This repository has been archived by the owner on Dec 22, 2022. It is now read-only.
Vertex k-Core Decomposition App #77
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Feature merge (dev to master)
Major directory structure change (`applications`->`algorithms`)
|
Merging this, I'll make some improvements and tag you in the new version. |
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Computes the k-core value for all vertices in the input graph. A k-core is a maximal subgraph in which all vertices have degree >= k. A vertex’s k-core value is the largest value of k for which it is a member of a k-core.
This implementation is intended for undirected graphs. For directed graphs, there are concepts of directional k-core values based on vertices' in- and out-degrees, but I have not yet implemented that.
How it works:
To find the k-cores, start with the full graph and set k=iteration. Then iteratively remove vertices (mark them as deleted) with degree <= k, set those vertices’ k-core values to the current value of k, and decrement the degree for all neighbor vertices. Increment k when all vertices with degree <= k have been removed. Repeat the vertex removal process. Continue until no vertices remain.
There are some differences in results between this and k-core app in
gunrock/gunrock, which come from differences in the graph pre-processing; specifically, directed graphs and self-loops. Graphs that are symmetric and contain no self-loops have same k-core results foressentialsandgunrock/gunrock. Graphs that are not symmetric and/or include self-loops will have different results, because the reported vertex degrees differ in the two graph implementations.