1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
5 // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
6 //
7 // This Source Code Form is subject to the terms of the Mozilla
8 // Public License v. 2.0. If a copy of the MPL was not distributed
9 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
10
11 #ifndef EIGEN_IO_H
12 #define EIGEN_IO_H
13
14 namespace Eigen {
15
16 enum { DontAlignCols = 1 };
17 enum { StreamPrecision = -1,
18 FullPrecision = -2 };
19
20 namespace internal {
21 template<typename Derived>
22 std::ostream & print_matrix(std::ostream & s, const Derived& _m, const IOFormat& fmt);
23 }
24
25 /** \class IOFormat
26 * \ingroup Core_Module
27 *
28 * \brief Stores a set of parameters controlling the way matrices are printed
29 *
30 * List of available parameters:
31 * - \b precision number of digits for floating point values, or one of the special constants \c StreamPrecision and \c FullPrecision.
32 * The default is the special value \c StreamPrecision which means to use the
33 * stream's own precision setting, as set for instance using \c cout.precision(3). The other special value
34 * \c FullPrecision means that the number of digits will be computed to match the full precision of each floating-point
35 * type.
36 * - \b flags an OR-ed combination of flags, the default value is 0, the only currently available flag is \c DontAlignCols which
37 * allows to disable the alignment of columns, resulting in faster code.
38 * - \b coeffSeparator string printed between two coefficients of the same row
39 * - \b rowSeparator string printed between two rows
40 * - \b rowPrefix string printed at the beginning of each row
41 * - \b rowSuffix string printed at the end of each row
42 * - \b matPrefix string printed at the beginning of the matrix
43 * - \b matSuffix string printed at the end of the matrix
44 *
45 * Example: \include IOFormat.cpp
46 * Output: \verbinclude IOFormat.out
47 *
48 * \sa DenseBase::format(), class WithFormat
49 */
50 struct IOFormat
51 {
52 /** Default contructor, see class IOFormat for the meaning of the parameters */
53 IOFormat(int _precision = StreamPrecision, int _flags = 0,
54 const std::string& _coeffSeparator = " ",
55 const std::string& _rowSeparator = "\n", const std::string& _rowPrefix="", const std::string& _rowSuffix="",
56 const std::string& _matPrefix="", const std::string& _matSuffix="")
matPrefixIOFormat57 : matPrefix(_matPrefix), matSuffix(_matSuffix), rowPrefix(_rowPrefix), rowSuffix(_rowSuffix), rowSeparator(_rowSeparator),
58 rowSpacer(""), coeffSeparator(_coeffSeparator), precision(_precision), flags(_flags)
59 {
60 int i = int(matSuffix.length())-1;
61 while (i>=0 && matSuffix[i]!='\n')
62 {
63 rowSpacer += ' ';
64 i--;
65 }
66 }
67 std::string matPrefix, matSuffix;
68 std::string rowPrefix, rowSuffix, rowSeparator, rowSpacer;
69 std::string coeffSeparator;
70 int precision;
71 int flags;
72 };
73
74 /** \class WithFormat
75 * \ingroup Core_Module
76 *
77 * \brief Pseudo expression providing matrix output with given format
78 *
79 * \param ExpressionType the type of the object on which IO stream operations are performed
80 *
81 * This class represents an expression with stream operators controlled by a given IOFormat.
82 * It is the return type of DenseBase::format()
83 * and most of the time this is the only way it is used.
84 *
85 * See class IOFormat for some examples.
86 *
87 * \sa DenseBase::format(), class IOFormat
88 */
89 template<typename ExpressionType>
90 class WithFormat
91 {
92 public:
93
WithFormat(const ExpressionType & matrix,const IOFormat & format)94 WithFormat(const ExpressionType& matrix, const IOFormat& format)
95 : m_matrix(matrix), m_format(format)
96 {}
97
98 friend std::ostream & operator << (std::ostream & s, const WithFormat& wf)
99 {
100 return internal::print_matrix(s, wf.m_matrix.eval(), wf.m_format);
101 }
102
103 protected:
104 const typename ExpressionType::Nested m_matrix;
105 IOFormat m_format;
106 };
107
108 /** \returns a WithFormat proxy object allowing to print a matrix the with given
109 * format \a fmt.
110 *
111 * See class IOFormat for some examples.
112 *
113 * \sa class IOFormat, class WithFormat
114 */
115 template<typename Derived>
116 inline const WithFormat<Derived>
format(const IOFormat & fmt)117 DenseBase<Derived>::format(const IOFormat& fmt) const
118 {
119 return WithFormat<Derived>(derived(), fmt);
120 }
121
122 namespace internal {
123
124 template<typename Scalar, bool IsInteger>
125 struct significant_decimals_default_impl
126 {
127 typedef typename NumTraits<Scalar>::Real RealScalar;
runsignificant_decimals_default_impl128 static inline int run()
129 {
130 using std::ceil;
131 using std::log;
132 return cast<RealScalar,int>(ceil(-log(NumTraits<RealScalar>::epsilon())/log(RealScalar(10))));
133 }
134 };
135
136 template<typename Scalar>
137 struct significant_decimals_default_impl<Scalar, true>
138 {
139 static inline int run()
140 {
141 return 0;
142 }
143 };
144
145 template<typename Scalar>
146 struct significant_decimals_impl
147 : significant_decimals_default_impl<Scalar, NumTraits<Scalar>::IsInteger>
148 {};
149
150 /** \internal
151 * print the matrix \a _m to the output stream \a s using the output format \a fmt */
152 template<typename Derived>
153 std::ostream & print_matrix(std::ostream & s, const Derived& _m, const IOFormat& fmt)
154 {
155 if(_m.size() == 0)
156 {
157 s << fmt.matPrefix << fmt.matSuffix;
158 return s;
159 }
160
161 typename Derived::Nested m = _m;
162 typedef typename Derived::Scalar Scalar;
163 typedef typename Derived::Index Index;
164
165 Index width = 0;
166
167 std::streamsize explicit_precision;
168 if(fmt.precision == StreamPrecision)
169 {
170 explicit_precision = 0;
171 }
172 else if(fmt.precision == FullPrecision)
173 {
174 if (NumTraits<Scalar>::IsInteger)
175 {
176 explicit_precision = 0;
177 }
178 else
179 {
180 explicit_precision = significant_decimals_impl<Scalar>::run();
181 }
182 }
183 else
184 {
185 explicit_precision = fmt.precision;
186 }
187
188 std::streamsize old_precision = 0;
189 if(explicit_precision) old_precision = s.precision(explicit_precision);
190
191 bool align_cols = !(fmt.flags & DontAlignCols);
192 if(align_cols)
193 {
194 // compute the largest width
195 for(Index j = 0; j < m.cols(); ++j)
196 for(Index i = 0; i < m.rows(); ++i)
197 {
198 std::stringstream sstr;
199 sstr.copyfmt(s);
200 sstr << m.coeff(i,j);
201 width = std::max<Index>(width, Index(sstr.str().length()));
202 }
203 }
204 s << fmt.matPrefix;
205 for(Index i = 0; i < m.rows(); ++i)
206 {
207 if (i)
208 s << fmt.rowSpacer;
209 s << fmt.rowPrefix;
210 if(width) s.width(width);
211 s << m.coeff(i, 0);
212 for(Index j = 1; j < m.cols(); ++j)
213 {
214 s << fmt.coeffSeparator;
215 if (width) s.width(width);
216 s << m.coeff(i, j);
217 }
218 s << fmt.rowSuffix;
219 if( i < m.rows() - 1)
220 s << fmt.rowSeparator;
221 }
222 s << fmt.matSuffix;
223 if(explicit_precision) s.precision(old_precision);
224 return s;
225 }
226
227 } // end namespace internal
228
229 /** \relates DenseBase
230 *
231 * Outputs the matrix, to the given stream.
232 *
233 * If you wish to print the matrix with a format different than the default, use DenseBase::format().
234 *
235 * It is also possible to change the default format by defining EIGEN_DEFAULT_IO_FORMAT before including Eigen headers.
236 * If not defined, this will automatically be defined to Eigen::IOFormat(), that is the Eigen::IOFormat with default parameters.
237 *
238 * \sa DenseBase::format()
239 */
240 template<typename Derived>
241 std::ostream & operator <<
242 (std::ostream & s,
243 const DenseBase<Derived> & m)
244 {
245 return internal::print_matrix(s, m.eval(), EIGEN_DEFAULT_IO_FORMAT);
246 }
247
248 } // end namespace Eigen
249
250 #endif // EIGEN_IO_H
251