IO: Start to refactor agent to/from_string

Created `agent_writer.hpp` to provide a more streamlined interface to agent parsing and output. Moved the `to_string` function out of agent Also changed the agent type of the DeGroot model, so that it contains the opinion as `agent.data.opinion`. Co-authored-by: Amrita Goswami <[email protected]>
seldon-code · Mar 18, 2024 · 6daca16 · 6daca16
1 parent ee6e0f4
commit 6daca16
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Showing 7 changed files with 71 additions and 24 deletions.
diff --git a/include/agent.hpp b/include/agent.hpp
@@ -17,11 +17,6 @@ class Agent
     virtual ~Agent() = default;
 
     void from_string( const std::string & str );
-
-    virtual std::string to_string() const
-    {
-        return fmt::format( "{:.16f}", data );
-    }
 };
 
 template<>

diff --git a/include/agent_writer.hpp b/include/agent_writer.hpp
@@ -0,0 +1,20 @@
+#pragma once
+#include <fmt/format.h>
+
+namespace Seldon
+{
+
+template<typename AgentT>
+std::string agent_to_string( const AgentT & agent )
+{
+    static_assert( false, "Base implementation not valid" );
+    return "";
+}
+
+template<typename AgentT>
+std::string opinion_to_string( const AgentT & agent )
+{
+    return fmt::format( "{}", agent.data.opinion );
+}
+
+} // namespace Seldon
diff --git a/include/models/ActivityDrivenModel.hpp b/include/models/ActivityDrivenModel.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include "agent.hpp"
+#include "agent_writer.hpp"
 #include "model.hpp"
 #include "network.hpp"
 #include <cstddef>
@@ -21,10 +22,16 @@ struct ActivityAgentData
 };
 
 template<>
-inline std::string Agent<ActivityAgentData>::to_string() const
+inline std::string agent_to_string<Agent<ActivityAgentData>>( const Agent<ActivityAgentData> & agent )
 {
-    return fmt::format( "{}, {}, {}", data.opinion, data.activity, data.reluctance );
-};
+    return fmt::format( "{}, {}, {}", agent.data.opinion, agent.data.activity, agent.data.reluctance );
+}
+
+template<>
+inline std::string opinion_to_string<Agent<ActivityAgentData>>( const Agent<ActivityAgentData> & agent )
+{
+    return fmt::format( "{}", agent.data.opinion );
+}
 
 template<>
 inline void Agent<ActivityAgentData>::from_string( const std::string & str )

diff --git a/include/models/DeGroot.hpp b/include/models/DeGroot.hpp
@@ -1,16 +1,40 @@
 #pragma once
 #include "agent.hpp"
+#include "agent_writer.hpp"
 #include "model.hpp"
 #include "network.hpp"
 #include <vector>
 
 namespace Seldon
 {
 
-class DeGrootModel : public Model<Agent<double>>
+struct DeGrootAgentData
+{
+    double opinion = 0; // x_i
+};
+
+template<>
+inline std::string agent_to_string<Agent<DeGrootAgentData>>( const Agent<DeGrootAgentData> & agent )
+{
+    return fmt::format( "{}", agent.data.opinion );
+}
+
+template<>
+inline std::string opinion_to_string<Agent<DeGrootAgentData>>( const Agent<DeGrootAgentData> & agent )
+{
+    return agent_to_string( agent );
+}
+
+template<>
+inline void Agent<DeGrootAgentData>::from_string( const std::string & str )
+{
+    data.opinion = std::stod( str );
+};
+
+class DeGrootModel : public Model<Agent<DeGrootAgentData>>
 {
 public:
-    using AgentT           = Agent<double>;
+    using AgentT           = Agent<DeGrootAgentData>;
     using NetworkT         = Network<AgentT>;
     double convergence_tol = 1e-12;
 

diff --git a/include/util/io.hpp b/include/util/io.hpp
@@ -1,4 +1,5 @@
 #pragma once
+#include "agent_writer.hpp"
 #include "fstream"
 #include "network.hpp"
 #include <fmt/core.h>
@@ -48,7 +49,7 @@ void opinions_to_file( const Network<AgentT> & network, const std::string & file
     fmt::print( fs, "# idx_agent, opinion[...]\n" );
     for( size_t idx_agent = 0; idx_agent < n_agents; idx_agent++ )
     {
-        std::string row = fmt::format( "{:>5}, {:>25}\n", idx_agent, network.agents[idx_agent].to_string() );
+        std::string row = fmt::format( "{:>5}, {:>25}\n", idx_agent, agent_to_string( network.agents[idx_agent] ) );
         fs << row;
     }
     fs.close();

diff --git a/src/models/DeGroot.cpp b/src/models/DeGroot.cpp
@@ -18,7 +18,7 @@ DeGrootModel::DeGrootModel( NetworkT & network )
 
     for( size_t i = 0; i < network.agents.size(); i++ )
     {
-        network.agents[i].data = double( i ) / double( network.agents.size() );
+        network.agents[i].data.opinion = double( i ) / double( network.agents.size() );
     }
 }
 
@@ -31,23 +31,23 @@ void DeGrootModel::iteration()
 
     for( size_t i = 0; i < network.agents.size(); i++ )
     {
-        auto neighbour_buffer       = network.get_neighbours( i );
-        auto weight_buffer          = network.get_weights( i );
-        agents_current_copy[i].data = 0.0;
+        auto neighbour_buffer               = network.get_neighbours( i );
+        auto weight_buffer                  = network.get_weights( i );
+        agents_current_copy[i].data.opinion = 0.0;
         for( size_t j = 0; j < neighbour_buffer.size(); j++ )
         {
             j_index = neighbour_buffer[j];
             weight  = weight_buffer[j];
-            agents_current_copy[i].data += weight * network.agents[j_index].data;
+            agents_current_copy[i].data.opinion += weight * network.agents[j_index].data.opinion;
         }
     }
 
     max_opinion_diff = 0;
     // Update the original agent opinions
     for( std::size_t i = 0; i < network.agents.size(); i++ )
     {
-        max_opinion_diff
-            = std::max( max_opinion_diff, std::abs( network.agents[i].data - agents_current_copy[i].data ) );
+        max_opinion_diff = std::max(
+            max_opinion_diff, std::abs( network.agents[i].data.opinion - agents_current_copy[i].data.opinion ) );
         network.agents[i] = agents_current_copy[i];
     }
 }

diff --git a/test/test_deGroot.cpp b/test/test_deGroot.cpp
@@ -26,10 +26,10 @@ TEST_CASE( "Test the DeGroot Model Symmetric", "[DeGroot]" )
     auto network = Network( std::move( neighbour_list ), std::move( weight_list ), Network::EdgeDirection::Incoming );
     auto model   = DeGrootModel( network );
 
-    model.convergence_tol  = 1e-6;
-    model.max_iterations   = 100;
-    network.agents[0].data = 0.0;
-    network.agents[1].data = 1.0;
+    model.convergence_tol          = 1e-6;
+    model.max_iterations           = 100;
+    network.agents[0].data.opinion = 0.0;
+    network.agents[1].data.opinion = 1.0;
 
     do
     {
@@ -39,7 +39,7 @@ TEST_CASE( "Test the DeGroot Model Symmetric", "[DeGroot]" )
     INFO( fmt::format( "N_iterations = {} (with convergence_tol {})\n", model.n_iterations(), model.convergence_tol ) );
     for( size_t i = 0; i < n_agents; i++ )
     {
-        INFO( fmt::format( "Opinion {} = {}\n", i, network.agents[i].data ) );
-        REQUIRE_THAT( network.agents[i].data, WithinAbs( 0.5, model.convergence_tol * 10.0 ) );
+        INFO( fmt::format( "Opinion {} = {}\n", i, network.agents[i].data.opinion ) );
+        REQUIRE_THAT( network.agents[i].data.opinion, WithinAbs( 0.5, model.convergence_tol * 10.0 ) );
     }
 }