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2018-08-06 16:31:53 +0100 commented answer Help with graphs

I understand this and I have reached that point.

However in the first question, I can't write every single graph, I need something that aoutomatically reads all ~100 graphs that are in the graph6 file. Moreover some of the graphs sage doesn't read at all - it gives errors because of certain symbols in the string of the graph.

For the second question finding the independent sets is ok, but then I need an algorithm which contracts the independent sets into new smaller graphs, so that I find hom G.

2018-08-06 15:42:28 +0100 received badge  Student (source)
2018-08-06 13:07:18 +0100 asked a question Help with graphs

I am trying to find the set of (surjective) homomorphic images of the Groetzsch Graph - G. I have two ideas, but I am stuck at both. Help with either would be very much appreciated.

1.I try narrowing down the candidate homomorphic images to graphs with chromatic number at least 4 and number of vertices at most 10 in house of graphs. Then i get a graph6 file and try to check if each of those graphs is a homomorphic image of G. This doesn't work because I don't know how exactly to import the graph6 file into sage.
2. Find the independent sets of G and find all the ways I can combine them into homomorphic images. I' ve heard that this is possible, but seems like a rather daunting task for me because I am very new with sage.

2018-08-06 13:07:18 +0100 asked a question Help with graphs

I am trying to find the set of (surjective) homomorphic images of the Groetzsch Graph - G. I have two ideas, but I am stuck at both. Help with either would be very much appreciated.

1.I try narrowing down the candidate homomorphic images to graphs with chromatic number at least 4 and number of vertices at most 10 in house of graphs. Then i get a graph6 file and try to check if each of those graphs is a homomorphic image of G. This doesn't work because I don't know how exactly to import the graph6 file into sage.

  1. Find the independent sets of G and find all the ways I can combine them into homomorphic images. I' ve heard that this is possible, but seems like a rather daunting task for me because I am very new with sage.