Parameters

Parameters are items of information which apply to the entire catalogue. Examples are the equinox or epoch of the celestial coordinates in the catalogue. The attributes of a parameter are given in Table . In CAT version 8.1 parameters must be scalars. However, they have the attributes dimensionality and size to allow for the possibility of vector parameters in future versions of CAT.

Table: Attributes of parameters

Attribute	Name	Data	Mand-	Default
		type	-atory
Name	NAME	_CHAR	$\bullet$
Data type	DTYPE	_INTEGER	$\bullet$
Character size	CSIZE	_INTEGER		CAT__SZVAL
Dimensionality	DIMS	_INTEGER		scalar: CAT__SCALR
Size§	SIZE	_INTEGER		1
Units	UNITS	_CHAR		` '
External format	EXFMT	_CHAR		varies with data type
Preferential display	PRFDSP	_LOGICAL		true
Comments	COMM	_CHAR		` '
Value	VALUE	varies		zero or ` '
Modification date	DATE	_DOUBLE		0.0D0

The size of character strings; other data types have CSIZE = 0.

§

SIZE is a single-element array, not a scalar.

All these attributes, except VALUE, are deliberately identical to the corresponding attributes for columns (see Table  and Section , above, for details).