Improve subgraph from QuotientVertex and other small improvements (#113)

Author: mtfishman

Project.toml

@@ -1,7 +1,7 @@
 name = "NamedGraphs"
 uuid = "678767b0-92e7-4007-89e4-4527a8725b19"
 authors = ["Matthew Fishman <[email protected]>, Joseph Tindall <[email protected]> and contributors"]
-version = "0.8.1"
+version = "0.8.2"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"

docs/src/index.md

@@ -23,21 +23,7 @@ NamedGraphs.jl is supported by the Flatiron Institute, a division of the Simons
 
 ## Installation instructions
 
-This package resides in the `ITensor/ITensorRegistry` local registry.
-In order to install, simply add that registry through your package manager.
-This step is only required once.
-```julia
-julia> using Pkg: Pkg
-
-julia> Pkg.Registry.add(url="https://github.com/ITensor/ITensorRegistry")
-```
-or:
-```julia
-julia> Pkg.Registry.add(url="[email protected]:ITensor/ITensorRegistry.git")
-```
-if you want to use SSH credentials, which can make it so you don't have to enter your Github ursername and password when registering packages.
-
-Then, the package can be added as usual through the package manager:
+The package can be added as usual through the package manager:
 
 ```julia
 julia> Pkg.add("NamedGraphs")

docs/src/reference.md

@@ -1,5 +1,5 @@
 # Reference
 
 ```@autodocs
-Modules = [NamedGraphs, NamedGraphs.GraphsExtensions, NamedGraphs.NamedGraphGenerators, NamedGraphs.Keys]
+Modules = [NamedGraphs, NamedGraphs.GraphsExtensions, NamedGraphs.NamedGraphGenerators, NamedGraphs.PartitionedGraphs, NamedGraphs.Keys]
 ```

src/abstractnamedgraph.jl

@@ -379,7 +379,11 @@ function Graphs.rem_edge!(graph::AbstractNamedGraph, edge)
 end
 
 function Graphs.has_edge(graph::AbstractNamedGraph, edge::AbstractNamedEdge)
-    return has_edge(position_graph(graph), edge_to_position_edge(graph, edge))
+    src_position = get(vertex_positions(graph), src(edge), nothing)
+    isnothing(src_position) && return false
+    dst_position = get(vertex_positions(graph), dst(edge), nothing)
+    isnothing(dst_position) && return false
+    return has_edge(position_graph(graph), src_position, dst_position)
 end
 
 # handles two-argument edge constructors like src,dst

src/lib/PartitionedGraphs/src/PartitionedGraphs.jl

@@ -5,22 +5,22 @@ A library for partitioned graphs and their quotients.
 
 This module provides data structures and functionalities to work with partitioned graphs,
 including quotient vertices and edges, as well as views of partitioned graphs.
-It defines an abstract supertype [`AbstractPartitionedGraph`](@ref) for graphs that have
+It defines an abstract supertype `AbstractPartitionedGraph` for graphs that have
 some notion of a non-trivial partitioning of their vertices. It also provides 
 a interface of functions that can be overloaded on any subtype of `Graphs.AbstractGraph` to
-make this subtype behave like a partitioned graph, without itself subtyping [`AbstractPartitionedGraph`](@ref).
+make this subtype behave like a partitioned graph, without itself subtyping `AbstractPartitionedGraph`.
 
 It defines the following concrete types:
-- [`QuotientVertex`](@ref): Represents a vertex in the quotient graph.
-- [`QuotientEdge`](@ref): Represents an edge in the quotient graph.
-- [`PartitionedView`](@ref): A lightweight view of a partitioned graph.
-- [`PartitionedGraph`](@ref): An implementation of a partitioned graph with extra caching
-    not provided by [`PartitionedView`](@ref).
-- [`QuotientView`](@ref): A view of the quotient graph derived from a partitioned graph.
+- `QuotientVertex`: Represents a vertex in the quotient graph.
+- `QuotientEdge`: Represents an edge in the quotient graph.
+- `PartitionedView`: A lightweight view of a partitioned graph.
+- `PartitionedGraph`: An implementation of a partitioned graph with extra caching
+    not provided by `PartitionedView`.
+- `QuotientView`: A view of the quotient graph derived from a partitioned graph.
 It provides the following functions:
-- [`partitionedgraph`](@ref): Partitions an `AbstractGraph`.
-- [`departition`](@ref): Removes a single layer of partitioning from a partitioned graph.
-- [`unpartition`](@ref): Recursively removes all layers of partitioning from a partitioned graph.
+- `partitionedgraph`: Partitions an `AbstractGraph`.
+- `departition`: Removes a single layer of partitioning from a partitioned graph.
+- `unpartition`: Recursively removes all layers of partitioning from a partitioned graph.
 
 ## Interfaces
 

src/lib/PartitionedGraphs/src/abstractpartitionedgraph.jl

@@ -161,6 +161,8 @@ function Base.:(==)(pg1::AbstractPartitionedGraph, pg2::AbstractPartitionedGraph
     return true
 end
 
-function NamedGraphs._induced_subgraph(pg::AbstractPartitionedGraph, vlist)
-    return NamedGraphs._induced_subgraph(unpartitioned_graph(pg), vlist)
+function NamedGraphs.induced_subgraph_from_vertices(
+        pg::AbstractPartitionedGraph, subvertices
+    )
+    return NamedGraphs.induced_subgraph_from_vertices(unpartitioned_graph(pg), subvertices)
 end

src/lib/PartitionedGraphs/src/partitionedgraph.jl

@@ -154,13 +154,13 @@ function Graphs.rem_edge!(pg::PartitionedGraph, edge::AbstractEdge)
 end
 
 ### PartitionedGraph Specific Functions
-function partitionedgraph_induced_subgraph(pg::PartitionedGraph, vlist)
-    sub_pg_graph, _ = induced_subgraph(pg.graph, vlist)
+function NamedGraphs.induced_subgraph_from_vertices(pg::PartitionedGraph, subvertices)
+    sub_pg_graph, _ = induced_subgraph(pg.graph, subvertices)
     sub_partitioned_vertices = copy(pg.partitioned_vertices)
     for qv in quotientvertices(pg)
         pv = parent(qv)
 
-        vs = intersect(vlist, sub_partitioned_vertices[pv])
+        vs = intersect(subvertices, sub_partitioned_vertices[pv])
         if !isempty(vs)
             sub_partitioned_vertices[pv] = vs
         else
@@ -170,7 +170,9 @@ function partitionedgraph_induced_subgraph(pg::PartitionedGraph, vlist)
 
     return PartitionedGraph(sub_pg_graph, sub_partitioned_vertices), nothing
 end
-
-function NamedGraphs._induced_subgraph(pg::PartitionedGraph, vlist)
-    return partitionedgraph_induced_subgraph(pg, vlist)
+function NamedGraphs.induced_subgraph_from_vertices(
+        pg::PartitionedGraph, subvertices::SubVertices{<:QuotientVertex}
+    )
+    sg, vs = NamedGraphs.induced_subgraph_from_vertices(pg, subvertices.vertices)
+    return unpartitioned_graph(sg), vs
 end

src/lib/PartitionedGraphs/src/quotientedge.jl

@@ -2,6 +2,12 @@ using Graphs: AbstractGraph, Graphs, AbstractEdge, dst, src, ne, has_edge
 using ..NamedGraphs: AbstractNamedEdge
 using ..NamedGraphs.GraphsExtensions: GraphsExtensions, not_implemented, rem_edges!, rem_edge
 
+"""
+    QuotientEdge(e)
+
+Represents a super-edge in a partitioned graph corresponding to the set of edges
+in between partitions `src(e)` and `dst(e)`.
+"""
 struct QuotientEdge{V, E <: AbstractEdge{V}} <: AbstractNamedEdge{V}
     edge::E
 end
@@ -20,10 +26,10 @@ Base.reverse(se::QuotientEdge) = QuotientEdge(reverse(parent(se)))
 Return the the quotient edge corresponding to `edge` of the graph `g`. Note,
 the returned quotient edge may be a self-loop.
 
-See also: [`quotientedges`](@ref), [`quotienttvertex`](@ref).
+See also: `quotientedges`, `quotienttvertex`.
 """
-quotientedge(pg::AbstractGraph, p::Pair) = quotientedge(pg, edgetype(pg)(p))
-function quotientedge(g::AbstractGraph, edge)
+quotientedge(g::AbstractGraph, edge::Pair) = quotientedge(g, edgetype(g)(edge))
+function quotientedge(g::AbstractGraph, edge::AbstractEdge)
     if !has_edge(g, edge)
         throw(ArgumentError("Graph does not have an edge $edge"))
     end
@@ -79,7 +85,7 @@ has_quotientedge(g::AbstractGraph, se::QuotientEdge) = has_edge(quotient_graph(g
 
 Returns the number of edges in `g` that correspond to the quotient edge `qe`.
 
-See also: [`nv`](@ref).
+See also: `nv`.
 """
 Graphs.ne(g::AbstractGraph, se::QuotientEdge) = length(edges(g, se))
 

src/lib/PartitionedGraphs/src/quotientvertex.jl

@@ -4,6 +4,12 @@ using ..NamedGraphs.GraphsExtensions: GraphsExtensions, rem_vertices!, subgraph
 using ..NamedGraphs.OrderedDictionaries: OrderedIndices
 
 
+"""
+    QuotientVertex(v)
+
+Represents a super-vertex in a partitioned graph corresponding to the set of vertices
+in partition `v`.
+"""
 struct QuotientVertex{V}
     vertex::V
 end
@@ -59,6 +65,25 @@ function GraphsExtensions.rem_vertices!(g::AbstractGraph, sv::QuotientVertex)
 end
 rem_quotientvertex!(pg::AbstractGraph, sv::QuotientVertex) = rem_vertices!(pg, sv)
 
-function NamedGraphs.to_vertices(g::AbstractGraph, sv::Union{SV, Vector{SV}}) where {SV <: QuotientVertex}
-    return vertices(g, sv)
+# Represents a set of subvertices corresponding to a set of quotient vertices.
+struct SubVertices{QV, V, Vs <: AbstractVector{V}} <: AbstractVector{V}
+    quotientvertices::QV
+    vertices::Vs
+end
+Base.size(v::SubVertices) = size(v.vertices)
+Base.getindex(v::SubVertices, I...) = v.vertices[I...]
+
+function NamedGraphs.to_vertices(g::AbstractGraph, qv::QuotientVertex)
+    return SubVertices(qv, vertices(g, qv))
+end
+function NamedGraphs.to_vertices(g::AbstractGraph, qv::AbstractVector{<:QuotientVertex})
+    return SubVertices(qv, vertices(g, qv))
+end
+
+# Special case so that `subgraph(g, QuotientVertex(v))` returns an unpartitioned graph.
+function NamedGraphs.induced_subgraph_from_vertices(
+        g::AbstractGraph, subvertices::SubVertices{<:QuotientVertex}
+    )
+    sg, vs = NamedGraphs.induced_subgraph_from_vertices(g, subvertices.vertices)
+    return unpartitioned_graph(sg), vs
 end

src/lib/PartitionedGraphs/src/quotientview.jl

@@ -11,19 +11,17 @@ Base.parent(qg::QuotientView) = qg.graph
 parent_graph_type(g::AbstractGraph) = parent_graph_type(typeof(g))
 parent_graph_type(::Type{<:QuotientView{V, G}}) where {V, G} = G
 
-function Base.convert(GT::Type{<:AbstractGraph}, qv::QuotientView)
+function Base.copy(qv::QuotientView)
     qg = quotient_graph_type(parent_graph_type(qv))(vertices(qv))
     add_edges!(qg, edges(qv))
-    return convert(GT, qg)
+    return qg
 end
 
 NamedGraphs.edgetype(Q::Type{<:QuotientView}) = quotient_graph_edgetype(parent_graph_type(Q))
 
 Graphs.vertices(qg::QuotientView) = parent.(quotientvertices(parent(qg)))
 Graphs.edges(qg::QuotientView) = parent.(quotientedges(parent(qg)))
 
-Base.copy(g::QuotientView) = QuotientView(copy(parent(g)))
-
 function NamedGraphs.position_graph_type(type::Type{<:QuotientView})
     return position_graph_type(quotient_graph_type(parent_graph_type(type)))
 end
@@ -38,16 +36,14 @@ function Graphs.rem_edge!(qg::QuotientView, v)
 end
 
 for f in [
-        :(NamedGraphs.namedgraph_induced_subgraph),
+        :(NamedGraphs.induced_subgraph_from_vertices),
         :(NamedGraphs.ordered_vertices),
         :(NamedGraphs.vertex_positions),
         :(NamedGraphs.position_graph),
     ]
     @eval begin
-        function $f(
-                g::QuotientView{V, G}, args...; kwargs...
-            ) where {V, G}
-            return $f(convert(AbstractGraph, g), args...; kwargs...)
+        function $f(g::QuotientView, args...; kwargs...)
+            return $f(copy(g), args...; kwargs...)
         end
     end
 end