DataStore¶
-
class
gammapy.data.
DataStore
(hdu_table=None, obs_table=None)[source]¶ Bases:
object
IACT data store.
The data selection and access happens using an observation and an HDU index file as described at IACT data storage.
For a usage example see cta.html
- Parameters
- hdu_table
HDUIndexTable
HDU index table
- obs_table
ObservationTable
Observation index table
- hdu_table
Examples
Here’s an example how to create a
DataStore
to access H.E.S.S. data:>>> from gammapy.data import DataStore >>> data_store = DataStore.from_dir('$GAMMAPY_DATA/hess-dl3-dr1') >>> data_store.info()
Attributes Summary
Default HDU table filename.
Default observation table filename.
Methods Summary
check
([checks])Check index tables and data files.
copy_obs
(obs_id, outdir[, hdu_class, …])Create a new
DataStore
containing a subset of observations.from_dir
(base_dir[, hdu_table_filename, …])Create from a directory.
from_events_files
(paths)Create from a list of event filenames.
from_file
(filename[, hdu_hdu, hdu_obs])Create from a FITS file.
get_observations
([obs_id, skip_missing])Generate a
Observations
.info
([show])Print some info.
obs
(obs_id)Access a given
Observation
.Attributes Documentation
-
DEFAULT_HDU_TABLE
= 'hdu-index.fits.gz'¶ Default HDU table filename.
-
DEFAULT_OBS_TABLE
= 'obs-index.fits.gz'¶ Default observation table filename.
Methods Documentation
-
check
(checks='all')[source]¶ Check index tables and data files.
This is a generator that yields a list of dicts.
-
copy_obs
(obs_id, outdir, hdu_class=None, verbose=False, overwrite=False)[source]¶ Create a new
DataStore
containing a subset of observations.- Parameters
- obs_idarray-like,
ObservationTable
List of observations to copy
- outdirstr, Path
Directory for the new store
- hdu_classlist of str
- verbosebool
Print copied files
- overwritebool
Overwrite
- obs_idarray-like,
-
classmethod
from_dir
(base_dir, hdu_table_filename=None, obs_table_filename=None)[source]¶ Create from a directory.
- Parameters
- base_dirstr, Path
Base directory of the data files.
- hdu_table_filenamestr, Path
Filename of the HDU index file. May be specified either relative to
base_dir
or as an absolute path. If None, the default filename will be looked for.- obs_table_filenamestr, Path
Filename of the observation index file. May be specified either relative to
base_dir
or as an absolute path. If None, the default filename will be looked for.
-
classmethod
from_events_files
(paths)[source]¶ Create from a list of event filenames.
HDU and observation index tables will be created from the EVENTS header.
IRFs are found only if you have a
CALDB
environment variable set, and if the EVENTS files contain the following keys:TELESCOP
(example:TELESCOP = CTA
)CALDB
(example:CALDB = 1dc
)IRF
(example:IRF = South_z20_50h
)
This method is useful specifically if you want to load data simulated with ctobssim
Examples
This is how you can access a single event list:
from gammapy.data import DataStore path = "$GAMMAPY_DATA/cta-1dc/data/baseline/gps/gps_baseline_110380.fits" data_store = DataStore.from_events_files([path]) observations = data_store.get_observations()
You can now analyse this data as usual (see any Gammapy tutorial).
If you have multiple event files, you have to make the list. Here’s an example using
Path.glob
to get a list of all events files in a given folder:import os from pathlib import Path path = Path(os.environ["GAMMAPY_DATA"]) / "cta-1dc/data" paths = list(path.rglob("*.fits")) data_store = DataStore.from_events_files(paths) observations = data_store.get_observations()
Note that you have a lot of flexibility to select the observations you want, by having a few lines of custom code to prepare
paths
, or to select a subset via a method on thedata_store
or theobservations
objects.If you want to generate HDU and observation index files, write the tables to disk:
data_store.hdu_table.write("hdu-index.fits.gz") data_store.obs_table.write("obs-index.fits.gz")
-
classmethod
from_file
(filename, hdu_hdu='HDU_INDEX', hdu_obs='OBS_INDEX')[source]¶ Create from a FITS file.
The FITS file must contain both index files.
- Parameters
- filenamestr, Path
FITS filename
- hdu_hdustr or int
FITS HDU name or number for the HDU index table
- hdu_obsstr or int
FITS HDU name or number for the observation index table
-
get_observations
(obs_id=None, skip_missing=False)[source]¶ Generate a
Observations
.- Parameters
- obs_idlist
Observation IDs (default of
None
means “all”)- skip_missingbool, optional
Skip missing observations, default: False
- Returns
- observations
Observations
Container holding a list of
Observation
- observations
-
obs
(obs_id)[source]¶ Access a given
Observation
.- Parameters
- obs_idint
Observation ID.
- Returns
- observation
Observation
Observation container
- observation