# An amptek Mini-X xray tube spectrum.
#
import numpy as np
import matplotlib.pyplot as plt
import astropy.units as u
import padre_meddea
from padre_meddea.io.amptek import read_mca
mca_file = padre_meddea._test_files_directory / "minix_20kV_15uA_sdd.mca"
spec = read_mca(mca_file)
f = spec.meta['calib']
energy_ax = f(spec.spectral_axis.value)
fig, ax = plt.subplots(layout="constrained")
ax.plot(energy_ax, spec.flux)  # doctest: +SKIP
ax.set_xlabel("energy [keV]")  # doctest: +SKIP
ax.set_ylabel("Counts")  # doctest: +SKIP
ax.set_yscale("log")
for this_roi in spec.meta['roi']:
    ax.axvspan(f(this_roi.lower.value), f(this_roi.upper.value), alpha=0.2)  # doctest: +SKIP