Maps

class gammapy.maps.Maps(**kwargs)

Bases: collections.abc.MutableMapping

A Dictionary containing Map objects sharing the same geometry.

This class simplifies handling and I/O of maps collections.

For maps with different geometries, use a regular dict.

Attributes Summary

geom	Map geometry as a Geom object.

Methods Summary

clear()
from_geom(geom, names[, kwargs_list])	Create map dictionary from a geometry.
from_hdulist(hdulist[, hdu_bands])	Create map dictionary from a HDU list.
get(k[,d])
items()
keys()
pop(k[,d])	If key is not found, d is returned if given, otherwise KeyError is raised.
popitem()	as a 2-tuple; but raise KeyError if D is empty.
read(filename[, checksum])	Read map dictionary from file.
setdefault(k[,d])
to_hdulist([hdu_bands])	Convert map dictionary to list of HDUs.
update([E, ]**F)	If E present and has a .keys() method, does: for k in E: D[k] = E[k] If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v In either case, this is followed by: for k, v in F.items(): D[k] = v
values()
write(filename[, overwrite, checksum])	Write map dictionary to file.

Attributes Documentation

geom

Map geometry as a Geom object.

Methods Documentation

clear() → None.  Remove all items from D.

classmethod from_geom(geom, names, kwargs_list=None)

Create map dictionary from a geometry.

Parameters

geomGeom

The input geometry that will be used by all maps.

nameslist of str

The list of all map names.

kwargs_listlist of dict

the list of arguments to be passed to from_geom().

Returns

mapsMaps

Maps object.

classmethod from_hdulist(hdulist, hdu_bands='BANDS')

Create map dictionary from a HDU list.

Because FITS keywords are case-insensitive, all key names will return as lower-case.

Parameters

hdulistHDUList

List of HDUs.

hdu_bandsstr, optional

Name of the HDU with the BANDS table. If set to None, each map should have its own hdu_band. Default is ‘BANDS’.

Returns

mapsMaps

Maps object.

get(k[, d]) → D[k] if k in D, else d.  d defaults to None.

items() → a set-like object providing a view on D's items

keys() → a set-like object providing a view on D's keys

pop(k[, d]) → v, remove specified key and return the corresponding value.

If key is not found, d is returned if given, otherwise KeyError is raised.

popitem() → (k, v), remove and return some (key, value) pair

as a 2-tuple; but raise KeyError if D is empty.

classmethod read(filename, checksum=False)

Read map dictionary from file.

Because FITS keywords are case-insensitive, all key names will return as lower-case.

Parameters

filenamestr

Filename to read from.

Returns

mapsMaps

Maps object.

setdefault(k[, d]) → D.get(k,d), also set D[k]=d if k not in D

to_hdulist(hdu_bands='BANDS')

Convert map dictionary to list of HDUs.

Parameters

hdu_bandsstr, optional

Name of the HDU with the BANDS table. If set to None, each map will have its own hdu_band. Default is ‘BANDS’.

Returns

hdulistHDUList

Map dataset list of HDUs.

update([E, ]**F) → None.  Update D from mapping/iterable E and F.

If E present and has a .keys() method, does: for k in E: D[k] = E[k] If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v In either case, this is followed by: for k, v in F.items(): D[k] = v

values() → an object providing a view on D's values

write(filename, overwrite=False, checksum=False)

Write map dictionary to file.

Parameters

filenamestr

Filename to write to.

overwritebool, optional

Overwrite existing file. Default is False.

checksumbool, optional

When True adds both DATASUM and CHECKSUM cards to the headers written to the file. Default is False.