Re: [R] Extracting correlation in a nlme model

2009-05-20 Thread Christine A.

Hello,

for calculation of intraclass correlation coefficient for a simple Random
Intercept model, the function ICC1.lme() in the package psychometric can
be applied.

Best regards, 
Christine Adrion






Kenneth Roy Cabrera Torres wrote:
 
 Hi R users:
 
 Is there a function to obtain the correlation within groups
 from this very simple lme model?
 
 modeloMx1
 Linear mixed-effects model fit by REML
   Data: barrag 
   Log-restricted-likelihood: -70.92739
   Fixed: fza_tension ~ 1 
 (Intercept) 
90.86667 
 
 Random effects:
  Formula: ~1 | molde
 (Intercept) Residual
 StdDev:2.610052 2.412176
 
 Number of Observations: 30
 Number of Groups: 3 
 
 I want to obtain \rho = \sigma_b^2 / (\sigma_b^2 + \sigma^2)
 
 I know that I obtain \sigma_b^2 and \sigma^2 with
 
 VarCorr(modeloMx1)
 
 molde = pdLogChol(1) 
 Variance StdDev  
 (Intercept) 6.812374 2.610052
 Residual5.818593 2.412176
 
 But, I want to know if I can obtain
 \rho = 6.8123/(6.8123 + 5.8185) = 0.53934 straightforward.
 
 Thank you for you help.
 
 Kenneth
 
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-
Christine Adrion, Dipl.-Stat., MPH
 
Ludwig-Maximilians-Universitaet Muenchen
IBE – Institut für Medizinische Informations-
verarbeitung, Biometrie und Epidemiologie 
Marchioninistr. 15
81377 Muenchen
GERMANY
 
Tel.:  +49 (0)89 7095-4483
eMail: adr...@ibe.med.uni-muenchen.de  
Internet: http://ibe.web.med.uni-muenchen.de
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[R] Extracting correlation in a nlme model

2009-05-19 Thread Kenneth Roy Cabrera Torres
Hi R users:

Is there a function to obtain the correlation within groups
from this very simple lme model?

 modeloMx1
Linear mixed-effects model fit by REML
  Data: barrag 
  Log-restricted-likelihood: -70.92739
  Fixed: fza_tension ~ 1 
(Intercept) 
   90.86667 

Random effects:
 Formula: ~1 | molde
(Intercept) Residual
StdDev:2.610052 2.412176

Number of Observations: 30
Number of Groups: 3 

I want to obtain \rho = \sigma_b^2 / (\sigma_b^2 + \sigma^2)

I know that I obtain \sigma_b^2 and \sigma^2 with

 VarCorr(modeloMx1)

molde = pdLogChol(1) 
Variance StdDev  
(Intercept) 6.812374 2.610052
Residual5.818593 2.412176

But, I want to know if I can obtain
\rho = 6.8123/(6.8123 + 5.8185) = 0.53934 straightforward.

Thank you for you help.

Kenneth

__
R-help@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.