python algorithm matlab graph-theory depth-first-search

Calling Python in MATLAB

In the below code, I have a Depth First Search with the pseudocode and the python code. My first question is how can I call this program in MATLAB?

I can use the following:

system('python DFS.py')

But I want to call it like:

py.DFS();

And store the data in MATLAB, but when I execute the code it says Unable to resolve the name py.DFS.

My second question is, how can I change the code in python to where it takes a MATLAB adjacency list and runs that in the code, instead of putting the adjacency list directly in the python code?

#DFS(G, u)
    #u.visited = true
    #for each v within G.adj[u]
        #if v.visited == false
            #DFS(G,v)

#init() {
    #For each u within G
        #u.visited == false
    #For each u within G
        #DFS(G,u)
#}

# DFS algorithm in Python


# DFS algorithm
def dfs(graph, start, visited=None):
    if visited is None:
        visited = set()
    visited.add(start)

    print(start)

    for next in graph[start] - visited:
        dfs(graph, next, visited)
    return visited


graph = {'1': set(['2', '4', '5']),
         '2': set(['1', '4', '3']),
         '3': set(['2', '4', '6']),
         '4': set(['1', '2', '3', '5', '6', '7']),
         '5': set(['1', '4', '7', '8']),
         '6': set(['3', '4', '7', '10']),
         '7': set(['4', '5', '6', '8', '10']),
         '8': set(['5', '7', '9']),
         '9': set(['8', '10']),
         '10': set(['6', '7', '9'])}

dfs(graph, '1')

n = len(graph)
s = pow(n, n-2) #number of spanning tree graphs
print("This is the number of spanning trees: ", s)

Solution

Make sure the folder containing the DFS.py file is added to your python search path. I think you need to call it in MATLAB as:

visited = py.DFS.dfs(graph, start);

You should initialize graph and start before call the function above. You can create a python list in MATLAB using:

graph = py.list({1.5,3.0,2.5})

Also, your dfs function return values can be accessed in MATLAB.