Create Semantic Trajectory Pattern Tree

Problem: I have to create in Matlab the function CreateNode(semantic, support, children)

Input: Semantic Trajectory Pattern
Output: Semantic Trajectory Pattern Tree
1 root <-- CreateNode(0,0,0)
2   node <-- root
3   foreach semantic S in STP do
4       if \exists a child nc of node semantic trajectory S \include nc.semantic then node <--nc
5           if S is the last element in STP 
6              then node.support=STP.support
7           end
8       else
9          child <--CreateNode(S,STP.support,0)
10         node.appendChild(child)
11         node <-- child
12      end
13   end
14 end
15 return root

Can you give me some suggestions to create it? I have no idea how to create a tree in Matlab.