astIntraMap

Create an IntraMap

Description:

This function creates a new IntraMap and optionally initialises its attributes.

An IntraMap is a specialised form of Mapping which encapsulates a privately-defined coordinate transformation function (e.g. written in C) so that it may be used like any other AST Mapping. This allows you to create Mappings that perform any conceivable coordinate transformation.

However, an IntraMap is intended for use within a single program or a private suite of software, where all programs have access to the same coordinate transformation functions (i.e. can be linked against them). IntraMaps should not normally be stored in datasets which may be exported for processing by other software, since that software will not have the necessary transformation functions available, resulting in an error.

You must register any coordinate transformation functions to be used using astIntraReg before creating an IntraMap.

Synopsis

AstIntraMap ∗astIntraMap( const char ∗name, int nin, int nout, const char ∗options, ... )

Parameters:

name
Pointer to a null-terminated string containing the name of the transformation function to use (which should previously have been registered using astIntraReg). This name is case sensitive. All white space will be removed before use.
nin
The number of input coordinates. This must be compatible with the number of input coordinates accepted by the transformation function (as specified when this function was registered using astIntraReg).
nout
The number of output coordinates. This must be compatible with the number of output coordinates produced by the transformation function (as specified when this function was registered using astIntraReg).
options
Pointer to a null-terminated string containing an optional comma-separated list of attribute assignments to be used for initialising the new IntraMap. The syntax used is identical to that for the astSet function and may include " printf" format specifiers identified by " %" symbols in the normal way.
...
If the " options" string contains " %" format specifiers, then an optional list of additional arguments may follow it in order to supply values to be substituted for these specifiers. The rules for supplying these are identical to those for the astSet function (and for the C " printf" function).

Returned Value

astIntraMap()
A pointer to the new IntraMap.

Notes:

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