Question

I’m trying to write a program which computes the variable called P for a set of numbers (i=1:10), except for one number (ind), which is chosen each time.

The first time P is calculated for i=1:10 and for example the number 4 is chosen as ind and used and we don’t want it to be included in the next iteration. So this next iteration P has to be calculated for i=[1:3 5:10].

How can i handle this? What I have this far is:

for i=1:10

    i=1:i
        t = sum(Job(i,2))
    i=1:10
        P = mean(Job(i,2))
        Index= Job(i,4)/Job(i,2)*exp(-max(Job(i,1)-Job(i,2)-t,0)/2*P)
        X=max(Index)
        ind=find(Index >= X)
    completion_time(Job(ind,3))= machine_free_time + Job(ind,2)
    machine_free_time = completion_time(Job(ind,3))
    Lateness(Job(ind,3))= completion_time(Job(ind,3)) - Job(ind,1)
    Tardiness(Job(ind,3))= max(Lateness(Job(ind,3)),0)
end

Answer 1

Two ways of doing this:

1. Remove elements from a vector

   idcs = 1:10; % initially all values are included from 1 to 10
   for ii=1:10
       idx = choose one out of idcs
       % do your calculation
       % remove idx from idcs
       idcs(idcs==idx)=[];
   end
   

2. Use a 2nd vector to keep hold of which values are already used:

   idcs = 1:10;
   valused=false(size(idcs));
   for ii=1:10
       idx = choose one out of idcs(~valused)
       % do your calculation
       % set the used value to true
       valused(idcs=idx)=true;
   end
   

So for example to use this 2nd method with the thing you’re trying to do, I think it’ll go like this:

vector_i = 1:10
vector_i_used = false(size(vector_i));

for kk=1:10 % main loop
    P = calculateP( vector_i(~vector_i_used) );
    % ...
    ind = calculateInd(P, vector_i(~vector_i_used));
    vector_i_used(vector_i==ind) = true;
end