Hi,

Does tapply change the order when applied on a factor? Below is the code I
tried.

> mylevels<-c("IN0020020155","IN0019800021","IN0020020064")
>
mydata<-c("IN0020020155","IN0019800021","IN0020020064","IN0020020155","IN0019800021","IN0019800021","IN0020020064","IN0020020064","IN0019800021")
> myfactor<-factor(mydata,levels=mylevels)
> myfactor
[1] IN0020020155 IN0019800021 IN0020020064 IN0020020155 IN0019800021
IN0019800021 IN0020020064 IN0020020064 IN0019800021
Levels: IN0020020155 IN0019800021 IN0020020064
> summary(myfactor)
IN0020020155 IN0019800021 IN0020020064
           2            4            3

# Everything fine upto this point. The order of levels is maintained as it
is.

> mysummary<-tapply(myfactor,mydata,length)
> mysummary
IN0019800021 IN0020020064 IN0020020155
           4            3            2

# Now the order has changed.

Is this the expected behavior? Any idea on how to avoid the change in order?

Regards,
Chirantan

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