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A Library for Handling
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Description:
This routine
returns a signed value representing the axis increment from axis value v1 to axis value
v2.
For a simple Frame, this is a trivial operation returning the difference between the two axis values. But
for other derived classes of Frame (such as a SkyFrame) this is not the case.
Invocation
RESULT =
AST_AXDISTANCE( THIS, AXIS, V1, V2, STATUS )
Arguments
THIS = INTEGER (Given)
Pointer
to the Frame.
AXIS = INTEGER (Given)
The index of the axis to which the supplied
values refer. The first axis has index 1.
V1 = DOUBLE PRECISION (Given)
The first
axis value.
V2 = DOUBLE PRECISION (Given)
The second axis value.
STATUS =
INTEGER (Given and Returned)
The global status.
Returned Value
AST_AXDISTANCE =
DOUBLE PRECISION
The distance from the first to the second axis value.
Notes:
-
This function will return a " bad" result value (AST__BAD) if any of the input values has this
value.
-
A " bad" value will also be returned if this function is invoked with STATUS set to an error value, or if
it should fail for any reason.
Copyright (C) 2021 East Asian Observatory
- ←Prev
- AST
A Library for Handling
World Coordinate
Systems
in Astronomy - Next→
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