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pythonmatplotlibhealpy

Plot Polarization from fits file using Healpy

I'd like to access the polarization from a fits file and plot it using Healpy. I see that Healpix has a built in option called POLARIZATION, but I don't see the same options for Healpy.

How can I plot this data?

Thanks!

Edit: @AndreaZonca Here is the code I am currently using to plot temperature:

t = "%s Field - WMAP at W Band (90 GHz) Foreground Reduced iquma"%(name)
map = hp.read_map(band_iquma)
hp.cartview(map,title = t, coord = ['G','C'],max = .25, min = -.25, unit = 'mk',\
            lonra = range[0], latra = range[1])
hp.graticule()
plt.show()

The website where I got this file says that polarization data is included in the fits file.

And this website says that HealPix can plot polarization if given the keyword POLARIZATION and a number 1,2, or 3.

http://healpix.jpl.nasa.gov/html/idlnode10.htm

Solution

  • The keyword you are looking for is field in read_map, if you set it to (0,1,2) you will read both temperature and polarization. Then you can plot Q slicing the map with [1] and U with [2]. See:

    http://healpy.readthedocs.org/en/latest/generated/healpy.fitsfunc.read_map.html