deleting rows in a matrix?

I want to delete corresponded rows in mother matrix x when x2 have duplicated rows, the following code may explain the goal:

 x=[1 0 0 1 1;1 0 1 0 1;1 1 0 0 1]; %mother matrix
y=[5 -2 -1 -1 -1]; 
x2=[]; 
for k=1:size(x,1)
    x2=[x2;x(k,:)*y'];
end

so this code will give x2=[3;3;2] which means row '1' and row '2' are considered the same and I want to use only one row and delete the other, how can I do that?

[Walter Roberson]

Does the order of the rows need to stay the same?

Answer 1

[Walter Roberson]

[x2u, x2u_idx] = unique(x2, 'stable');
new_x = x(x2u_idx, :);

[JacobM]

Perfect! thanks Walter

Answer 2

[Thorsten]

new_x = x(unique(x2),:);

[JacobM]

I thought of this too but this command would remove the rows in x2 but not x, I want to remove the rows in x that corresponds to duplicated one in x2. and also the problem is that, the number of rows in x is not fixed and it may increase or decrease. so I want to have the code generalised.

I thought also of using the for loop but it would take more time for big matrix,

what do you think?

[JacobM]

 x=[1 0 0 1 1;1 0 1 0 1;1 1 0 0 1];
y=[5 -2 -1 -1 -1];
x2=[];
for k=1:size(x,1)
    x2=[x2;x(k,:)*y'];
end      
[x_val,x_idx]=unique(x2);
for i=1:size(x_idx)
    j=x_idx(i);
    new_x(i,:)=x(j,:);
end

i did this and it works but looking for simpler code?

[JacobM]

Thanks Thorsten for your input, it is really appreciated!