How many people in the room have the same birthday

Birthday.m

for i=1:365
    % let's simulate 1000 times
    for j=1:1000
        % make a vector of random numbers (1 to 365) i times
        test=randi(365,[1 i]);
        % test if there is a duplicate 
        dupbirthday(i,j)=~(length(test) == length(unique(test)));
    end
end

for i=1:365
    % calculate percentage of times there is a duplicate birthday in 1000 trials
    perdupbirthday(i)=sum(dupbirthday(i,:))/1000;
end

% plot it
plot(perdupbirthday)