feat: Write node metadata to json

Author: Anton Eriksson

src/core/StateNetwork.h

@@ -176,6 +176,8 @@ class StateNetwork {
   std::map<unsigned int, std::string>& names() { return m_names; }
   const std::map<unsigned int, std::string>& names() const { return m_names; }
 
+  virtual const std::map<unsigned int, std::vector<int>>& metaData() const = 0;
+
   bool haveDirectedInput() const { return m_haveDirectedInput; }
   bool haveMemoryInput() const { return m_haveMemoryInput; }
   bool higherOrderInputMethodCalled() const { return m_higherOrderInputMethodCalled; }

src/io/Network.h

@@ -92,7 +92,7 @@ class Network : public StateNetwork {
   virtual void readMetaData(const std::string& filename);
 
   unsigned int numMetaDataColumns() const { return m_numMetaDataColumns; }
-  const std::map<unsigned int, std::vector<int>>& metaData() const { return m_metaData; }
+  const std::map<unsigned int, std::vector<int>>& metaData() const override { return m_metaData; }
 
   bool isMultilayerNetwork() const { return !m_layerNodeToStateId.empty(); }
   const std::map<unsigned int, std::map<unsigned int, unsigned int>>& layerNodeToStateId() const { return m_layerNodeToStateId; }

src/io/Output.cpp

@@ -382,6 +382,19 @@ void writeJsonTree(InfomapBase& im, const StateNetwork& network, std::ostream& o
 
   const auto multilevelModules = im.getMultilevelModules(states);
 
+  auto metaData = network.metaData();
+  auto writeMeta = [&metaData](auto& outStream, auto nodeId) {
+    outStream << "\"metadata\":{";
+    auto meta = metaData[nodeId];
+    for (unsigned int i = 0; i < meta.size(); ++i) {
+      outStream << '"' << i << "\":"
+                << '"' << meta[i] << '"'; // metadata class as string to highlight that this is a categorical variable
+      if (i < meta.size() - 1)
+        outStream << ',';
+    }
+    outStream << "},";
+  };
+
   // don't append a comma after the last entry
   auto first = true;
 
@@ -435,6 +448,11 @@ void writeJsonTree(InfomapBase& im, const StateNetwork& network, std::ostream& o
                   << "\"flow\":" << node.data.flow << ","
                   << "\"mec\":" << it.modularCentrality() << ",";
 
+        // can't currently use both memory and meta map equation
+        if (im.haveMetaData() && !states) {
+          writeMeta(outStream, node.physicalId);
+        }
+
         if (states) {
           outStream << "\"stateId\":" << node.stateId << ",";
           if (im.isMultilayerNetwork())