlights what's missing from  
your question:

  .... An example in R code.

-- 
David Winsemius, MD
West Hartford, CT

Hi Shatha,

There is a function built into the core packages that lets you easily
extract coefficients.  See the documentation for ?coef
For the standard errors, you can extract them from a model object
yourself, but that can be a bit of a pain.  An alternative is to use
se.coef from package "arm".

install.packages("arm")
require(arm)
?se.coef

As to how you actually do the calculations once you have the needed
data, that is up to you.

HTH,

Josh

On Fri, Apr 22, 2011 at 3:30 PM, Shatha Omar <shathaomar2 at gmail.com>
wrote:
> Dear,
>
> i am a student and I need help in comparing between different slopes and
> finding whther there is a significant difference between them?
>
> Thanks a lot
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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>


-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/