Package gavo :: Package protocols :: Module soda

Module soda

Helper functions for SODA manipulators.

This primarily comprises various WCS helpers. It is built on base.coords, which is where you'll get the wcsFields.

Note that this must not use things from protocols.datalink, as it is imported from there. Essentially, use this space for helpers for SODA manipulations that are generic enough to be kept outside of the RD but not generic enough to go do base.coords.

Classes
	EmptyData raise this when you notice you won't have any data to return.
	DatalinkFault A datalink error ("fault", as it's called in the spec).
	FormatNow can be raised by data functions to abort all further processing and format the current descriptor.data.
	DeliverNow can be raised by data functions to abort all further processing and return the current descriptor.data to the client.

Functions

ensureSkyWCS(descriptor)
furnishes a soda fits descriptor with skyWCS and spatialAxes attributes if necessary.

source code

iterSpatialAxisKeys(descriptor, axisMetaOverrides)
yields SODA inputKeys for spatial cutouts along the spatial coordinate axes.

source code

iterOtherAxisKeys(descriptor, axisMetaOverrides)
yields inputKeys for all non-spatial WCS axes.

source code

addPolygonSlices(descriptor, poly, srcPar='Unknown')
adds slicings in descriptor.slices for a pgsphere.SPoly poly. source code

doAxisCutout(descriptor, args)
updates descriptor.data on a FITS descriptor, interpreting the parameters defined by iter*AxisKeys, passed in in args.

source code

Variables
	DEFAULT_SEMANTICS = `'http://dc.g-vo.org/datalink#other'`
	__package__ = `'gavo.protocols'`

Function Details

ensureSkyWCS(descriptor)

source code

furnishes a soda fits descriptor with skyWCS and spatialAxes attributes if necessary.

This is usually called by the functions needing this automatically, and it's a no-op if it has already run.

skyWCS will be None after this function as run if no usable WCS is found; otherwise, it will be a astropy.wcs.WCS instance. Additionally, spatialAxes will be a sequence of 1-based axis indices, and an empty dictionary axisNames is available to be filled by metaMakers. It will then map the SODA parameter name to either a FITS axis index or to the special WCSLONG, WCSLAT values.