How can I compare a set of variables?

Given a set of variables:

x1= 1;
x2= 3;
x3= 4;
x4= 3;
x5= 3;
x6= 1;
x7=2;

Is there a way in MATLAB to scan through the variables and identify which one are equal and output something like this?

x1=[1 1];
x2=[3 3 3];
x3=[4];
x7=[2];

Answer 1

[Andrei Bobrov]

x= [1;
3;
4;
3;
3;
1;
2]

[~,~,c] = unique(x,'stable');
x_out = accumarray(c,x,[],@(x){x});

Answer 2

[KSSV]

x1= 1;
x2= 3;
x3= 4;
x4= 3;
x5= 3;
x6= 1;
x7=2;

x = [x1 x2 x3 x4 x5 x6 x7] ; 
[c,ia,ib] = unique(x) ;
iwant = cell(length(c),1) ; 
for i = 1:length(c)
    iwant{i} = x(ib==i) ; 
end
celldisp(iwant)

Answer 3

[CC LAI]

x1= 1;

x2= 3;

x3= 4;

x4= 3;

x5= 3;

x6= 1;

x7=2;

x = [x1 x2 x3 x4 x5 x6 x7] ;

[c,ia,ib] = unique(x) ;

iwant = cell(length(c),1) ;

for i = 1:length(c)

iwant{i} = x(ib==i) ;

end

celldisp(iwant)