EDispKernelMap

class gammapy.irf.EDispKernelMap(edisp_kernel_map, exposure_map=None)

Bases: IRFMap

Energy dispersion kernel map.

Parameters:

edisp_kernel_mapMap

The input energy dispersion kernel map. Should be a Map with 2 non-spatial axes. Reconstructed and true energy axes should be given in this specific order.

exposure_mapMap, optional

Associated exposure map. Needs to have a consistent map geometry.

Attributes Summary

edisp_map
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_diagonal_response(energy_axis, ...[, geom])	Create an energy dispersion map with diagonal response.
from_edisp_kernel(edisp[, geom])	Create an energy dispersion map from the input 1D kernel.
from_gauss(energy_axis, energy_axis_true, ...)	Create an energy dispersion map from the input 1D kernel.
from_geom(geom)	Create energy dispersion map from geometry.
from_hdulist(hdulist[, hdu, hdu_bands, ...])	Create from HDUList.
get_edisp_kernel([position, energy_axis])	Get energy dispersion at a given position.
peek([figsize])	Quick-look summary plots.
read(filename[, format, hdu, checksum])	Read an IRF_map from file and create corresponding object.
resample_energy_axis(energy_axis[, weights])	Return a resampled EDispKernelMap.
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_image([weights])	Return a 2D EdispKernelMap by summing over the reconstructed energy axis.
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

edisp_map

has_single_spatial_bin

mask_safe_image

Mask safe for the map.

required_axes = ['energy', 'energy_true']

tag = 'edisp_kernel_map'

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_diagonal_response(energy_axis, energy_axis_true, geom=None)

Create an energy dispersion map with diagonal response.

Parameters:

energy_axisMapAxis

Energy axis.

energy_axis_trueMapAxis

True energy axis

geomGeom, optional

The (2D) geometry object to use. If None, an all sky geometry with 2 bins is created. Default is None.

Returns:

edisp_mapEDispKernelMap

Energy dispersion kernel map.

classmethod from_edisp_kernel(edisp, geom=None)

Create an energy dispersion map from the input 1D kernel.

The kernel will be duplicated over all spatial bins.

Parameters:

edispEDispKernel

The input 1D kernel.

geomGeom, optional

The (2D) geometry object to use. If None, an all sky geometry with 2 bins is created. Default is None.

Returns:

edisp_mapEDispKernelMap

Energy dispersion kernel map.

classmethod from_gauss(energy_axis, energy_axis_true, sigma, bias, pdf_threshold=1e-06, geom=None)

Create an energy dispersion map from the input 1D kernel.

The kernel will be duplicated over all spatial bins.

Parameters:

energy_axis_trueQuantity

Bin edges of true energy axis.

energy_axisQuantity

Bin edges of reconstructed energy axis.

biasfloat or ndarray

Center of Gaussian energy dispersion, bias.

sigmafloat or ndarray

RMS width of Gaussian energy dispersion, resolution.

pdf_thresholdfloat, optional

Zero suppression threshold. Default is 1e-6.

geomGeom, optional

The (2D) geometry object to use. If None, an all sky geometry with 2 bins is created. Default is None.

Returns:

edisp_mapEDispKernelMap

Energy dispersion kernel map.

classmethod from_geom(geom)

Create energy dispersion map from geometry.

By default, a diagonal energy dispersion matrix is created.

Parameters:

geomGeom

Energy dispersion map geometry.

Returns:

edisp_mapEDispKernelMap

Energy dispersion kernel 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.

get_edisp_kernel(position=None, energy_axis=None)

Get energy dispersion at a given position.

Parameters:

positionSkyCoord or SkyRegion, optional

The target position. Should be a single coordinates. Default is None.

energy_axisMapAxis, optional

Reconstructed energy axis, only used for checking. Default is None.

Returns:

edispEnergyDispersion

The energy dispersion (i.e. rmf object).

peek(figsize=(15, 5))

Quick-look summary plots.

Plots corresponding to the center of the map.

Parameters:

figsizetuple, optional

Size of the figure. Default is (15, 5).

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.

resample_energy_axis(energy_axis, weights=None)

Return a resampled EDispKernelMap.

Bins are grouped according to the edges of the reconstructed energy axis provided. The true energy is left unchanged.

Parameters:

energy_axisMapAxis

The reconstructed energy axis to use for the grouping.

weights: `~gammapy.maps.Map`, optional

Weights to be applied. Default is None.

Returns:

edispEDispKernelMap

Energy dispersion kernel 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_image(weights=None)

Return a 2D EdispKernelMap by summing over the reconstructed energy axis.

Parameters:

weights: `~gammapy.maps.Map`, optional

Weights to be applied. Default is None.

Returns:

edispEDispKernelMap

Energy dispersion kernel map.

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.