Read and plot the APF spectra

read_idl_sav.py

import numpy as np
from scipy.io import readsav

from matplotlib import pyplot as plt

w_idl = readsav("w_rl23.2142")
w = w_idl["w"]  # wavelengths in AA

fl_idl = readsav("rl23.2127")
f = fl_idl["sp"]  # fluxes in arbitrary units

print(w.shape)
print(f.shape)
# each array is 65 orders, 4608 pixels

# which echelle order we want to plot
order = 40

fig, ax = plt.subplots(nrows=1)
ax.plot(w[order], f[order])
ax.set_xlabel(r"$\lambda$ [$\AA$]")
ax.set_ylabel("counts")
plt.show()
# fig.savefig("spectrum.png")