Hello all,

I was playing around with Shortest path example. I decided to write my own 
input format to match with SNAP's LJ dataset (

<http://snap.stanford.edu/data/soc-LiveJournal1.html)>http://snap.stanford.edu/data/soc-LiveJournal1.html
 ). This is an edge format so I wrote LongFloatTextEdgeInputFormat (which is 
similar to IntNullTextEdgeInputFormat given in io/formats directory).

To test this I had following input :


0 1

0 2

0 3

1 2

2 0

2 3


And all edges have weight 1.

I tried running ShortestPath example by specifying the edge input format and 
the above input file and I got the following output :

0 2.0

1 0

2 1.0

3 0


Notice that for vertex 3 it should be 2 (source is vertex 1). I thought there 
is some problem with my input format, so went back to vertex input format as 
specified in the quick start guide. Here is my vertex input in JSON format :

[0,0,[[1,1],[2,1],[3,1]]]
[1,0,[[2,1]]]
[2,0,[[3,1],[0,1]]]


Notice that vertex 3 doesn't have any outgoing edge so I didn't added an entry 
for it. Even with this I got the same output. Then I enabled debug and found 
that

Vertex 3 doesn't execute Superstep 0 at all. It only executed Superstep 3 and 4 
(in Superstep 3 it receives a message from vertex 2). Also, in Superstep 3 it 
shows that it has vertex value = 0.

Does it mean that vertices with no outgoing edges are not "active" in the 
beginning? Is there any way to fix this?


A quick and dirty fix will be adding a line to vertex input file - [3, 0, []]

but what if I don't want to use vertex input format and use edge input format 
as described above?


Thank you.

Sincerely,
Vivek

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