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.