[R] Factor Variable frequency

[chalabi.elahe at yahoo.de]

Hi all,
I have the following df:


    $ Protocol       : Factor w/ 48 levels "DP FS QTSE SAG",..: 2 3 43 42 31 36 37 30 28 5 ...
    
    $ Speed         : chr  "SLOW" "SLOW" "SLOW" "VerySLOW" ...
How can I get the most frequent Protocol when Speed is "SLOW"?
Thanks for any help!
Elahe