Fix wealth distribution chart functionality

- Add get_wealth_histogram() method to EconomicModel for histogram data
- Add new API endpoint /simulation/<id>/distribution for chart data
- Extend main data API with include_distribution parameter
- Update real-time progress updates to include distribution data
- Fix frontend updateCharts() to handle wealth distribution chart
- Add distribution data processing in simulation.js
- Update test_charts.py to verify histogram functionality

Resolves issue where wealth distribution chart was not updating during simulations.

app/models/economic_model.py

@@ -177,8 +177,8 @@ class EconomicSimulation:
             gini_coefficient=gini,
             wealth_concentration_top10=wealth_conc,
             capital_share=capital_share,
-            average_wealth=np.mean(total_wealth_data),
+            average_wealth=float(np.mean(total_wealth_data)),
-            median_wealth=np.median(total_wealth_data)
+            median_wealth=float(np.median(total_wealth_data))
         )
     
     def _calculate_gini_coefficient(self, wealth_data: List[float]) -> float:
@@ -296,6 +296,67 @@ class EconomicSimulation:
         
         return distribution
     
+    def get_wealth_histogram(self, num_bins: int = 10) -> Tuple[List[str], List[int]]:
+        """
+        Get wealth distribution as histogram data for charting.
+        
+        Args:
+            num_bins: Number of bins for the histogram
+            
+        Returns:
+            Tuple of (bin_labels, bin_counts) for histogram chart
+        """
+        if not self.agents:
+            return [], []
+        
+        # Get current total wealth for all agents (capital + consumption)
+        wealth_values = []
+        for agent in self.agents:
+            if agent.wealth_history and agent.consumption_history:
+                total_wealth = agent.wealth_history[-1] + agent.consumption_history[-1]
+            else:
+                total_wealth = agent.initial_capital + agent.initial_consumption
+            wealth_values.append(total_wealth)
+        
+        if not wealth_values:
+            return [], []
+        
+        # Calculate histogram bins
+        min_wealth = min(wealth_values)
+        max_wealth = max(wealth_values)
+        
+        if min_wealth == max_wealth:
+            # All agents have same wealth
+            return [f"${min_wealth:.0f}"], [len(wealth_values)]
+        
+        # Create bins
+        bin_width = (max_wealth - min_wealth) / num_bins
+        bins = [min_wealth + i * bin_width for i in range(num_bins + 1)]
+        
+        # Count agents in each bin
+        bin_counts = [0] * num_bins
+        bin_labels = []
+        
+        for i in range(num_bins):
+            # Create label for this bin
+            bin_start = bins[i]
+            bin_end = bins[i + 1]
+            if i == num_bins - 1:  # Last bin includes upper bound
+                bin_labels.append(f"${bin_start:.0f} - ${bin_end:.0f}")
+            else:
+                bin_labels.append(f"${bin_start:.0f} - ${bin_end:.0f}")
+            
+            # Count agents in this bin
+            for wealth in wealth_values:
+                if i == num_bins - 1:  # Last bin includes upper bound
+                    if bin_start <= wealth <= bin_end:
+                        bin_counts[i] += 1
+                else:
+                    if bin_start <= wealth < bin_end:
+                        bin_counts[i] += 1
+        
+        return bin_labels, bin_counts
+    
     def update_parameters(self, new_parameters: SimulationParameters):
         """
         Update simulation parameters and restart with new settings.

app/routes/api.py

@@ -111,6 +111,9 @@ def start_simulation(simulation_id: str):
                     
                     # Emit progress update every 10 iterations or at milestones
                     if i % 10 == 0 or i == total_iterations - 1:
+                        # Get distribution data for real-time chart updates
+                        bin_labels, bin_counts = simulation.get_wealth_histogram(10)
+                        
                         progress_data = {
                             'simulation_id': simulation_id,
                             'iteration': snapshot.iteration,
@@ -119,7 +122,11 @@ def start_simulation(simulation_id: str):
                             'total_wealth': snapshot.total_wealth,
                             'gini_coefficient': snapshot.gini_coefficient,
                             'capital_share': snapshot.capital_share,
-                            'wealth_concentration_top10': snapshot.wealth_concentration_top10
+                            'wealth_concentration_top10': snapshot.wealth_concentration_top10,
+                            'distribution': {
+                                'labels': bin_labels,
+                                'counts': bin_counts
+                            }
                         }
                         
                         socketio.emit('simulation_progress', progress_data, 
@@ -272,6 +279,19 @@ def get_simulation_data(simulation_id: str):
                 'capital_shares': capital_over_time
             }
         
+        # Include current wealth distribution histogram if requested
+        if request.args.get('include_distribution', '').lower() == 'true':
+            num_bins = request.args.get('bins', 10, type=int)
+            if num_bins < 1 or num_bins > 50:
+                num_bins = 10
+            
+            bin_labels, bin_counts = simulation.get_wealth_histogram(num_bins)
+            response_data['distribution'] = {
+                'labels': bin_labels,
+                'counts': bin_counts,
+                'bins': num_bins
+            }
+        
         return jsonify(response_data)
         
     except Exception as e:
@@ -279,6 +299,49 @@ def get_simulation_data(simulation_id: str):
         return jsonify({'error': 'Internal server error'}), 500
 
 
+@api_bp.route('/simulation/<simulation_id>/distribution', methods=['GET'])
+def get_wealth_distribution(simulation_id: str):
+    """
+    Get current wealth distribution histogram for charting.
+    
+    Args:
+        simulation_id: Unique simulation identifier
+        
+    Query Parameters:
+        bins: Number of histogram bins (default: 10)
+        
+    Returns:
+        JSON response with histogram data
+    """
+    try:
+        simulation = simulation_manager.get_simulation(simulation_id)
+        
+        if not simulation:
+            return jsonify({'error': 'Simulation not found'}), 404
+        
+        # Get number of bins from query parameter
+        num_bins = request.args.get('bins', 10, type=int)
+        if num_bins < 1 or num_bins > 50:
+            num_bins = 10  # Default to 10 bins
+        
+        # Get histogram data
+        bin_labels, bin_counts = simulation.get_wealth_histogram(num_bins)
+        
+        return jsonify({
+            'simulation_id': simulation_id,
+            'histogram': {
+                'labels': bin_labels,
+                'counts': bin_counts,
+                'total_agents': len(simulation.agents),
+                'bins': num_bins
+            }
+        })
+        
+    except Exception as e:
+        current_app.logger.error(f"Error getting wealth distribution: {str(e)}")
+        return jsonify({'error': 'Internal server error'}), 500
+
+
 @api_bp.route('/simulation/<simulation_id>/export/<format_type>', methods=['GET'])
 def export_simulation_data(simulation_id: str, format_type: str):
     """

app/static/js/simulation.js

@@ -15,7 +15,11 @@ let currentSimulation = {
         totalWealth: [],
         giniCoefficients: [],
         capitalShare: [],
-        top10Share: []
+        top10Share: [],
+        distribution: {
+            labels: [],
+            counts: []
+        }
     }
 };
 
@@ -445,7 +449,11 @@ function resetSimulation() {
             totalWealth: [],
             giniCoefficients: [],
             capitalShare: [],
-            top10Share: []
+            top10Share: [],
+            distribution: {
+                labels: [],
+                counts: []
+            }
         }
     };
     
@@ -596,6 +604,12 @@ function updateSimulationProgress(data) {
         currentSimulation.data.capitalShare.push(data.capital_share || 0);
         currentSimulation.data.top10Share.push(data.wealth_concentration_top10 || 0);
         
+        // Update distribution data if available
+        if (data.distribution && data.distribution.labels && data.distribution.counts) {
+            currentSimulation.data.distribution.labels = data.distribution.labels;
+            currentSimulation.data.distribution.counts = data.distribution.counts;
+        }
+        
         updateCharts();
         updateMetricsDisplay(data);
     }
@@ -619,6 +633,13 @@ function updateCharts() {
         charts.inequality.data.datasets[1].data = currentSimulation.data.top10Share;
         charts.inequality.update('none');
     }
+    
+    // Wealth Distribution Chart
+    if (charts.distribution && currentSimulation.data.distribution.labels.length > 0) {
+        charts.distribution.data.labels = currentSimulation.data.distribution.labels;
+        charts.distribution.data.datasets[0].data = currentSimulation.data.distribution.counts;
+        charts.distribution.update('none');
+    }
 }
 
 /**
@@ -658,7 +679,7 @@ async function onSimulationComplete(data) {
     // Fetch complete simulation data and populate charts
     try {
         const response = await window.MarkovEconomics.utils.apiRequest(
-            `/api/simulation/${currentSimulation.id}/data?include_evolution=true`
+            `/api/simulation/${currentSimulation.id}/data?include_evolution=true&include_distribution=true`
         );
         
         if (response.evolution) {
@@ -669,6 +690,12 @@ async function onSimulationComplete(data) {
             currentSimulation.data.top10Share = response.evolution.top10_shares || [];
             currentSimulation.data.capitalShare = response.evolution.capital_shares || [];
             
+            // Update distribution data
+            if (response.distribution) {
+                currentSimulation.data.distribution.labels = response.distribution.labels;
+                currentSimulation.data.distribution.counts = response.distribution.counts;
+            }
+            
             // Update charts with complete data
             updateCharts();
             

test_charts.py

@@ -17,8 +17,8 @@ print('Started simulation:', start_resp.json()['status'])
 # Wait for completion
 time.sleep(3)
 
-# Get evolution data
+# Get evolution data with distribution
-data_resp = requests.get(f'http://localhost:5000/api/simulation/{sim_id}/data?include_evolution=true')
+data_resp = requests.get(f'http://localhost:5000/api/simulation/{sim_id}/data?include_evolution=true&include_distribution=true')
 result = data_resp.json()
 
 print('\nFinal metrics:')
@@ -28,7 +28,40 @@ print(f'  Final Total Wealth: ${result["evolution"]["total_wealth"][-1]:.2f}')
 print(f'  Top 10% data points: {len(result["evolution"].get("top10_shares", []))}')
 print(f'  Capital share data points: {len(result["evolution"].get("capital_shares", []))}')
 
+# Test wealth distribution
+if 'distribution' in result:
+    dist_data = result['distribution']
+    print(f'\nWealth Distribution:')
+    print(f'  Bins: {dist_data.get("bins", 0)}')
+    print(f'  Labels: {len(dist_data.get("labels", []))}')
+    print(f'  Counts: {len(dist_data.get("counts", []))}')
+    
+    if dist_data.get('labels') and dist_data.get('counts'):
+        print('\n  Distribution Histogram:')
+        for label, count in zip(dist_data['labels'], dist_data['counts']):
+            bar = '█' * max(1, count // 2)  # Visual bar representation
+            print(f'    {label:<20} {count:>3} agents {bar}')
+        print('\n✅ Wealth distribution chart should now work!')
+    else:
+        print('\n❌ No distribution data available')
+else:
+    print('\n❌ No distribution data in response')
+
+# Test dedicated distribution endpoint
+print('\nTesting dedicated distribution endpoint...')
+dist_resp = requests.get(f'http://localhost:5000/api/simulation/{sim_id}/distribution?bins=8')
+if dist_resp.status_code == 200:
+    dist_result = dist_resp.json()
+    hist_data = dist_result.get('histogram', {})
+    print(f'  Total agents: {hist_data.get("total_agents", 0)}')
+    print(f'  Bins: {hist_data.get("bins", 0)}')
+    print(f'  Labels count: {len(hist_data.get("labels", []))}')
+    print(f'  Counts sum: {sum(hist_data.get("counts", []))}')
+    print('\n✅ Distribution endpoint working!')
+else:
+    print(f'\n❌ Distribution endpoint failed: {dist_resp.status_code}')
+
 if len(result["evolution"]["gini_coefficients"]) > 0:
-    print('\n✅ Charts should now be populated with data!')
+    print('\n🎯 All charts should now be populated with data!')
 else:
     print('\n❌ No data available for charts')