R devel - May 2015 - Compatibility issue between lme4 and kml (operateur "[")

Hi all,

There is a compatibility issue between the package 'lme4' and my package
'kml'. I define the "[" operator. It works just fine in my
package (1). If I
try to use the lme4 package, then it does no longer work (2). Moreover, it
has some kind of strange behavior (3). Do you know what is wrong? Any idea
of how I can correct that?

Thanks for your help
Christophe

--- 8< ----------------- Code for reproductible example -------------------
library(kml)
dn <- gald(1)
dn["traj"]
library(lme4)
dn["traj"]
setMethod(   ### Simplified version ###
  "[",
  signature=signature(x="ClusterLongData", i="character",
j="ANY",drop="ANY"),
  definition=function (x, i, j="missing", ..., drop = TRUE){
      x <- as(x, "LongData")
      return(x[i, j])
    }
)
dn["traj"]
dn["traj"]

--- 8< ----------------- Execution of the previous code -------------------
> library(kml)
Le chargement a n?cessit? le package : clv
Le chargement a n?cessit? le package : cluster
Le chargement a n?cessit? le package : class
Le chargement a n?cessit? le package : longitudinalData
Le chargement a n?cessit? le package : rgl
Le chargement a n?cessit? le package : misc3d
> dn <- gald(1)
  ###########
 #### (1] ####
### (1) the "[" operator works just fine
> dn["traj"]
      t0   t1    t2    t3    t4   t5   t6    t7    t8    t9   t10
i1 -3.11 4.32  2.17  1.82  4.90 7.34 0.83 -2.70  5.36  4.96  3.16
i2 -7.11 1.40 -2.40 -2.96  4.31 0.50 1.25  0.52 -0.04  7.55  5.50
i3  2.80 6.23  6.08  2.87  2.58 2.88 6.58 -2.38  2.30 -1.74 -3.23
i4  2.24 0.91  6.50 10.92 11.32 7.79 7.78 10.69  9.15  1.07 -0.51

  ###########
 #### (2) ####
### using 'lme4', it does no longer work
> library(lme4)
Le chargement a n?cessit? le package : Matrix
Le chargement a n?cessit? le package : Rcpp
> dn["traj"]
Error in x[i, j] : 
  erreur d'?valuation de l'argument 'j' lors de la s?lection
d'une m?thode
pour la fonction '[' : Erreur : l'argument "j" est
manquant, avec aucune
valeur par d?faut

  ###########
 #### (3) ####
### If I define again the "[", it does not work the first time I call
it,
but it work the second time!
> setMethod(
+   "[",
+   signature=signature(x="ClusterLongData", i="character",
j="ANY",drop="ANY"),
+   definition=function (x, i, j="missing", ..., drop = TRUE){
+       x <- as(x, "LongData")
+       return(x[i, j])
+     }
+ )
[1] "["

### No working the first time I use it
> dn["traj"]
Error in dn["traj"] : 
  l'argument "j" est manquant, avec aucune valeur par d?faut

### But working the second time
> dn["traj"]
      t0   t1    t2    t3    t4   t5   t6    t7    t8    t9   t10
i1 -3.11 4.32  2.17  1.82  4.90 7.34 0.83 -2.70  5.36  4.96  3.16
i2 -7.11 1.40 -2.40 -2.96  4.31 0.50 1.25  0.52 -0.04  7.55  5.50
i3  2.80 6.23  6.08  2.87  2.58 2.88 6.58 -2.38  2.30 -1.74 -3.23
i4  2.24 0.91  6.50 10.92 11.32 7.79 7.78 10.69  9.15  1.07 -0.51






--
View this message in context:
http://r.789695.n4.nabble.com/Compatibility-issue-between-lme4-and-kml-operateur-tp4707670.html
Sent from the R devel mailing list archive at Nabble.com.