| 59 | typename real_type |
| 60 | > |
| 61 | __normal_call bool_type polyroots ( |
| 62 | real_type _aa, // aa*xx^2+bb*xx+cc=0 |
| 63 | real_type _bb, |
| 64 | real_type _cc, |
| 65 | __write_ptr (real_type) _xx |
| 66 | ) |
| 67 | { |
| 68 | real_type _rt = |
| 69 | std::numeric_limits |
| 70 | <real_type>::epsilon() ; |
| 71 | |
| 72 | bool_type _real = false ; |
| 73 | |
| 74 | real_type _sq = _bb * _bb - |
| 75 | (real_type)+4. * _aa * _cc ; |
| 76 | |
| 77 | if (_sq >= (real_type)+0.) // real roots |
| 78 | { |
| 79 | _sq = std::sqrt(_sq) ; |
| 80 | |
| 81 | _xx[0] = (-_bb + _sq) ; |
| 82 | _xx[1] = (-_bb - _sq) ; |
| 83 | |
| 84 | real_type _xm = std::max ( |
| 85 | std::abs(_xx[0]), |
| 86 | std::abs(_xx[1])) ; |
| 87 | |
| 88 | if (std::abs(_aa) > |
| 89 | std::abs(_xm) * _rt) |
| 90 | { |
| 91 | _real = true ; |
| 92 | |
| 93 | _aa *=(real_type)+2. ; |
| 94 | |
| 95 | _xx[0] /= _aa ; |
| 96 | _xx[1] /= _aa ; |
| 97 | } |
| 98 | else |
| 99 | if (std::abs(_bb) > |
| 100 | std::abs(_cc) * _rt) |
| 101 | { |
| 102 | _real = true ; |
| 103 | |
| 104 | _xx[0] = -_cc / _bb ; |
| 105 | _xx[1] = -_cc / _bb ; |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | return _real ; |
| 110 | } |
| 111 | |
| 112 | /* |
| 113 | -------------------------------------------------------- |
nothing calls this directly
no outgoing calls
no test coverage detected