[R] how to make automatically each level from data.frame to vector

From: Muhammad Subianto <subianto_at_gmail.com>
Date: Sun 13 Nov 2005 - 07:37:27 EST

Dear R-helpers,
Suppose I have dataset like this below:
data(HairEyeColor)
dfHEC <- as.data.frame(as.table(HairEyeColor)) my.dfHEC <- data.frame(Hair=rep(dfHEC$Hair,dfHEC$Freq),

                       Eye=rep(dfHEC$Eye,dfHEC$Freq),
                       Sex=rep(dfHEC$Sex,dfHEC$Freq))
my.dfHEC
my.dfHEC$Hair

my.dfHEC$Eye
my.dfHEC$Sex

and I know all levels for Hair, Eye and Sex. In my case, I want to "expand.grid" all attributes but in Hair I only include "Black" hair:

Hair.e <- c("Black")
Eye.e <- c("Brown","Blue","Hazel","Green") Sex.e <- c("Male","Female")

#I can do like,
dfHEC.Black <- expand.grid(Hair.e,Eye.e,Sex.e) dfHEC.Black

My question is how to make automatically each level from data.frame to vector. I don't want to make definition for each level again (Hair.e, Eye.e, Sex.e). In the others word, how can I make "expand.grid" (each level) from data.frame automatically if Hair is only ("Black"). The result I need like,

   Var1 Var2 Var3
1 Black Brown Male
2 Black Blue Male
3 Black Hazel Male
4 Black Green Male
5 Black Brown Female
6 Black Blue Female
7 Black Hazel Female
8 Black Green Female

Thanks in advance.
Best, Muhammad Subianto

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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sun Nov 13 08:16:26 2005