samp_data=data.frame(a=1:5),b=c('22','23','34','21','43'),c=c('11','12','13','54','43'))

samp_data
 a  b  c
 1 22 11
 2 23 12
 3 34 13
 4 21 54
 5 43 43

str(samp_data)
'data.frame':   5 obs. of  3 variables:
 $ a: int  1 2 3 4 5
 $ b: Factor w/ 5 levels "21","22","23",..: 2 3 4 1 5
 $ c: Factor w/ 5 levels "11","12","13",..: 1 2 3 5 4

1
22
11
2
23
12
3
34
13

dat <- data.frame(samp_data[1], stack(samp_data[2:ncol(samp_data)]))
dat <- melt(samp_data, id.vars=1)