gonum.org/v1/gonum@v0.14.0/mathext/internal/amos/amoslib/zunik.f (about)

     1        SUBROUTINE ZUNIK(ZRR, ZRI, FNU, IKFLG, IPMTR, TOL, INIT, PHIR,
     2       * PHII, ZETA1R, ZETA1I, ZETA2R, ZETA2I, SUMR, SUMI, CWRKR, CWRKI)
     3  C***BEGIN PROLOGUE  ZUNIK
     4  C***REFER TO  ZBESI,ZBESK
     5  C
     6  C        ZUNIK COMPUTES PARAMETERS FOR THE UNIFORM ASYMPTOTIC
     7  C        EXPANSIONS OF THE I AND K FUNCTIONS ON IKFLG= 1 OR 2
     8  C        RESPECTIVELY BY
     9  C
    10  C        W(FNU,ZR) = PHI*EXP(ZETA)*SUM
    11  C
    12  C        WHERE       ZETA=-ZETA1 + ZETA2       OR
    13  C                          ZETA1 - ZETA2
    14  C
    15  C        THE FIRST CALL MUST HAVE INIT=0. SUBSEQUENT CALLS WITH THE
    16  C        SAME ZR AND FNU WILL RETURN THE I OR K FUNCTION ON IKFLG=
    17  C        1 OR 2 WITH NO CHANGE IN INIT. CWRK IS A COMPLEX WORK
    18  C        ARRAY. IPMTR=0 COMPUTES ALL PARAMETERS. IPMTR=1 COMPUTES PHI,
    19  C        ZETA1,ZETA2.
    20  C
    21  C***ROUTINES CALLED  ZDIV,ZLOG,ZSQRT,D1MACH
    22  C***END PROLOGUE  ZUNIK
    23  C     COMPLEX CFN,CON,CONE,CRFN,CWRK,CZERO,PHI,S,SR,SUM,T,T2,ZETA1,
    24  C    *ZETA2,ZN,ZR
    25        DOUBLE PRECISION AC, C, CON, CONEI, CONER, CRFNI, CRFNR, CWRKI,
    26       * CWRKR, FNU, PHII, PHIR, RFN, SI, SR, SRI, SRR, STI, STR, SUMI,
    27       * SUMR, TEST, TI, TOL, TR, T2I, T2R, ZEROI, ZEROR, ZETA1I, ZETA1R,
    28       * ZETA2I, ZETA2R, ZNI, ZNR, ZRI, ZRR, D1MACH
    29        INTEGER I, IDUM, IKFLG, INIT, IPMTR, J, K, L
    30        DIMENSION C(120), CWRKR(16), CWRKI(16), CON(2)
    31        DATA ZEROR,ZEROI,CONER,CONEI / 0.0D0, 0.0D0, 1.0D0, 0.0D0 /
    32        DATA CON(1), CON(2)  /
    33       1 3.98942280401432678D-01,  1.25331413731550025D+00 /
    34        DATA C(1), C(2), C(3), C(4), C(5), C(6), C(7), C(8), C(9), C(10),
    35       1     C(11), C(12), C(13), C(14), C(15), C(16), C(17), C(18),
    36       2     C(19), C(20), C(21), C(22), C(23), C(24)/
    37       3     1.00000000000000000D+00,    -2.08333333333333333D-01,
    38       4     1.25000000000000000D-01,     3.34201388888888889D-01,
    39       5    -4.01041666666666667D-01,     7.03125000000000000D-02,
    40       6    -1.02581259645061728D+00,     1.84646267361111111D+00,
    41       7    -8.91210937500000000D-01,     7.32421875000000000D-02,
    42       8     4.66958442342624743D+00,    -1.12070026162229938D+01,
    43       9     8.78912353515625000D+00,    -2.36408691406250000D+00,
    44       A     1.12152099609375000D-01,    -2.82120725582002449D+01,
    45       B     8.46362176746007346D+01,    -9.18182415432400174D+01,
    46       C     4.25349987453884549D+01,    -7.36879435947963170D+00,
    47       D     2.27108001708984375D-01,     2.12570130039217123D+02,
    48       E    -7.65252468141181642D+02,     1.05999045252799988D+03/
    49        DATA C(25), C(26), C(27), C(28), C(29), C(30), C(31), C(32),
    50       1     C(33), C(34), C(35), C(36), C(37), C(38), C(39), C(40),
    51       2     C(41), C(42), C(43), C(44), C(45), C(46), C(47), C(48)/
    52       3    -6.99579627376132541D+02,     2.18190511744211590D+02,
    53       4    -2.64914304869515555D+01,     5.72501420974731445D-01,
    54       5    -1.91945766231840700D+03,     8.06172218173730938D+03,
    55       6    -1.35865500064341374D+04,     1.16553933368645332D+04,
    56       7    -5.30564697861340311D+03,     1.20090291321635246D+03,
    57       8    -1.08090919788394656D+02,     1.72772750258445740D+00,
    58       9     2.02042913309661486D+04,    -9.69805983886375135D+04,
    59       A     1.92547001232531532D+05,    -2.03400177280415534D+05,
    60       B     1.22200464983017460D+05,    -4.11926549688975513D+04,
    61       C     7.10951430248936372D+03,    -4.93915304773088012D+02,
    62       D     6.07404200127348304D+00,    -2.42919187900551333D+05,
    63       E     1.31176361466297720D+06,    -2.99801591853810675D+06/
    64        DATA C(49), C(50), C(51), C(52), C(53), C(54), C(55), C(56),
    65       1     C(57), C(58), C(59), C(60), C(61), C(62), C(63), C(64),
    66       2     C(65), C(66), C(67), C(68), C(69), C(70), C(71), C(72)/
    67       3     3.76327129765640400D+06,    -2.81356322658653411D+06,
    68       4     1.26836527332162478D+06,    -3.31645172484563578D+05,
    69       5     4.52187689813627263D+04,    -2.49983048181120962D+03,
    70       6     2.43805296995560639D+01,     3.28446985307203782D+06,
    71       7    -1.97068191184322269D+07,     5.09526024926646422D+07,
    72       8    -7.41051482115326577D+07,     6.63445122747290267D+07,
    73       9    -3.75671766607633513D+07,     1.32887671664218183D+07,
    74       A    -2.78561812808645469D+06,     3.08186404612662398D+05,
    75       B    -1.38860897537170405D+04,     1.10017140269246738D+02,
    76       C    -4.93292536645099620D+07,     3.25573074185765749D+08,
    77       D    -9.39462359681578403D+08,     1.55359689957058006D+09,
    78       E    -1.62108055210833708D+09,     1.10684281682301447D+09/
    79        DATA C(73), C(74), C(75), C(76), C(77), C(78), C(79), C(80),
    80       1     C(81), C(82), C(83), C(84), C(85), C(86), C(87), C(88),
    81       2     C(89), C(90), C(91), C(92), C(93), C(94), C(95), C(96)/
    82       3    -4.95889784275030309D+08,     1.42062907797533095D+08,
    83       4    -2.44740627257387285D+07,     2.24376817792244943D+06,
    84       5    -8.40054336030240853D+04,     5.51335896122020586D+02,
    85       6     8.14789096118312115D+08,    -5.86648149205184723D+09,
    86       7     1.86882075092958249D+10,    -3.46320433881587779D+10,
    87       8     4.12801855797539740D+10,    -3.30265997498007231D+10,
    88       9     1.79542137311556001D+10,    -6.56329379261928433D+09,
    89       A     1.55927986487925751D+09,    -2.25105661889415278D+08,
    90       B     1.73951075539781645D+07,    -5.49842327572288687D+05,
    91       C     3.03809051092238427D+03,    -1.46792612476956167D+10,
    92       D     1.14498237732025810D+11,    -3.99096175224466498D+11,
    93       E     8.19218669548577329D+11,    -1.09837515608122331D+12/
    94        DATA C(97), C(98), C(99), C(100), C(101), C(102), C(103), C(104),
    95       1     C(105), C(106), C(107), C(108), C(109), C(110), C(111),
    96       2     C(112), C(113), C(114), C(115), C(116), C(117), C(118)/
    97       3     1.00815810686538209D+12,    -6.45364869245376503D+11,
    98       4     2.87900649906150589D+11,    -8.78670721780232657D+10,
    99       5     1.76347306068349694D+10,    -2.16716498322379509D+09,
   100       6     1.43157876718888981D+08,    -3.87183344257261262D+06,
   101       7     1.82577554742931747D+04,     2.86464035717679043D+11,
   102       8    -2.40629790002850396D+12,     9.10934118523989896D+12,
   103       9    -2.05168994109344374D+13,     3.05651255199353206D+13,
   104       A    -3.16670885847851584D+13,     2.33483640445818409D+13,
   105       B    -1.23204913055982872D+13,     4.61272578084913197D+12,
   106       C    -1.19655288019618160D+12,     2.05914503232410016D+11,
   107       D    -2.18229277575292237D+10,     1.24700929351271032D+09/
   108        DATA C(119), C(120)/
   109       1    -2.91883881222208134D+07,     1.18838426256783253D+05/
   110  C
   111        IF (INIT.NE.0) GO TO 40
   112  C-----------------------------------------------------------------------
   113  C     INITIALIZE ALL VARIABLES
   114  C-----------------------------------------------------------------------
   115        RFN = 1.0D0/FNU
   116  C-----------------------------------------------------------------------
   117  C     OVERFLOW TEST (ZR/FNU TOO SMALL)
   118  C-----------------------------------------------------------------------
   119        TEST = D1MACH(1)*1.0D+3
   120        AC = FNU*TEST
   121        IF (DABS(ZRR).GT.AC .OR. DABS(ZRI).GT.AC) GO TO 15
   122        ZETA1R = 2.0D0*DABS(DLOG(TEST))+FNU
   123        ZETA1I = 0.0D0
   124        ZETA2R = FNU
   125        ZETA2I = 0.0D0
   126        PHIR = 1.0D0
   127        PHII = 0.0D0
   128        RETURN
   129     15 CONTINUE
   130        TR = ZRR*RFN
   131        TI = ZRI*RFN
   132        SR = CONER + (TR*TR-TI*TI)
   133        SI = CONEI + (TR*TI+TI*TR)
   134        CALL ZSQRT(SR, SI, SRR, SRI)
   135        STR = CONER + SRR
   136        STI = CONEI + SRI
   137        CALL ZDIV(STR, STI, TR, TI, ZNR, ZNI)
   138        CALL ZLOG(ZNR, ZNI, STR, STI, IDUM)
   139        ZETA1R = FNU*STR
   140        ZETA1I = FNU*STI
   141        ZETA2R = FNU*SRR
   142        ZETA2I = FNU*SRI
   143        CALL ZDIV(CONER, CONEI, SRR, SRI, TR, TI)
   144        SRR = TR*RFN
   145        SRI = TI*RFN
   146        CALL ZSQRT(SRR, SRI, CWRKR(16), CWRKI(16))
   147        PHIR = CWRKR(16)*CON(IKFLG)
   148        PHII = CWRKI(16)*CON(IKFLG)
   149        IF (IPMTR.NE.0) RETURN
   150        CALL ZDIV(CONER, CONEI, SR, SI, T2R, T2I)
   151        CWRKR(1) = CONER
   152        CWRKI(1) = CONEI
   153        CRFNR = CONER
   154        CRFNI = CONEI
   155        AC = 1.0D0
   156        L = 1
   157        DO 20 K=2,15
   158          SR = ZEROR
   159          SI = ZEROI
   160          DO 10 J=1,K
   161            L = L + 1
   162            STR = SR*T2R - SI*T2I + C(L)
   163            SI = SR*T2I + SI*T2R
   164            SR = STR
   165     10   CONTINUE
   166          STR = CRFNR*SRR - CRFNI*SRI
   167          CRFNI = CRFNR*SRI + CRFNI*SRR
   168          CRFNR = STR
   169          CWRKR(K) = CRFNR*SR - CRFNI*SI
   170          CWRKI(K) = CRFNR*SI + CRFNI*SR
   171          AC = AC*RFN
   172          TEST = DABS(CWRKR(K)) + DABS(CWRKI(K))
   173          IF (AC.LT.TOL .AND. TEST.LT.TOL) GO TO 30
   174     20 CONTINUE
   175        K = 15
   176     30 CONTINUE
   177        INIT = K
   178     40 CONTINUE
   179        IF (IKFLG.EQ.2) GO TO 60
   180  C-----------------------------------------------------------------------
   181  C     COMPUTE SUM FOR THE I FUNCTION
   182  C-----------------------------------------------------------------------
   183        SR = ZEROR
   184        SI = ZEROI
   185        DO 50 I=1,INIT
   186          SR = SR + CWRKR(I)
   187          SI = SI + CWRKI(I)
   188     50 CONTINUE
   189        SUMR = SR
   190        SUMI = SI
   191        PHIR = CWRKR(16)*CON(1)
   192        PHII = CWRKI(16)*CON(1)
   193        RETURN
   194     60 CONTINUE
   195  C-----------------------------------------------------------------------
   196  C     COMPUTE SUM FOR THE K FUNCTION
   197  C-----------------------------------------------------------------------
   198        SR = ZEROR
   199        SI = ZEROI
   200        TR = CONER
   201        DO 70 I=1,INIT
   202          SR = SR + TR*CWRKR(I)
   203          SI = SI + TR*CWRKI(I)
   204          TR = -TR
   205     70 CONTINUE
   206        SUMR = SR
   207        SUMI = SI
   208        PHIR = CWRKR(16)*CON(2)
   209        PHII = CWRKI(16)*CON(2)
   210        RETURN
   211        END