[35] | 1 | /*! |
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| 2 | * \file |
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| 3 | * \brief Error functions - header file |
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| 4 | * \author Tony Ottosson and Adam Piatyszek |
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| 5 | * |
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| 6 | * ------------------------------------------------------------------------- |
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| 7 | * |
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| 8 | * IT++ - C++ library of mathematical, signal processing, speech processing, |
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| 9 | * and communications classes and functions |
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| 10 | * |
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| 11 | * Copyright (C) 1995-2007 (see AUTHORS file for a list of contributors) |
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| 12 | * |
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| 13 | * This program is free software; you can redistribute it and/or modify |
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| 14 | * it under the terms of the GNU General Public License as published by |
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| 15 | * the Free Software Foundation; either version 2 of the License, or |
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| 16 | * (at your option) any later version. |
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| 17 | * |
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| 18 | * This program is distributed in the hope that it will be useful, |
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| 19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 21 | * GNU General Public License for more details. |
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| 22 | * |
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| 23 | * You should have received a copy of the GNU General Public License |
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| 24 | * along with this program; if not, write to the Free Software |
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| 25 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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| 26 | * |
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| 27 | * ------------------------------------------------------------------------- |
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| 28 | */ |
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| 29 | |
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| 30 | #ifndef ERROR_H |
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| 31 | #define ERROR_H |
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| 32 | |
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| 33 | #ifndef _MSC_VER |
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| 34 | # include <itpp/config.h> |
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| 35 | #else |
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| 36 | # include <itpp/config_msvc.h> |
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| 37 | #endif |
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| 38 | |
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| 39 | #include <itpp/base/help_functions.h> |
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| 40 | |
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| 41 | |
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| 42 | //!\addtogroup errorfunc |
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| 43 | //!@{ |
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| 44 | |
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| 45 | #ifndef HAVE_ERF |
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| 46 | //! \brief Error function |
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| 47 | double erf(double x); |
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| 48 | #endif |
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| 49 | |
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| 50 | #ifndef HAVE_ERFC |
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| 51 | //! Complementary error function |
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| 52 | double erfc(double x); |
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| 53 | #endif |
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| 54 | |
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| 55 | //!@} |
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| 56 | |
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| 57 | |
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| 58 | namespace itpp { |
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| 59 | |
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| 60 | //!\addtogroup errorfunc |
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| 61 | //!@{ |
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| 62 | |
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| 63 | /*! |
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| 64 | * \brief Error function for complex argument |
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| 65 | * \author Adam Piatyszek |
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| 66 | * |
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| 67 | * This function calculates a well known error function \c erf(z) |
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| 68 | * for complex \c z. The implementation is based on unofficial |
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| 69 | * implementation for Octave. Here is a part of the author's note |
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| 70 | * from original sources: |
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| 71 | * |
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| 72 | * Put together by John Smith john at arrows dot demon dot co dot uk, |
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| 73 | * using ideas by others. |
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| 74 | * |
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| 75 | * Calculate \c erf(z) for complex \c z. |
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| 76 | * Three methods are implemented; which one is used depends on z. |
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| 77 | * |
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| 78 | * The code includes some hard coded constants that are intended to |
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| 79 | * give about 14 decimal places of accuracy. This is appropriate for |
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| 80 | * 64-bit floating point numbers. |
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| 81 | */ |
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| 82 | std::complex<double> erf(const std::complex<double>& z); |
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| 83 | |
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| 84 | //! Inverse of error function |
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| 85 | double erfinv(double x); |
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| 86 | |
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| 87 | //! Q-function |
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| 88 | double Qfunc(double x); |
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| 89 | |
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| 90 | |
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| 91 | // ---------------------------------------------------------------------- |
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| 92 | // functions for matrices and vectors |
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| 93 | // ---------------------------------------------------------------------- |
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| 94 | |
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| 95 | //! Error function |
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| 96 | inline vec erf(const vec &x) |
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| 97 | { |
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| 98 | return apply_function<double>(::erf, x); |
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| 99 | } |
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| 100 | //! Error function |
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| 101 | inline mat erf(const mat &x) |
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| 102 | { |
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| 103 | return apply_function<double>(::erf, x); |
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| 104 | } |
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| 105 | //! Error function |
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| 106 | inline cvec erf(const cvec &x) |
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| 107 | { |
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| 108 | return apply_function<std::complex<double> >(erf, x); |
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| 109 | } |
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| 110 | //! Error function |
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| 111 | inline cmat erf(const cmat &x) |
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| 112 | { |
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| 113 | return apply_function<std::complex<double> >(erf, x); |
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| 114 | } |
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| 115 | |
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| 116 | //! Inverse of error function |
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| 117 | inline vec erfinv(const vec &x) |
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| 118 | { |
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| 119 | return apply_function<double>(erfinv, x); |
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| 120 | } |
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| 121 | //! Inverse of error function |
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| 122 | inline mat erfinv(const mat &x) |
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| 123 | { |
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| 124 | return apply_function<double>(erfinv, x); |
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| 125 | } |
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| 126 | |
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| 127 | //! Complementary error function |
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| 128 | inline vec erfc(const vec &x) |
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| 129 | { |
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| 130 | return apply_function<double>(::erfc, x); |
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| 131 | } |
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| 132 | //! Complementary error function |
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| 133 | inline mat erfc(const mat &x) |
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| 134 | { |
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| 135 | return apply_function<double>(::erfc, x); |
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| 136 | } |
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| 137 | |
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| 138 | //! Q-function |
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| 139 | inline vec Qfunc(const vec &x) |
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| 140 | { |
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| 141 | return apply_function<double>(Qfunc, x); |
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| 142 | } |
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| 143 | |
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| 144 | //! Q-function |
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| 145 | inline mat Qfunc(const mat &x) |
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| 146 | { |
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| 147 | return apply_function<double>(Qfunc, x); |
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| 148 | } |
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| 149 | //!@} |
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| 150 | |
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| 151 | } // namespace itpp |
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| 152 | |
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| 153 | #endif // #ifndef ERROR_H |
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| 154 | |
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| 155 | |
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| 156 | |
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