def NAA_net_area(measurement, energy):
    """
    NAA_net_area determines the net area of a given peak without the use
    of compton regions. It generates a region of interest (ROI) based on
    full width half maximum (FWHM). A line is generated using the edges of the
    ROI and an integral of the line is determined. The gross counts of the peak
    are then subtracted by the integral and a net area and uncertainty are
    determined and returned.
    """
    E0 = measurement.energy_cal[0]
    Eslope = measurement.energy_cal[1]
    sample_counts = measurement.data
    energy_channel = int((energy - E0) / Eslope)

    region_size = 1.3
    # Rough estimate of FWHM.
    fwhm = 0.05*energy**0.5
    fwhm_channel = int(region_size * (fwhm - E0) / Eslope)
    # peak gross area
    gross_counts_peak = sum(sample_counts[(energy_channel - fwhm_channel):
                                          (energy_channel + fwhm_channel)])
    peak_channels = measurement.channel[(energy_channel - fwhm_channel):
                                        (energy_channel + fwhm_channel)]
    # first and last channel counts of peak
    start_peak_c = sample_counts[(energy_channel - fwhm_channel)]
    end_peak_c = sample_counts[(energy_channel + fwhm_channel)]

    # generate line under peak
    compton_area = (start_peak_c + end_peak_c) / 2 * len(peak_channels)
    net_area = gross_counts_peak - compton_area

    # evaluate uncertainty
    net_area_uncertainty = (gross_counts_peak + compton_area)**0.5
    return net_area, net_area_uncertainty