cal.py

# Filename: cal.py
# Aim: to write the telescope cal to the fits data file.

import numpy as np
from astropy.io import fits

def getcal(calon,caloff,leng):

    period = calon+caloff
    N = int(leng/period)+1

    cal_p = np.zeros(period,dtype=bool)
    cal_p[0:calon] = True
    calarr = np.tile(cal_p,N)
    calstat = calarr[0:leng]

    return calstat

def cal2fits(hdul,calon=1,caloff=1,expose=1,caltype='low',update=True):

    calon  = round(calon/expose)
    caloff = round(caloff/expose)

    

    leng = hdul[1].header['NAXIS2']
    calstat = getcal(calon,caloff,leng)

    if update:
        hdul[1].header.set('CALTYPE',caltype,'Tcal type, low or high',before='EXTVER')
        if 'CALSTAT' in hdul[1].columns.names:
            hdul[1].data['CALSTAT'] = calstat

        else:

            new_col = fits.Column(name='CALSTAT',format='1L',array=calstat)
            newhdu = fits.BinTableHDU.from_columns(hdul[1].columns + fits.ColDefs([new_col]))
            hdul[1].data = newhdu.data

        hdul.flush()
    return calstat