1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2006-2008 Benoit Jacob <[email protected]>
5 // Copyright (C) 2008 Gael Guennebaud <[email protected]>
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 * - \b fill character printed to fill the empty space in aligned columns
45 *
46 * Example: \include IOFormat.cpp
47 * Output: \verbinclude IOFormat.out
48 *
49 * \sa DenseBase::format(), class WithFormat
50 */
51 struct IOFormat
52 {
53 /** Default constructor, see class IOFormat for the meaning of the parameters */
54 IOFormat(int _precision = StreamPrecision, int _flags = 0,
55 const std::string& _coeffSeparator = " ",
56 const std::string& _rowSeparator = "\n", const std::string& _rowPrefix="", const std::string& _rowSuffix="",
57 const std::string& _matPrefix="", const std::string& _matSuffix="", const char _fill=' ')
matPrefixIOFormat58 : matPrefix(_matPrefix), matSuffix(_matSuffix), rowPrefix(_rowPrefix), rowSuffix(_rowSuffix), rowSeparator(_rowSeparator),
59 rowSpacer(""), coeffSeparator(_coeffSeparator), fill(_fill), precision(_precision), flags(_flags)
60 {
61 // TODO check if rowPrefix, rowSuffix or rowSeparator contains a newline
62 // don't add rowSpacer if columns are not to be aligned
63 if((flags & DontAlignCols))
64 return;
65 int i = int(matSuffix.length())-1;
66 while (i>=0 && matSuffix[i]!='\n')
67 {
68 rowSpacer += ' ';
69 i--;
70 }
71 }
72 std::string matPrefix, matSuffix;
73 std::string rowPrefix, rowSuffix, rowSeparator, rowSpacer;
74 std::string coeffSeparator;
75 char fill;
76 int precision;
77 int flags;
78 };
79
80 /** \class WithFormat
81 * \ingroup Core_Module
82 *
83 * \brief Pseudo expression providing matrix output with given format
84 *
85 * \tparam ExpressionType the type of the object on which IO stream operations are performed
86 *
87 * This class represents an expression with stream operators controlled by a given IOFormat.
88 * It is the return type of DenseBase::format()
89 * and most of the time this is the only way it is used.
90 *
91 * See class IOFormat for some examples.
92 *
93 * \sa DenseBase::format(), class IOFormat
94 */
95 template<typename ExpressionType>
96 class WithFormat
97 {
98 public:
99
WithFormat(const ExpressionType & matrix,const IOFormat & format)100 WithFormat(const ExpressionType& matrix, const IOFormat& format)
101 : m_matrix(matrix), m_format(format)
102 {}
103
104 friend std::ostream & operator << (std::ostream & s, const WithFormat& wf)
105 {
106 return internal::print_matrix(s, wf.m_matrix.eval(), wf.m_format);
107 }
108
109 protected:
110 typename ExpressionType::Nested m_matrix;
111 IOFormat m_format;
112 };
113
114 namespace internal {
115
116 // NOTE: This helper is kept for backward compatibility with previous code specializing
117 // this internal::significant_decimals_impl structure. In the future we should directly
118 // call digits10() which has been introduced in July 2016 in 3.3.
119 template<typename Scalar>
120 struct significant_decimals_impl
121 {
runsignificant_decimals_impl122 static inline int run()
123 {
124 return NumTraits<Scalar>::digits10();
125 }
126 };
127
128 /** \internal
129 * print the matrix \a _m to the output stream \a s using the output format \a fmt */
130 template<typename Derived>
print_matrix(std::ostream & s,const Derived & _m,const IOFormat & fmt)131 std::ostream & print_matrix(std::ostream & s, const Derived& _m, const IOFormat& fmt)
132 {
133 using internal::is_same;
134 using internal::conditional;
135
136 if(_m.size() == 0)
137 {
138 s << fmt.matPrefix << fmt.matSuffix;
139 return s;
140 }
141
142 typename Derived::Nested m = _m;
143 typedef typename Derived::Scalar Scalar;
144 typedef typename
145 conditional<
146 is_same<Scalar, char>::value ||
147 is_same<Scalar, unsigned char>::value ||
148 is_same<Scalar, numext::int8_t>::value ||
149 is_same<Scalar, numext::uint8_t>::value,
150 int,
151 typename conditional<
152 is_same<Scalar, std::complex<char> >::value ||
153 is_same<Scalar, std::complex<unsigned char> >::value ||
154 is_same<Scalar, std::complex<numext::int8_t> >::value ||
155 is_same<Scalar, std::complex<numext::uint8_t> >::value,
156 std::complex<int>,
157 const Scalar&
158 >::type
159 >::type PrintType;
160
161 Index width = 0;
162
163 std::streamsize explicit_precision;
164 if(fmt.precision == StreamPrecision)
165 {
166 explicit_precision = 0;
167 }
168 else if(fmt.precision == FullPrecision)
169 {
170 if (NumTraits<Scalar>::IsInteger)
171 {
172 explicit_precision = 0;
173 }
174 else
175 {
176 explicit_precision = significant_decimals_impl<Scalar>::run();
177 }
178 }
179 else
180 {
181 explicit_precision = fmt.precision;
182 }
183
184 std::streamsize old_precision = 0;
185 if(explicit_precision) old_precision = s.precision(explicit_precision);
186
187 bool align_cols = !(fmt.flags & DontAlignCols);
188 if(align_cols)
189 {
190 // compute the largest width
191 for(Index j = 0; j < m.cols(); ++j)
192 for(Index i = 0; i < m.rows(); ++i)
193 {
194 std::stringstream sstr;
195 sstr.copyfmt(s);
196 sstr << static_cast<PrintType>(m.coeff(i,j));
197 width = std::max<Index>(width, Index(sstr.str().length()));
198 }
199 }
200 std::streamsize old_width = s.width();
201 char old_fill_character = s.fill();
202 s << fmt.matPrefix;
203 for(Index i = 0; i < m.rows(); ++i)
204 {
205 if (i)
206 s << fmt.rowSpacer;
207 s << fmt.rowPrefix;
208 if(width) {
209 s.fill(fmt.fill);
210 s.width(width);
211 }
212 s << static_cast<PrintType>(m.coeff(i, 0));
213 for(Index j = 1; j < m.cols(); ++j)
214 {
215 s << fmt.coeffSeparator;
216 if(width) {
217 s.fill(fmt.fill);
218 s.width(width);
219 }
220 s << static_cast<PrintType>(m.coeff(i, j));
221 }
222 s << fmt.rowSuffix;
223 if( i < m.rows() - 1)
224 s << fmt.rowSeparator;
225 }
226 s << fmt.matSuffix;
227 if(explicit_precision) s.precision(old_precision);
228 if(width) {
229 s.fill(old_fill_character);
230 s.width(old_width);
231 }
232 return s;
233 }
234
235 } // end namespace internal
236
237 /** \relates DenseBase
238 *
239 * Outputs the matrix, to the given stream.
240 *
241 * If you wish to print the matrix with a format different than the default, use DenseBase::format().
242 *
243 * It is also possible to change the default format by defining EIGEN_DEFAULT_IO_FORMAT before including Eigen headers.
244 * If not defined, this will automatically be defined to Eigen::IOFormat(), that is the Eigen::IOFormat with default parameters.
245 *
246 * \sa DenseBase::format()
247 */
248 template<typename Derived>
249 std::ostream & operator <<
250 (std::ostream & s,
251 const DenseBase<Derived> & m)
252 {
253 return internal::print_matrix(s, m.eval(), EIGEN_DEFAULT_IO_FORMAT);
254 }
255
256 } // end namespace Eigen
257
258 #endif // EIGEN_IO_H
259