CadcClass

class astroquery.cadc.CadcClass(url=None, tap_plus_handler=None, verbose=None)[source]

Bases: astroquery.query.BaseQuery

Class for accessing CADC data. Typical usage:

result = Cadc.query_region(‘08h45m07.5s +54d18m00s’, collection=’CFHT’)

… do something with result (optional) such as filter as in example below

urls = Cadc.get_data_urls(result[result[‘target_name’]==’Nr3491_1’])

… access data

Other ways to query the CADC data storage:

  • target name:
    Cadc.query_region(SkyCoord.from_name(‘M31’))
  • target name in the metadata:
    Cadc.query_name(‘M31-A-6’) # queries as a like ‘%lower(name)%’
  • TAP query on the CADC metadata (CAOM2 format -
    http://www.opencadc.org/caom2/) Cadc.get_tables() # list the tables Cadc.get_table(table_name) # list table schema Cadc.query

Initialize Cadc object

Parameters:

url : str, optional, default ‘None;

a url to use instead of the default

tap_plus_handler : deprecated

verbose : deprecated

Returns:

Cadc object

Attributes Summary

CADCDATALINK_SERVICE_URI
CADCLOGIN_SERVICE_URI
CADCTAP_SERVICE_URI
CADC_REGISTRY_URL
TIMEOUT
cadctap
data_link_url

Methods Summary

create(*args, **kwargs) Queries the service and returns a table object.
create_async(query[, maxrec, uploads]) Creates a TAP job to execute and returns it to the caller.
exec_sync(query[, maxrec, uploads, output_file]) Run a query and return the results or save them in a output_file
get_collections() Query CADC for all the hosted collections
get_data_urls(query_result[, …]) Function to map the results of a CADC query into URLs to corresponding data that can be later downloaded.
get_image_list(query_result, coordinates, radius) Function to map the results of a CADC query into URLs to corresponding data and cutouts that can be later downloaded.
get_images(coordinates, radius[, …]) A coordinate-based query function that returns a list of fits files with cutouts around the passed in coordinates.
get_images_async(coordinates, radius[, …]) A coordinate-based query function that returns a list of context managers with cutouts around the passed in coordinates.
get_table(table[, verbose]) Gets the specified table
get_tables([only_names, verbose]) Gets all public tables
list_async_jobs([verbose]) Returns all the asynchronous jobs
list_jobs(*args, **kwargs) Queries the service and returns a table object.
load_async_job(jobid[, verbose]) Loads an asynchronous job
load_job(*args, **kwargs) Queries the service and returns a table object.
login([user, password, certificate_file]) Login, set varibles to use for logging in
logout([verbose]) Logout
query_name(*args, **kwargs) Queries the service and returns a table object.
query_name_async(name) Query CADC metadata for a name and return the corresponding metadata in
query_region(*args, **kwargs) Queries the service and returns a table object.
query_region_async(coordinates[, radius, …]) Queries the CADC for a region around the specified coordinates.
run_query(query, operation[, output_file, …])

Deprecated since version 0.4.0.

Attributes Documentation

CADCLOGIN_SERVICE_URI = 'ivo://cadc.nrc.ca/gms'
CADCTAP_SERVICE_URI = 'ivo://cadc.nrc.ca/argus'
CADC_REGISTRY_URL = 'http://www.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/reg/resource-caps'
TIMEOUT = 30
cadctap

Methods Documentation

create(*args, **kwargs)

Queries the service and returns a table object.

Creates a TAP job to execute and returns it to the caller. The caller then can start the execution and monitor the job. Typical (no error handling) sequence of events:

job = create_async(query) job = job.run().wait() job.raise_if_error() result = job.fetch_result() job.delete() # optional

See pyvo.dal.tap for details about the AsyncTAPJob

Parameters:

query : str, mandatory

SQL to execute

maxrec : int

the maximum records to return. defaults to the service default

uploads:

Temporary tables to upload and run with the queries

output_file: str or file handler:

File to save the results to

Returns:

table : A Table object.

Notes

Support for other output formats (tsv, csv) to be added as soon as they are available in pyvo.

create_async(query, maxrec=None, uploads=None)[source]

Creates a TAP job to execute and returns it to the caller. The caller then can start the execution and monitor the job. Typical (no error handling) sequence of events:

job = create_async(query) job = job.run().wait() job.raise_if_error() result = job.fetch_result() job.delete() # optional

See pyvo.dal.tap for details about the AsyncTAPJob

Parameters:

query : str, mandatory

SQL to execute

maxrec : int

the maximum records to return. defaults to the service default

uploads:

Temporary tables to upload and run with the queries

output_file: str or file handler:

File to save the results to

Returns:

AsyncTAPJob

the query instance

Notes

Support for other output formats (tsv, csv) to be added as soon as they are available in pyvo.

exec_sync(query, maxrec=None, uploads=None, output_file=None)[source]

Run a query and return the results or save them in a output_file

Parameters:

query : str, mandatory

SQL to execute

maxrec : int

the maximum records to return. defaults to the service default

uploads:

Temporary tables to upload and run with the queries

output_file: str or file handler:

File to save the results to

Returns:

Results of running the query in (for now) votable format

Notes

Support for other output formats (tsv, csv) to be added as soon as they are available in pyvo.

get_collections()[source]

Query CADC for all the hosted collections

Returns:

A dictionary of collections hosted at the CADC where the key is the

collection and value represents details of that collection.

get_data_urls(query_result, include_auxiliaries=False)[source]

Function to map the results of a CADC query into URLs to corresponding data that can be later downloaded.

The function uses the IVOA DataLink Service (http://www.ivoa.net/documents/DataLink/) implemented at the CADC. It works directly with the results produced by query_region and query_name but in principle it can work with other query results produced with the Cadc query as long as the results contain the ‘publisherID’ column. This column is part of the ‘caom2.Plane’ table.

Parameters:

query_result : A Table object

Result returned by query_region or query_name. In general, the result of any CADC TAP query that contains the ‘publisherID’ column can be use here.

include_auxiliaries : boolean

True to return URLs to auxiliary files such as previews, False otherwise

Returns:

A list of URLs to data.

get_image_list(query_result, coordinates, radius)[source]

Function to map the results of a CADC query into URLs to corresponding data and cutouts that can be later downloaded.

The function uses the IVOA DataLink Service (http://www.ivoa.net/documents/DataLink/) implemented at the CADC. It works directly with the results produced by query_region and query_name but in principle it can work with other query results produced with the Cadc query as long as the results contain the ‘publisherID’ column. This column is part of the ‘caom2.Plane’ table.

Parameters:

query_result : A Table object

Result returned by query_region or query_name. In general, the result of any CADC TAP query that contains the ‘publisherID’ column can be used here.

coordinates : str or astropy.coordinates.

Center of the cutout area.

radius : str or astropy.units.Quantity.

The radius of the cutout area.

Returns:

list : A list of URLs to cutout data.

get_images(coordinates, radius, collection=None, get_url_list=False, show_progress=False)[source]

A coordinate-based query function that returns a list of fits files with cutouts around the passed in coordinates.

Parameters:

coordinates : str or astropy.coordinates.

Coordinates around which to query.

radius : str or astropy.units.Quantity

The radius of the cone search AND cutout area.

collection : str, optional

Name of the CADC collection to query.

get_url_list : bool, optional

If True, returns the list of data urls rather than the downloaded FITS files. Default is False.

show_progress : bool, optional

Whether to display a progress bar if the file is downloaded from a remote server. Default is False.

Returns:

list : A list of HDUList objects (or a list of

str if returning urls).

get_images_async(coordinates, radius, collection=None, get_url_list=False, show_progress=False)[source]

A coordinate-based query function that returns a list of context managers with cutouts around the passed in coordinates.

Parameters:

coordinates : str or astropy.coordinates.

Coordinates around which to query.

radius : str or astropy.units.Quantity

The radius of the cone search AND cutout area.

collection : str, optional

Name of the CADC collection to query.

get_url_list : bool, optional

If True, returns the list of data urls rather than the list of context managers. Default is False.

show_progress : bool, optional

Whether to display a progress bar if the file is downloaded from a remote server. Default is False.

Returns:

list : A list of context-managers that yield readable file-like objects

get_table(table, verbose=None)[source]

Gets the specified table

Parameters:

table : str, mandatory

full qualified table name (i.e. schema name + table name)

verbose : deprecated

Returns:

A table object

get_tables(only_names=False, verbose=None)[source]

Gets all public tables

Parameters:

only_names : bool, optional, default False

True to load table names only

verbose : deprecated

Returns:

A list of table objects

list_async_jobs(verbose=None)[source]

Returns all the asynchronous jobs

Parameters:verbose : deprecated
Returns:A list of Job objects
list_jobs(*args, **kwargs)

Queries the service and returns a table object.

Returns all the asynchronous jobs

Parameters:verbose : deprecated
Returns:table : A Table object.
load_async_job(jobid, verbose=None)[source]

Loads an asynchronous job

Parameters:

jobid : str, mandatory

job identifier

verbose : deprecated

Returns:

A Job object

load_job(*args, **kwargs)

Queries the service and returns a table object.

Loads an asynchronous job

Parameters:

jobid : str, mandatory

job identifier

verbose : deprecated

Returns:

table : A Table object.

login(user=None, password=None, certificate_file=None)[source]

Login, set varibles to use for logging in

Parameters:

user : str, required if certificate is None

username to login with

password : str, required if user is set

password to login with

certificate : str, required if user is None

path to certificate to use with logging in

Notes

This will soon be deprecated as it does not make sense to login with certificates.

logout(verbose=None)[source]

Logout

Parameters:verbose : deprecated

Notes

This method will soon be deprecated as it doesn’t make sense to login and logout with certificates.

query_name(*args, **kwargs)

Queries the service and returns a table object.

Query CADC metadata for a name and return the corresponding metadata in
the CAOM2 format (http://www.opencadc.org/caom2/).
Parameters:

name: str

name of object to query for

Returns:

table : A Table object.

query_name_async(name)[source]
Query CADC metadata for a name and return the corresponding metadata in
the CAOM2 format (http://www.opencadc.org/caom2/).
Parameters:

name: str

name of object to query for

Returns:

response : Table

Results of the query in a tabular format.

query_region(*args, **kwargs)

Queries the service and returns a table object.

Queries the CADC for a region around the specified coordinates.

Parameters:

coordinates : str or astropy.coordinates.

coordinates around which to query

radius : str or astropy.units.Quantity.

the radius of the cone search

collection: Name of the CADC collection to query, optional

get_query_payload : bool, optional

Just return the dict of HTTP request parameters.

Returns:

table : A Table object.

query_region_async(coordinates, radius=<Quantity 0.01666667 deg>, collection=None, get_query_payload=False)[source]

Queries the CADC for a region around the specified coordinates.

Parameters:

coordinates : str or astropy.coordinates.

coordinates around which to query

radius : str or astropy.units.Quantity.

the radius of the cone search

collection: Name of the CADC collection to query, optional

get_query_payload : bool, optional

Just return the dict of HTTP request parameters.

Returns:

response : requests.Response

The HTTP response returned from the service. All async methods should return the raw HTTP response.

run_query(query, operation, output_file=None, output_format='votable', verbose=None, background=False, upload_resource=None, upload_table_name=None)[source]

Deprecated since version 0.4.0: Use exec_sync or create_async instead

Runs a query

Parameters:

query : str, mandatory

query to be executed

operation : str, mandatory,

‘sync’ or ‘async’ to run a synchronous or asynchronous job

output_file : str, optional, default None

file name where the results are saved if dumpToFile is True. If this parameter is not provided, the jobid is used instead

output_format : str, optional, default ‘votable’

results format, ‘csv’, ‘tsv’ and ‘votable’

verbose : deprecated

save_to_file : bool, optional, default ‘False’

if True, the results are saved in a file instead of using memory

background : bool, optional, default ‘False’

when the job is executed in asynchronous mode, this flag specifies whether the execution will wait until results are available

upload_resource: str, optional, default None

resource to be uploaded to UPLOAD_SCHEMA

upload_table_name: str, required if uploadResource is provided,

default None resource temporary table name associated to the uploaded resource

Returns:

A Job object