CODEWITHSUNDEEP
rdataframe
NewUsr_stat
NewUsr_stat

Reputation: 2583

Collapse a data.frame into a vector

I have a data frame like this: 

COL1  COL2  COL3 

   a           h
   b     f    
   c     g       
   d           j

I would like the following output:

 COL  
   a    
   b    
   c    
   d   
   f   
   g   
   h   
   j

How this can be done? Thanks in advance!

Upvotes: 3

Views: 7935

Answers (3)

Sven Hohenstein
Sven Hohenstein

Reputation: 81693

You could use unlist:

dat <- data.frame(A1 = letters[1:3],
                  A2 = letters[2:4],
                  A3 = c("f", "a", "b"), stringsAsFactors = FALSE)

unlist(dat)

# A11 A12 A13 A21 A22 A23 A31 A32 A33 
# "a" "b" "c" "b" "c" "d" "f" "a" "b"

Upvotes: 3

Dason
Dason

Reputation: 61933

do.call(c, your_data_frame)

An example:

> dat <- data.frame(a = 1:3, b = 2:4)
> do.call(c, dat)
a1 a2 a3 b1 b2 b3 
 1  2  3  2  3  4

This takes each column of the data.frame and treats it as a separate input into c so you're just concatenating everything into a single vector.

Upvotes: 4

A5C1D2H2I1M1N2O1R2T1
A5C1D2H2I1M1N2O1R2T1

Reputation: 193527

If your data.frame is named dat, try:

unlist(dat, use.names=FALSE)

You may also want to try the following:

as.character(unlist(dat, use.names=FALSE))
c(na.omit(as.character(unlist(dat, use.names=FALSE))))

which might be useful if your data are entered as factors.

Also, in your question, you make it appear that you don't actually have a basic "vector", but rather a one-column data.frame. Thus, something like dat2 <- data.frame(COL = c(na.omit(as.character(unlist(dat, use.names=FALSE))))) might be what you're looking for.

Upvotes: 9

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