1 | /*****************************************************************************\ |
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2 | * Computer Algebra System SINGULAR |
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3 | \*****************************************************************************/ |
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4 | /** @file facFactorize.h |
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5 | * |
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6 | * multivariate factorization over Q(a) |
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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 | #ifndef FAC_FACTORIZE_H |
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16 | #define FAC_FACTORIZE_H |
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17 | |
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18 | // #include "config.h" |
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19 | |
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20 | #include "facBivar.h" |
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21 | #include "facFqBivarUtil.h" |
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22 | |
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23 | /// Factorization over Q (a) |
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24 | /// |
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25 | /// @return @a multiFactorize returns a factorization of F |
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26 | CFList |
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27 | multiFactorize (const CanonicalForm& F, ///< [in] poly to be factored |
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28 | const Variable& v ///< [in] some algebraic variable |
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29 | ); |
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30 | |
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31 | /// factorize a squarefree multivariate polynomial over \f$ Q(\alpha) \f$ |
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32 | /// |
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33 | /// @return @a ratSqrfFactorize returns a list of monic factors, the first |
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34 | /// element is the leading coefficient. |
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35 | #ifdef HAVE_NTL |
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36 | inline |
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37 | CFList ratSqrfFactorize (const CanonicalForm & G, ///< [in] a multivariate poly |
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38 | const Variable& v |
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39 | ) |
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40 | { |
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41 | if (getNumVars (G) == 2) |
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42 | return ratBiSqrfFactorize (G, v); |
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43 | CanonicalForm F= G; |
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44 | if (isOn (SW_RATIONAL)) |
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45 | F *= bCommonDen (F); |
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46 | CFList result= multiFactorize (F, v); |
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47 | if (isOn (SW_RATIONAL)) |
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48 | { |
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49 | normalize (result); |
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50 | result.insert (Lc(F)); |
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51 | } |
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52 | return result; |
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53 | } |
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54 | |
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55 | /// factorize a multivariate polynomial over \f$ Q(\alpha) \f$ |
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56 | /// |
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57 | /// @return @a ratFactorize returns a list of monic factors with |
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58 | /// multiplicity, the first element is the leading coefficient. |
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59 | inline |
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60 | CFFList ratFactorize (const CanonicalForm& G, ///< [in] a multivariate poly |
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61 | const Variable& v |
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62 | ) |
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63 | { |
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64 | if (getNumVars (G) == 2) |
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65 | { |
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66 | CFFList result= ratBiFactorize (G,v); |
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67 | return result; |
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68 | } |
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69 | CanonicalForm F= G; |
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70 | CanonicalForm LcF= Lc (F); |
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71 | if (isOn (SW_RATIONAL)) |
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72 | F *= bCommonDen (F); |
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73 | |
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74 | CFFList result; |
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75 | CFFList sqrfFactors= sqrFree (F); |
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76 | for (CFFListIterator i= sqrfFactors; i.hasItem(); i++) |
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77 | { |
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78 | CFList tmp= ratSqrfFactorize (i.getItem().factor(), v); |
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79 | for (CFListIterator j= tmp; j.hasItem(); j++) |
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80 | { |
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81 | if (j.getItem().inCoeffDomain()) continue; |
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82 | result.append (CFFactor (j.getItem(), i.getItem().exp())); |
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83 | } |
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84 | } |
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85 | if (isOn (SW_RATIONAL)) |
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86 | { |
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87 | normalize (result); |
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88 | result.insert (CFFactor (LcF, 1)); |
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89 | } |
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90 | return result; |
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91 | } |
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92 | #endif |
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93 | |
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94 | #endif |
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95 | |
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