Summary

This notebook is to study how the PSF varies across the CCD. Something is strange with the sigma calculation that leaves artifacts. Work in progress.



In [1]:

    
import desimodel.io
import numpy as np



In [2]:

    
psf = desimodel.io.load_psf('r')



In [3]:

    
nwave = nspec = 500
wavelengths = np.linspace(psf.wmin_all, psf.wmax_all, nwave)
sigx = np.zeros((nspec, nwave))
for i in range(nspec):
    sigx[i] = psf.xsigma(i, wavelengths)



In [4]:

    
%pylab inline









    



Populating the interactive namespace from numpy and matplotlib



In [15]:

    
imshow(sigx - np.median(sigx), vmin=-0.05, vmax=0.05)
set_cmap('RdBu')
colorbar()









    Out[15]:





<matplotlib.colorbar.Colorbar instance at 0x1100b8b90>



In [ ]:

    
psf.xsigma()