R add rows from colum in 1 table to the bottom of a column in a different table -

i have table (a) columns a1 , a2. have numeric values. want take column a1 , a2 table(b) , place them @ bottom of table(a) in columns a1 , a2. basically, have 2 datasets in different tables , want combine them 1 can analysis. appreciated!

let's have table 1 column , 3 rows: 1,2,3. have table b 1 column , 3 rows: 4,5,6. want output 1 column 6 rows: 1,2,3,4,5,6

this literally rbind() - 2 matrices or data.frames same columns can bound second object passed being bound new rows first. won't work vectors unless turn them matrices.

a = data.frame(a1=c(1,2,3),a2=c("a","b","c")) b = data.frame(a1=c(4,5,6),a2=c("d","e","f")) ab = rbind(a,b) ab  #  a1 a2 #1  1  #2  2  b #3  3  c #4  4  d #5  5  e #6  6  f  = data.frame(a1=c(1,2,3)) b = data.frame(a1=c(4,5,6)) ab = rbind(a,b) ab  #  a1 #1  1 #2  2 #3  3 #4  4 #5  5 #6  6  = matrix(c(1,2,3),ncol=1) b = matrix(c(4,5,6),ncol=1) ab = rbind(a,b) ab  #     [,1] #[1,]    1 #[2,]    2 #[3,]    3 #[4,]    4 #[5,]    5 #[6,]    6