# Licensed under a 3-clause BSD style license - see LICENSE.rst
import abc
import copy
import inspect
import logging
import numpy as np
from astropy import units as u
from astropy.io import fits
from .io import find_bands_hdu, find_hdu
from .utils import INVALID_INDEX
__all__ = ["Geom"]
log = logging.getLogger(__name__)
def get_shape(param):
if param is None:
return tuple()
if not isinstance(param, tuple):
param = [param]
return max([np.array(p, ndmin=1).shape for p in param])
def pix_tuple_to_idx(pix):
"""Convert a tuple of pixel coordinate arrays to a tuple of pixel indices.
Pixel coordinates are rounded to the closest integer value.
Parameters
----------
pix : tuple
Tuple of pixel coordinates with one element for each dimension
Returns
-------
idx : `~numpy.ndarray`
Array of pixel indices
"""
idx = []
for p in pix:
p = np.array(p, ndmin=1)
if np.issubdtype(p.dtype, np.integer):
idx += [p]
else:
p_idx = np.rint(p).astype(int)
p_idx[~np.isfinite(p)] = INVALID_INDEX.int
idx += [p_idx]
return tuple(idx)
[docs]class Geom(abc.ABC):
"""Map geometry base class.
See also: `~gammapy.maps.WcsGeom` and `~gammapy.maps.HpxGeom`
"""
# workaround for the lru_cache pickle issue
# see e.g. https://github.com/cloudpipe/cloudpickle/issues/178
def __getstate__(self):
state = self.__dict__.copy()
for key, value in state.items():
func = getattr(value, "__wrapped__", None)
if func is not None:
state[key] = func
return state
@property
@abc.abstractmethod
def data_shape(self):
"""Shape of the Numpy data array matching this geometry."""
pass
[docs] def data_nbytes(self, dtype="float32"):
"""Estimate memory usage in megabytes of the Numpy data array
matching this geometry depending on the given type.
Parameters
----------
dtype : data-type
The desired data-type for the array. Default is "float32"
Returns
-------
memory : `~astropy.units.Quantity`
Estimated memory usage in megabytes (MB)
"""
return (np.empty(self.data_shape, dtype).nbytes * u.byte).to("MB")
@property
@abc.abstractmethod
def is_allsky(self):
pass
@property
@abc.abstractmethod
def center_coord(self):
pass
@property
@abc.abstractmethod
def center_pix(self):
pass
@property
@abc.abstractmethod
def center_skydir(self):
pass
[docs] @classmethod
def from_hdulist(cls, hdulist, hdu=None, hdu_bands=None):
"""Load a geometry object from a FITS HDUList.
Parameters
----------
hdulist : `~astropy.io.fits.HDUList`
HDU list containing HDUs for map data and bands.
hdu : str
Name or index of the HDU with the map data.
hdu_bands : str
Name or index of the HDU with the BANDS table. If not
defined this will be inferred from the FITS header of the
map HDU.
Returns
-------
geom : `~Geom`
Geometry object.
"""
if hdu is None:
hdu = find_hdu(hdulist)
else:
hdu = hdulist[hdu]
if hdu_bands is None:
hdu_bands = find_bands_hdu(hdulist, hdu)
if hdu_bands is not None:
hdu_bands = hdulist[hdu_bands]
return cls.from_header(hdu.header, hdu_bands)
[docs] def to_bands_hdu(self, hdu_bands=None, format="gadf"):
table_hdu = self.axes.to_table_hdu(format=format, hdu_bands=hdu_bands)
cols = table_hdu.columns.columns
cols.extend(self._make_bands_cols())
return fits.BinTableHDU.from_columns(
cols, header=table_hdu.header, name=table_hdu.name
)
@abc.abstractmethod
def _make_bands_cols(self):
pass
[docs] @abc.abstractmethod
def get_idx(self, idx=None, local=False, flat=False):
"""Get tuple of pixel indices for this geometry.
Returns all pixels in the geometry by default. Pixel indices
for a single image plane can be accessed by setting ``idx``
to the index tuple of a plane.
Parameters
----------
idx : tuple, optional
A tuple of indices with one index for each non-spatial
dimension. If defined only pixels for the image plane with
this index will be returned. If none then all pixels
will be returned.
local : bool
Flag to return local or global pixel indices. Local
indices run from 0 to the number of pixels in a given
image plane.
flat : bool, optional
Return a flattened array containing only indices for
pixels contained in the geometry.
Returns
-------
idx : tuple
Tuple of pixel index vectors with one vector for each
dimension.
"""
pass
[docs] @abc.abstractmethod
def get_coord(self, idx=None, flat=False):
"""Get the coordinate array for this geometry.
Returns a coordinate array with the same shape as the data
array. Pixels outside the geometry are set to NaN.
Coordinates for a single image plane can be accessed by
setting ``idx`` to the index tuple of a plane.
Parameters
----------
idx : tuple, optional
A tuple of indices with one index for each non-spatial
dimension. If defined only coordinates for the image
plane with this index will be returned. If none then
coordinates for all pixels will be returned.
flat : bool, optional
Return a flattened array containing only coordinates for
pixels contained in the geometry.
Returns
-------
coords : tuple
Tuple of coordinate vectors with one vector for each
dimension.
"""
pass
[docs] @abc.abstractmethod
def coord_to_pix(self, coords):
"""Convert map coordinates to pixel coordinates.
Parameters
----------
coords : tuple
Coordinate values in each dimension of the map. This can
either be a tuple of numpy arrays or a MapCoord object.
If passed as a tuple then the ordering should be
(longitude, latitude, c_0, ..., c_N) where c_i is the
coordinate vector for axis i.
Returns
-------
pix : tuple
Tuple of pixel coordinates in image and band dimensions.
"""
pass
[docs] def coord_to_idx(self, coords, clip=False):
"""Convert map coordinates to pixel indices.
Parameters
----------
coords : tuple or `~MapCoord`
Coordinate values in each dimension of the map. This can
either be a tuple of numpy arrays or a MapCoord object.
If passed as a tuple then the ordering should be
(longitude, latitude, c_0, ..., c_N) where c_i is the
coordinate vector for axis i.
clip : bool
Choose whether to clip indices to the valid range of the
geometry. If false then indices for coordinates outside
the geometry range will be set -1.
Returns
-------
pix : tuple
Tuple of pixel indices in image and band dimensions.
Elements set to -1 correspond to coordinates outside the
map.
"""
pix = self.coord_to_pix(coords)
return self.pix_to_idx(pix, clip=clip)
[docs] @abc.abstractmethod
def pix_to_coord(self, pix):
"""Convert pixel coordinates to map coordinates.
Parameters
----------
pix : tuple
Tuple of pixel coordinates.
Returns
-------
coords : tuple
Tuple of map coordinates.
"""
pass
[docs] @abc.abstractmethod
def pix_to_idx(self, pix, clip=False):
"""Convert pixel coordinates to pixel indices.
Returns -1 for pixel coordinates that lie outside of the map.
Parameters
----------
pix : tuple
Tuple of pixel coordinates.
clip : bool
Choose whether to clip indices to the valid range of the
geometry. If false then indices for coordinates outside
the geometry range will be set -1.
Returns
-------
idx : tuple
Tuple of pixel indices.
"""
pass
[docs] @abc.abstractmethod
def contains(self, coords):
"""Check if a given map coordinate is contained in the geometry.
Parameters
----------
coords : tuple or `~gammapy.maps.MapCoord`
Tuple of map coordinates.
Returns
-------
containment : `~numpy.ndarray`
Bool array.
"""
pass
[docs] def contains_pix(self, pix):
"""Check if a given pixel coordinate is contained in the geometry.
Parameters
----------
pix : tuple
Tuple of pixel coordinates.
Returns
-------
containment : `~numpy.ndarray`
Bool array.
"""
idx = self.pix_to_idx(pix)
return np.all(np.stack([t != INVALID_INDEX.int for t in idx]), axis=0)
[docs] def slice_by_idx(self, slices):
"""Create a new geometry by slicing the non-spatial axes.
Parameters
----------
slices : dict
Dict of axes names and integers or `slice` object pairs. Contains one
element for each non-spatial dimension. For integer indexing the
corresponding axes is dropped from the map. Axes not specified in the
dict are kept unchanged.
Returns
-------
geom : `~Geom`
Sliced geometry.
"""
axes = self.axes.slice_by_idx(slices)
return self._init_copy(axes=axes)
[docs] def rename_axes(self, names, new_names):
"""Rename axes contained in the geometry
Parameters
----------
names : list or str
Names of the axes.
new_names : list or str
New names of the axes (list must be of same length than `names`).
Returns
-------
geom : `~Geom`
Renamed geometry.
"""
axes = self.axes.rename_axes(names=names, new_names=new_names)
return self._init_copy(axes=axes)
@property
def as_energy_true(self):
"""If the geom contains an energy axis rename it to energy true"""
return self.rename_axes(names="energy", new_names="energy_true")
@property
def has_energy_axis(self):
"""Whether geom has an energy axis"""
return ("energy" in self.axes.names) ^ ("energy_true" in self.axes.names)
[docs] @abc.abstractmethod
def to_image(self):
"""Create 2D image geometry (drop non-spatial dimensions).
Returns
-------
geom : `~Geom`
Image geometry.
"""
pass
[docs] @abc.abstractmethod
def to_cube(self, axes):
"""Append non-spatial axes to create a higher-dimensional geometry.
This will result in a new geometry with
N+M dimensions where N is the number of current dimensions and
M is the number of axes in the list.
Parameters
----------
axes : list
Axes that will be appended to this geometry.
Returns
-------
geom : `~Geom`
Map geometry.
"""
pass
[docs] def squash(self, axis_name):
"""Squash geom axis.
Parameters
----------
axis_name : str
Axis to squash.
Returns
-------
geom : `Geom`
Geom with squashed axis.
"""
axes = self.axes.squash(axis_name=axis_name)
return self.to_image().to_cube(axes=axes)
[docs] def drop(self, axis_name):
"""Drop an axis from the geom.
Parameters
----------
axis_name : str
Name of the axis to remove.
Returns
-------
geom : `Geom`
New geom with the axis removed.
"""
axes = self.axes.drop(axis_name=axis_name)
return self.to_image().to_cube(axes=axes)
[docs] def pad(self, pad_width, axis_name):
"""
Pad the geometry at the edges.
Parameters
----------
pad_width : {sequence, array_like, int}
Number of values padded to the edges of each axis.
axis_name : str
Name of the axis to pad.
Returns
-------
geom : `~Geom`
Padded geometry.
"""
if axis_name is None:
return self._pad_spatial(pad_width)
else:
axes = self.axes.pad(axis_name=axis_name, pad_width=pad_width)
return self.to_image().to_cube(axes)
@abc.abstractmethod
def _pad_spatial(self, pad_width):
pass
[docs] @abc.abstractmethod
def crop(self, crop_width):
"""
Crop the geometry at the edges.
Parameters
----------
crop_width : {sequence, array_like, int}
Number of values cropped from the edges of each axis.
Returns
-------
geom : `~Geom`
Cropped geometry.
"""
pass
[docs] @abc.abstractmethod
def downsample(self, factor, axis_name):
"""Downsample the spatial dimension of the geometry by a given factor.
Parameters
----------
factor : int
Downsampling factor.
axis_name : str
Axis to downsample.
Returns
-------
geom : `~Geom`
Downsampled geometry.
"""
pass
[docs] @abc.abstractmethod
def upsample(self, factor, axis_name=None):
"""Upsample the spatial dimension of the geometry by a given factor.
Parameters
----------
factor : int
Upsampling factor.
axis_name : str
Axis to upsample.
Returns
-------
geom : `~Geom`
Upsampled geometry.
"""
pass
[docs] def resample_axis(self, axis):
"""Resample geom to a new axis binning.
This method groups the existing bins into a new binning.
Parameters
----------
axis : `MapAxis`
New map axis.
Returns
-------
map : `Geom`
Geom with resampled axis.
"""
axes = self.axes.resample(axis=axis)
return self._init_copy(axes=axes)
[docs] def replace_axis(self, axis):
"""Replace axis with a new one.
Parameters
----------
axis : `MapAxis`
New map axis.
Returns
-------
map : `Geom`
Geom with replaced axis.
"""
axes = self.axes.replace(axis=axis)
return self._init_copy(axes=axes)
[docs] @abc.abstractmethod
def solid_angle(self):
"""Solid angle (`~astropy.units.Quantity` in ``sr``)."""
pass
@property
def is_image(self):
"""Whether the geom is an image without extra dimensions."""
if self.axes is None:
return True
return len(self.axes) == 0
@property
def is_flat(self):
"""Whether the geom non spatial axes have length 1, equivalent to an image."""
if self.is_image:
return True
else:
valid = True
for axis in self.axes:
valid = valid and (axis.nbin == 1)
return valid
def _init_copy(self, **kwargs):
"""Init map geom instance by copying missing init arguments from self."""
argnames = inspect.getfullargspec(self.__init__).args
argnames.remove("self")
for arg in argnames:
value = getattr(self, "_" + arg)
if arg not in kwargs:
kwargs[arg] = copy.deepcopy(value)
return self.__class__(**kwargs)
[docs] def copy(self, **kwargs):
"""Copy and overwrite given attributes.
Parameters
----------
**kwargs : dict
Keyword arguments to overwrite in the map geometry constructor.
Returns
-------
copy : `Geom`
Copied map geometry.
"""
return self._init_copy(**kwargs)
[docs] def energy_mask(self, energy_min=None, energy_max=None, round_to_edge=False):
"""Create a mask for a given energy range.
The energy bin must be fully contained to be included in the mask.
Parameters
----------
energy_min, energy_max : `~astropy.units.Quantity`
Energy range
Returns
-------
mask : `~numpy.ndarray`
Energy mask
"""
from . import Map
# get energy axes and values
energy_axis = self.axes["energy"]
if round_to_edge:
energy_min, energy_max = energy_axis.round([energy_min, energy_max])
# TODO: make this more general
shape = (-1, 1) if self.is_hpx else (-1, 1, 1)
energy_edges = energy_axis.edges.reshape(shape)
# set default values
energy_min = energy_min if energy_min is not None else energy_edges[0]
energy_max = energy_max if energy_max is not None else energy_edges[-1]
mask = (energy_edges[:-1] >= energy_min) & (energy_edges[1:] <= energy_max)
data = np.broadcast_to(mask, shape=self.data_shape)
return Map.from_geom(geom=self, data=data, dtype=data.dtype)