1 | /*****************************************************************************\ |
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2 | * Computer Algebra System SINGULAR |
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3 | \*****************************************************************************/ |
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4 | /** @file facFqFactorizeUtil.h |
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5 | * |
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6 | * This file provides utility functions for multivariate factorization |
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7 | * |
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8 | * @author Martin Lee |
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9 | * |
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10 | **/ |
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11 | /*****************************************************************************/ |
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12 | |
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13 | #ifndef FAC_FQ_FACTORIZE_UTIL_H |
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14 | #define FAC_FQ_FACTORIZE_UTIL_H |
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15 | |
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16 | // #include "config.h" |
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17 | #include "canonicalform.h" |
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18 | #include "cf_map.h" |
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19 | |
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20 | /// append @a factors2 to @a factors1 and decompress |
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21 | /// |
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22 | static inline |
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23 | void decompressAppend (CFList& factors1, ///< [in,out] a list of polys, |
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24 | ///< returns @a factors2 appended |
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25 | ///< to it and everything is |
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26 | ///< decompressed |
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27 | const CFList& factors2, ///< [in] a list of polys |
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28 | const CFMap& N ///< [in] a map |
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29 | ) |
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30 | { |
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31 | for (CFListIterator i= factors1; i.hasItem(); i++) |
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32 | i.getItem()= N (i.getItem()); |
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33 | for (CFListIterator i= factors2; i.hasItem(); i++) |
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34 | factors1.append (N (i.getItem())); |
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35 | } |
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36 | |
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37 | |
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38 | /// swap elements in @a factors2 and append them to @a factors1 |
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39 | /// |
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40 | void appendSwap (CFList& factors1, ///< [in,out] a list of polys, |
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41 | ///< returns swapped elements of @a |
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42 | ///< factors2 appended to it |
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43 | const CFList& factors2, ///< [in] a list of polys |
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44 | const int swapLevel1, ///< [in] level of variable to be |
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45 | ///< swapped with x, 0 if no swapping |
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46 | const int swapLevel2, ///< [in] level of variable to be |
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47 | ///< swapped with x, 0 if no swapping |
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48 | const Variable& x ///< [in] a variable |
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49 | ); |
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50 | |
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51 | /// swap elements in @a factors |
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52 | void swap (CFList& factors, ///< [in] a list of polys, returns swapped |
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53 | ///< elements of factors |
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54 | const int swapLevel1, ///< [in] level of variable to be |
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55 | ///< swapped with x, 0 if no swapping |
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56 | const int swapLevel2, ///< [in] level of variable to be |
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57 | ///< swapped with x, 0 if no swapping |
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58 | const Variable& x ///< [in] a variable |
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59 | ); |
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60 | |
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61 | /// swap elements of @a factors2, append them to @a factors1 and decompress |
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62 | void appendSwapDecompress ( |
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63 | CFList& factors1, ///< [in,out] a list of polys, |
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64 | ///< returns swapped elements of @a |
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65 | ///< factors2 appended to it and |
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66 | ///< everything is decompressed |
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67 | const CFList& factors2, ///< [in] a list of polys |
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68 | const CFMap& N, ///< [in] a map |
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69 | const int swapLevel, ///< [in] level of variable to be |
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70 | ///< swapped with x, 0 if no swapping |
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71 | const Variable& x ///< [in] a variable |
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72 | ); |
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73 | |
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74 | /// swap elements of @a factors2, append them to @a factors1 and decompress |
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75 | void appendSwapDecompress ( |
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76 | CFList& factors1, ///< [in,out] a list of polys, |
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77 | ///< returns swapped elements of @a |
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78 | ///< factors2 appended to it and |
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79 | ///< everything is decompressed |
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80 | const CFList& factors2, ///< [in] a list of polys |
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81 | const CFMap& N, ///< [in] a map |
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82 | const int swapLevel1, ///< [in] level of variable to be |
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83 | ///< swapped with x, 0 if no swapping |
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84 | const int swapLevel2, ///< [in] level of variable to be |
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85 | ///< swapped with x, 0 if no swapping |
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86 | const Variable& x ///< [in] a variable |
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87 | ); |
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88 | |
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89 | |
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90 | /// compute lifting bounds |
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91 | /// |
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92 | /// @return @a liftingBounds returns an array containing the lift bounds for A |
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93 | int* liftingBounds (const CanonicalForm& A, ///< [in] a compressed poly |
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94 | const int& bivarLiftBound ///< [in] lift bound for |
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95 | ///< @a biFactorizer() |
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96 | ); |
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97 | |
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98 | /// shift evaluation point to zero |
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99 | /// @return @a shift2Zero returns @a F shifted by @a evaluation s.t. 0 is a |
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100 | /// valid evaluation point |
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101 | /// @sa evalPoints(), reverseShift() |
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102 | CanonicalForm |
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103 | shift2Zero (const CanonicalForm& F, ///< [in] a compressed poly |
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104 | CFList& Feval, ///< [in,out] an empty list, returns |
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105 | ///< @a F successively evaluated |
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106 | ///< at 0 |
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107 | const CFList& evaluation,///< [in] a valid evaluation point |
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108 | int l= 2 ///< [in] level at which the evaluation |
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109 | ///< starts |
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110 | ); |
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111 | |
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112 | /// reverse shifting the evaluation point to zero |
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113 | /// |
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114 | /// @return @a reverseShift returns a poly whose shift to zero is reversed |
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115 | /// @sa shift2Zero(), evalPoints() |
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116 | CanonicalForm reverseShift (const CanonicalForm& F, ///< [in] a compressed poly |
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117 | const CFList& evaluation,///< [in] a valid |
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118 | ///< evaluation point |
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119 | int l= 2 ///< [in] level at which |
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120 | ///< the evaluation starts |
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121 | ); |
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122 | |
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123 | /// check if @a F consists of more than just the leading coeff wrt. Variable (1) |
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124 | /// |
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125 | /// @return as described above |
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126 | bool isOnlyLeadingCoeff (const CanonicalForm& F ///< [in] some poly |
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127 | ); |
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128 | |
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129 | /// sort CFFList by the number variables in a factor |
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130 | CFFList sortCFFListByNumOfVars (CFFList & F ///< [in,out] a list of factors |
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131 | ); |
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132 | |
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133 | /// like getVars but each variable x occuring in @a F is raised to x^degree (F,x) |
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134 | CanonicalForm myGetVars (const CanonicalForm& F ///< [in] a polynomial |
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135 | ); |
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136 | |
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137 | /// evaluate @a F at @a evaluation |
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138 | /// |
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139 | /// @return @a evaluateAtEval returns a list containing the successive |
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140 | /// evaluations of @a F, last entry is @a F again |
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141 | CFList |
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142 | evaluateAtEval (const CanonicalForm& F, ///<[in] some poly |
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143 | const CFArray& evaluation ///<[in] some evaluation point |
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144 | ); |
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145 | |
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146 | /// evaluate @a F at @a evaluation |
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147 | /// |
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148 | /// @return @a evaluateAtEval returns a list containing the successive |
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149 | /// evaluations of @a F starting at level @a l, last entry is @a F again |
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150 | CFList |
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151 | evaluateAtEval (const CanonicalForm& F, ///<[in] some poly |
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152 | const CFList& evaluation,///<[in] some evaluation point |
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153 | int l ///<[in] level to start at |
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154 | ); |
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155 | |
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156 | /// evaluate F successively n-2 at 0 |
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157 | /// |
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158 | /// @return returns a list of successive evaluations of F, ending with F |
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159 | CFList evaluateAtZero (const CanonicalForm& F ///< [in] some poly |
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160 | ); |
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161 | |
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162 | /// divides factors by their content wrt. Variable(1) and checks if these polys |
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163 | /// divide F |
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164 | /// |
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165 | /// @return returns factors of F |
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166 | CFList recoverFactors (const CanonicalForm& F, ///< [in] some poly F |
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167 | const CFList& factors ///< [in] some list of |
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168 | ///< factor candidates |
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169 | ); |
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170 | |
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171 | /// divides factors shifted by evaluation by their content wrt. Variable(1) and |
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172 | /// checks if these polys divide F |
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173 | /// |
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174 | /// @return returns factors of F |
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175 | CFList recoverFactors (const CanonicalForm& F, ///< [in] some poly F |
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176 | const CFList& factors, ///< [in] some list of |
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177 | ///< factor candidates |
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178 | const CFList& evaluation ///< [in] evaluation point |
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179 | ); |
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180 | |
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181 | /// checks if factors divide F, if so F is divided by this factor and the factor |
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182 | /// is divided by its content wrt. Variable(1) and the entry in index at the |
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183 | /// position of the factor is set to 1, otherwise the entry in index is set to 0 |
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184 | /// |
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185 | /// @return returns factors of F |
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186 | CFList recoverFactors (CanonicalForm& F, ///< [in,out] some poly F |
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187 | const CFList& factors,///< [in] some list of |
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188 | ///< factor candidates |
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189 | int* index ///< [in] position of real factors |
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190 | ); |
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191 | |
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192 | #endif |
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193 | /* FAC_FQ_FACTORIZE_UTIL_H */ |
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194 | |
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