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SUBROUTINE sla_DCC2S (V, A, B)
*+
* - - - - - -
* D C C 2 S
* - - - - - -
*
* Direction cosines to spherical coordinates (double precision)
*
* Given:
* V d(3) x,y,z vector
*
* Returned:
* A,B d spherical coordinates in radians
*
* The spherical coordinates are longitude (+ve anticlockwise
* looking from the +ve latitude pole) and latitude. The
* Cartesian coordinates are right handed, with the x axis
* at zero longitude and latitude, and the z axis at the
* +ve latitude pole.
*
* If V is null, zero A and B are returned.
* At either pole, zero A is returned.
*
* P.T.Wallace Starlink July 1989
*
* Copyright (C) 1995 Rutherford Appleton Laboratory
*-
IMPLICIT NONE
DOUBLE PRECISION V(3),A,B
DOUBLE PRECISION X,Y,Z,R
X = V(1)
Y = V(2)
Z = V(3)
R = SQRT(X*X+Y*Y)
IF (R.EQ.0D0) THEN
A = 0D0
ELSE
A = ATAN2(Y,X)
END IF
IF (Z.EQ.0D0) THEN
B = 0D0
ELSE
B = ATAN2(Z,R)
END IF
END
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