[7bf145] | 1 | /*****************************************************************************\ |
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| 2 | * Computer Algebra System SINGULAR |
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| 3 | \*****************************************************************************/ |
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| 4 | /** @file facFqFactorizeUtil.cc |
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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 | * @internal @version \$Id$ |
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| 11 | * |
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| 12 | **/ |
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| 13 | /*****************************************************************************/ |
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| 14 | |
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| 15 | #include <config.h> |
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| 16 | |
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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 | static inline |
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| 21 | void appendSwap (CFList& factors1, const CFList& factors2, const int |
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| 22 | swapLevel1, const int swapLevel2, const Variable& x) |
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| 23 | { |
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| 24 | for (CFListIterator i= factors2; i.hasItem(); i++) |
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| 25 | { |
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| 26 | if (swapLevel1) |
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| 27 | { |
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| 28 | if (swapLevel2) |
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| 29 | factors1.append (swapvar (swapvar (i.getItem(), x, |
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| 30 | Variable (swapLevel2)), Variable (swapLevel1), x)); |
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| 31 | else |
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| 32 | factors1.append (swapvar (i.getItem(), Variable (swapLevel1), x)); |
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| 33 | } |
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| 34 | else |
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| 35 | { |
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| 36 | if (swapLevel2) |
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| 37 | factors1.append (swapvar (i.getItem(), x, Variable (swapLevel2))); |
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| 38 | else |
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| 39 | factors1.append (i.getItem()); |
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| 40 | } |
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| 41 | } |
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| 42 | return; |
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| 43 | } |
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| 44 | |
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[d52c12] | 45 | |
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[7bf145] | 46 | void swap (CFList& factors, const int swapLevel1, const int swapLevel2, const |
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| 47 | Variable& x) |
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| 48 | { |
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| 49 | for (CFListIterator i= factors; i.hasItem(); i++) |
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| 50 | { |
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| 51 | if (swapLevel1) |
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| 52 | { |
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| 53 | if (swapLevel2) |
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| 54 | i.getItem()= swapvar (swapvar (i.getItem(), x, Variable (swapLevel2)), |
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| 55 | Variable (swapLevel1), x); |
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| 56 | else |
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| 57 | i.getItem()= swapvar (i.getItem(), Variable (swapLevel1), x); |
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| 58 | } |
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| 59 | else |
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| 60 | { |
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| 61 | if (swapLevel2) |
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| 62 | i.getItem()= swapvar (i.getItem(), x, Variable (swapLevel2)); |
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| 63 | } |
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| 64 | } |
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| 65 | return; |
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| 66 | } |
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| 67 | |
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| 68 | void appendSwapDecompress (CFList& factors1, const CFList& factors2, |
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| 69 | const CFMap& N, const int swapLevel, const |
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| 70 | Variable& x) |
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| 71 | { |
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| 72 | for (CFListIterator i= factors1; i.hasItem(); i++) |
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| 73 | { |
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| 74 | if (swapLevel) |
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| 75 | i.getItem()= swapvar (i.getItem(), Variable (swapLevel), x); |
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| 76 | i.getItem()= N(i.getItem()); |
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| 77 | } |
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| 78 | for (CFListIterator i= factors2; i.hasItem(); i++) |
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| 79 | { |
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| 80 | if (!i.getItem().inCoeffDomain()) |
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| 81 | factors1.append (N (i.getItem())); |
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| 82 | } |
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| 83 | return; |
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| 84 | } |
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| 85 | |
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| 86 | void appendSwapDecompress (CFList& factors1, const CFList& factors2, |
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| 87 | const CFMap& N, const int swapLevel1, |
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| 88 | const int swapLevel2, const Variable& x) |
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| 89 | { |
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| 90 | for (CFListIterator i= factors1; i.hasItem(); i++) |
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| 91 | { |
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| 92 | if (swapLevel1) |
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| 93 | { |
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| 94 | if (swapLevel2) |
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| 95 | i.getItem()= |
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| 96 | N (swapvar (swapvar (i.getItem(), Variable (swapLevel2), x), x, |
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| 97 | Variable (swapLevel1))); |
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| 98 | else |
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| 99 | i.getItem()= N (swapvar (i.getItem(), x, Variable (swapLevel1))); |
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| 100 | } |
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| 101 | else |
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| 102 | { |
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| 103 | if (swapLevel2) |
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| 104 | i.getItem()= N (swapvar (i.getItem(), Variable (swapLevel2), x)); |
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| 105 | else |
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| 106 | i.getItem()= N (i.getItem()); |
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| 107 | } |
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| 108 | } |
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| 109 | for (CFListIterator i= factors2; i.hasItem(); i++) |
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| 110 | { |
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| 111 | if (!i.getItem().inCoeffDomain()) |
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| 112 | factors1.append (N (i.getItem())); |
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| 113 | } |
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| 114 | return; |
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| 115 | } |
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| 116 | |
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| 117 | int* liftingBounds (const CanonicalForm& A, const int& bivarLiftBound) |
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| 118 | { |
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| 119 | int j= A.level() - 1; |
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| 120 | int* liftBounds= new int [j]; |
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| 121 | liftBounds[0]= bivarLiftBound; |
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| 122 | for (int i= 1; i < j; i++) |
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| 123 | { |
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| 124 | liftBounds[i]= degree (A, Variable (i + 2)) + 1 + |
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| 125 | degree (LC (A, 1), Variable (i + 2)); |
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| 126 | } |
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| 127 | return liftBounds; |
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| 128 | } |
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| 129 | |
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[d52c12] | 130 | CanonicalForm shift2Zero (const CanonicalForm& F, CFList& Feval, const CFList& evaluation) |
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[7bf145] | 131 | { |
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| 132 | CanonicalForm A= F; |
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| 133 | int k= A.level(); |
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| 134 | for (CFListIterator i= evaluation; i.hasItem(); i++, k--) |
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| 135 | A= A (Variable (k) + i.getItem(), k); |
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| 136 | CanonicalForm buf= A; |
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| 137 | Feval= CFList(); |
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| 138 | Feval.append (buf); |
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| 139 | for (k= A.level(); k > 2; k--) |
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| 140 | { |
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| 141 | buf= mod (buf, Variable (k)); |
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| 142 | Feval.insert (buf); |
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| 143 | } |
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| 144 | return A; |
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| 145 | } |
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| 146 | |
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| 147 | CanonicalForm reverseShift (const CanonicalForm& F, const CFList& evaluation) |
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| 148 | { |
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| 149 | int l= evaluation.length() + 1; |
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| 150 | CanonicalForm result= F; |
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| 151 | CFListIterator j= evaluation; |
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| 152 | for (int i= l; i > 1; i--, j++) |
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| 153 | { |
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| 154 | if (F.level() < i) |
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| 155 | continue; |
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| 156 | result= result (Variable (i) - j.getItem(), i); |
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| 157 | } |
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| 158 | return result; |
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| 159 | } |
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| 160 | |
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| 161 | |
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