[AstroPy] Loading wavelength from FITS spectrum

Éric Depagne eric at depagne.org
Thu Jul 4 04:43:19 EDT 2013


Le jeudi 4 juillet 2013 à 03:51:20, Gustavo Bragança a écrit :
> Hi,
> 
Hi Gustavo, 

> Is there any easy way to load the values of wavelength from a FITS spectrum
> using astropy?
> 
> I could obtain the wavelengths by using some values of the header, but I
> was wondering if there is an easy way.
> 
I use the following code to get the wavelength and intensity:
def readspec(fitsfile):
        f = pyfits.open(fitsfile)
        cdelt1 = f[0].header['CDELT1']
        crval1 = f[0].header['CRVAL1']
        start = crval1 - f[0].header['CRPIX1'] * cdelt1
        end = start + cdelt1 * f[0].shape[0] - cdelt1/10.
        x = numpy.arange(start, end, cdelt1)
        f.close()
        return x, f[0].data

I'm not sure it's the best way to do so, but it works.

HTH.

Éric.

Un clavier azerty en vaut deux
----------------------------------------------------------
Éric Depagne                            eric at depagne.org



More information about the AstroPy mailing list