A Python script for graphing RR Lyrae data.

graph_rr_lyrae.py

import sys
import matplotlib.pyplot as plt

def main():
    if not len(sys.argv) == 3:
        print("Invalid number of arguments.")
        print("python graph_rr_lyrae.py INPUTFILE OUTPUTFILE")

        sys.exit(1)
    else:
        input_file = sys.argv[1]
        output_file = sys.argv[2]

        (times, light_values) = parse_data_file(input_file)
        create_graph(times, light_values, output_file)

        print("Successfully saved graph to {0}".format(output_file))

def parse_data_file(input_file):
    lines = [line.rstrip('\n').split(" ") for line in open(input_file)]

    # Parse in the input data
    times = [line[0] for line in lines]
    light_values = [line[1] for line in lines]
    
    return times, light_values

def create_graph(times, light_values, output_file):
    # Create the graph
    plt.plot(times, light_values, label='input  data')
    plt.xlabel('time')
    plt.ylabel('light')

    # Save the graph to the output file
    plt.savefig(output_file)

# Run the main method of the script
if __name__ == '__main__':
    main()