SIAQuery

class pyvo.dal.SIAQuery(baseurl, pos=None, *, size=None, format=None, intersect=None, verbosity=None, session=None, **keywords)

Bases: DALQuery

a class for preparing an query to an SIA service. Query constraints are added via its service type-specific methods. The various execute() functions will submit the query and return the results.

The base URL for the query, which controls where the query will be sent when one of the execute functions is called, is typically set at construction time; however, it can be updated later via the baseurl to send a configured query to another service.

In addition to the search constraint attributes described below, search parameters can be set generically by name via dict semantics.

The typical function for submitting the query is execute(); however, alternate execute functions provide the response in different forms, allowing the caller to take greater control of the result processing.

initialize the query object with a baseurl and the given parameters

Parameters:

baseurlstr

the base URL for the SIA service

posSkyCoord class or sequence of two floats

the position of the center of the rectangular search region. assuming icrs decimal degrees if unit is not specified.

sizeQuantity class or up to 2 floats.

the full rectangular size of the search region along the RA and Dec directions. converted if it’s a iterable containing scalars, assuming decimal degrees.

sizeQuantity class or scalar float

the size of the rectangular region around pos. assuming icrs decimal degrees if unit is not specified.

formatstr

the image format(s) of interest. “all” (server-side default) indicates all available formats; “graphic” indicates graphical images (e.g. jpeg, png, gif; not FITS); “metadata” indicates that no images should be returned–only an empty table with complete metadata; “image/*” indicates a particular image format where * can have values like “fits”, “jpeg”, “png”, etc.

intersectstr

a token indicating how the returned images should intersect with the search region; recognized values include:

COVERS	select images that completely cover the search region
ENCLOSED	select images that are complete enclosed by the region
OVERLAPS	select any image that overlaps the search region (server-side default)
CENTER	select images whose center is within the search region

verbosityint

an integer value that indicates the volume of columns to return in the result table. 0 means the minimum set of columsn, 3 means as many columns as are available.

sessionobject

optional session to use for network requests

**keywords

additional parameters can be given via arbitrary case insensitive keyword arguments. Where there is overlap with the parameters set by the other arguments to this function, these keywords will override.

Attributes Summary

format	the image format(s) of interest.
intersect	a token indicating how the returned images should intersect with the search region; recognized values include:
pos	the position of the center of the rectangular search region as a SkyCoord instance.
size	the size of the rectangular region around pos as a Quantity instance.
verbosity	an integer value that indicates the volume of columns to return in the result table.

Methods Summary

execute()

submit the query and return the results as a SIAResults instance

Attributes Documentation

format

the image format(s) of interest. “all” (default) indicates all available formats; “graphic” indicates graphical images (e.g. jpeg, png, gif; not FITS); “metadata” indicates that no images should be returned–only an empty table with complete metadata; “image/*” indicates a particular image format where * can have values like “fits”, “jpeg”, “png”, etc.

intersect

a token indicating how the returned images should intersect with the search region; recognized values include:

COVERS	select images that completely cover the search region
ENCLOSED	select images that are complete enclosed by the region
OVERLAPS	select any image that overlaps with the search region
CENTER	select images whose center is within the search region

pos

the position of the center of the rectangular search region as a SkyCoord instance.

size

the size of the rectangular region around pos as a Quantity instance.

verbosity

an integer value that indicates the volume of columns to return in the result table. 0 means the minimum set of columsn, 3 means as many columns as are available.

Methods Documentation

execute()

submit the query and return the results as a SIAResults instance

Raises:

DALServiceError

for errors connecting to or communicating with the service

DALQueryError

for errors either in the input query syntax or other user errors detected by the service

DALFormatError

for errors parsing the VOTable response