[BioC] merge two dataframes

[Ghislaine Guigon]

Hi,

I would try to merge 2 dataframes x1, x2 with same structure. ID is the 
common columns. I don't understand why the result,  x,  is composed of NA ?
Is someone understand the problem ?

The code is :

 > x2[1:3,]
              ID     sVOL logSignalMean
4340 8559;27*L11 3189.818    11.6392584
4335  8547;27*L9 3419.657    11.7396359
3267 6441;27*I18    0.000    -0.4460873
 > x1[1:3,]
              ID     sVOL logSignalMean
4339 8557;25*L11 2972.267    11.5373480
4334  8545;25*L9 3380.747    11.7231263
3266 6439;25*I18    0.000    -0.4460873
 > x<- merge(x1,x2,by.x=ID,by.y=ID,suffixes=c("1","2"))
 > x[1:3,]
       ID sVOL1 logSignalMean1 sVOL2 logSignalMean2
NA   <NA>    NA             NA    NA             NA
NA.1 <NA>    NA             NA    NA             NA
NA.2 <NA>    NA             NA    NA             NA

thanks,
gg