 ←Prev
 AST
A Library for Handling
World Coordinate Systems
in Astronomy  Next→
 TOC ↑
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
$\ast $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) 2019 East Asian Observatory
 ←Prev
 AST
A Library for Handling
World
Coordinate Systems
in Astronomy  Next→
 TOC ↑