Merge pull request #380 from olynch/visualize-presentation

ENH: Add function to visualize presentation

docs/literate/graphics/graphviz_schema_visualization.jl

@@ -0,0 +1,13 @@
+# # Visualizing Acset Schemas with Graphviz
+#
+#md # [![](https://img.shields.io/badge/show-nbviewer-579ACA.svg)](@__NBVIEWER_ROOT_URL__/generated/graphics/graphviz_wiring_diagrams.ipynb)
+#
+# It is convenient to visualize schemas in a non-textual way; often schemas can have many objects, homs and attributes, and it is hard to keep these all in your head.
+#
+# For this reason, we provide a function which takes a schema and produces a visual representation of it, using the Catlab Graphviz interface.
+#
+# This is as simple as the following code. These figures are by no means publication-quality, but they can be useful for interactive development.
+
+using Catlab.Present, Catlab.Graphics, Catlab.Graphs
+
+to_graphviz(Graphs.BasicGraphs.TheoryWeightedGraph)

docs/make.jl

@@ -58,6 +58,7 @@ makedocs(
         "generated/graphics/graphviz_wiring_diagrams.md",
         "generated/graphics/tikz_wiring_diagrams.md",
         "generated/graphics/layouts_vs_drawings.md",
+        "generated/graphics/graphviz_schema_visualization.md",
       ],
     ],
     "Modules" => Any[

src/core/Present.jl

@@ -9,7 +9,7 @@ in applications like knowledge representation.
 """
 module Present
 export @present, Presentation, generator, generators, has_generator, equations,
-  add_generator!, add_generators!, add_definition!, add_equation!
+  add_generator!, add_generators!, add_definition!, add_equation!, generator_index
 
 using Base.Meta: ParseError
 using Compat
@@ -117,6 +117,10 @@ function add_definition!(pres::Presentation, name::Symbol, rhs::GATExpr)
   generator
 end
 
+""" Get the index of a generator
+"""
+generator_index(pres::Presentation, x::Symbol) = pres.generator_name_index[x].second
+
 # Presentation macro
 ####################
 

src/graphics/GraphvizGraphs.jl

@@ -7,6 +7,8 @@ using Compat: isnothing
 using StaticArrays: StaticVector, SVector
 
 using ...Graphs
+using ...Present
+using ...Theories
 import ..Graphviz
 
 # Property graphs
@@ -276,4 +278,50 @@ function to_graphviz(g::AbstractHalfEdgeGraph;
   to_graphviz(pg)
 end
 
+# Schemas
+#########
+
+
+""" Construct a graph representing the schema
+"""
+function to_graphviz_graph(pres::Presentation{Schema})
+  obs,homs,datas,attrs = generators.(Ref(pres), [:Ob,:Hom,:Data,:Attr])
+  g = PropertyGraph{Any}()
+
+  add_vertices!(g,length(obs))
+  for (i,ob) in enumerate(obs)
+    set_vprop!(g,i,:label,string(nameof(ob)))
+    set_vprop!(g,i,:shape,"plain")
+    set_vprop!(g,i,:margin,"2")
+  end
+
+  add_vertices!(g,length(datas))
+  for (i,data) in enumerate(datas)
+    set_vprop!(g,i+length(obs),:label,string(nameof(data)))
+  end
+
+  add_edges!(g,
+             generator_index.(Ref(pres), nameof.(dom.(homs))),
+             generator_index.(Ref(pres), nameof.(codom.(homs))))
+  for (i,hom) in enumerate(homs)
+    set_eprop!(g,i,:label,string(nameof(hom)))
+    set_eprop!(g,i,:len,"2")
+  end
+  
+  add_edges!(g,
+             generator_index.(Ref(pres), nameof.(dom.(attrs))),
+             length(obs) .+ generator_index.(Ref(pres), nameof.(codom.(attrs))))
+  for (i,attr) in enumerate(attrs)
+    set_eprop!(g,i+length(homs),:label,string(nameof(attr)))
+    set_eprop!(g,i+length(homs),:len,"2")
+  end
+
+  set_gprop!(g,:graph,Dict(:rankdir => "LR"))
+  set_gprop!(g,:prog,"neato")
+
+  g
+end
+
+to_graphviz(pres::Presentation{Schema}) = to_graphviz(to_graphviz_graph(pres))
+
 end