MapAxes

class gammapy.maps.MapAxes(axes)

Bases: collections.abc.Sequence

MapAxis container class.

Parameters

axeslist of MapAxis

List of map axis objects.

Attributes Summary

names	Names of the axes
shape	Shape of the axes

Methods Summary

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)	Make a sequence of MapAxis objects.
from_table_hdu(hdu[, format])	Create MapAxes from BinTableHDU
index(axis_name)	Get index in list
index_data(axis_name)	Get data index of the axes
pix_to_coord(pix)	Convert pixel coordinates to map coordinates.
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([header])	Convert axes to FITS header
to_table([format])	Convert axes to table
to_table_hdu([format, prefix])	Make FITS table columns for map axes.
upsample(factor, axis_name)	Upsample axis by a given factor

Attributes Documentation

names

Names of the axes

shape

Shape of the axes

Methods Documentation

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)

Make a sequence of MapAxis objects.

classmethod from_table_hdu(hdu, format=None)

Create MapAxes from BinTableHDU

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

pix_to_coord(pix)

Convert pixel coordinates to map coordinates.

Parameters

pixtuple

Tuple of pixel coordinates.

Returns

coordstuple

Tuple of map coordinates.

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(header=None)

Convert axes to FITS header

Parameters

headerHeader

If a header is provided it is extended with the information. Otherwise a new one is created.

Returns

headerHeader

FITS header.

to_table(format=None)

Convert axes to table

Parameters

format{“gadf-dl3”}

Format to use.

Returns

tableTable

Table with axis data

to_table_hdu(format=None, prefix=None)

Make FITS table columns for map axes.

Parameters

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

Format to use.

prefixstr

HDU name prefix 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