[R] Standard errors of least squares adjusted means

Mark Difford mark_difford at yahoo.co.uk
Thu Jan 22 09:10:23 CET 2009


Hi Bruno,

Apropos of "ls-means" ...

>> I have tried help.search and RSiteSearch with several terms including
>> "standard errors", "least square means", "adjusted means".

And "ls-means," which is what "you" call them?

There are many threads on this, spanning many years. The following,

RSiteSearch("ls-means")

will get you to some, e.g.:

http://finzi.psych.upenn.edu/R/Rhelp02a/archive/103520.html

Read through to the bottom.

There are much better ways of examining/summarizing, your model. See, for
instance, the effects package of Prof. Fox and functions in the Design
package of Prof. Harrell.

HTH, Mark.


Bruno Estigarribia wrote:
> 
> Hello,
> 
> I have the following model:
> lm.7 <- lm(Y ~ F + C1 + C2 , data = EM4)
> F is a 4-level factor, the rest are covariates centered at their mean (Y 
> is a two-column matrix).
> I have tried to find functions to give the model-adjusted means 
> (adjusted at the covariates'means) and their standard deviations for each.
> (That is, what I believe is called in SAS "least square or LS-means, 
> whose errors one obtains by STDERR)
> I have tried help.search and RSiteSearch with several terms including 
> "standard errors", "least square means", "adjusted means". I have found 
> how to extract the SE from coefficients (se.coef from package arm), or 
> the SE for contrasts (se.contrast from package stats), but not the SE 
> for an adjusted mean.
> Thank you,
> 
> -- 
> Bruno Estigarribia
> Postdoctoral Fellow
> FPG Child Development Institute
> Neurodevelopmental Disorders Research Center
> University of North Carolina at Chapel Hill
> 
> 105 Smith Level Rd
> Chapel Hill, NC 27599-8180
> USA
> + 1 (919) 843-7685
> 
> ______________________________________________
> 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.
> 
> 

-- 
View this message in context: http://www.nabble.com/Standard-errors-of-least-squares-adjusted-means-tp21598897p21599542.html
Sent from the R help mailing list archive at Nabble.com.



More information about the R-help mailing list