cbinu.f
115 lines
| 3.9 KiB
| text/x-fortran
|
FortranFixedLexer
| r1601 | *DECK CBINU | |||
| SUBROUTINE CBINU (Z, FNU, KODE, N, CY, NZ, RL, FNUL, TOL, ELIM, | ||||
| + ALIM) | ||||
| C***BEGIN PROLOGUE CBINU | ||||
| C***SUBSIDIARY | ||||
| C***PURPOSE Subsidiary to CAIRY, CBESH, CBESI, CBESJ, CBESK and CBIRY | ||||
| C***LIBRARY SLATEC | ||||
| C***TYPE ALL (CBINU-A, ZBINU-A) | ||||
| C***AUTHOR Amos, D. E., (SNL) | ||||
| C***DESCRIPTION | ||||
| C | ||||
| C CBINU COMPUTES THE I FUNCTION IN THE RIGHT HALF Z PLANE | ||||
| C | ||||
| C***SEE ALSO CAIRY, CBESH, CBESI, CBESJ, CBESK, CBIRY | ||||
| C***ROUTINES CALLED CASYI, CBUNI, CMLRI, CSERI, CUOIK, CWRSK | ||||
| C***REVISION HISTORY (YYMMDD) | ||||
| C 830501 DATE WRITTEN | ||||
| C 910415 Prologue converted to Version 4.0 format. (BAB) | ||||
| C***END PROLOGUE CBINU | ||||
| COMPLEX CW, CY, CZERO, Z | ||||
| REAL ALIM, AZ, DFNU, ELIM, FNU, FNUL, RL, TOL | ||||
| INTEGER I, INW, KODE, N, NLAST, NN, NUI, NW, NZ | ||||
| DIMENSION CY(N), CW(2) | ||||
| DATA CZERO / (0.0E0,0.0E0) / | ||||
| C***FIRST EXECUTABLE STATEMENT CBINU | ||||
| NZ = 0 | ||||
| AZ = ABS(Z) | ||||
| NN = N | ||||
| DFNU = FNU + (N-1) | ||||
| IF (AZ.LE.2.0E0) GO TO 10 | ||||
| IF (AZ*AZ*0.25E0.GT.DFNU+1.0E0) GO TO 20 | ||||
| 10 CONTINUE | ||||
| C----------------------------------------------------------------------- | ||||
| C POWER SERIES | ||||
| C----------------------------------------------------------------------- | ||||
| CALL CSERI(Z, FNU, KODE, NN, CY, NW, TOL, ELIM, ALIM) | ||||
| INW = ABS(NW) | ||||
| NZ = NZ + INW | ||||
| NN = NN - INW | ||||
| IF (NN.EQ.0) RETURN | ||||
| IF (NW.GE.0) GO TO 120 | ||||
| DFNU = FNU + (NN-1) | ||||
| 20 CONTINUE | ||||
| IF (AZ.LT.RL) GO TO 40 | ||||
| IF (DFNU.LE.1.0E0) GO TO 30 | ||||
| IF (AZ+AZ.LT.DFNU*DFNU) GO TO 50 | ||||
| C----------------------------------------------------------------------- | ||||
| C ASYMPTOTIC EXPANSION FOR LARGE Z | ||||
| C----------------------------------------------------------------------- | ||||
| 30 CONTINUE | ||||
| CALL CASYI(Z, FNU, KODE, NN, CY, NW, RL, TOL, ELIM, ALIM) | ||||
| IF (NW.LT.0) GO TO 130 | ||||
| GO TO 120 | ||||
| 40 CONTINUE | ||||
| IF (DFNU.LE.1.0E0) GO TO 70 | ||||
| 50 CONTINUE | ||||
| C----------------------------------------------------------------------- | ||||
| C OVERFLOW AND UNDERFLOW TEST ON I SEQUENCE FOR MILLER ALGORITHM | ||||
| C----------------------------------------------------------------------- | ||||
| CALL CUOIK(Z, FNU, KODE, 1, NN, CY, NW, TOL, ELIM, ALIM) | ||||
| IF (NW.LT.0) GO TO 130 | ||||
| NZ = NZ + NW | ||||
| NN = NN - NW | ||||
| IF (NN.EQ.0) RETURN | ||||
| DFNU = FNU+(NN-1) | ||||
| IF (DFNU.GT.FNUL) GO TO 110 | ||||
| IF (AZ.GT.FNUL) GO TO 110 | ||||
| 60 CONTINUE | ||||
| IF (AZ.GT.RL) GO TO 80 | ||||
| 70 CONTINUE | ||||
| C----------------------------------------------------------------------- | ||||
| C MILLER ALGORITHM NORMALIZED BY THE SERIES | ||||
| C----------------------------------------------------------------------- | ||||
| CALL CMLRI(Z, FNU, KODE, NN, CY, NW, TOL) | ||||
| IF(NW.LT.0) GO TO 130 | ||||
| GO TO 120 | ||||
| 80 CONTINUE | ||||
| C----------------------------------------------------------------------- | ||||
| C MILLER ALGORITHM NORMALIZED BY THE WRONSKIAN | ||||
| C----------------------------------------------------------------------- | ||||
| C----------------------------------------------------------------------- | ||||
| C OVERFLOW TEST ON K FUNCTIONS USED IN WRONSKIAN | ||||
| C----------------------------------------------------------------------- | ||||
| CALL CUOIK(Z, FNU, KODE, 2, 2, CW, NW, TOL, ELIM, ALIM) | ||||
| IF (NW.GE.0) GO TO 100 | ||||
| NZ = NN | ||||
| DO 90 I=1,NN | ||||
| CY(I) = CZERO | ||||
| 90 CONTINUE | ||||
| RETURN | ||||
| 100 CONTINUE | ||||
| IF (NW.GT.0) GO TO 130 | ||||
| CALL CWRSK(Z, FNU, KODE, NN, CY, NW, CW, TOL, ELIM, ALIM) | ||||
| IF (NW.LT.0) GO TO 130 | ||||
| GO TO 120 | ||||
| 110 CONTINUE | ||||
| C----------------------------------------------------------------------- | ||||
| C INCREMENT FNU+NN-1 UP TO FNUL, COMPUTE AND RECUR BACKWARD | ||||
| C----------------------------------------------------------------------- | ||||
| NUI = FNUL-DFNU + 1 | ||||
| NUI = MAX(NUI,0) | ||||
| CALL CBUNI(Z, FNU, KODE, NN, CY, NW, NUI, NLAST, FNUL, TOL, ELIM, | ||||
| * ALIM) | ||||
| IF (NW.LT.0) GO TO 130 | ||||
| NZ = NZ + NW | ||||
| IF (NLAST.EQ.0) GO TO 120 | ||||
| NN = NLAST | ||||
| GO TO 60 | ||||
| 120 CONTINUE | ||||
| RETURN | ||||
| 130 CONTINUE | ||||
| NZ = -1 | ||||
| IF(NW.EQ.(-2)) NZ=-2 | ||||
| RETURN | ||||
| END | ||||
