Minimal python & kivy script for spectral reduction

minimal_kivy.py

import fast_fits as extract
from datatypes import FitsImage, ExtractedSpectrum, Robust2D
import sys
from kivy.garden.graph import Graph, SmoothLinePlot
from custom_widgets import ImagePane
from kivy.base import runTouchApp
from image_arithmetic import im_divide, im_subtract

if __name__ == '__main__':
    widget = ImagePane()
    
    dither1 = FitsImage(sys.argv[1], load=True)
    dither2 = FitsImage(sys.argv[2], load=True)
    flats = FitsImage(sys.argv[3], load=True)
    tracedir = int(sys.argv[4])
    
    diff_image1 = im_subtract(im_divide(dither1, flats),
                                 im_divide(dither2, flats))
    diff_image1.change_parameters({'mode':'asinh'})
    widget.load_data(diff_image1)
    runTouchApp(widget)
    
    #region = map(int,raw_input('Region pixel coords> ').split())
    region = [141,245,1023,285]
    dither1 = im_divide(dither1.data_array[region[0]:region[2],
                                           region[1]:region[3]],
                        flats.data_array[region[0]:region[2],
                                         region[1]:region[3]])
    dither2 = im_divide(dither2.data_array[region[0]:region[2],
                                           region[1]:region[3]],
                        flats.data_array[region[0]:region[2],
                                         region[1]:region[3]])
    diff_image0 = im_subtract(dither1, dither2)
    peak1 = extract.find_peak_2d(diff_image0, tracedir=tracedir)
    peak2 = extract.find_peak_2d(diff_image0, tracedir=tracedir, pn='neg')
    
    cross_section = Robust2D(diff_image0,  index=True).combine(axis=(tracedir+1)%2, method='median')
    mmx = cross_section.minmax
    
    widget2 = Graph(xlabel='Pixel', ylabel='Mean counts', x_ticks_minor=5,
                    x_ticks_major=10, y_ticks_minor=5, y_ticks_major=10,
                    x_grid_label=True, y_grid_label=True, xlog=False, 
                    ylog=False, x_grid=False, y_grid=False, xmin=0, 
                    xmax=diff_image0.shape[tracedir], ymin=float(mmx[0]), 
                    ymax=float(mmx[1]))
    
    trace = SmoothLinePlot(points=zip(cross_section, cross_section.x),
                           color=[1,0,0,1])
    
    widget2.add_plot(trace)
    runTouchApp(widget2)
    
    cens = map(float,raw_input('Trace centers> ').split())
    p_init = [(cross_section.interp(x), x, 3.) for x in cens]
    
    spec, telluric = extract.reduce_dither_pair(dither1, dither2, p_init,
                                                trace_direction=tracedir)
    spec = ExtractedSpectrum(spec)
    spec.save()