Package gavo :: Package stc :: Module dm

Module dm

Definition of the structure of the internal representation (the AST).

For now, we want to be able to capture what STC-S can do (and a bit more). This means that we do not support generic coordinates (yet), elements, xlink and all the other stuff.

Classes
	RefPos is a reference position.
	TimeFrame
	SpaceFrame
	SpectralFrame
	RedshiftFrame
	CoordSys is an astronomical coordinate system.
	SpectralType
	TimeType
	SpaceType
	RedshiftType
	VelocityType
	CooWiggle A wiggle given in coordinates.
	RadiusWiggle An wiggle given as a radius.
	MatrixWiggle A matrix for specifying wiggle.
	SpaceCoo
	VelocityCoo
	RedshiftCoo
	TimeCoo
	SpectralCoo
	SpaceInterval
	PositionInterval
	VelocityInterval
	RedshiftInterval
	TimeInterval
	SpectralInterval
	AllSky
	Circle
	Ellipse
	Box
	Polygon
	Convex
	Union
	Intersection
	Difference
	Not
	STCSpec is an STC specification, i.e., the root of an STC tree.

Functions

binarizeCompound(compound)
returns compound as a binary tree.

source code

debinarizeCompound(compound)
returns compound with flattened operators.

source code

fromPgSphere(refFrame, pgGeom)
Returns an AST for a pgsphere object as defined in utils.pgsphere.

source code

Variables
	NullRefPos = `<RefPos >`
	__package__ = `'gavo.stc'`

Function Details

binarizeCompound(compound)

source code

returns compound as a binary tree.

For unions and intersections, compounds consisting of more than two operands will be split up into parts of two arguments each.

fromPgSphere(refFrame, pgGeom)

source code

Returns an AST for a pgsphere object as defined in utils.pgsphere.

This interprets the pgSphere box as a coordinate interval, which is wrong but probably what most VO protocols expect.