MapAxes

class gammapy.maps.MapAxes(axes, n_spatial_axes=None)

Bases: collections.abc.Sequence

MapAxis container class.

Parameters

axeslist of MapAxis

List of map axis objects.

Attributes Summary

center_coord	Center coordinates
is_flat	Whether axes is flat
is_unidimensional	Whether axes is unidimensional
iter_with_reshape	Iterate by shape
names	Names of the axes
primary_axis	Primary extra axis, defined as the one longest
reverse	Reverse axes order
shape	Shape of the axes

Methods Summary

assert_names(required_names)	Assert required axis names and order
bin_volume()	Bin axes volume
coord_to_idx(coord[, clip])	Transform from axis to pixel indices.
coord_to_pix(coord)	Transform from axis to pixel coordinates.
count(value)
downsample(factor, axis_name)	Downsample axis by a given factor
drop(axis_name)	Drop an axis.
from_default(axes[, n_spatial_axes])	Make a sequence of MapAxis objects.
from_table(table[, format])	Create MapAxes from table
from_table_hdu(hdu[, format])	Create MapAxes from BinTableHDU
get_coord([mode, axis_name])	Get axes coordinates
index(axis_name)	Get index in list
index_data(axis_name)	Get data index of the axes
pad(axis_name, pad_width)	Pad axes
pix_to_coord(pix)	Convert pixel coordinates to map coordinates.
pix_to_idx(pix[, clip])	Convert pix to idx
replace(axis)	Replace a given axis
resample(axis)	Resample axis binning.
slice_by_idx(slices)	Create a new geometry by slicing the non-spatial axes.
squash(axis_name)	Squash axis.
to_header([format])	Convert axes to FITS header
to_table([format])	Convert axes to table
to_table_hdu([format, hdu_bands])	Make FITS table columns for map axes.
upsample(factor, axis_name)	Upsample axis by a given factor

Attributes Documentation

center_coord

Center coordinates

is_flat

Whether axes is flat

is_unidimensional

Whether axes is unidimensional

iter_with_reshape

Iterate by shape

names

Names of the axes

primary_axis

Primary extra axis, defined as the one longest

Returns

axisMapAxis

Map axis

reverse

Reverse axes order

shape

Shape of the axes

Methods Documentation

assert_names(required_names)

Assert required axis names and order

Parameters

required_nameslist of str

Required

bin_volume()

Bin axes volume

Returns

bin_volumeQuantity

Bin volume

coord_to_idx(coord, clip=True)

Transform from axis to pixel indices.

Parameters

coorddict of ndarray or MapCoord

Array of axis coordinate values.

Returns

pixtuple of ndarray

Array of pixel indices values.

coord_to_pix(coord)

Transform from axis to pixel coordinates.

Parameters

coorddict of ndarray

Array of axis coordinate values.

Returns

pixtuple of ndarray

Array of pixel coordinate values.

count(value) → integer -- return number of occurrences of value

downsample(factor, axis_name)

Downsample axis by a given factor

Parameters

factorint

Upsampling factor.

axis_namestr

Axis to upsample.

Returns

axesMapAxes

Map axes

drop(axis_name)

Drop an axis.

Parameters

axis_namestr

Name of the axis to remove.

Returns

axesMapAxes

Axes with squashed axis.

classmethod from_default(axes, n_spatial_axes=None)

Make a sequence of MapAxis objects.

classmethod from_table(table, format='gadf')

Create MapAxes from table

Parameters

tableTable

Bin table HDU

format{“gadf”, “gadf-dl3”, “fgst-ccube”, “fgst-template”, “fgst-bexcube”, “ogip-arf”}

Format to use.

Returns

axesMapAxes

Map axes object

classmethod from_table_hdu(hdu, format='gadf')

Create MapAxes from BinTableHDU

Parameters

hduBinTableHDU

Bin table HDU

Returns

axesMapAxes

Map axes object

get_coord(mode='center', axis_name=None)

Get axes coordinates

Parameters

mode{“center”, “edges”}

Coordinate center or edges

axis_namestr

Axis name for which mode=’edges’ applies

Returns

coordsdict of Quanity

Map coordinates

index(axis_name)

Get index in list

index_data(axis_name)

Get data index of the axes

Parameters

axis_namestr

Name of the axis.

Returns

idxint

Data index

pad(axis_name, pad_width)

Pad axes

Parameters

axis_namestr

Name of the axis to pad.

pad_widthint or tuple of int

Pad width

Returns

axesMapAxes

Axes with squashed axis.

pix_to_coord(pix)

Convert pixel coordinates to map coordinates.

Parameters

pixtuple

Tuple of pixel coordinates.

Returns

coordstuple

Tuple of map coordinates.

pix_to_idx(pix, clip=False)

Convert pix to idx

Parameters

pixtuple of ndarray

Pixel coordinates.

clipbool

Choose whether to clip indices to the valid range of the axis. If false then indices for coordinates outside the axi range will be set -1.

Returns

idxtuple ndarray

Pixel indices.

replace(axis)

Replace a given axis

Parameters

axisMapAxis

Map axis

Returns

axesMapAxes

Map axe

resample(axis)

Resample axis binning.

This method groups the existing bins into a new binning.

Parameters

axisMapAxis

New map axis.

Returns

axesMapAxes

Axes object with resampled axis.

slice_by_idx(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 corresponding axes is dropped from the map. Axes not specified in the dict are kept unchanged.

Returns

geomGeom

Sliced geometry.

squash(axis_name)

Squash axis.

Parameters

axis_namestr

Axis to squash.

Returns

axesMapAxes

Axes with squashed axis.

to_header(format='gadf')

Convert axes to FITS header

Parameters

format{“gadf”}

Header format

Returns

headerHeader

FITS header.

to_table(format='gadf')

Convert axes to table

Parameters

format{“gadf”, “gadf-dl3”, “fgst-ccube”, “fgst-template”, “ogip”, “ogip-sherpa”, “ogip-arf”, “ogip-arf-sherpa”}

Format to use.

Returns

tableTable

Table with axis data

to_table_hdu(format='gadf', hdu_bands=None)

Make FITS table columns for map axes.

Parameters

format{“gadf”, “fgst-ccube”, “fgst-template”}

Format to use.

hdu_bandsstr

Name of the bands HDU to use.

Returns

hduBinTableHDU

Bin table HDU.

upsample(factor, axis_name)

Upsample axis by a given factor

Parameters

factorint

Upsampling factor.

axis_namestr

Axis to upsample.

Returns

axesMapAxes

Map axes