My questions is how can join two or more data frames in system R?
For example:
I have two data frames:
first:
   x  y  z
1  3  2  4
2  4  5  7
3  5  6  8
second:
   x  y  z
1  1  1  1
2  4  5  7
I need this:
   x  y  z
1  3  2  4
2  4  5  7
3  5  6  8
4  1  1  1
5  4  5  7
I tried to use append for each vector, like this:
for( i in 1:length(first)){
mix[[i]]<-append(first[i], second[i])}f<-do.call(rbind, mix)
But It didn't work like I needed. I didn't get my matrix, i got some different structure.
 
     
    