def test_sg_to_gal(self):
for line in self.tevcat:
l,b = line[3]
sgl,sgb = line[2]
sg = astro.I3SuperGalactic(sgl*I3Units.degree,
sgb*I3Units.degree)
gal = astro.I3GetGalacticFromSuperGalactic(sg)
self.assertAlmostEqual(gal.l/I3Units.degree,l,2)
self.assertAlmostEqual(gal.b/I3Units.degree,b,2)
def test_gal_from_sg(self):
random.seed(0)
for n in range(10000):
sg = astro.I3SuperGalactic(random.uniform(0,2*math.pi),
random.uniform(-math.pi/2,math.pi/2),
)
gal = astro.I3GetGalacticFromSuperGalactic(sg)
sgprime = astro.I3GetSuperGalacticFromGalactic(gal)
self.assert_almost_equal(math.cos(sg.b)*sg.l,math.cos(sgprime.b)*sgprime.l,1e-9)
self.assert_almost_equal(sg.b,sgprime.b,1e-10)
self.assert_less(astro.angular_distance(sg.l,sg.b,sgprime.l,sgprime.b),1e-10)
def test_reference_points(self):
#Test the reference points that define the galactic coordinate system
#take from Wikipedia, the orignal paper was in B1950
#celestial north pole
eq = astro.I3Equatorial((12+51.4/60.)*15*I3Units.degree,
27.13 * I3Units.degree)
gal = astro.I3GetGalacticFromEquatorial(eq)
self.assertAlmostEqual(gal.b/I3Units.degree,+90,1)
#south pole
eq.ra = (+51.4/60.)*15*I3Units.degree
eq.dec = -27.13 * I3Units.degree
gal = astro.I3GetGalacticFromEquatorial(eq)
self.assertAlmostEqual(gal.b/I3Units.degree,-90,1)
#galactic center
eq.ra = (17+45.6/60.)*15*I3Units.degree
eq.dec = -28.94 * I3Units.degree
gal = astro.I3GetGalacticFromEquatorial(eq)
self.assertAlmostEqual(gal.b/I3Units.degree,0,1)
self.assertAlmostEqual(gal.l/I3Units.degree,360,1)
#anti-center
eq.ra = (5+45.6/60.)*15*I3Units.degree
eq.dec = +28.94 * I3Units.degree
gal = astro.I3GetGalacticFromEquatorial(eq)
self.assertAlmostEqual(gal.b/I3Units.degree,0,1)
self.assertAlmostEqual(gal.l/I3Units.degree,180,1)
#now test the reverse transform
#galactic north pole
gal = astro.I3Galactic( 0 * I3Units.degree,
+90 * I3Units.degree)
eq = astro.I3GetEquatorialFromGalactic(gal)
self.assertAlmostEqual(eq.ra/I3Units.degree,
(12+51.4/60.)*15.,1)
self.assertAlmostEqual(eq.dec/I3Units.degree,
27.13,1)
#south pole
gal.l = 0 * I3Units.degree
gal.b = -90 * I3Units.degree
eq = astro.I3GetEquatorialFromGalactic(gal)
self.assertAlmostEqual(eq.ra/I3Units.degree,
(0+51.4/60.)*15.,1)
self.assertAlmostEqual(eq.dec/I3Units.degree,
-27.13,1)
#galactic center
gal.l = 0 * I3Units.degree
gal.b = 0 * I3Units.degree
eq = astro.I3GetEquatorialFromGalactic(gal)
self.assertAlmostEqual(eq.ra/I3Units.degree,
(17+45.6/60.)*15.,1)
self.assertAlmostEqual(eq.dec/I3Units.degree,
-28.94,1)
#anti center
gal.l = 0 * I3Units.degree
gal.b = 180 * I3Units.degree
eq = astro.I3GetEquatorialFromGalactic(gal)
self.assertAlmostEqual(eq.ra/I3Units.degree,
(5+45.6/60.)*15.,1)
self.assertAlmostEqual(eq.dec/I3Units.degree,
+28.94,1)
#supergalactic north pole
sg = astro.I3SuperGalactic()
sg.b = 90 *I3Units.degree
sg.l = 0 *I3Units.degree
gal = astro.I3GetGalacticFromSuperGalactic(sg)
self.assertAlmostEqual(gal.l/I3Units.degree,
47.37,6)
self.assertAlmostEqual(gal.b/I3Units.degree,
6.32,6)
eq = astro.I3GetEquatorialFromSuperGalactic(sg)
print(eq.ra/I3Units.degree/15,eq.dec/I3Units.degree)
self.assertAlmostEqual(eq.ra/I3Units.degree,
18.92*15,1)
self.assertAlmostEqual(eq.dec/I3Units.degree,
15.7,1)
#supergalactic origin
sg = astro.I3SuperGalactic()
sg.b = 0 *I3Units.degree
sg.l = 0 *I3Units.degree
gal = astro.I3GetGalacticFromSuperGalactic(sg)
self.assertAlmostEqual(gal.l/I3Units.degree,
137.37,6)
self.assertAlmostEqual(gal.b/I3Units.degree,
0,6)
eq = astro.I3GetEquatorialFromSuperGalactic(sg)
self.assertAlmostEqual(eq.ra/I3Units.degree,
2.82*15,1)
self.assertAlmostEqual(eq.dec/I3Units.degree,
59.5,1)