IRFMap

class gammapy.irf.IRFMap(irf_map, exposure_map)

Bases: object

IRF map base class for DL4 instrument response functions.

Attributes Summary

has_single_spatial_bin
mask_safe_image	Mask safe for the map.
required_axes
tag

Methods Summary

copy()	Copy IRF map.
cutout(position, width[, mode, min_npix])	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

has_single_spatial_bin

mask_safe_image

Mask safe for the map.

required_axes

tag

Methods Documentation

copy()

Copy IRF map.

cutout(position, width, mode='trim', min_npix=3)

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”.

min_npixbool, optional

Force width to a minimmum number of pixels. Default is 3. The default is 3 pixels so interpolation is done correctly if the binning of the IRF is larger than the width of the analysis region.

Returns:

cutoutIRFMap

Cutout IRF map.

downsample(factor, axis_name=None, weights=None)

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')

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)

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)

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)

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')

Convert to HDUList.

Parameters:

format{“gadf”, “gtpsf”}, optional

File format. Default is “gadf”.

Returns:

hdu_listHDUList

HDU list.

to_region_nd_map(region)

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)

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.