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REAL FUNCTION sla_PAV ( V1, V2 )
*+
* - - - -
* P A V
* - - - -
*
* Position angle of one celestial direction with respect to another.
*
* (single precision)
*
* Given:
* V1 r(3) direction cosines of one point
* V2 r(3) direction cosines of the other point
*
* (The coordinate frames correspond to RA,Dec, Long,Lat etc.)
*
* The result is the bearing (position angle), in radians, of point
* V2 with respect to point V1. It is in the range +/- pi. The
* sense is such that if V2 is a small distance east of V1, the
* bearing is about +pi/2. Zero is returned if the two points
* are coincident.
*
* V1 and V2 do not have to be unit vectors.
*
* The routine sla_BEAR performs an equivalent function except
* that the points are specified in the form of spherical
* coordinates.
*
* Called: sla_DPAV
*
* Last revision: 11 September 2005
*
* Copyright P.T.Wallace. All rights reserved.
*
* License:
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see SLA_CONDITIONS); if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*
*-
IMPLICIT NONE
REAL V1(3), V2(3)
INTEGER I
DOUBLE PRECISION D1(3), D2(3)
DOUBLE PRECISION sla_DPAV
* Call the double precision version.
DO I=1,3
D1(I) = V1(I)
D2(I) = V2(I)
END DO
sla_PAV = REAL(sla_DPAV(D1,D2))
END
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