17 lines
472 B
Fortran
17 lines
472 B
Fortran
C $Id: LEGND0.f,v 1.1 2009/06/09 21:51:53 daven Exp $
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SUBROUTINE LEGND0 (X,PL,N)
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C---Calculates ORDINARY LEGENDRE fns of X (real)
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C--- from P[0] = PL(1) = 1, P[1] = X, .... P[N-1] = PL(N)
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IMPLICIT NONE
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INTEGER N,I
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REAL*8 X,PL(N),DEN
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C---Always does PL(2) = P[1]
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PL(1) = 1.D0
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PL(2) = X
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DO I=3,N
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DEN = (I-1)
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PL(I) = PL(I-1)*X*(2.d0-1.D0/DEN) - PL(I-2)*(1.d0-1.D0/DEN)
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ENDDO
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RETURN
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END
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