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iancze/log_wavelength.py

Last active November 18, 2019 00:40
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log_wavelength.py
import numpy as np
c_kms = 2.99792458e5 # km/s
dv = 0.5 # km/s
wl_start = 5000.0
wl_end = 5100.0
CDELT1 = np.log10(dv/c_kms + 1.)
CRVAL1 = np.log10(wl_start)
CRVALN = np.log10(wl_end)
NAXIS1 = (CRVALN - CRVAL1) / CDELT1
p = np.arange(NAXIS1)
wl = 10 ** (CRVAL1 + CDELT1 * p)
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