def pixel_var_psf(shape, var, psf_threshold=6):
shape = data2np(shape, 'float')
var = data2np(var, 'float')
if len(shape) != 2:
raise ValueError('Invalid shape length [%d]. 2D shape must have'
'length = 2.' % len(shape))
if len(var) != 2:
raise ValueError('Invalid var length [%d]. 2D variance must have'
'length = 2.' % len(var))
# Define variance in x and y axes.
var_2d_array = ((var / (np.floor(shape / 100.) * 100. + 100 *
(shape < 100))) * np.array([np.arange(1, x) for x in
shape + 1]).T).T
# Define the shape of each pixel PSF.
psf_shape = psf_threshold * var + 1
# Generate the PSF cube.
pv_psf = [single_psf(psf_shape, x).T for x in
np.array(list(product(*var_2d_array)), dtype='float')]
return np.array(pv_psf).T
def psf_var_convolve(image, psf):
# Function to select slices of an image.
def select_slices(image_shape, sub_shape):
ranges = np.array([np.arange(i) for i in image_shape])
limits = np.array([ranges.T + sub_shape / 2 + 1,
ranges.T + 1.5 * sub_shape + 1]).T
return np.array([np.array([slice(*i), slice(*j)]) for i in limits[0]
for j in limits[1]])
# Function to convolve a PSF with a sub-image.
def get_convolve(sub_image, psf):
return np.multiply(sub_image, np.rot90(psf, 2)).sum()
# Pad image borders by PSF size.
image_pad = pad2d(image, psf.shape[1:])
# Get sub-image slices of the padded image.
slices = select_slices(image.shape, data2np(psf.shape[1:]))
# Convolve sub-images with PSFs.
image_conv = np.array([[get_convolve(image_pad[list(x)], y)]
for x, y in zip(slices, psf)])
return np.reshape(image_conv, image.shape)
def _window(self, pos, func=None):
pos = data2np(pos)
if pos.size != 2:
raise ValueError('The pixel position must have a size of 2.')
window = self.pad_data[[slice(a - b, a + b + 1) for a, b in
izip(pos, self.pixel_rad)]]
if isinstance(func, type(None)):
return window
else:
return func(window)
def map2matrix(data_map, layout):
"""Map to Matrix
This method transforms a 2D map to a 2D matrix
Parameters
----------
data_map : np.ndarray
Input data map, 2D array
layout : tuple
2D layout of 2D images
Returns
-------
np.ndarray 2D matrix
Raises
------
ValueError
For invalid layout
"""
layout = data2np(layout)
# Select n objects
n_obj = np.prod(layout)
# Get the shape of the galaxy images
gal_shape = (data2np(data_map.shape) / layout)[0]
# Stack objects from map
data_matrix = []
for i in range(n_obj):
lower = (gal_shape * (i / layout[1]), gal_shape * (i % layout[1]))
upper = (gal_shape * (i / layout[1] + 1),
gal_shape * (i % layout[1] + 1))
data_matrix.append((data_map[lower[0]:upper[0],
lower[1]:upper[1]]).reshape(gal_shape**2))
return np.array(data_matrix).T
def _window(self, pos, func=None, *args):
pos = data2np(pos)
if pos.size != 2:
raise ValueError('The pixel position must have a size of 2.')
window = self.pad_data[[
slice(a - b, a + b + 1) for a, b in izip(pos, self.pixel_rad)
]]
if isinstance(func, type(None)):
return window
else:
return func(window, *args)
def single_psf(shape, var):
# Convert inputs to Numpy arrays
shape = data2np(shape)
var = data2np(var)
if len(shape) != 2:
raise ValueError('Invalid shape length [%d]. 2D shape must have'
'length = 2.' % len(shape))
if len(var) != 2:
raise ValueError('Invalid var length [%d]. 2D variance must have'
'length = 2.' % len(var))
# Single pixel point
psf = np.zeros(shape)
psf[zip(shape / 2)] = 1
# Gaussian filter with given variance
psf = gaussian_filter(psf, var)
return psf / psf.sum()
def map2matrix(data_map, layout):
layout = data2np(layout)
# Select n objects
n_obj = np.prod(layout)
# Get the shape of the galaxy images
gal_shape = (data2np(data_map.shape) / layout)[0]
# Stack objects from map
data_matrix = []
for i in range(n_obj):
lower = (gal_shape * (i / layout[1]),
gal_shape * (i % layout[1]))
upper = (gal_shape * (i / layout[1] + 1),
gal_shape * (i % layout[1] + 1))
data_matrix.append((data_map[lower[0]:upper[0],
lower[1]:upper[1]]).reshape(gal_shape ** 2))
return np.array(data_matrix).T
def cube2map(data_cube, layout):
layout = data2np(layout)
# Select n objects
n_obj = np.prod(layout)
temp = data_cube[:, :, :n_obj]
# Map objects from cube
data_map = np.zeros((layout * temp.shape[:2]))
for i in range(n_obj):
lower = (temp.shape[0] * (i / layout[1]),
temp.shape[0] * (i % layout[1]))
upper = (temp.shape[0] * (i / layout[1] + 1),
temp.shape[0] * (i % layout[1] + 1))
data_map[lower[0]:upper[0], lower[1]:upper[1]] = temp[:, :, i]
return data_map
def matrix2map(data_matrix, map_shape):
"""Matrix to Map
This method transforms a 2D matrix to a 2D map
Parameters
----------
data_matrix : np.ndarray
Input data matrix, 2D array
map_shape : tuple
2D shape of the output map
Returns
-------
np.ndarray 2D map
Raises
------
ValueError
For invalid layout
"""
map_shape = data2np(map_shape)
# Get the shape and layout of the galaxy images
gal_shape = np.sqrt(data_matrix.shape[0])
layout = np.array(map_shape / np.repeat(gal_shape, 2), dtype='int')
# Map objects from matrix
data_map = np.zeros(map_shape)
temp = data_matrix.reshape(gal_shape, gal_shape, data_matrix.shape[1])
for i in range(data_matrix.shape[1]):
lower = (gal_shape * (i / layout[1]), gal_shape * (i % layout[1]))
upper = (gal_shape * (i / layout[1] + 1),
gal_shape * (i % layout[1] + 1))
data_map[lower[0]:upper[0], lower[1]:upper[1]] = temp[:, :, i]
return data_map
def matrix2map(data_matrix, map_shape):
map_shape = data2np(map_shape)
# Get the shape and layout of the galaxy images
gal_shape = np.sqrt(data_matrix.shape[0])
layout = np.array(map_shape / np.repeat(gal_shape, 2), dtype='int')
# Map objects from matrix
data_map = np.zeros(map_shape)
temp = data_matrix.reshape(gal_shape, gal_shape, data_matrix.shape[1])
for i in range(data_matrix.shape[1]):
lower = (gal_shape * (i / layout[1]),
gal_shape * (i % layout[1]))
upper = (gal_shape * (i / layout[1] + 1),
gal_shape * (i % layout[1] + 1))
data_map[lower[0]:upper[0], lower[1]:upper[1]] = temp[:, :, i]
return data_map
def psf_pca_parts(psf, thresholds, n_pieces, return_coef=True,
coef_shape=None):
# Convert inputs to Numpy arrays
thresholds = data2np(thresholds)
# Split the PSF into pieces.
pieces = np.split(psf, np.arange(1, n_pieces) * psf.shape[2] /
n_pieces, axis=2)
# Get the princicpal components for each of the pieces.
res = [psf_pca(piece, thresholds[0], 'full', False)
for piece in pieces]
psf_pcs_pieces = np.vstack([val.T for val in res]).T
# Get the final princicpal components.
psf_pcs = psf_pca(psf_pcs_pieces, thresholds[1], 'full', False)
if return_coef:
# Get the PCA coefficients.
return psf_pcs, get_coef(psf, psf_pcs, coef_shape)
else:
return psf_pcs
