def test_numexpr_num_threads(self):
with _environment('OMP_NUM_THREADS', '5'):
# NUMEXPR_NUM_THREADS has priority
with _environment('NUMEXPR_NUM_THREADS', '3'):
if 'sparc' in platform.machine():
self.assertEqual(1, numexpr._init_num_threads())
else:
self.assertEqual(3, numexpr._init_num_threads())
def test_omp_num_threads(self):
with _environment('OMP_NUM_THREADS', '5'):
self.assertEquals(5, numexpr._init_num_threads())
def test_numexpr_num_threads(self):
with _environment('OMP_NUM_THREADS', '5'):
# NUMEXPR_NUM_THREADS has priority
with _environment('NUMEXPR_NUM_THREADS', '3'):
self.assertEquals(3, numexpr._init_num_threads())
def test_omp_num_threads(self):
with _environment('OMP_NUM_THREADS', '5'):
if 'sparc' in platform.machine():
self.assertEqual(1, numexpr._init_num_threads())
else:
self.assertEqual(5, numexpr._init_num_threads())
def array_factor(self, az, el, antpos, freq):
r""" Computes the array factor :math:`\mathcal{A}` (i.e.
the far-field radiation pattern obtained for an array
of :math:`n_{\rm ant}` radiators).
.. math::
\mathcal{A} = \left| \sum_{n_{\scriptscriptstyle \rm ant}} e^{2 \pi i \frac{\nu}{c} (\varphi_0 - \varphi)} \right|^2
.. math::
\varphi = \underset{\scriptstyle n_{\scriptscriptstyle \rm ant}\, \times\, 3}{\mathbf{P}_{\rm ant}} \cdot \pmatrix{
\cos(\phi)\cos(\theta)\\
\sin(\phi)\cos(\theta)\\
\sin(\theta)
}
.. math::
\varphi_0 = \underset{\scriptstyle n_{\scriptscriptstyle \rm ant}\, \times\, 3}{\mathbf{P}_{\rm ant}} \cdot \pmatrix{
\cos(\phi_0)\cos(\theta_0)\\
\sin(\phi_0)\cos(\theta_0)\\
\sin(\theta_0)
}
:math:`\mathbf{P}_{\rm ant}` is the antenna position
matrix, :math:`\phi` and :math:`\theta` are the sky
local coordinates (azimuth and elevation respectively)
gridded on a HEALPix representation, whereas
:math:`\phi_0` and :math:`\theta_0` are the pointing
direction in local coordinates.
:param az:
Pointing azimuth (in degrees if `float`)
:type az: `float` or :class:`~astropy.units.Quantity`
:param el:
Pointing elevation (in degrees if `float`)
:type el: `float` or :class:`~astropy.units.Quantity`
:param antpos:
Antenna positions shaped as (n_ant, 3)
:type antpos: :class:`~numpy.ndarray`
:param freq:
Frequency (in MHz if `float`)
:type freq: `float` or :class:`~astropy.units.Quantity`
:returns: Array factor
:rtype: :class:`~numpy.ndarray`
"""
def get_phi(az, el, antpos):
""" az, el in radians
"""
xyz_proj = np.array(
[np.cos(az) * np.cos(el),
np.sin(az) * np.cos(el),
np.sin(el)])
antennas = np.array(antpos)
phi = np.dot(antennas, xyz_proj)
return phi
if not isinstance(az, u.Quantity):
az *= u.deg
if not isinstance(el, u.Quantity):
el *= u.deg
self.phase_center = to_radec(ho_coord(az=az, alt=el, time=self.time))
phi0 = get_phi(az=[az.to(u.rad).value],
el=[el.to(u.rad).value],
antpos=antpos)
phi_grid = get_phi(az=self.ho_coords.az.rad,
el=self.ho_coords.alt.rad,
antpos=antpos)
nt = ne.set_num_threads(ne._init_num_threads())
delay = ne.evaluate('phi_grid-phi0')
coeff = 2j * np.pi / wavelength(freq).value
if self.ncpus == 1:
# Normal
af = ne.evaluate('sum(exp(coeff*delay),axis=0)')
# elif self.ncpus == 'numba':
# af = perfcompute(coeff * delay)
else:
# Multiproc
af = np.sum(mp_expo(self.ncpus, coeff, delay), axis=0)
#return np.abs(af * af.conjugate())
return np.real(af * af.conjugate())
