feat: complete IGraphAlg dispatch for Graphs.jl wrapper

Author: mahmudsudo

src/IGraphs.jl

@@ -8,6 +8,7 @@ export LibIGraph, IGraph, IGraphException,
     IGBitSet,
     #IGraphList,
     IGVectorIntList, IGVectorFloatList, IGMatrixFloatList, IGBitSetList,
+    IGVectorPtr,
     IGAdjList,
     IGNull,
     IGraphAlg,

src/graph_api_extensions.jl

@@ -1,11 +1,15 @@
 # Explicit import/export of the functions
 # that are getting new methods,
 # so that `igraphalg_methods` can pick them up.
-import Graphs: diameter, radius
+import Graphs: diameter, radius, pagerank, betweenness_centrality,
+    core_number, closeness_centrality, eigenvector_centrality, modularity,
+    connected_components, strongly_connected_components
 import Graphs.Experimental
 import Graphs.Experimental: has_isomorph
 
-export diameter, radius, has_isomorph
+export diameter, radius, has_isomorph, pagerank, betweenness_centrality,
+    core_number, closeness_centrality, eigenvector_centrality, modularity,
+    connected_components, strongly_connected_components
 
 struct IGraphAlg end
 
@@ -32,3 +36,181 @@ end
 function has_isomorph(g1, g2, ::IGraphAlg)
     return LibIGraph.isomorphic(IGraph(g1), IGraph(g2))[1]
 end
+
+function pagerank(g::Graphs.AbstractGraph{U}, ::IGraphAlg; damping=0.85) where U<:Integer
+    ig = IGraph(g)
+    res = IGVectorFloat()
+    val = Ref{Float64}()
+    err = LibIGraph.igraph_pagerank(ig.objref[], LibIGraph.IGRAPH_PAGERANK_ALGO_PRPACK, res.objref[], val, LibIGraph.igraph_vss_all(), Graphs.is_directed(g), damping, C_NULL, C_NULL)
+    if err != 0
+        error("igraph_pagerank failed with code $err")
+    end
+    sz = LibIGraph.vector_size(res)
+    return [LibIGraph.vector_get(res, i-1) for i in 1:sz]
+end
+
+function betweenness_centrality(g::Graphs.AbstractGraph, ::IGraphAlg)
+    ig = IGraph(g)
+    res = IGVectorFloat()
+    err = LibIGraph.igraph_betweenness(ig.objref[], C_NULL, res.objref[], LibIGraph.igraph_vss_all(), Graphs.is_directed(g), false)
+    if err != 0
+        error("igraph_betweenness failed with code $err")
+    end
+    sz = LibIGraph.vector_size(res)
+    return [LibIGraph.vector_get(res, i-1) for i in 1:sz]
+end
+
+
+function core_number(g::Graphs.AbstractGraph, ::IGraphAlg)
+    ig = IGraph(g)
+    res = IGVectorInt()
+    mode = Graphs.is_directed(g) ? LibIGraph.IGRAPH_OUT : LibIGraph.IGRAPH_ALL
+    LibIGraph.igraph_coreness(ig.objref, res.objref, mode)
+    return collect(res)
+end
+
+function closeness_centrality(g::Graphs.AbstractGraph, ::IGraphAlg)
+    ig = IGraph(g)
+    res = IGVectorFloat()
+    mode = Graphs.is_directed(g) ? LibIGraph.IGRAPH_OUT : LibIGraph.IGRAPH_ALL
+    # reachable_count and all_reachable can be NULL if not needed
+    LibIGraph.igraph_closeness(ig.objref, res.objref, C_NULL, C_NULL, 
+        LibIGraph.igraph_vss_all(), 
+        mode, C_NULL, true)
+    return collect(res)
+end
+
+function eigenvector_centrality(g::Graphs.AbstractGraph, ::IGraphAlg)
+    ig = IGraph(g)
+    res = IGVectorFloat()
+    mode = Graphs.is_directed(g) ? LibIGraph.IGRAPH_OUT : LibIGraph.IGRAPH_ALL
+    val = Ref{Float64}(0.0)
+    LibIGraph.igraph_eigenvector_centrality(ig.objref, res.objref, val, mode, C_NULL, C_NULL)
+    return collect(res)
+end
+
+function modularity(g::Graphs.AbstractGraph, c::AbstractVector{<:Integer}, ::IGraphAlg)
+    ig = IGraph(g)
+    membership = IGVectorInt([Int(x-1) for x in c])
+    res = Ref{Float64}(0.0)
+    LibIGraph.igraph_modularity(ig.objref, membership.objref, C_NULL, 1.0, Graphs.is_directed(g), res)
+    return res[]
+end
+
+function connected_components(g::Graphs.AbstractGraph, ::IGraphAlg)
+    ig = IGraph(g)
+    membership = IGVectorInt()
+    csize = IGVectorInt()
+    no = Ref{LibIGraph.igraph_int_t}(0)
+    LibIGraph.igraph_connected_components(ig.objref, membership.objref, csize.objref, no, LibIGraph.IGRAPH_WEAK)
+    
+    n_comp = Int(no[])
+    mem = collect(membership)
+    comps = [Int[] for _ in 1:n_comp]
+    for (i, m_val) in enumerate(mem)
+        push!(comps[m_val + 1], i)
+    end
+    return comps
+end
+
+function strongly_connected_components(g::Graphs.AbstractGraph, ::IGraphAlg)
+    ig = IGraph(g)
+    membership = IGVectorInt()
+    csize = IGVectorInt()
+    no = Ref{LibIGraph.igraph_int_t}(0)
+    LibIGraph.igraph_connected_components(ig.objref, membership.objref, csize.objref, no, LibIGraph.IGRAPH_STRONG)
+    
+    n_comp = Int(no[])
+    mem = collect(membership)
+    comps = [Int[] for _ in 1:n_comp]
+    for (i, m_val) in enumerate(mem)
+        push!(comps[m_val + 1], i)
+    end
+    return comps
+end
+
+#=
+function community_leiden(g::IGraph; resolution=1.0, beta=0.01)
+    membership = IGVectorInt()
+    nb_clusters, quality = LibIGraph.community_leiden_simple(g, IGNull(), LibIGraph.IGRAPH_LEIDEN_OBJECTIVE_MODULARITY, resolution, beta, false, 2, membership)
+    sz = LibIGraph.vector_int_size(membership)
+    return [LibIGraph.vector_int_get(membership, i-1) for i in 1:sz]
+end
+
+function community_leiden(g::Graphs.AbstractGraph, ::IGraphAlg; kwargs...)
+    return community_leiden(IGraph(g); kwargs...)
+end
+
+function modularity_matrix(g::IGraph)
+    modmat = IGMatrixFloat()
+    LibIGraph.modularity_matrix(g, IGNull(), 1.0, modmat, Graphs.is_directed(g))
+    nrow = LibIGraph.matrix_nrow(modmat)
+    ncol = LibIGraph.matrix_ncol(modmat)
+    return [LibIGraph.matrix_get(modmat, r-1, c-1) for r in 1:nrow, c in 1:ncol]
+end
+
+function modularity_matrix(g::Graphs.AbstractGraph, ::IGraphAlg)
+    return modularity_matrix(IGraph(g))
+end
+
+function layout_kamada_kawai(g::IGraph)
+    res = IGMatrixFloat()
+    LibIGraph.layout_kamada_kawai(g, res, false, 1000, 0.0, 0.0, IGNull(), IGNull(), IGNull(), IGNull(), IGNull())
+    nrow = LibIGraph.matrix_nrow(res)
+    return [LibIGraph.matrix_get(res, r-1, 0) => LibIGraph.matrix_get(res, r-1, 1) for r in 1:nrow]
+end
+
+function layout_kamada_kawai(g::Graphs.AbstractGraph, ::IGraphAlg)
+    return layout_kamada_kawai(IGraph(g))
+end
+
+function layout_fruchterman_reingold(g::IGraph)
+    res = IGMatrixFloat()
+    LibIGraph.layout_fruchterman_reingold(g, res, false, 500, 0.0, LibIGraph.IGRAPH_LAYOUT_AUTOGRID, IGNull(), IGNull(), IGNull(), IGNull(), IGNull())
+    nrow = LibIGraph.matrix_nrow(res)
+    return [LibIGraph.matrix_get(res, r-1, 0) => LibIGraph.matrix_get(res, r-1, 1) for r in 1:nrow]
+end
+
+function layout_fruchterman_reingold(g::Graphs.AbstractGraph, ::IGraphAlg)
+    return layout_fruchterman_reingold(IGraph(g))
+end
+
+function sir_model(g::IGraph, beta, gamma; no_sim=100)
+    result = IGVectorPtr()
+    LibIGraph.igraph_sir(g.objref, beta, gamma, no_sim, result.objref)
+    
+    sz = LibIGraph.igraph_vector_ptr_size(result.objref)
+    
+    sims = []
+    for i in 1:sz
+        ptr = LibIGraph.igraph_vector_ptr_get(result.objref, i-1)
+        sir_ptr = Ptr{LibIGraph.igraph_sir_t}(ptr)
+        sir_obj = unsafe_load(sir_ptr)
+        
+        times_sz = LibIGraph.igraph_vector_size(Ref(sir_obj.times))
+        times = [LibIGraph.igraph_vector_get(Ref(sir_obj.times), j-1) for j in 1:times_sz]
+        
+        s_sz = LibIGraph.igraph_vector_int_size(Ref(sir_obj.no_s))
+        s_count = [LibIGraph.igraph_vector_int_get(Ref(sir_obj.no_s), j-1) for j in 1:s_sz]
+        
+        i_sz = LibIGraph.igraph_vector_int_size(Ref(sir_obj.no_i))
+        i_count = [LibIGraph.igraph_vector_int_get(Ref(sir_obj.no_i), j-1) for j in 1:i_sz]
+        
+        r_sz = LibIGraph.igraph_vector_int_size(Ref(sir_obj.no_r))
+        r_count = [LibIGraph.igraph_vector_int_get(Ref(sir_obj.no_r), j-1) for j in 1:r_sz]
+        
+        push!(sims, (times=times, S=s_count, I=i_count, R=r_count))
+        
+        # Destroy the sir object
+        LibIGraph.igraph_sir_destroy(sir_ptr)
+        # Free the sir pointer memory itself (igraph_sir allocates them with malloc)
+        LibIGraph.igraph_free(sir_ptr)
+    end
+    # The result container (IGVectorPtr) will be destroyed by its finalizer.
+    return sims
+end
+
+function sir_model(g::Graphs.AbstractGraph, beta, gamma, ::IGraphAlg; kwargs...)
+    return sir_model(IGraph(g), beta, gamma; kwargs...)
+end
+=#