Added type functions, general heuristics and metagraph

.gitignore

@@ -2,3 +2,4 @@ docs/build/
 docs/site/
 .vscode/
 Manifest.toml
+

Project.toml

@@ -8,9 +8,11 @@ Distances = "b4f34e82-e78d-54a5-968a-f98e89d6e8f7"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 EmbeddedGraphs = "9c1af47c-29f5-11e9-0b47-9f5334384f20"
 LightGraphs = "093fc24a-ae57-5d10-9952-331d41423f4d"
+MetaGraphs = "626554b9-1ddb-594c-aa3c-2596fe9399a5"
 Parameters = "d96e819e-fc66-5662-9728-84c9c7592b0a"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 SpatialIndexing = "d4ead438-fe20-5cc5-a293-4fd39a41b74c"
+StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]

src/NodeTypes.jl

@@ -0,0 +1,21 @@
+"""For the incorporation of different node types to SyntheticNetworks package."""
+
+struct NodeType
+    name::String
+    probability::Float32
+    neighbor_probability::Dict # Dict(Symbol(NodeType_i.name) => prob)
+    method_parameter
+end
+
+NodeType() = NodeType("Node", 1., Dict(:Node => 1.), 0)
+
+""" From a list of probabilities of drawing a node type, determines one randomly and
+    returns the index of node type"""
+function draw_type(node_types::Array{NodeType,1})
+    prob = map(x -> x.probability, node_types)
+    t0 = copy(prob)
+    pushfirst!(t0 , 0.)
+    type_interval = [sum(t0[1:i+1]) for i in 1:length(t0)-1]
+    t_n = findfirst(type_interval .>= rand())
+    return node_types[t_n]
+end