将data.frame的所有列合并为一个（向量串联）

Question

I want to convert this data.frame

C1  C2  C3  C4
q   t   p   k   
g   l   i   y
f   d   t   r

to a data.frame with a single column with this order of elements q,t,p,k,g,l,i,y,f,d,t,r . Note that it is not a concatenation of columns.

Result:

C1
q
t
p
k
l
i
y
f
d
t
r

Answer 1

We can transpose the data.frame to a matrix , concatenate to convert it to vector and create a single column data.frame

data.frame(C1 = c(t(df)))
#   C1
#1   q
#2   t
#3   p
#4   k
#5   g
#6   l
#7   i
#8   y
#9   f
#10  d
#11  t
#12  r

data

df <- structure(list(C1 = c("q", "g", "f"), C2 = c("t", "l", "d"), 
C3 = c("p", "i", "t"), C4 = c("k", "y", "r")), class = "data.frame", 
 row.names = c(NA, -3L))