def test_galactic_conversions():
lon, lat = angles.from_degrees(067.4482), angles.from_degrees(19.2373)
ra, dec = gal_to_eq(lon, lat)
lon2, lat2 = eq_to_gal(ra, dec)
print "vega galactic", angles.to_degrees(lon), angles.to_degrees(lat)
print "vega equtorial", angles.to_degrees(ra), angles.to_degrees(dec)
print "vega galactic", angles.to_degrees(lon2), angles.to_degrees(lat2)
lon3, lat3 = eq_to_gal_quaternions(ra, dec)
print "vega equtorial", angles.to_degrees(ra), angles.to_degrees(dec)
print "vega galactic", angles.to_degrees(lon3), angles.to_degrees(lat3)
def eq_to_gal(ra, dec):
"""
expects dec between -pi/2 and pi/2
compares to pyephem within 0.45 arcsec
returns lon, lat in radians
"""
alpha = galactic_north_equatorial[0]
delta = galactic_north_equatorial[1]
la = angles.from_degrees(122.932 - 90.0)
b = arcsin(sin(dec) * sin(delta) + cos(dec) * cos(delta) * cos(ra - alpha))
l = arctan2(
sin(dec) * cos(delta) - cos(dec) * sin(delta) * cos(ra - alpha),
cos(dec) * sin(ra - alpha)) + la
l += 2.0 * pylab.pi * (l < 0)
l = l % (2.0 * pylab.pi)
return l, b
def run_test():
nside = 512
center = map(angles.from_degrees, [-92.0, -1.0])
scale = 1.0
fwhm = angles.from_arcmin(16.0)
radius = angles.from_degrees(3.0)
hit_map, signal_map = _generate_beam_map(nside, center, scale, fwhm, radius)
guess_center = map(angles.from_degrees, [-91.5, -1.1])
guess_fwhm = angles.from_arcmin(24.0)
fit = fit_map(hit_map, signal_map, guess_center, guess_fwhm)
print fit_string(fit)
signal_map[hit_map == 0] = pylab.nan
xsize = 1000
reso_arcmin = angles.to_arcmin(radius*2.5) / float(xsize)
#healpy.mollview(signal_map)
healpy.gnomview(signal_map, rot=map(angles.to_degrees, center), xsize=xsize, reso=reso_arcmin)
pylab.show()
def gal_to_eq(l, b):
"""
Inputs:
l: galactic longitude
b: galactic latitude
Returns:
ra, dec
compares to pyephem within 0.45 arcsec
"""
alpha = galactic_north_equatorial[0]
delta = galactic_north_equatorial[1]
la = angles.from_degrees(122.932 - 90.0)
dec = arcsin(sin(b) * sin(delta) + cos(b) * cos(delta) * sin(l - la))
ra = arctan2(
cos(b) * cos(l - la),
sin(b) * cos(delta) - cos(b) * sin(delta) * sin(l - la)) + alpha
ra += 2.0 * pylab.pi * (ra < 0)
ra = ra % (2.0 * pylab.pi)
return ra, dec
#! /usr/bin/env python
import os
import time
import pylab
from pylab import cos, sin, pi, arccos, arcsin, arctan2, sqrt, array, floor
from numpy import ndarray
from math import floor
from leap.lib.units import angles
from leap.lib.geometry import point_picking
from leap.lib.geometry import mollweide
from leap.lib.geometry import ebex_quaternion
galactic_north_equatorial = (angles.from_degrees(192.85948),
angles.from_degrees(27.12825))
galactic_center_equatorial = (angles.from_degrees(266.4049948010461),
angles.from_degrees(-28.93617396013869))
def eq_to_gal_quaternions(ra, dec, roll):
if False:
quat = [
-0.196253758775, -0.483210685419, 0.699229740143, 0.488947509127
]
rotation = ebex_quaternion.Quaternion(quat)
if True:
euler = [1.681402537745, -1.050488402394, 5.873385265060]
rotation = ebex_quaternion.Quaternion(euler)
attitude = ebex_quaternion.Quaternion([ra, dec, roll])
attitude = rotation * attitude
return attitude.equatorial