Utils

JointConfig

class vtspy.JointConfig(files=None, config_file='config.yaml', verbosity=1, **kwargs)

Bases: object

This is to generate the configuration file compatible to the Fermipy configuration. The input file is the VERITAS event file from EventDisplay. The format can be either `.root’ or `.fits’.

Parameters

  • files (str) – a input file or directory containing root or fits files (root or fits)

  • config_file (str) – Fermi config filename (yaml) Default: config.yaml

  • verbosity (int) –

  • **kwargs – passed to JointConfig.init

change_time_interval(tmin, tmax, scale='utc', instrument='all')

Change and update a time interval

Args: tmin (float or str): start time tmax (float or str): end time scale (str): “utc”, “mjd”, or “met”

Default: “utc”

instrument (str): “fermi”, “veritas”, or “all”

Default: “all”

static get_config(config_file='config.yaml')

Read a config file.

Parameters

config_file (str) – Fermi config filename (yaml) Default: config.yaml

init(files=None, config_file='config.yaml', **kwargs)

Generate a default configuration file :param files: a input file or directory containing :type files: str :param root or fits files: :type root or fits files: root or fits

config_file (str): Fermi config filename (yaml)

Default: config.yaml fermi_outdir (str): path to the Fermi-LAT output directory Default: ./fermi/

fermi_data (str): path to the Fermi-LAT data directory

Default: ./fermi/

veritas_outdir (str): path to the VERITAS output directory

Default: ./veritas/ veritas_data (str): path to the VERITAS data directory Default: ./veritas/

joint_outdir (str): path to the joint-fit output directory

Default: ./joint/

**kwargs

classmethod print_config(config_file='config.yaml')

print a config file.

Parameters

config_file (str) – Fermi config filename (yaml) Default: config.yaml

static set_config(info, config_file='config.yaml')

Write inputs into a config file.

Parameters

  • info (dict) – overwrite the input info into a config file

  • config_file (str) – Fermi config filename (yaml) Default: config.yaml

classmethod update_config(info, instrument, config_file='config.yaml')

Update a config file.

Parameters

  • info (dict) – update info in a config file

  • instrument (str) – either fermi or veritas

  • config_file (str) – Fermi config filename (yaml) Default: config.yaml

DownloadFermiData

class vtspy.DownloadFermiData(config_file='config.yaml', dtype='Photon', verbosity=1)

Bases: object

manual_download(address=None)

When an error occurs, one can manually download the data

Parameters

address (str, optional) – address to the Fermi-LAT data page.

Others

vtspy.utils.CEL2GAL(ra, dec)

Convert CEL (celestial) coordinates to GAL (galactic) coordinates.

Parameters

  • ra (float) – right ascension in degrees

  • dec (float) – declination in degrees

Returns

deg, deg

vtspy.utils.GAL2CEL(l, b)

Convert MJD (Modified Julian Day) to UTC.

Parameters

mjd (astorpy.time) – MJD time

Returns

UTC

Return type

astropy.time

vtspy.utils.LiMaSiginficance(N_on, N_off, alpha, type=1)

Calculate the Li&Ma significance

Parameters

  • N_on (int) – the number of events from the ON region

  • N_off (int) – the number of events from the OFF region

  • alpha (float) – the relative exposure time

  • type (int) – method for calculating signficance 1: Li&MA, 2: chisq Default: 1

Return

float: Li&Ma significance

vtspy.utils.MET2UTC(met, return_astropy=False)

Convert Fermi MET (Mission Elapsed Time) to UTC (Coordinated Universal Time).

Parameters

  • met (float) – MET time in seconds

  • return_astropy (bool) – return astropy.time

Returns

UTC time

Return type

str, astropy.time (optional)

vtspy.utils.METnow()

Return the current MET.

Returns

Fermi MET

Return type

float

vtspy.utils.MJD2UTC(mjd, return_astropy=False)

Convert MJD (Modified Julian Day) to UTC.

Parameters

  • mjd (astorpy.time) – MJD time

  • return_astropy (bool) – return astropy.time

Returns

UTC time

Return type

str, astropy.time (optional)

vtspy.utils.UTC2MET(utc)

Convert UTC to Fermi MET (mission elapsed time).

Parameters

utc (astorpy.time) – UTC time

Returns

MET

Return type

float

vtspy.utils.UTC2MJD(utc)

Convert UTC to MJD.

Parameters

mjd (astorpy.time) – MJD time

Returns

MJD

Return type

float

vtspy.utils.bright_source_list(source, save_npy=True)
vtspy.utils.convertROOT2fits(files, eff, **kwargs)
vtspy.utils.define_time_intervals(tmin, tmax, binsz=None, nbins=None)

Define time intervals by either a bin size or the number of bins

Parameters

  • tmin (float) – minimum time

  • tmax (float) – maximum time

  • binsz (astropy.Quantity, optional) – bin size with astropy.units

  • nbins (int, optional) – the number of bins

Returns

time interval (astropy.Time)

Return type

list

vtspy.utils.generatePHA(config)
vtspy.utils.generatePSF(config, **kwargs)
vtspy.utils.generateRSP(config)
vtspy.utils.logger(verbosity=1)

Set a log level:

  • 1: info, warning, error

  • 2: debug, info, warning, error

  • 0: warning, error

  • -1: error

Parameters

verbosity (int) – Default: 1

Returns

UTC time

Return type

astorpy.time

vtspy.utils.time_filter(obs, time, time_format=None)

Filter the observations by time

Parameters

  • obs (gammapy.observations) – the list of observations

  • time (list) – the list of times

  • time_format (str, optional) – passed to astropy.Time