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SUBROUTINE sla_DVN (V, UV, VM)
*+
* - - - -
* D V N
* - - - -
*
* Normalizes a 3-vector also giving the modulus (double precision)
*
* Given:
* V dp(3) vector
*
* Returned:
* UV dp(3) unit vector in direction of V
* VM dp modulus of V
*
* If the modulus of V is zero, UV is set to zero as well
*
* P.T.Wallace Starlink 23 November 1995
*
* Copyright (C) 1995 Rutherford Appleton Laboratory
*-
IMPLICIT NONE
DOUBLE PRECISION V(3),UV(3),VM
INTEGER I
DOUBLE PRECISION W1,W2
* Modulus
W1=0D0
DO I=1,3
W2=V(I)
W1=W1+W2*W2
END DO
W1=SQRT(W1)
VM=W1
* Normalize the vector
IF (W1.LE.0D0) W1=1D0
DO I=1,3
UV(I)=V(I)/W1
END DO
END
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