ANOVA between objects in two lists

Question

I want to perform a ANOVA between objects that are stored in two separate lists, however rather then performing them one at a time like this

> anova(output.02[[1]], output.03[[1]])
               Model df      AIC      BIC    logLik   Test  L.Ratio p-value
output.02[[1]]     1  9 11221.77 11279.72 -5601.884                        
output.03[[1]]     2 13 11222.90 11306.60 -5598.450 1 vs 2 6.868822   0.143

> anova(output.02[[2]], output.03[[2]])
           Model df      AIC      BIC    logLik   Test  L.Ratio p-value
output.02[[2]]     1  9 10976.36 11034.31 -5479.182                        
output.03[[2]]     2 13 10974.90 11058.60 -5474.449 1 vs 2 9.465378  0.0505

I would like to use a loop to perform an ANOVA between the objects in each list. I tried using the mapply function however the output did not produce the results I was expecting.

> mapply(anova, output.02, output.03)
        zimmrec   zdelrec   zdigiback zspotword zsdmt     zglobcog  zmmse    
call    factor,2  factor,2  factor,2  factor,2  factor,2  factor,2  factor,2 
Model   Integer,2 Integer,2 Integer,2 Integer,2 Integer,2 Integer,2 Integer,2
df      Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2
AIC     Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2
BIC     Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2
logLik  Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2
Test    factor,2  factor,2  factor,2  factor,2  factor,2  factor,2  factor,2 
L.Ratio Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2
p-value Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2 Numeric,2

Any suggestions on how I can do this?

Thanks

Edit: Reproducible example

attach(Orthodont)
set.seed(1234)

#example response variables 
Orthodont$v1 <- rnorm(n=108, mean=20, sd=1)
Orthodont$v2 <- rnorm(n=108, mean=31, sd=2.8)
Orthodont$v3 <- rnorm(n=108, mean=15, sd=1.5)
head(Orthodont)

#function to loop the response variables through a lme function
#produces first batch of models
myfunc <- function(X){
  lapply(X, function(.col){
    y <- .col
    out <- with(Orthodont, lme(y ~ age, random = ~ age | Subject, method = "ML", na.action = na.exclude, control = lmeControl(opt = "optim")))    
    out 
  })
}
output.02 <- myfunc(Orthodont[5:7]) #first list of models 

myfunc2 <- function(X){
  lapply(X, function(.col){
    y <- .col
    out <- with(Orthodont, lme(y ~ age + Sex, random = ~ age | Subject, method = "ML", na.action = na.exclude, control = lmeControl(opt = "optim")))    
    out 
  })
}
output.03 <- myfunc2(Orthodont[5:7])# second list of models

#anova for each pair of models 
anova(output.02[[1]], output.03[[1]])
anova(output.02[[2]], output.03[[2]])
anova(output.02[[3]], output.03[[3]])

#mapply function
mapply(anova, output.02, output.03) 

Answer 1

Use the SIMPLIFY parameter:

mapply(anova, output.02, output.03, SIMPLIFY=FALSE) 
#$v1
#                 Model df      AIC      BIC    logLik   Test   L.Ratio p-value
#dots[[1L]][[1L]]     1  6 324.4204 340.5132 -156.2102                         
#dots[[2L]][[1L]]     2  7 326.2229 344.9978 -156.1115 1 vs 2 0.1974693  0.6568
#
#$v2
#                 Model df      AIC      BIC    logLik   Test  L.Ratio p-value
#dots[[1L]][[2L]]     1  6 524.0956 540.1884 -256.0478                        
#dots[[2L]][[2L]]     2  7 525.7577 544.5326 -255.8788 1 vs 2 0.337934   0.561
#
#$v3
#                 Model df      AIC      BIC    logLik   Test  L.Ratio p-value
#dots[[1L]][[3L]]     1  6 387.4002 403.4930 -187.7001                        
#dots[[2L]][[3L]]     2  7 389.1333 407.9082 -187.5667 1 vs 2 0.266947  0.6054

Answer 2

You could use sapply

MyRes <- sapply(1:length(output.02), function(x) {
    anova(output.02[[x]], output.03[[x]])})