[7bf145] | 1 | /*****************************************************************************\ |
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[806c18] | 2 | * Computer Algebra System SINGULAR |
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[7bf145] | 3 | \*****************************************************************************/ |
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| 4 | /** @file facFqFactorizeUtil.cc |
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[806c18] | 5 | * |
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[7bf145] | 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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[e4fe2b] | 13 | #include "config.h" |
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[7bf145] | 14 | |
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| 15 | #include "canonicalform.h" |
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| 16 | #include "cf_map.h" |
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| 17 | |
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[806c18] | 18 | static inline |
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[7bf145] | 19 | void appendSwap (CFList& factors1, const CFList& factors2, const int |
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[806c18] | 20 | swapLevel1, const int swapLevel2, const Variable& x) |
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[7bf145] | 21 | { |
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[806c18] | 22 | for (CFListIterator i= factors2; i.hasItem(); i++) |
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| 23 | { |
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| 24 | if (swapLevel1) |
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[7bf145] | 25 | { |
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| 26 | if (swapLevel2) |
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[806c18] | 27 | factors1.append (swapvar (swapvar (i.getItem(), x, |
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[7bf145] | 28 | Variable (swapLevel2)), Variable (swapLevel1), x)); |
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| 29 | else |
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[806c18] | 30 | factors1.append (swapvar (i.getItem(), Variable (swapLevel1), x)); |
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[7bf145] | 31 | } |
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[806c18] | 32 | else |
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[7bf145] | 33 | { |
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| 34 | if (swapLevel2) |
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[806c18] | 35 | factors1.append (swapvar (i.getItem(), x, Variable (swapLevel2))); |
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| 36 | else |
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| 37 | factors1.append (i.getItem()); |
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[7bf145] | 38 | } |
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| 39 | } |
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| 40 | return; |
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| 41 | } |
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| 42 | |
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[d52c12] | 43 | |
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[7bf145] | 44 | void swap (CFList& factors, const int swapLevel1, const int swapLevel2, const |
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[806c18] | 45 | Variable& x) |
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[7bf145] | 46 | { |
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[806c18] | 47 | for (CFListIterator i= factors; i.hasItem(); i++) |
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| 48 | { |
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| 49 | if (swapLevel1) |
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[7bf145] | 50 | { |
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| 51 | if (swapLevel2) |
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[806c18] | 52 | i.getItem()= swapvar (swapvar (i.getItem(), x, Variable (swapLevel2)), |
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[7bf145] | 53 | Variable (swapLevel1), x); |
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| 54 | else |
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[806c18] | 55 | i.getItem()= swapvar (i.getItem(), Variable (swapLevel1), x); |
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[7bf145] | 56 | } |
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[806c18] | 57 | else |
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[7bf145] | 58 | { |
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| 59 | if (swapLevel2) |
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[806c18] | 60 | i.getItem()= swapvar (i.getItem(), x, Variable (swapLevel2)); |
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[7bf145] | 61 | } |
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| 62 | } |
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| 63 | return; |
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| 64 | } |
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| 65 | |
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[806c18] | 66 | void appendSwapDecompress (CFList& factors1, const CFList& factors2, |
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[7bf145] | 67 | const CFMap& N, const int swapLevel, const |
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[806c18] | 68 | Variable& x) |
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[7bf145] | 69 | { |
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[806c18] | 70 | for (CFListIterator i= factors1; i.hasItem(); i++) |
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[7bf145] | 71 | { |
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[806c18] | 72 | if (swapLevel) |
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[7bf145] | 73 | i.getItem()= swapvar (i.getItem(), Variable (swapLevel), x); |
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| 74 | i.getItem()= N(i.getItem()); |
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| 75 | } |
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[806c18] | 76 | for (CFListIterator i= factors2; i.hasItem(); i++) |
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[7bf145] | 77 | { |
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[806c18] | 78 | if (!i.getItem().inCoeffDomain()) |
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[7bf145] | 79 | factors1.append (N (i.getItem())); |
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| 80 | } |
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| 81 | return; |
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| 82 | } |
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| 83 | |
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[806c18] | 84 | void appendSwapDecompress (CFList& factors1, const CFList& factors2, |
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| 85 | const CFMap& N, const int swapLevel1, |
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| 86 | const int swapLevel2, const Variable& x) |
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[7bf145] | 87 | { |
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[806c18] | 88 | for (CFListIterator i= factors1; i.hasItem(); i++) |
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[7bf145] | 89 | { |
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[806c18] | 90 | if (swapLevel1) |
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[7bf145] | 91 | { |
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[806c18] | 92 | if (swapLevel2) |
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[7bf145] | 93 | i.getItem()= |
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| 94 | N (swapvar (swapvar (i.getItem(), Variable (swapLevel2), x), x, |
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| 95 | Variable (swapLevel1))); |
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[806c18] | 96 | else |
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[7bf145] | 97 | i.getItem()= N (swapvar (i.getItem(), x, Variable (swapLevel1))); |
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| 98 | } |
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[806c18] | 99 | else |
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[7bf145] | 100 | { |
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| 101 | if (swapLevel2) |
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| 102 | i.getItem()= N (swapvar (i.getItem(), Variable (swapLevel2), x)); |
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| 103 | else |
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| 104 | i.getItem()= N (i.getItem()); |
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| 105 | } |
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| 106 | } |
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[806c18] | 107 | for (CFListIterator i= factors2; i.hasItem(); i++) |
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| 108 | { |
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| 109 | if (!i.getItem().inCoeffDomain()) |
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[7bf145] | 110 | factors1.append (N (i.getItem())); |
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| 111 | } |
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| 112 | return; |
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| 113 | } |
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| 114 | |
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[806c18] | 115 | int* liftingBounds (const CanonicalForm& A, const int& bivarLiftBound) |
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[7bf145] | 116 | { |
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| 117 | int j= A.level() - 1; |
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| 118 | int* liftBounds= new int [j]; |
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| 119 | liftBounds[0]= bivarLiftBound; |
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[806c18] | 120 | for (int i= 1; i < j; i++) |
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[7bf145] | 121 | { |
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[806c18] | 122 | liftBounds[i]= degree (A, Variable (i + 2)) + 1 + |
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[7bf145] | 123 | degree (LC (A, 1), Variable (i + 2)); |
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| 124 | } |
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| 125 | return liftBounds; |
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| 126 | } |
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| 127 | |
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[6deedd] | 128 | CanonicalForm shift2Zero (const CanonicalForm& F, CFList& Feval, const CFList& evaluation, int l) |
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[7bf145] | 129 | { |
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| 130 | CanonicalForm A= F; |
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[6deedd] | 131 | int k= evaluation.length() + l - 1; |
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[7bf145] | 132 | for (CFListIterator i= evaluation; i.hasItem(); i++, k--) |
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| 133 | A= A (Variable (k) + i.getItem(), k); |
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| 134 | CanonicalForm buf= A; |
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| 135 | Feval= CFList(); |
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| 136 | Feval.append (buf); |
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| 137 | for (k= A.level(); k > 2; k--) |
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| 138 | { |
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| 139 | buf= mod (buf, Variable (k)); |
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| 140 | Feval.insert (buf); |
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| 141 | } |
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| 142 | return A; |
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| 143 | } |
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| 144 | |
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[6deedd] | 145 | CanonicalForm reverseShift (const CanonicalForm& F, const CFList& evaluation, int l) |
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[7bf145] | 146 | { |
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[6deedd] | 147 | int k= evaluation.length() + l - 1; |
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[7bf145] | 148 | CanonicalForm result= F; |
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| 149 | CFListIterator j= evaluation; |
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[6deedd] | 150 | for (int i= k; j.hasItem() && (i > l - 1); i--, j++) |
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[7bf145] | 151 | { |
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| 152 | if (F.level() < i) |
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| 153 | continue; |
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| 154 | result= result (Variable (i) - j.getItem(), i); |
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| 155 | } |
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| 156 | return result; |
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| 157 | } |
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| 158 | |
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| 159 | |
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