Index: /fact/tools/pyscripts/pyfact/plotters.py
===================================================================
--- /fact/tools/pyscripts/pyfact/plotters.py	(revision 13073)
+++ /fact/tools/pyscripts/pyfact/plotters.py	(revision 13074)
@@ -8,4 +8,6 @@
 import numpy as np
 import matplotlib.pyplot as plt
+import os.path
+import sys
 
 class Plotter(object):
@@ -76,6 +78,12 @@
     def __init__(self, name, ion=True, grid=True, fname=None, map_file_path = '../map_dn.txt', vmin=None, vmax=None):
         """ initialize the object """
+        path = os.path.abspath(__file__)
+        path = os.path.dirname(path)
+        map_file_path = os.path.join(path, map_file_path)
+        if not os.path.isfile(map_file_path):
+            print 'not able to find file:', map_file_path
+            sys.exit(-2)
+            
         self.name  = name
-        
         if ion:
             plt.ion()
@@ -142,8 +150,10 @@
         if ydata.ndim > 1:
             ydata = ydata.flatten()
-        
-        plt.hist(ydata, bins, range, label=label, log=log)
         if label:
+            plt.hist(ydata, bins, range, label=label, log=log)
             plt.legend()
+        else:
+            plt.hist(ydata, bins, range, log=log)
+            
         plt.title(self.name)