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 A Library for Handling
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Description: 
 This function finds the distance between two points whose 
Frame
coordinates are given. The distance calculated is that along the geodesic curve that
joins the two points.
For example, in a basic Frame, the distance calculated will be the Cartesian distance
along the straight line joining the two points. For a more specialised Frame describing
a sky coordinate system, however, it would be the distance along the great circle
passing through two sky positions.  
Synopsis 
 double astDistance( AstFrame
this,
const double point1[], const double point2[] )  
 Parameters: 
  this  
 Pointer to the
Frame.  
  point1  
 An array of double, with one element for each Frame axis (
Naxes
attribute) containing the coordinates of the first point.  
 point2  
 An array of
double, with one element for each Frame axis containing the coordinates of the second
point.  
    Returned Value 
  astDistance  
 The distance between the two points.  
   
Notes: 
 
- 
This function will return a "bad"result value (AST__BAD) if any of the input
coordinates has this value.
 
- 
A "bad"value will also be returned if this function is invoked with the AST error
status set, or if it should fail for any reason.
 
  Copyright (C) 2021 East Asian Observatory
  -  ←Prev 
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 A Library for Handling
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Coordinate Systems
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