IRFMap#

class gammapy.irf.IRFMap(irf_map, exposure_map)[source]#

Bases: object

IRF map base class for DL4 instrument response functions.

Attributes Summary

mask_safe_image

Mask safe for the map.

required_axes

tag

Methods Summary

copy()

Copy IRF map.

cutout(position, width[, mode])

Cutout IRF map.

downsample(factor[, axis_name, weights])

Downsample the spatial dimension by a given factor.

from_hdulist(hdulist[, hdu, hdu_bands, ...])

Create from HDUList.

read(filename[, format, hdu, checksum])

Read an IRF_map from file and create corresponding object.

slice_by_idx(slices)

Slice sub dataset.

stack(other[, weights, nan_to_num])

Stack IRF map with another one in place.

to_hdulist([format])

Convert to HDUList.

to_region_nd_map(region)

Extract IRFMap in a given region or position.

write(filename[, overwrite, format, checksum])

Write IRF map to fits.

Attributes Documentation

mask_safe_image#

Mask safe for the map.

required_axes#
tag#

Methods Documentation

copy()[source]#

Copy IRF map.

cutout(position, width, mode='trim')[source]#

Cutout IRF map.

Parameters
positionSkyCoord

Center position of the cutout region.

widthtuple of Angle

Angular sizes of the region in (lon, lat) in that specific order. If only one value is passed, a square region is extracted.

mode{‘trim’, ‘partial’, ‘strict’}, optional

Mode option for Cutout2D, for details see Cutout2D. Default is “trim”.

Returns
cutoutIRFMap

Cutout IRF map.

downsample(factor, axis_name=None, weights=None)[source]#

Downsample the spatial dimension by a given factor.

Parameters
factorint

Downsampling factor.

axis_namestr

Axis to downsample. By default, spatial axes are downsampled.

weightsMap, optional

Map with weights downsampling. Default is None.

Returns
mapIRFMap

Downsampled IRF map.

classmethod from_hdulist(hdulist, hdu=None, hdu_bands=None, exposure_hdu=None, exposure_hdu_bands=None, format='gadf')[source]#

Create from HDUList.

Parameters
hdulistHDUList

HDU list.

hdustr, optional

Name or index of the HDU with the IRF map. Default is None.

hdu_bandsstr, optional

Name or index of the HDU with the IRF map BANDS table. Default is None.

exposure_hdustr, optional

Name or index of the HDU with the exposure map data. Default is None.

exposure_hdu_bandsstr, optional

Name or index of the HDU with the exposure map BANDS table. Default is None.

format{“gadf”, “gtpsf”}, optional

File format. Default is “gadf”.

Returns
irf_mapIRFMap

IRF map.

classmethod read(filename, format='gadf', hdu=None, checksum=False)[source]#

Read an IRF_map from file and create corresponding object.

Parameters
filenamestr or Path

File name.

format{“gadf”, “gtpsf”}, optional

File format. Default is “gadf”.

hdustr or int

HDU location. Default is None.

checksumbool

If True checks both DATASUM and CHECKSUM cards in the file headers. Default is False.

Returns
irf_mapPSFMap, EDispMap or EDispKernelMap

IRF map.

slice_by_idx(slices)[source]#

Slice sub dataset.

The slicing only applies to the maps that define the corresponding axes.

Parameters
slicesdict

Dictionary 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 dictionary are kept unchanged.

Returns
map_outIRFMap

Sliced IRF map object.

stack(other, weights=None, nan_to_num=True)[source]#

Stack IRF map with another one in place.

Parameters
otherIRFMap

IRF map to be stacked with this one.

weightsMap, optional

Map with stacking weights. Default is None.

nan_to_num: bool, optional

Non-finite values are replaced by zero if True. Default is True.

to_hdulist(format='gadf')[source]#

Convert to HDUList.

Parameters
format{“gadf”, “gtpsf”}, optional

File format. Default is “gadf”.

Returns
hdu_listHDUList

HDU list.

to_region_nd_map(region)[source]#

Extract IRFMap in a given region or position.

If a region is given a mean IRF is computed, if a position is given the IRF is interpolated.

Parameters
regionSkyRegion or SkyCoord

Region or position where to get the map.

Returns
irfIRFMap

IRF map with region geometry.

write(filename, overwrite=False, format='gadf', checksum=False)[source]#

Write IRF map to fits.

Parameters
filenamestr or Path

Filename to write to.

overwritebool, optional

Overwrite existing file. Default is False.

format{“gadf”, “gtpsf”}, optional

File format. Default is “gadf”.

checksumbool, optional

When True adds both DATASUM and CHECKSUM cards to the headers written to the file. Default is False.