Name

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  angsep

Purpose

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  Compute the angular distance between two spherical coordinates.

Description

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Category

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  Mathematical

Calling Sequence

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  ans=angsep(ra1,dec1,ra2,dec2)

Inputs

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  ra1 - RA of first position (radians)
  dec1 - Dec of first position (radians)
  ra2 - RA of second position (radians)
  dec2 - Dec of second position (radians)

Optional Input Parameters

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Keyword Input Parameters

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Outputs

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  return value is the angular distance in radians.

Keyword Output Parameters

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Common Blocks

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Side Effects

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Restrictions

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Procedure

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Modification History

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  Written by Marc W. buie, Lowell Observatory, 1997/09/08
  2009/02/26, MWB, added protection against round off error generating NaN