Understanding an error returned by stargazer in R

Question

I am trying to reproduce a simplified version of the R output described in this posting . More generally, this is related to my attempt to use the stargazer() function to generate a LaTex table from an lmer object.

Following the author's posting, I've loaded the appropriate libraries and successfully created two lmer objects using the following code:

library(lme4)
library(stargazer)
data(cake)
M1 <- lmer(angle ~ temp + (1 | replicate) + (1|recipe:replicate), cake, REML= FALSE)
M2 <- lmer(angle ~ factor(temperature) + (1 | replicate) + (1|recipe:replicate), cake, REML= FALSE)

When I attempt the following code, it returns the error below:

stargazer(M1, M2, style="ajps", 
title="An Illustrative Model Using Cake Data", 
dep.var.labels.include = FALSE, 
covariate.labels=c( "Temperature (Continuous)", 
"Temperature (Factor $<$ 185)", 
 "Temperature (Factor $<$ 195)", 
"Temperature (Factor $<$ 205)", 
"Temperature (Factor $<$ 215)", 
"Temperature (Factor $<$ 225)"))

 Error in objects[[i]]$zelig.call : $ operator not defined for this S4 class

I do not understand the source of this error, nor how to remedy it, and I would be greatly appreciative of any help.

I am using RStudio version 0.99.441 in Desktop Mode.

My R version info is as follow:

platform       x86_64-apple-darwin13.4.0   
arch           x86_64                      
os             darwin13.4.0                
system         x86_64, darwin13.4.0        
status                                     
major          3                           
minor          2.0                         
year           2015                        
month          04                          
day            16                          
svn rev        68180                       
language       R                           
version.string R version 3.2.0 (2015-04-16)
nickname       Full of Ingredients     

My version of the stargazer package is 5.1, and my version of lme4 is 1.1-7

Answer 1

You may add the following codes before you run stargazer .

class(M1) <- "lmerMod"
class(M2) <- "lmerMod"