optional command line options

km3io/utils/KModuleRates.py

 """
-Usage: extract-dom-rates.py -f INPUT_FILE -o OUTPUT_FILE -a DETECTOR_FILE
+Usage: extract-dom-rates.py -i INPUT_FILE [-o OUTPUT_FILE -d DETECTOR_FILE]
 
 Options:
   -h --help                              Help.
-  -f --input_file INPUT_FILE             Input file.
+  -i --input_file INPUT_FILE             Input file.
   -o --output_file OUTPUT_FILE           Output file.
-  -a --detector_file DETECTOR_FILE       Detector file.
-  -s --chunk_size CHUNK_SIZE             Number of slices dumped to memory at once.[default: 10000]
+  -d --detector_file DETECTOR_FILE       Detector file.
+  -s --chunk_size CHUNK_SIZE             Number of slices dumped to memory at once.  [default: 10000]
 """
 
 from docopt import docopt
@@ -16,7 +16,7 @@ import km3pipe.hardware
 import os
 import numpy as np
 import h5py
-
+from pathlib import Path
 
 def create_matrix(dom_ids, dom_rates, dom_map):
     rows = len(dom_map)
@@ -53,8 +53,21 @@ def main():
     for key in arguments:
         data[key.replace("-", "")] = arguments[key]
 
+    if (data["output_file"]==None):
+        data["output_file"]=Path(arguments['--input_file']).stem+'.rates.hdf5'
     # Read list of modules from detector file, and map to indices.
-    detector = km3pipe.hardware.Detector(data["detector_file"])
+
+    reader = km3io.online.SummarysliceReader(data["input_file"], 10000)
+
+    dom_ids = []
+
+    if (data["detector_file"]==None):
+        print("No detector file supplied, analysing summaryslices to check for available module IDs.")
+        for s in reader.summaryslices:
+            dom_ids.append(np.unique(ak.flatten(s.slices.dom_id)))
+        np.unique(ak.flatten(dom_ids))
+    else:
+        dom_ids=km3pipe.hardware.Detector(data["detector_file"]).dom_ids
 
     dom2index = {}
     index2dom = {}
@@ -70,7 +83,6 @@ def main():
     h5.create_dataset("frame_indices", (0,), maxshape=(None,))
 
     # Read the channel rates from the summary slices, calculate the total module rates, and save them to the output file
-    reader = km3io.online.SummarysliceReader(data["input_file"], 10000)
 
     for ss_chunk in reader:
         frame_indices = ss_chunk.headers.frame_index