--- a/python/moving.py	Thu May 14 23:18:44 2015 +0200
+++ b/python/moving.py	Fri May 15 23:09:49 2015 +0200
@@ -1081,6 +1081,8 @@
             from numpy import NaN
             if lane is None:
                 plot(list(self.getTimeInterval()), self.curvilinearPositions.positions[0], options, **kwargs)
+                if withOrigin:
+                    plot([self.getFirstInstant()], [self.curvilinearPositions.positions[0][0]], 'ro', **kwargs)
             else:
                 instants = []
                 coords = []
@@ -1092,8 +1094,8 @@
                         instants.append(NaN)
                         coords.append(NaN)
                 plot(instants, coords, options, **kwargs)
-            if withOrigin:
-                plot([self.getFirstInstant()], [self.curvilinearPositions.positions[0][0]], 'ro', **kwargs)
+                if withOrigin and len(instants)>0:
+                    plot([instants[0]], [coords[0]], 'ro', **kwargs)
         else:
             print('Object {} has no curvilinear positions'.format(self.getNum()))        
 

--- a/python/storage.py	Thu May 14 23:18:44 2015 +0200
+++ b/python/storage.py	Fri May 15 23:09:49 2015 +0200
@@ -648,6 +648,9 @@
     for example, there seems to be 5 simulation steps per simulated second in VISSIM, 
     so simulationStepsPerTimeUnit should be 5, 
     so that all times correspond to the number of the simulation step (and can be stored as integers)
+    
+    Objects positions will be considered only after warmUpLastInstant 
+    (if the object has no such position, it won't be loaded)
 
     Assumed to be sorted over time'''
     objects = {} # dictionary of objects index by their id
@@ -658,10 +661,10 @@
         data = read_csv(filename, delimiter=';', comment='*', header=0, skiprows = 1)
         generatePDLaneColumn(data)
         data['TIME'] = data['$VEHICLE:SIMSEC']*simulationStepsPerTimeUnit
+        if warmUpLastInstant is not None:
+            data = data[data['TIME']>=warmUpLastInstant]
         grouped = data.loc[:,['NO','TIME']].groupby(['NO'], as_index = False)
         instants = grouped['TIME'].agg({'first': min, 'last': max})
-        if warmUpLastInstant is not None:
-            instants = instants[instants['first'] >= warmUpLastInstant]
         for row_index, row in instants.iterrows():
             objNum = int(row['NO'])
             tmp = data[data['NO'] == objNum]
@@ -670,7 +673,6 @@
             objects[objNum].curvilinearPositions = moving.CurvilinearTrajectory(S = round(tmp['POS'].tolist(), nDecimals), Y = round(tmp['POSLAT'].tolist(), nDecimals), lanes = tmp['LANE'].tolist())
         return objects.values()
     else:
-        firstInstants = {}
         inputfile = openCheck(filename, quitting = True)
         # data = pd.read_csv(filename, skiprows=15, delimiter=';')
         # skip header: 15 lines + 1
@@ -682,13 +684,12 @@
             s = float(data[4])
             y = float(data[5])
             lane = data[2]+'_'+data[3]
-            if objNum not in firstInstants:
-                firstInstants[objNum] = instant
-                if warmUpLastInstant is None or firstInstants[objNum] >= warmUpLastInstant:
+            if objNum not in objects:
+                if warmUpLastInstant is None or instant >= warmUpLastInstant:
                     if nObjects < 0 or len(objects) < nObjects:
                         objects[objNum] = moving.MovingObject(num = objNum, timeInterval = moving.TimeInterval(instant, instant))
                         objects[objNum].curvilinearPositions = moving.CurvilinearTrajectory()
-            if (warmUpLastInstant is None or firstInstants[objNum] >= warmUpLastInstant) and objNum in objects:
+            if (warmUpLastInstant is None or instant >= warmUpLastInstant) and objNum in objects:
                 objects[objNum].timeInterval.last = instant
                 objects[objNum].curvilinearPositions.addPositionSYL(s, y, lane)
             line = readline(inputfile, '*$')