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statistic Q
3 messages · Shatha Omar, David Winsemius, Joshua Wiley
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]]
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/