1 | /*! |
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2 | * \file |
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3 | * \brief Definition of numerical integration |
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4 | * \author Tony Ottosson |
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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 INTEGRATION_H |
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31 | #define INTEGRATION_H |
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32 | |
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33 | #include <limits> |
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34 | |
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35 | |
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36 | namespace itpp { |
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37 | |
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38 | /*! |
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39 | \addtogroup integration |
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40 | \brief Numerical integration routines |
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41 | */ |
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42 | |
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43 | //@{ |
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44 | |
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45 | /*! |
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46 | 1-dimensional numerical Simpson quadrature integration |
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47 | |
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48 | Calculate the 1-dimensional integral |
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49 | \f[ |
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50 | \int_a^b f(x) dx |
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51 | \f] |
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52 | |
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53 | Uses an adaptive Simpson quadrature method. See [Gander] for more |
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54 | details. The integrand is specified as a function \code double |
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55 | f(double) \endcode. |
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56 | |
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57 | Example: |
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58 | \code |
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59 | #include "itpp/itbase.h" |
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60 | |
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61 | double f(const double x) |
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62 | { |
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63 | return x*log(x); |
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64 | } |
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65 | |
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66 | int main() |
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67 | { |
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68 | double res = quad( f, 1.5, 3.5); |
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69 | cout << "res = " << res << endl; |
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70 | |
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71 | return 0; |
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72 | } |
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73 | \endcode |
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74 | |
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75 | References: |
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76 | |
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77 | [Gander] Gander, W. and W. Gautschi, "Adaptive Quadrature - |
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78 | Revisited", BIT, Vol. 40, 2000, pp. 84-101. |
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79 | This document is also available at http://www.inf.ethz.ch/personal/gander. |
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80 | */ |
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81 | double quad(double (*f)(double), double a, double b, |
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82 | double tol = std::numeric_limits<double>::epsilon()); |
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83 | |
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84 | /*! |
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85 | 1-dimensional numerical adaptive Lobatto quadrature integration |
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86 | |
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87 | Calculate the 1-dimensional integral |
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88 | \f[ |
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89 | \int_a^b f(x) dx |
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90 | \f] |
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91 | |
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92 | Uses an adaptive Lobatto quadrature method. See [Gander] for more |
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93 | details. The integrand is specified as a function \code double |
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94 | f(double) \endcode. |
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95 | |
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96 | Example: |
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97 | \code |
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98 | #include "itpp/itbase.h" |
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99 | |
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100 | double f(const double x) |
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101 | { |
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102 | return x*log(x); |
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103 | } |
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104 | |
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105 | int main() |
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106 | { |
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107 | double res = quadl( f, 1.5, 3.5); |
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108 | cout << "res = " << res << endl; |
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109 | |
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110 | return 0; |
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111 | } |
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112 | \endcode |
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113 | |
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114 | References: |
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115 | |
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116 | [Gander] Gander, W. and W. Gautschi, "Adaptive Quadrature - |
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117 | Revisited", BIT, Vol. 40, 2000, pp. 84-101. |
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118 | This document is also available at http:// www.inf.ethz.ch/personal/gander. |
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119 | */ |
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120 | double quadl(double (*f)(double), double a, double b, |
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121 | double tol = std::numeric_limits<double>::epsilon()); |
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122 | |
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123 | //@} |
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124 | |
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125 | } // namespace itpp |
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126 | |
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127 | #endif // #ifndef INTEGRATION_H |
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