How to create an indicator function?

Dear community,

I ve got following situation. I created a vector (MCxT)(MC=Monte Carlo Trials, T=time in years) which gives me the development of the population over time. I show you one Monte Carlo Trial for the next 10 years. It looks like that:

1000  990  978  968  952  937  923  905  885  864

Now comes my problem, in the next step I would like to create an indicator matrix which does the following:

1. Matrix (N x T), that means each row characterise one person, with an integer 1

2. The Matrix should be constant (N x T), in this case (1000 x 10) BUT if someone dies, which should be randomly generated, the indicator should be zero. That means in t=2, we should have 1000 rows, with 990 entry values of 1 and 10 entry values of 0.

3. And once someone passed away the 0 should be kept in that row until T.

Does anybody have an idea how to do that or could give me a hint how to start.

Would be a great help if someone knows how to get the next step from (N x T) with 1000 entries of 1 to t=2 with 990 entries of 1 and 10 of 0, so that Matlab reads that number in t=2 and knows what to do with that number.

Thank you verrrry much in advance.

Best dennis