Merge pull request #112 from sblunt/improve_read_error_msg

Add exception messages for when input dates are in JD and when orbitize can't find input file.

orbitize/read_input.py

@@ -84,7 +84,10 @@ def read_file(filename):
                          dtype=(float,int,float,float,float,float,'S5'))
 
     # read file
-    input_table = read(filename)
+    try:
+        input_table = read(filename)
+    except:
+        raise Exception('Unable to read file: {}. \n Please check file path and format.'.format(filename))
     num_measurements = len(input_table)
 
     # Decide if input was given in the orbitize style
@@ -159,8 +162,14 @@ def read_file(filename):
     # loop through each row and format table
     index=0
     for row in input_table:
+        # First check if epoch is a number
+        try:
+            float_epoch = np.float(row['epoch'])
+        except:
+            raise Exception('Problem reading epoch in the input file. Epoch should be given in MJD.')
         # check epoch format and put in MJD
         if row['epoch'] > 2400000.5: # assume this is in JD
+            print('Converting input epochs from JD to MJD.\n')
             MJD = row['epoch'] - 2400000.5
         else:
             MJD = row['epoch']