00001 SUBROUTINE CBUNK(Z, FNU, KODE, MR, N, Y, NZ, TOL, ELIM, ALIM) 00002 C***BEGIN PROLOGUE CBUNK 00003 C***REFER TO CBESK,CBESH 00004 C 00005 C CBUNK COMPUTES THE K BESSEL FUNCTION FOR FNU.GT.FNUL. 00006 C ACCORDING TO THE UNIFORM ASYMPTOTIC EXPANSION FOR K(FNU,Z) 00007 C IN CUNK1 AND THE EXPANSION FOR H(2,FNU,Z) IN CUNK2 00008 C 00009 C***ROUTINES CALLED CUNK1,CUNK2 00010 C***END PROLOGUE CBUNK 00011 COMPLEX Y, Z 00012 REAL ALIM, AX, AY, ELIM, FNU, TOL, XX, YY 00013 INTEGER KODE, MR, N, NZ 00014 DIMENSION Y(N) 00015 NZ = 0 00016 XX = REAL(Z) 00017 YY = AIMAG(Z) 00018 AX = ABS(XX)*1.7321E0 00019 AY = ABS(YY) 00020 IF (AY.GT.AX) GO TO 10 00021 C----------------------------------------------------------------------- 00022 C ASYMPTOTIC EXPANSION FOR K(FNU,Z) FOR LARGE FNU APPLIED IN 00023 C -PI/3.LE.ARG(Z).LE.PI/3 00024 C----------------------------------------------------------------------- 00025 CALL CUNK1(Z, FNU, KODE, MR, N, Y, NZ, TOL, ELIM, ALIM) 00026 GO TO 20 00027 10 CONTINUE 00028 C----------------------------------------------------------------------- 00029 C ASYMPTOTIC EXPANSION FOR H(2,FNU,Z*EXP(M*HPI)) FOR LARGE FNU 00030 C APPLIED IN PI/3.LT.ABS(ARG(Z)).LE.PI/2 WHERE M=+I OR -I 00031 C AND HPI=PI/2 00032 C----------------------------------------------------------------------- 00033 CALL CUNK2(Z, FNU, KODE, MR, N, Y, NZ, TOL, ELIM, ALIM) 00034 20 CONTINUE 00035 RETURN 00036 END
1.7.1
