Transcript for:
Understanding Adjacency Matrices in Networks

so we're gonna talk about an adjacency matrix here and an adjacency matrix is really useful because networks are really beautiful I love drawing them but they're kind of hard to understand and are also hard to perform sort of mathematical calculations on so if we can take this and turn it into matrix we can then start sort of manipulating it mathematically now the process is really simple we've got this little matrix here ABCDE ABCDE and now we're just gonna fill it in with zeros and ones now if two points are connected we're going to put a one at their intersection if two points aren't connected we're going to put a zero at their intersection all right a and C well let's let's do things in order a and B are not connected all right a and B are not connected so we give it a zero and also a and B are not connected so there's gonna be like a matching a B a B okay what about a a all right a is not connected to itself so give that a zero or AC AC is connected and so is C a ad ad is connected ie is connected all right let's do the matching ones ad ad a a e okay what about all the B's have you done B a so that's easy BBB B he's not connected to itself so a zero BC is connected to each other BC BC B DB D is not connected BD 0 BD 0 b e is connected b e1 beeves 1 ok CCC is not connected to itself CD C is not connected to D and CD not connected and see II see no c e is not connected c e is not connected d is not connected to itself de D is not connected to a Edie is not connected to E and finally E is connected to itself via a loop so that's an adjacency matrix and one thing I want you to look at with this adjacency matrix of this graph is that if I draw a diagonal line through this matrix it's symmetrical because AC I see this lines up with this so it's like a butterfly print that one ae lines up with that one a folding in on itself and so that's something to note here with this particular adjacency matrix in with these types of networks it's simple sort of network here we're going to end up with symmetry