*DECK CBUNK SUBROUTINE CBUNK (Z, FNU, KODE, MR, N, Y, NZ, TOL, ELIM, ALIM) C***BEGIN PROLOGUE CBUNK C***SUBSIDIARY C***PURPOSE Subsidiary to CBESH and CBESK C***LIBRARY SLATEC C***TYPE ALL (CBUNK-A, ZBUNK-A) C***AUTHOR Amos, D. E., (SNL) C***DESCRIPTION C C CBUNK COMPUTES THE K BESSEL FUNCTION FOR FNU.GT.FNUL. C ACCORDING TO THE UNIFORM ASYMPTOTIC EXPANSION FOR K(FNU,Z) C IN CUNK1 AND THE EXPANSION FOR H(2,FNU,Z) IN CUNK2 C C***SEE ALSO CBESH, CBESK C***ROUTINES CALLED CUNK1, CUNK2 C***REVISION HISTORY (YYMMDD) C 830501 DATE WRITTEN C 910415 Prologue converted to Version 4.0 format. (BAB) C***END PROLOGUE CBUNK COMPLEX Y, Z REAL ALIM, AX, AY, ELIM, FNU, TOL, XX, YY INTEGER KODE, MR, N, NZ DIMENSION Y(N) C***FIRST EXECUTABLE STATEMENT CBUNK NZ = 0 XX = REAL(Z) YY = AIMAG(Z) AX = ABS(XX)*1.7321E0 AY = ABS(YY) IF (AY.GT.AX) GO TO 10 C----------------------------------------------------------------------- C ASYMPTOTIC EXPANSION FOR K(FNU,Z) FOR LARGE FNU APPLIED IN C -PI/3.LE.ARG(Z).LE.PI/3 C----------------------------------------------------------------------- CALL CUNK1(Z, FNU, KODE, MR, N, Y, NZ, TOL, ELIM, ALIM) GO TO 20 10 CONTINUE C----------------------------------------------------------------------- C ASYMPTOTIC EXPANSION FOR H(2,FNU,Z*EXP(M*HPI)) FOR LARGE FNU C APPLIED IN PI/3.LT.ABS(ARG(Z)).LE.PI/2 WHERE M=+I OR -I C AND HPI=PI/2 C----------------------------------------------------------------------- CALL CUNK2(Z, FNU, KODE, MR, N, Y, NZ, TOL, ELIM, ALIM) 20 CONTINUE RETURN END