36 lines
1.3 KiB
FortranFixed
36 lines
1.3 KiB
FortranFixed
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SUBROUTINE ZBUNK(ZR, ZI, FNU, KODE, MR, N, YR, YI, NZ, TOL, ELIM,
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* ALIM)
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C***BEGIN PROLOGUE ZBUNK
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C***REFER TO ZBESK,ZBESH
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C
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C ZBUNK COMPUTES THE K BESSEL FUNCTION FOR FNU.GT.FNUL.
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C ACCORDING TO THE UNIFORM ASYMPTOTIC EXPANSION FOR K(FNU,Z)
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C IN ZUNK1 AND THE EXPANSION FOR H(2,FNU,Z) IN ZUNK2
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C
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C***ROUTINES CALLED ZUNK1,ZUNK2
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C***END PROLOGUE ZBUNK
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C COMPLEX Y,Z
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DOUBLE PRECISION ALIM, AX, AY, ELIM, FNU, TOL, YI, YR, ZI, ZR
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INTEGER KODE, MR, N, NZ
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DIMENSION YR(N), YI(N)
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NZ = 0
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AX = DABS(ZR)*1.7321D0
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AY = DABS(ZI)
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IF (AY.GT.AX) GO TO 10
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C-----------------------------------------------------------------------
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C ASYMPTOTIC EXPANSION FOR K(FNU,Z) FOR LARGE FNU APPLIED IN
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C -PI/3.LE.ARG(Z).LE.PI/3
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C-----------------------------------------------------------------------
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CALL ZUNK1(ZR, ZI, FNU, KODE, MR, N, YR, YI, NZ, TOL, ELIM, ALIM)
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GO TO 20
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10 CONTINUE
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C-----------------------------------------------------------------------
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C ASYMPTOTIC EXPANSION FOR H(2,FNU,Z*EXP(M*HPI)) FOR LARGE FNU
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C APPLIED IN PI/3.LT.ABS(ARG(Z)).LE.PI/2 WHERE M=+I OR -I
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C AND HPI=PI/2
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C-----------------------------------------------------------------------
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CALL ZUNK2(ZR, ZI, FNU, KODE, MR, N, YR, YI, NZ, TOL, ELIM, ALIM)
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20 CONTINUE
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RETURN
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END
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