deleting rows using setdiff?

I have two different matrices, x & x1, and they are related. x is generated to be compared to y, all elements that are not availbe in y need to be ignored in the output matrix. So, the output matrix Tx has the rows of x1 that are results of comparison between x and y.

I used this code, but couldn't figure out how to delete the rows using the idx results;

 x1=[1 0 0;0 1 1;1 0 2;2 0 1;2 2 2];
% x & x1 are related.
x=[2;1;5;6;8]; 
y=[1;2;5;6]; % wanted values of x1
[z,idx]=setdiff(x,y,'rows')
%Tx should return the values of x1
% based on the comparison matrix z
% whih contains unwanted rows
Tx=setdiff(x1,[idx],'rows','stable');

the output is expexted to be Tx=[1 0 0;0 1 1;1 0 2;2 0 1]; %row5 is deleted

Answer 1

[dpb]

For what you're looking for, ismember is better than setdiff --

x=[2;1;5;6;8]; 
y=[1;2;5;6]; % wanted values of x1
>> Tx=x1(ismember(x,y),:)
Tx =
     1     0     0
     0     1     1
     1     0     2
     2     0     1
>>