Libraries for (label propagation algorithms/frequent subgraph mining) for graphs in R
This is an old post, but there is a subgraph package and accompanying book/documentation for doing this in R:
https://www.csc.ncsu.edu/faculty/samatova/practical-graph-mining-with-R/PracticalGraphMiningWithR.html

Although I personally don't get the connection between subgraph mining and label propagation in this case. SVD++ might be closer to what you're looking for (supported by GraphX of Spark, which I think also supports label propagation).
http://spark.apache.org/graphx/