Adjacency Matrix

[Omni]

When demonstrating the 4x4 Incidence Matrix at 5:30

Example had:                                 
      1     2      3     4                              
A     2     0      0     0                        
B     2     5      2     0                        
C     0     0      2     1                        
D     0     5      0     1     
                   
Shouldn't it be: b/c of Directions
     1    2    3    4
A    2    0    0    0
B    0    5    2    0
C    0    0    2    1
D    0    5    0    0

Adjacency Matrix

[garypettie]

Great catch Omni!
It looks like I ignored the directions on the graph when drawing out the incidence matrix.

Taking directionality into account, the correct matrix would be:

  1 2 3 4
A 2 0 0 0 
B 0 5 2 0 
C 0 0 2 1
D 0 5 0 0 

Note that edges 2 and 3 are non-directed, so you can traverse them in both directions.