pythonipythonhealpy

healpy: galactic and equatorial plane drawing fails


I am very new with healpy and python, but I would like to draw a skymap with the galactic plane and the equatorial plane in galactic coordinates. The first issue that I have is that I am not able to draw a strait line:

import healpy as hp
import numpy as np
import pylab as pl

hp.mollview(title="Galactic coordinate map")
hp.graticule()

theta = [90., 90.]
phi = [-180., 180.]


hp.projplot(theta, phi, 'r-', coord='G')
pl.show()

I was trying to follow this documentation: https://healpy.readthedocs.org/en/1.5.0/generated/healpy.visufunc.projplot.html

Also I am not sure where to get the coordinates for the galactic plane and the equatorial plane.


Solution

  • Until the bug in healpy is not fixed it's possible to generate enough points resulting into a line:

    import healpy as hp
    import numpy as np
    import pylab as pl
    
    hp.mollview(title="Galactic coordinate map")
    hp.graticule()
    
    theta = [0.]*100
    phi = np.arange(0, 360, 3.6)
    
    
    hp.projplot(theta, phi, 'r-', coord='G')
    pl.show()