Fix crash in command_utilization_plot

DRAMSys/traceAnalyzer/scripts/metrics.py

@@ -49,6 +49,10 @@ def command_bus_utilisation_in_percent(connection):
                 ON Phases.PhaseName = CommandLengths.Command
     """)
     result = cursor.fetchone()[0]
+
+    if (result is None):
+        result = 0
+
     clk, _ = getClock(connection)
     traceEnd = getTraceEndTime(connection)
     cmdBusOccupied = result * clk

DRAMSys/traceAnalyzer/scripts/plots.py

@@ -488,6 +488,10 @@ def command_bus_utilisation_window(connection, tracePath, steps):
 
         cursor.execute(query_full, (left_limit, right_limit))
         result = cursor.fetchone()[0]
+
+        if (result is None):
+            result = 0
+
         cmdBusOccupied = result * clk
 
         time[i] = ((i * windowSize) - (windowSize / 2)) / 1000 # ps to ns