How to remove a value from a vector in a for loop?

Basically I am working with the variables k and l.

Originally I created a vector of N values and make a for loop from 1 to N.

In the for loop I put 2 randi functions that pick 2 values from 1 to N. The first one being k and the second one being l.

But now I want to exlude from the possibilities the to be picked the values that have already been picked. So no value is picked twice.

I tried using setdiff, yet I fail at implementing it.

This is what I tried doing.

for i = 1:1:N
        k = randi([1 N]);
        K = setdiff([1 N],[k]);
        l = randi([1 N]);
        L = setdiff([1 N],[l]);
        DS = randi([-1 1]);
       
        if DS == 1 && A(1,l) - unit > 0
            A(1,k) = A(1,k) + unit;
            A(1,l) = A(1,l) - unit;
        elseif DS == -1 && A(1,k) - unit > 0
            A(1,k) = A(1,k) - unit;
            A(1,l) = A(1,l) + unit;
        end

How would someone implement the idea?

Thank you

Answer 1

[Walter Roberson]

candidates = 1:N;        
kidx = randi(numel(candidates));
k = candidates(kidx);
candidates(kidx) = [];
lidx = randi(numel(candidates));
l = candidates(lidx);
candidates(lidx) = [];

Or....

klidz = randperm(numel(candidates), 2);
k = candidates(klidx(1));
l = candidates(klidx(2));
candidates(klidx) = [];

[Mikel Gonzalez Bribiesca]

Thank you, this worked very well with relative fast speed

Answer 2

[VBBV]

K = setdiff(randi([1 N]),[k]);

[VBBV]

you can also try this

k = randi([1 N])
K = setdiff(randi([1 N],1,i),[k])
L = setdiff(randi([1 N],1,i),[l]);

or do you mean this

k = randi([1 N])
K = setdiff(([1:N],[k]); % use values from  1:N  instead of just 1 and N
L = setdiff(([1:N],[l]);