def _objective(arg):
sys.stdout.write('.')
sys.stdout.flush()
pos_y = arg[0]
pos_x = arg[1]
mag = arg[2]
sep_ang = cartesian_to_polar(center, pos_y, pos_x)
fake = fake_planet(images=images,
psf=psf,
parang=parang,
position=(sep_ang[0], sep_ang[1]),
magnitude=mag,
psf_scaling=self.m_psf_scaling)
mask = create_mask(fake.shape[-2:], (self.m_cent_size, self.m_edge_size))
if self.m_reference_in_port is None:
_, im_res = pca_psf_subtraction(images=fake*mask,
angles=-1.*parang+self.m_extra_rot,
pca_number=self.m_pca_number,
pca_sklearn=None,
im_shape=None,
indices=None)
else:
im_reshape = np.reshape(fake*mask, (im_shape[0], im_shape[1]*im_shape[2]))
_, im_res = pca_psf_subtraction(images=im_reshape,
angles=-1.*parang+self.m_extra_rot,
pca_number=self.m_pca_number,
pca_sklearn=sklearn_pca,
im_shape=im_shape,
indices=None)
res_stack = combine_residuals(method=self.m_residuals, res_rot=im_res)
self.m_res_out_port.append(res_stack, data_dim=3)
chi_square = merit_function(residuals=res_stack[0, ],
merit=self.m_merit,
aperture=aperture,
sigma=self.m_sigma)
position = rotate_coordinates(center, (pos_y, pos_x), -self.m_extra_rot)
res = np.asarray([position[1],
position[0],
sep_ang[0]*pixscale,
(sep_ang[1]-self.m_extra_rot) % 360.,
mag,
chi_square])
self.m_flux_position_port.append(res, data_dim=2)
return chi_square
def _objective(arg):
sys.stdout.write('.')
sys.stdout.flush()
pos_y = arg[0]
pos_x = arg[1]
mag = arg[2]
sep_ang = cartesian_to_polar(center, pos_x, pos_y)
fake = fake_planet(images=images,
psf=psf,
parang=parang,
position=(sep_ang[0], sep_ang[1]),
magnitude=mag,
psf_scaling=self.m_psf_scaling)
im_shape = (fake.shape[-2], fake.shape[-1])
mask = create_mask(im_shape, [self.m_cent_size, self.m_edge_size])
_, im_res = pca_psf_subtraction(images=fake*mask,
angles=-1.*parang+self.m_extra_rot,
pca_number=self.m_pca_number)
stack = combine_residuals(method=self.m_residuals, res_rot=im_res)
self.m_res_out_port.append(stack, data_dim=3)
merit = merit_function(residuals=stack[0, ],
function=self.m_merit,
variance="poisson",
aperture=self.m_aperture,
sigma=self.m_sigma)
position = rotate_coordinates(center, (pos_y, pos_x), -self.m_extra_rot)
res = np.asarray((position[1],
position[0],
sep_ang[0]*pixscale,
(sep_ang[1]-self.m_extra_rot)%360.,
mag,
merit))
self.m_flux_position_port.append(res, data_dim=2)
return merit
def run(self) -> None:
"""
Run method of the module. Calculates the SNR and FPF for a specified position in a post-
processed image with the Student's t-test (Mawet et al. 2014). This approach assumes
Gaussian noise but accounts for small sample statistics.
Returns
-------
NoneType
None
"""
def _snr_optimize(arg):
pos_x, pos_y = arg
_, _, snr, _ = false_alarm(image=image,
x_pos=pos_x,
y_pos=pos_y,
size=self.m_aperture,
ignore=self.m_ignore)
return -snr
self.m_snr_out_port.del_all_data()
self.m_snr_out_port.del_all_attributes()
pixscale = self.m_image_in_port.get_attribute('PIXSCALE')
self.m_aperture /= pixscale
nimages = self.m_image_in_port.get_shape()[0]
bounds = ((self.m_position[0]+self.m_bounds[0][0], self.m_position[0]+self.m_bounds[0][1]),
(self.m_position[1]+self.m_bounds[1][0], self.m_position[1]+self.m_bounds[1][1]))
start_time = time.time()
for j in range(nimages):
progress(j, nimages, 'Calculating S/N and FPF...', start_time)
image = self.m_image_in_port[j, ]
center = center_subpixel(image)
if self.m_optimize:
result = minimize(fun=_snr_optimize,
x0=[self.m_position[0], self.m_position[1]],
method='SLSQP',
bounds=bounds,
tol=None,
options={'ftol': self.m_tolerance})
_, _, snr, fpf = false_alarm(image=image,
x_pos=result.x[0],
y_pos=result.x[1],
size=self.m_aperture,
ignore=self.m_ignore)
x_pos, y_pos = result.x[0], result.x[1]
else:
_, _, snr, fpf = false_alarm(image=image,
x_pos=self.m_position[0],
y_pos=self.m_position[1],
size=self.m_aperture,
ignore=self.m_ignore)
x_pos, y_pos = self.m_position[0], self.m_position[1]
sep_ang = cartesian_to_polar(center, y_pos, x_pos)
result = np.column_stack((x_pos, y_pos, sep_ang[0]*pixscale, sep_ang[1], snr, fpf))
self.m_snr_out_port.append(result, data_dim=2)
history = f'aperture [arcsec] = {self.m_aperture*pixscale:.2f}'
self.m_snr_out_port.copy_attributes(self.m_image_in_port)
self.m_snr_out_port.add_history('FalsePositiveModule', history)
self.m_snr_out_port.close_port()
def pixel_variance(var_type: str, images: np.ndarray, parang: np.ndarray,
cent_size: Optional[float], edge_size: Optional[float],
pca_number: int, residuals: str,
aperture: Tuple[int, int, float], sigma: float) -> float:
"""
Function to calculate the variance of the noise. After the PSF subtraction, images are rotated
in opposite direction of the regular derotation, therefore dispersing any companion or disk
signal. The noise is measured within an annulus.
Parameters
----------
var_type : str
Variance type ('gaussian' or 'hessian').
images : numpy.ndarray
Input images (3D).
parang : numpy.ndarray
Parallactic angles.
cent_size : float, None
Radius of the central mask (pix). No mask is used when set to None.
edge_size : float, None
Outer radius (pix) beyond which pixels are masked. No outer mask is used when set to
None.
pca_number : int
Number of principal components (PCs) used for the PSF subtraction.
residuals : str
Method for combining the residuals ('mean', 'median', 'weighted', or 'clipped').
aperture : tuple(int, int, float)
Aperture position (y, x) and radius (pix).
sigma : float, None
Standard deviation (pix) of the Gaussian kernel which is used to smooth the images.
Returns
-------
float
Variance of the pixel values. Either the variance of the pixel values ('gaussian') or
the variance of the determinant of the Hessian ('hessian').
"""
mask = create_mask(images.shape[-2:], (cent_size, edge_size))
_, im_res_derot = pca_psf_subtraction(images * mask, parang, pca_number)
res_noise = combine_residuals(residuals, im_res_derot)
sep_ang = cartesian_to_polar(center_subpixel(res_noise), aperture[0],
aperture[1])
if var_type == 'gaussian':
selected = select_annulus(res_noise[0, ], sep_ang[0] - aperture[2],
sep_ang[0] + aperture[2])
elif var_type == 'hessian':
hessian_rr, hessian_rc, hessian_cc = hessian_matrix(
image=res_noise[0, ],
sigma=sigma,
mode='constant',
cval=0.,
order='rc')
hes_det = (hessian_rr * hessian_cc) - (hessian_rc * hessian_rc)
selected = select_annulus(hes_det, sep_ang[0] - aperture[2],
sep_ang[0] + aperture[2])
return float(np.var(selected))
def merit_function(residuals: np.ndarray, merit: str,
aperture: Tuple[int, int, float], sigma: float) -> float:
"""
Function to calculate the figure of merit at a given position in the image residuals.
Parameters
----------
residuals : numpy.ndarray
Residuals of the PSF subtraction (2D).
merit : str
Figure of merit for the chi-square function ('hessian', 'poisson', or 'gaussian').
aperture : tuple(int, int, float)
Position (y, x) of the aperture center (pix) and aperture radius (pix).
sigma : float
Standard deviation (pix) of the Gaussian kernel which is used to smooth the residuals
before the chi-square is calculated.
Returns
-------
float
Chi-square ('poisson' and 'gaussian') or sum of the absolute values ('hessian').
"""
rr_grid = pixel_distance(im_shape=residuals.shape,
position=(aperture[0], aperture[1]))
indices = np.where(rr_grid < aperture[2])
if merit == 'hessian':
# This is not the chi-square but simply the sum of the absolute values
hessian_rr, hessian_rc, hessian_cc = hessian_matrix(image=residuals,
sigma=sigma,
mode='constant',
cval=0.,
order='rc')
hes_det = (hessian_rr * hessian_cc) - (hessian_rc * hessian_rc)
chi_square = np.sum(np.abs(hes_det[indices]))
elif merit == 'poisson':
if sigma > 0.:
residuals = gaussian_filter(input=residuals, sigma=sigma)
chi_square = np.sum(np.abs(residuals[indices]))
elif merit == 'gaussian':
# separation (pix) and position angle (deg)
sep_ang = cartesian_to_polar(center=center_subpixel(residuals),
y_pos=aperture[0],
x_pos=aperture[1])
if sigma > 0.:
residuals = gaussian_filter(input=residuals, sigma=sigma)
selected = select_annulus(image_in=residuals,
radius_in=sep_ang[0] - aperture[2],
radius_out=sep_ang[0] + aperture[2],
mask_position=aperture[0:2],
mask_radius=aperture[2])
chi_square = np.sum(residuals[indices]**2) / np.var(selected)
else:
raise ValueError(
'Figure of merit not recognized. Please use \'hessian\', \'poisson\' '
'or \'gaussian\'. Previous use of \'sum\' should now be set as '
'\'poisson\'.')
return chi_square
def run(self):
"""
Run method of the module. Calculates the SNR and FPF for a specified position in a post-
processed image with the Student's t-test (Mawet et al. 2014). This approach assumes
Gaussian noise but accounts for small sample statistics.
Returns
-------
NoneType
None
"""
def _fpf_minimize(arg):
pos_x, pos_y = arg
try:
_, _, _, fpf = false_alarm(image=image,
x_pos=pos_x,
y_pos=pos_y,
size=self.m_aperture,
ignore=self.m_ignore)
except ValueError:
fpf = float('inf')
return fpf
self.m_snr_out_port.del_all_data()
self.m_snr_out_port.del_all_attributes()
pixscale = self.m_image_in_port.get_attribute('PIXSCALE')
self.m_aperture /= pixscale
nimages = self.m_image_in_port.get_shape()[0]
start_time = time.time()
for j in range(nimages):
progress(j, nimages, 'Running FalsePositiveModule...', start_time)
image = self.m_image_in_port[j, ]
center = center_subpixel(image)
if self.m_optimize:
result = minimize(fun=_fpf_minimize,
x0=[self.m_position[0], self.m_position[1]],
method='Nelder-Mead',
tol=None,
options={
'xatol': self.m_tolerance,
'fatol': float('inf')
})
_, _, snr, fpf = false_alarm(image=image,
x_pos=result.x[0],
y_pos=result.x[1],
size=self.m_aperture,
ignore=self.m_ignore)
x_pos, y_pos = result.x[0], result.x[1]
else:
_, _, snr, fpf = false_alarm(image=image,
x_pos=self.m_position[0],
y_pos=self.m_position[1],
size=self.m_aperture,
ignore=self.m_ignore)
x_pos, y_pos = self.m_position[0], self.m_position[1]
sep_ang = cartesian_to_polar(center, x_pos, y_pos)
result = np.column_stack(
(x_pos, y_pos, sep_ang[0] * pixscale, sep_ang[1], snr, fpf))
self.m_snr_out_port.append(result, data_dim=2)
sys.stdout.write('Running FalsePositiveModule... [DONE]\n')
sys.stdout.flush()
history = f'aperture [arcsec] = {self.m_aperture*pixscale:.2f}'
self.m_snr_out_port.copy_attributes(self.m_image_in_port)
self.m_snr_out_port.add_history('FalsePositiveModule', history)
self.m_snr_out_port.close_port()
