ExtensionInfo.h
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1 /*****************************************************************************\
2  * Computer Algebra System SINGULAR
3 \*****************************************************************************/
4 /** @file ExtensionInfo.h
5  *
6  * This file provides a class to store information about finite fields and
7  * extensions thereof.
8  *
9  *
10  * @author Martin Lee
11  *
12  **/
13 /*****************************************************************************/
14 
15 #ifndef EXTENSION_INFO_H
16 #define EXTENSION_INFO_H
17 
18 // #include "config.h"
19 
20 #include "canonicalform.h"
21 
22 /** @class ExtensionInfo ExtensionInfo.h "factory/ExtensionInfo.h"
23  * ExtensionInfo contains information about extension.
24  * If @a m_extension is true we are in an extension of some initial field.
25  * If the initial field is \f$ F_p \f$ and we pass to \f$ F_p (\alpha) \f$
26  * then @a m_alpha is an algebraic variable, @a m_beta= Variable(1),
27  * @a m_gamma= @a m_delta= 1, @a m_GFDegree= 0, @a m_GFName= 'Z'. If we pass
28  * to some GF (p^k) then @a m_alpha= Variable (1), @a m_beta= Variable(1),
29  * @a m_gamma= @a m_delta= 1, @a m_GFDegree= 1, @a m_GFName= 'Z'.
30  * @n If the initial field is \f$ F_p (\epsilon) \f$, then @a m_beta=
31  * \f$ \epsilon \f$, @a m_alpha an algebraic variable defining an extension of
32  * \f$ F_p (\epsilon) \f$, @a m_gamma is a primitive element of
33  * \f$ F_p (\alpha) \f$, @a m_delta is a primitive element of
34  * \f$ F_p (\beta) \f$, @a m_GFDegree= 0, @a m_GFName= 'Z'.
35  * @n If the initial field is GF(p^k), then @a m_alpha= Variable (1),
36  * @a m_beta= Variable (1), @a m_gamma= 1, @a m_delta= 1, @a m_GFDegree()= k,
37  * @a m_GFName= gf_name of the initial field.
38  * @n If @a m_extension is false and the current field is \f$ F_p \f$ then
39  * @a m_alpha= Variable (1), @a m_beta= Variable (1), @a m_gamma= 1,
40  * @a m_delta= 1, @a m_GFDegree= 1, @a m_GFName= 'Z'.
41  * @n If the current field is \f$ F_p (\alpha) \f$ then
42  * @a m_alpha is some algebraic variable, @a m_beta= Variable (1),
43  * @a m_gamma= 1, @a m_delta= 1, @a m_GFDegree= 0, @a m_GFName= 'Z'.
44  * @n If the current field is GF then @a m_alpha= Variable (1),
45  * @a m_beta= Variable (1), @a m_gamma= 1, @a m_delta= 1,
46  * @a m_GFDegree= getGFDegree(), @a m_GFName= gf_name.
47  *
48  * @sa facFqBivar.h, facFqFactorize.h
49  */
51 {
52 private:
53  /// an algebraic variable or Variable (1)
55  /// an algebraic variable or Variable (1)
57  /// a primitive element of \f$ F_p (\alpha) \f$ or 1
59  /// a primitive element of \f$ F_p (\beta) \f$ or 1
61  /// GF degree or 1
63  /// name of GF variable
64  char m_GFName;
65  /// indicates if we are in an extension of some initial field
67 public:
68  /// \f$ F_p \f$ as initial field, if @a extension is true we are in some GF
69  ExtensionInfo (const bool extension ///< [in] some bool
70  );
71  /// Construct an @a ExtensionInfo
72  ExtensionInfo (const Variable& alpha, ///< [in] some algebraic variable
73  const Variable& beta, ///< [in] some algebraic variable
74  const CanonicalForm& gamma, ///< [in] some primitive element
75  ///< of \f$ F_p (\alpha) \f$
76  const CanonicalForm& delta, ///< [in] some primitive element
77  ///< of \f$ F_p (\beta) \f$
78  const int nGFDegree, ///< [in] GFDegree of initial field
79  const char cGFName, ///< [in] name of GF variable of
80  ///< initial field
81  const bool extension ///< [in] some bool
82  );
83  /// \f$ F_p (\beta) \f$ as initial field and switch to an extension given by
84  /// @a alpha, needs primitive elements @a gamma and @a delta for maps
85  /// between \f$ F_p (\alpha) \subset F_p (\beta) \f$
86  ExtensionInfo (const Variable& alpha, ///< [in] some algebraic variable
87  const Variable& beta, ///< [in] some algebraic variable
88  const CanonicalForm& gamma, ///< [in] some primitive element
89  ///< of \f$ F_p (\alpha) \f$
90  const CanonicalForm& delta ///< [in] some primitive element
91  ///< of \f$ F_p (\beta) \f$
92  );
93  /// \f$ F_p (\alpha) \f$ as initial field, if @a extension is false.
94  /// Else initial field is \f$ F_p \f$
95  ExtensionInfo (const Variable& alpha, ///< [in] some algebraic variable
96  const bool extension ///< [in] some bool
97  );
98 
99  ExtensionInfo (const Variable& alpha ///< [in] some algebraic variable
100  );
101 
102  /// GF as initial field
103  ExtensionInfo (const int nGFDegree, ///< [in] GF degree of initial field
104  const char cGFName, ///< [in] name of GF variable
105  const bool extension ///< [in] some bool
106  );
107 
108  /// getter
109  ///
110  /// @return @a getAlpha() returns @a m_alpha
112  {
113  return m_alpha;
114  }
115  /// getter
116  ///
117  /// @return @a getBeta() returns @a m_beta
118  Variable getBeta () const
119  {
120  return m_beta;
121  }
122  /// getter
123  ///
124  /// @return @a getGamma() returns @a m_gamma
126  {
127  return m_gamma;
128  }
129  /// getter
130  ///
131  /// @return @a getDelta() returns @a m_delta
133  {
134  return m_delta;
135  }
136  /// getter
137  ///
138  /// @return @a getGFDegree() returns @a m_GFDegree
139  int getGFDegree() const
140  {
141  return m_GFDegree;
142  }
143  /// getter
144  ///
145  /// @return @a getGFName() returns @a m_GFName
146  char getGFName() const
147  {
148  return m_GFName;
149  }
150  /// getter
151  ///
152  /// @return @a isInextension() returns @a m_extension
153  bool isInExtension() const
154  {
155  return m_extension;
156  }
157 };
158 
159 #endif
160 /* EXTENSION_INFO_H */
161 
bool isInExtension() const
getter
int m_GFDegree
GF degree or 1.
Definition: ExtensionInfo.h:62
CanonicalForm m_delta
a primitive element of or 1
Definition: ExtensionInfo.h:60
Variable m_beta
an algebraic variable or Variable (1)
Definition: ExtensionInfo.h:56
Variable getBeta() const
getter
char m_GFName
name of GF variable
Definition: ExtensionInfo.h:64
factory&#39;s class for variables
Definition: factory.h:115
CanonicalForm m_gamma
a primitive element of or 1
Definition: ExtensionInfo.h:58
factory&#39;s main class
Definition: canonicalform.h:75
Variable alpha
Definition: facAbsBiFact.cc:52
Variable getAlpha() const
getter
bool delta(X x, Y y, D d)
Definition: TestSuite.h:160
ExtensionInfo contains information about extension.
Definition: ExtensionInfo.h:50
Variable m_alpha
an algebraic variable or Variable (1)
Definition: ExtensionInfo.h:54
int getGFDegree() const
getter
CanonicalForm getGamma() const
getter
ExtensionInfo(const bool extension)
as initial field, if extension is true we are in some GF
bool m_extension
indicates if we are in an extension of some initial field
Definition: ExtensionInfo.h:66
char getGFName() const
getter
Variable beta
Definition: facAbsFact.cc:99
CanonicalForm getDelta() const
getter
Header for factory&#39;s main class CanonicalForm.