[R] packages masking other objects

[James Smith]

> hello all, 
> 
> I am trying to use the function getCovariateFormula(nlme) in conjunction with the library lme4. When I load both packages I get the following message and the getCovariateFormula function no longer works:
> 
> library(nlme)
> library(lme4)
> 
> Attaching package 'lme4':
> 
> 
>         The following object(s) are masked from package:nlme :
> 
>          contr.SAS getCovariateFormula getResponseFormula groupedData lmeControl 
> 
> I have tried removing the package after using it, with:
> detach(package:lme4)
> library(nlme)
> 
> but I still get an error message when I try to use getCovariateFormula. The line I use it in, and the error message is below:
> 
> rownames(table)<-c((getCovariateFormula(model1)),(getCovariateFormula(model2)),(getCovariateFormula(model3)),(getCovariateFormula(model4)),(getCovariateFormula(model5)),(getCovariateFormula(model6)),(getCovariateFormula(modelnull)))
> 
> Error in switch(mode(x), "NULL" = structure(NULL, class = "formula"),  : 
>         invalid formula
> 
> This line works fine when I run models with different structures that are not in the lme4 package.
> Does anyone have any suggestions about this ?
> Am I not removing the package completely ?
> 
> Any suggestions would be greatly appreciated
> Thanks
> James Smith
>