Rev 4872 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | |
| 2 | /* |
||
| 3 | * ==================================================== |
||
| 4 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
||
| 5 | * |
||
| 6 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
||
| 7 | * Permission to use, copy, modify, and distribute this |
||
| 8 | * software is freely granted, provided that this notice |
||
| 9 | * is preserved. |
||
| 10 | * ==================================================== |
||
| 11 | */ |
||
| 12 | |||
| 13 | |||
| 14 | * wrapper jn(int n, double x), yn(int n, double x) |
||
| 15 | * floating point Bessel's function of the 1st and 2nd kind |
||
| 16 | * of order n |
||
| 17 | * |
||
| 18 | * Special cases: |
||
| 19 | * y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal; |
||
| 20 | * y0(-ve)=y1(-ve)=yn(n,-ve) are NaN with invalid signal. |
||
| 21 | * Note 2. About jn(n,x), yn(n,x) |
||
| 22 | * For n=0, j0(x) is called, |
||
| 23 | * for n=1, j1(x) is called, |
||
| 24 | * for n |
||
| 25 | * from values of j0(x) and j1(x). |
||
| 26 | * for n>x, a continued fraction approximation to |
||
| 27 | * j(n,x)/j(n-1,x) is evaluated and then backward |
||
| 28 | * recursion is used starting from a supposed value |
||
| 29 | * for j(n,x). The resulting value of j(0,x) is |
||
| 30 | * compared with the actual value to correct the |
||
| 31 | * supposed value of j(n,x). |
||
| 32 | * |
||
| 33 | * yn(n,x) is similar in all respects, except |
||
| 34 | * that forward recursion is used for all |
||
| 35 | * values of n>1. |
||
| 36 | * |
||
| 37 | */ |
||
| 38 | |||
| 39 | |||
| 40 | #include |
||
| 41 | |||
| 42 | |||
| 43 | |||
| 44 | |||
| 45 | double jn(int n, double x) /* wrapper jn */ |
||
| 46 | #else |
||
| 47 | double jn(n,x) /* wrapper jn */ |
||
| 48 | double x; int n; |
||
| 49 | #endif |
||
| 50 | { |
||
| 51 | #ifdef _IEEE_LIBM |
||
| 52 | return __ieee754_jn(n,x); |
||
| 53 | #else |
||
| 54 | double z; |
||
| 55 | struct exception exc; |
||
| 56 | z = __ieee754_jn(n,x); |
||
| 57 | if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z; |
||
| 58 | if(fabs(x)>X_TLOSS) { |
||
| 59 | /* jn(|x|>X_TLOSS) */ |
||
| 60 | exc.type = TLOSS; |
||
| 61 | exc.name = "jn"; |
||
| 62 | exc.err = 0; |
||
| 63 | exc.arg1 = n; |
||
| 64 | exc.arg2 = x; |
||
| 65 | exc.retval = 0.0; |
||
| 66 | if (_LIB_VERSION == _POSIX_) |
||
| 67 | errno = ERANGE; |
||
| 68 | else if (!matherr(&exc)) { |
||
| 69 | errno = ERANGE; |
||
| 70 | } |
||
| 71 | if (exc.err != 0) |
||
| 72 | errno = exc.err; |
||
| 73 | return exc.retval; |
||
| 74 | } else |
||
| 75 | return z; |
||
| 76 | #endif |
||
| 77 | } |
||
| 78 | |||
| 79 | |||
| 80 | double yn(int n, double x) /* wrapper yn */ |
||
| 81 | #else |
||
| 82 | double yn(n,x) /* wrapper yn */ |
||
| 83 | double x; int n; |
||
| 84 | #endif |
||
| 85 | { |
||
| 86 | #ifdef _IEEE_LIBM |
||
| 87 | return __ieee754_yn(n,x); |
||
| 88 | #else |
||
| 89 | double z; |
||
| 90 | struct exception exc; |
||
| 91 | z = __ieee754_yn(n,x); |
||
| 92 | if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z; |
||
| 93 | if(x <= 0.0){ |
||
| 94 | /* yn(n,0) = -inf or yn(x<0) = NaN */ |
||
| 95 | #ifndef HUGE_VAL |
||
| 96 | #define HUGE_VAL inf |
||
| 97 | double inf = 0.0; |
||
| 98 | |||
| 99 | |||
| 100 | #endif |
||
| 101 | exc.type = DOMAIN; /* should be SING for IEEE */ |
||
| 102 | exc.name = "yn"; |
||
| 103 | exc.err = 0; |
||
| 104 | exc.arg1 = n; |
||
| 105 | exc.arg2 = x; |
||
| 106 | if (_LIB_VERSION == _SVID_) |
||
| 107 | exc.retval = -HUGE; |
||
| 108 | else |
||
| 109 | exc.retval = -HUGE_VAL; |
||
| 110 | if (_LIB_VERSION == _POSIX_) |
||
| 111 | errno = EDOM; |
||
| 112 | else if (!matherr(&exc)) { |
||
| 113 | errno = EDOM; |
||
| 114 | } |
||
| 115 | if (exc.err != 0) |
||
| 116 | errno = exc.err; |
||
| 117 | return exc.retval; |
||
| 118 | } |
||
| 119 | if(x>X_TLOSS) { |
||
| 120 | /* yn(x>X_TLOSS) */ |
||
| 121 | exc.type = TLOSS; |
||
| 122 | exc.name = "yn"; |
||
| 123 | exc.err = 0; |
||
| 124 | exc.arg1 = n; |
||
| 125 | exc.arg2 = x; |
||
| 126 | exc.retval = 0.0; |
||
| 127 | if (_LIB_VERSION == _POSIX_) |
||
| 128 | errno = ERANGE; |
||
| 129 | else if (!matherr(&exc)) { |
||
| 130 | errno = ERANGE; |
||
| 131 | } |
||
| 132 | if (exc.err != 0) |
||
| 133 | errno = exc.err; |
||
| 134 | return exc.retval; |
||
| 135 | } else |
||
| 136 | return z; |
||
| 137 | #endif |
||
| 138 | } |
||
| 139 | |||
| 140 | |||
| 141 |