### AST_CMPFRAME

Create a CmpFrame

#### Description:

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

A CmpFrame is a compound Frame which allows two component Frames (of any class) to be merged together to form a more complex Frame. The axes of the two component Frames then appear together in the resulting CmpFrame (those of the first Frame, followed by those of the second Frame).

Since a CmpFrame is itself a Frame, it can be used as a component in forming further CmpFrames. Frames of arbitrary complexity may be built from simple individual Frames in this way.

Also since a Frame is a Mapping, a CmpFrame can also be used as a Mapping. Normally, a CmpFrame is simply equivalent to a UnitMap, but if either of the component Frames within a CmpFrame is a Region (a sub-class of Frame), then the CmpFrame will use the Region as a Mapping when transforming values for axes described by the Region. Thus input axis values corresponding to positions which are outside the Region will result in bad output axis values.

#### Invocation

RESULT = AST_CMPFRAME( FRAME1, FRAME2, OPTIONS, STATUS )

#### Arguments

##### FRAME1 = INTEGER (Given)
Pointer to the first component Frame.
##### FRAME2 = INTEGER (Given)
Pointer to the second component Frame.
##### OPTIONS = CHARACTER $\ast$ ( $\ast$ ) (Given)
A character string containing an optional comma-separated list of attribute assignments to be used for initialising the new CmpFrame. The syntax used is identical to that for the AST_SET routine.
##### STATUS = INTEGER (Given and Returned)
The global status.

#### Returned Value

##### AST_CMPFRAME = INTEGER
A pointer to the new CmpFrame.

#### Notes:

• A null Object pointer (AST__NULL) will be returned if this function is invoked with STATUS set to an error value, or if it should fail for any reason.

#### Status Handling

The protected interface to this function includes an extra parameter at the end of the parameter list descirbed above. This parameter is a pointer to the integer inherited status variable: " int $\ast$status" .