Source code for cs_demux

#!/usr/bin/env python

A python script to demux the data from the cs system.

The data is supposed to come out in the following way:

CH01 .. CH02 .. CH03 .. CH04 .. INDEX .. FACET .. SAM COUNT .. usec COUNT
short   short   short   short   long     long     long          long

python --data_file="/home/sean/PROJECTS/workspace/acq400_hapi-1/user_apps/
python .\ --plot_facets=4 --data_file="C:/acq2106_112/000001/0000"

import numpy as np
import matplotlib.pyplot as plt
import argparse

[docs]def find_zero_index(args): # This function finds the first 0xaa55f154 short value in the data and then # uses it's position to check the index before this event sample and the # index after this event sample and checks the latter is one greater # than the former. If the values do not increment then go to the next # event sample and repeat. data = np.fromfile(args.data_file, dtype=np.uint32) for long_pos, long_val in enumerate(data): long = format(long_val, '08x') if long_val == 0xaa55f154: # Check current index first_es_position = long_pos break # loop over all the event samples. Look at the "index" value before and # after and check they have incremented. counter = 0 for pos, f_long_in_es in enumerate(data): if pos < first_es_position: continue if counter % (args.transient_length*6 + 24) == 0: counter += 1 if data[pos - 3] + 1 == data[pos + 27]: zero_index_long_pos = pos return zero_index_long_pos else: counter += 1 continue
[docs]def demux_data(args, zero_index): # Demuxes the data into a single dimension list that contains the data in # sequence. data = [] count = 0 with open(args.data_file, "rb") as f: # throw away all data before the "zeroth" index (the first es) chunk = np.fromfile(f, dtype=np.int32, count=int(zero_index)) while len(chunk) != 0: # if chunk size is zero we have run out of data #throw away es if count % args.transient_length == 0: chunk = np.fromfile(f, dtype=np.int32, count=24) # strip es # collect data into a new list chunk = np.fromfile(f, dtype=np.int16, count=4) data.extend(chunk) chunk = np.fromfile(f, dtype=np.int32, count=4) data.extend(chunk) count += 1 f.close() # close file when all the data has been loaded. return data
[docs]def save_data(args, data): np.tofile("test_file", data) return None
[docs]def plot_data(args, data): # plot all the data in order (not stacked) axes = ["Demuxed channels from acq1001", "CH01 \n (Sampled \n FACET)", "CH02 \n (Sampled \n INDEX)", "CH03 \n (Sampled \n Sine Wave)", "CH04 \n (Sampled \n Sine Wave)", "FACET", "INDEX", "Sample Count", "usec Count", "Samples"] f, plots = plt.subplots(8, 1) plots[0].set_title(axes[0]) for sp in range(0,8): if args.plot_facets != -1: try: # Plot ((number of facets) * (rtm len)) - 1 from each channel plots[sp].plot(data[sp:args.plot_facets * args.transient_length * 8 - 1:8]) except: print "Data exception met. Plotting all data instead." plots[sp].plot(data[sp:-1:8]) else: plots[sp].plot(data[sp:-1:8]) plots[sp].set(ylabel=axes[sp+1], xlabel=axes[-1]) return None
[docs]def run_main(): parser = argparse.ArgumentParser(description='cs demux') parser.add_argument('--plot', default=1, type=int, help="Plot data") parser.add_argument('--plot_facets', default=-1, type=int, help="No of facets" "to plot") parser.add_argument('--save', default=0, type=int, help="Save data") parser.add_argument('--transient_length', default=8192, type=int, help='transient length') parser.add_argument("--data_file", default="./shot_data", type=str, help="Name of" "data file") args = parser.parse_args() # zero_index should be the index of the first event sample where the # system value index increments over the event sample. zero_index = find_zero_index(args) # data = long list of CH01, CH02, CH03, CH04, INDEX, FACET, USEC data = demux_data(args, zero_index) if args.plot == 1: plot_data(args, data) if == 1: save_data(args, data)
if __name__ == '__main__': run_main()