Bandpass and flux resampling

Resampling a bandpass

Bandpass represented by arrays:

wave = np.array([...])
bandpass = np.array([...])

wave_sampling = 5e-9 # wavelength sampling interval


start, stop = wave[0], wave[-1]
num = int(round(sto-start) / wave_sampling*1e9)

resampled_wave = np.linspace(start, stop, num)
resampled_bandpass = np.interp(resampled_wave, wave, bandpass)

Bandpass represented by a Spectrum object:

bandpass = lentil.Spectrum(...)

wave_sampling = 5e-9 # wavelength sampling interval
trim_tol = 1e-2 # relative tolerance used to clip off nearly zero ends

bandpass.trim(trim_tol)
start, stop = flux.wave[0], flux.wave[-1]
num = int(round(sto-start) / wave_sampling*1e9)

resampled_wave = np.linspace(start, stop, num)
resampled_bandpass = bandpass.sample(wave, waveunit=bandpass.waveunit)

Resampling and rebinning flux

In this example, the flux is binned (instead of simply sampled) to preserve its integrated power.

flux = lentil.Spectrum(...)

wave_sampling = 5e-9 # wavelength sampling interval
trim_tol = 1e-2 # relative tolerance used to clip off nearly zero ends

flux.trim(ftrim_tol)
start, stop = flux.wave[0], flux.wave[-1]
num = int(round(sto-start) / wave_sampling*1e9)

wave = np.linspace(start, stop, num)
binned_flux = flux.bin(wave, waveunit=flux.waveunit)