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DOUBLE PRECISION FUNCTION alnrel(a)
C-----------------------------------------------------------------------
C EVALUATION OF THE FUNCTION LN(1 + A)
C-----------------------------------------------------------------------
C .. Scalar Arguments ..
DOUBLE PRECISION a
C ..
C .. Local Scalars ..
DOUBLE PRECISION p1,p2,p3,q1,q2,q3,t,t2,w,x
C ..
C .. Intrinsic Functions ..
INTRINSIC abs,dble,dlog
C ..
C .. Data statements ..
DATA p1/-.129418923021993D+01/,p2/.405303492862024D+00/,
+ p3/-.178874546012214D-01/
DATA q1/-.162752256355323D+01/,q2/.747811014037616D+00/,
+ q3/-.845104217945565D-01/
C ..
C .. Executable Statements ..
C--------------------------
IF (abs(a).GT.0.375D0) GO TO 10
t = a/ (a+2.0D0)
t2 = t*t
w = (((p3*t2+p2)*t2+p1)*t2+1.0D0)/ (((q3*t2+q2)*t2+q1)*t2+1.0D0)
alnrel = 2.0D0*t*w
RETURN
C
10 x = 1.D0 + dble(a)
alnrel = dlog(x)
RETURN
END
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