A quick and dirty prototype for writing SPE files in becquerel

write_spe.py

# Based off the implementation that is already in becquerel.parsers.SpeFile,
# but adapted to read *some* of the info from a Spectrum instance. 
# I'm a little fuzzy on the details of the SPE format (e.g. what is the difference
# between $ENER_CAL and $MCA_CAL) but this produces files that load without
# issue in Sandia's InterSpec tool. 

# This is a rough implementation as a prototype, it needs a lot of work.

def write_spe(
    spec,
    spectrum_id="",
    sample_description="",
    roi=None, # list of channel pairs
    ener_fit=None, # tuple of coeffs
    mca_cal=None, # tuple of coeffs
    shape_cal=None, # tuple of coeffs
    metadata=None, # dict
):
    s = ''
    s += '$SPEC_ID:\n'
    s += spectrum_id + '\n'
    s += '$SPEC_REM:\n'
    s += sample_description + '\n' 

    if spec.start_time is not None:
        s += '$DATE_MEA:\n'
        s += '{:%m/%d/%Y %H:%M:%S}\n'.format(spec.start_time) 

    s += '$MEAS_TIM:\n'
    livetime = 0.0 if spec.livetime is None else spec.livetime
    realtime = 0.0 if spec.realtime is None else spec.realtime
    s += '{:.0f} {:.0f}\n'.format(livetime, realtime) 

    s += '$DATA:\n'
    s += '{:.0f} {:d}\n'.format(spec.channels[0], len(spec.channels)) 
    for j in range(len(spec.channels)):
        s += '       {:.0f}\n'.format(spec.counts_vals[j]) 

    if roi is not None:
        s += '$ROI:\n'
        s += '{}\n'.format(len(roi))
        for (left, right) in roi:
            s += "{} {}\n".format(left, right)

    if ener_fit is not None:
        s += '$ENER_FIT:\n'
        s += '{:f} {:f}\n'.format(ener_fit[0], ener_fit[1])

    if mca_cal is not None:
        s += '$MCA_CAL:\n'
        n_coeff = len(mca_cal)
        s += '{:d}\n'.format(n_coeff)
        # s += '{:E}'.format(cal_coeff[0])
        for j in range(0, n_coeff):
            s += ' {:E}'.format(mca_cal[j])
        s += '\n' 

    if shape_cal is not None:
        s += '$SHAPE_CAL:\n'
        n_coeff = len(shape_cal)
        s += '{:d}\n'.format(n_coeff)
        s += '{:E}'.format(shape_cal[0])
        for j in range(1, n_coeff):
            s += ' {:E}'.format(shape_cal[j])
        s += '\n' 

    if metadata is not None:
        for key, values in metadata.items():
            s += '$' + key + ':\n'
            for val in values:
                s += str(val) + '\n' 

    return s[:-1]