Question

How can I define a set in Matlab which has these properties:

• Unique items
• Efficient search
• Ordered

Maybe there isn’t a built-in container, So how can I combine some stuff to gain above things as same as std::set in C++?

Answer 1

You can use Java’s HashSet like this:

>> x = java.util.HashSet;
>> x.add(1);
>> x.add(2);
>> x.contains(1)
ans = 
     1
>> x.contains(3)
ans = 
     0
>> x
x = 
[2.0, 1.0]

In the comments it was pointed out that a HashSet isn’t ordered. Which is totally true. My mistake! You could use a TreeSet instead, which is ordered:

>> x = java.util.TreeSet;
>> x.add(1);
>> x.add(3);
>> x.add(2);
>> x
x = 
[1.0, 2.0, 3.0]