RegionGeom

class gammapy.maps.RegionGeom(region, axes=None, wcs=None)

Bases: gammapy.maps.Geom

Map geometry representing a region on the sky.

Parameters

regionSkyRegion

Region object.

axeslist of MapAxis

Non-spatial data axes.

wcsWCS

Optional wcs object to project the region if needed.

Attributes Summary

axes
axes_names
binsz
center_coord	(astropy.coordinates.SkyCoord)
center_pix
center_skydir	Center skydir
data_shape	Shape of the Numpy data array matching this geometry.
frame
is_allsky
is_hpx
is_image
projection
region
wcs
width	Width of bounding box of the region

Methods Summary

bin_volume(self)
contains(self, coords)	Check if a given map coordinate is contained in the geometry.
contains_pix(self, pix)	Check if a given pixel coordinate is contained in the geometry.
coord_to_idx(self, coords[, clip])	Convert map coordinates to pixel indices.
coord_to_pix(self, coords)	Convert map coordinates to pixel coordinates.
coord_to_tuple(self, coord)	Generate a coordinate tuple compatible with this geometry.
copy(self, \*\*kwargs)	Copy and overwrite given attributes.
create(region, \*\*kwargs)	Create region.
crop(self)	Crop the geometry at the edges.
downsample(self, factor, axis)	Downsample the spatial dimension of the geometry by a given factor.
energy_mask(self[, emin, emax])	Create a mask for a given energy range.
from_hdulist(hdulist[, format])	Read region table and convert it to region list.
get_axis_by_name(self, name)	Get an axis by name (case in-sensitive).
get_axis_index_by_name(self, name)	Get an axis index by name (case in-sensitive).
get_coord(self[, frame])	Get map coordinates from the geometry.
get_idx(self)	Get tuple of pixel indices for this geometry.
make_bands_hdu(self[, hdu, hdu_skymap, conv])
pad(self)	Pad the geometry at the edges.
pix_to_coord(self, pix)	Convert pixel coordinates to map coordinates.
pix_to_idx(self, pix[, clip])	Convert pixel coordinates to pixel indices.
separation(self, position)
slice_by_idx(self, slices)	Create a new geometry by slicing the non-spatial axes.
solid_angle(self)	Solid angle (Quantity in sr).
to_cube(self, axes)	Append non-spatial axes to create a higher-dimensional geometry.
to_image(self)	Create 2D image geometry (drop non-spatial dimensions).
union(self, other)	Stack a RegionGeom by making the union
upsample(self, factor, axis)	Upsample the spatial dimension of the geometry by a given factor.

Attributes Documentation

axes

axes_names

binsz = 0.01

center_coord

(astropy.coordinates.SkyCoord)

center_pix

center_skydir

Center skydir

data_shape

Shape of the Numpy data array matching this geometry.

frame

is_allsky = False

is_hpx = False

is_image = False

projection = 'TAN'

region

wcs

width

Width of bounding box of the region

Methods Documentation

bin_volume(self)

contains(self, coords)

Check if a given map coordinate is contained in the geometry.

Parameters

coordstuple or MapCoord

Tuple of map coordinates.

Returns

containmentndarray

Bool array.

contains_pix(self, pix)

Check if a given pixel coordinate is contained in the geometry.

Parameters

pixtuple

Tuple of pixel coordinates.

Returns

containmentndarray

Bool array.

coord_to_idx(self, coords, clip=False)

Convert map coordinates to pixel indices.

Parameters

coordstuple 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.

clipbool

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

pixtuple

Tuple of pixel indices in image and band dimensions. Elements set to -1 correspond to coordinates outside the map.

coord_to_pix(self, coords)

Convert map coordinates to pixel coordinates.

Parameters

coordstuple

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

pixtuple

Tuple of pixel coordinates in image and band dimensions.

coord_to_tuple(self, coord)

Generate a coordinate tuple compatible with this geometry.

Parameters

coordMapCoord

copy(self, **kwargs)

Copy and overwrite given attributes.

Parameters

**kwargsdict

Keyword arguments to overwrite in the map geometry constructor.

Returns

copyGeom

Copied map geometry.

classmethod create(region, **kwargs)

Create region.

Parameters

regionstr or SkyRegion

Region

axeslist of MapAxis

Non spatial axes.

Returns

geomRegionGeom

Region geometry

crop(self)

Crop the geometry at the edges.

Parameters

crop_width{sequence, array_like, int}

Number of values cropped from the edges of each axis.

Returns

geomGeom

Cropped geometry.

downsample(self, factor, axis)

Downsample the spatial dimension of the geometry by a given factor.

Parameters

factorint

Downsampling factor.

axisstr

Axis to downsample.

Returns

geomGeom

Downsampled geometry.

energy_mask(self, emin=None, emax=None)

Create a mask for a given energy range.

The energy bin must be fully contained to be included in the mask.

Parameters

emin, emaxQuantity

Energy range

Returns

maskndarray

Energy mask

classmethod from_hdulist(hdulist, format='ogip')

Read region table and convert it to region list.

get_axis_by_name(self, name)

Get an axis by name (case in-sensitive).

Parameters

namestr

Name of the requested axis

Returns

axisMapAxis

Axis

get_axis_index_by_name(self, name)

Get an axis index by name (case in-sensitive).

Parameters

namestr

Axis name

Returns

indexint

Axis index

get_coord(self, frame=None)

Get map coordinates from the geometry.

Returns

coordMapCoord

Map coordinate object.

get_idx(self)

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

idxtuple, 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.

localbool

Flag to return local or global pixel indices. Local indices run from 0 to the number of pixels in a given image plane.

flatbool, optional

Return a flattened array containing only indices for pixels contained in the geometry.

Returns

idxtuple

Tuple of pixel index vectors with one vector for each dimension.

make_bands_hdu(self, hdu=None, hdu_skymap=None, conv=None)

pad(self)

Pad the geometry at the edges.

Parameters

pad_width{sequence, array_like, int}

Number of values padded to the edges of each axis.

Returns

geomGeom

Padded geometry.

pix_to_coord(self, pix)

Convert pixel coordinates to map coordinates.

Parameters

pixtuple

Tuple of pixel coordinates.

Returns

coordstuple

Tuple of map coordinates.

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

pixtuple

Tuple of pixel coordinates.

clipbool

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

idxtuple

Tuple of pixel indices.

separation(self, position)

slice_by_idx(self, slices)

Create a new geometry by slicing the non-spatial axes.

Parameters

slicesdict

Dict of axes names and integers or slice object pairs. Contains one element for each non-spatial dimension. For integer indexing the correspoding axes is dropped from the map. Axes not specified in the dict are kept unchanged.

Returns

geomGeom

Sliced geometry.

solid_angle(self)

Solid angle (Quantity in sr).

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

axeslist

Axes that will be appended to this geometry.

Returns

geomGeom

Map geometry.

to_image(self)

Create 2D image geometry (drop non-spatial dimensions).

Returns

geomGeom

Image geometry.

union(self, other)

Stack a RegionGeom by making the union

upsample(self, factor, axis)

Upsample the spatial dimension of the geometry by a given factor.

Parameters

factorint

Upsampling factor.

axisstr

Axis to upsample.

Returns

geomGeom

Upsampled geometry.