Join some matrices without repeating arrays

Suppose I have matrices r1, r2 and r3 as follows:

r1 = [50;10;90;30];
r2 = [60;50];
r3 = [30;20;100];

I need a join matrix r that it is included all arrays of other matrices. I used the following code:

r = [r1; r2; r3];

But I need a code that not repeated same arrays in r1, r2 and r3, like:

t = [50;10;90;30;60;20;100];

Answer 1

[Andrei Bobrov]

r1 = [50;10;90;30];
r2 = [60;50];
r3 = [30;20;100];

r = [r1; r2; r3];

[~,b] = unique(r,'first');
out = r(sort(b));

or

out = unique(r,'stable');