1 | /**************************************** |
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2 | * Computer Algebra System SINGULAR * |
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3 | ****************************************/ |
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4 | /* $Id$ */ |
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5 | /* |
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6 | * ABSTRACT:utils for hilbert driven kStd |
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7 | */ |
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8 | |
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9 | #include <kernel/mod2.h> |
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10 | #include <kernel/febase.h> |
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11 | #include <kernel/options.h> |
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12 | #include <kernel/polys.h> |
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13 | #include <kernel/intvec.h> |
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14 | #include <kernel/kutil.h> |
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15 | #include <kernel/stairc.h> |
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16 | #include <kernel/kstd1.h> |
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17 | #include <kernel/khstd.h> |
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18 | |
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19 | |
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20 | /*2 |
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21 | * compare the given hilbert series with the current one, |
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22 | * delete not needed pairs (if possible) |
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23 | */ |
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24 | void khCheck( ideal Q, intvec *w, intvec *hilb, int &eledeg, int &count, |
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25 | kStrategy strat) |
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26 | /* ideal S=strat->Shdl, poly p=strat->P.p */ |
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27 | /* |
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28 | * compute the number eledeg of elements with a degree >= deg(p) going into kStd, |
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29 | * p is already in S and for all further q going into S yields deg(q) >= deg(p), |
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30 | * the real computation is only done if the degree has changed, |
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31 | * then we have eledeg == 0 on this degree and we make: |
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32 | * - compute the Hilbert series newhilb from S |
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33 | * (hilb is the final Hilbert series) |
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34 | * - in module case: check that all comp up to strat->ak are used |
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35 | * - compute the eledeg from newhilb-hilb for the first degree deg with |
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36 | * newhilb-hilb != 0 |
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37 | * (Remark: consider the Hilbert series with coeff. up to infinity) |
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38 | * - clear the set L for degree < deg |
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39 | * the number count is only for statistics (in the caller initialise count = 0), |
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40 | * in order to get a first computation, initialise eledeg = 1 in the caller. |
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41 | * The weights w are needed in the module case, otherwise NULL. |
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42 | */ |
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43 | { |
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44 | intvec *newhilb; |
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45 | int deg,l,ln,mw; |
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46 | pFDegProc degp; |
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47 | |
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48 | eledeg--; |
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49 | if (eledeg == 0) |
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50 | { |
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51 | if (strat->ak>0) |
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52 | { |
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53 | char *used_comp=(char*)omAlloc0(strat->ak+1); |
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54 | int i; |
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55 | for(i=strat->sl;i>0;i--) |
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56 | { |
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57 | used_comp[pGetComp(strat->S[i])]='\1'; |
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58 | } |
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59 | for(i=strat->ak;i>0;i--) |
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60 | { |
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61 | if(used_comp[i]=='\0') |
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62 | { |
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63 | omFree((ADDRESS)used_comp); |
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64 | return; |
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65 | } |
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66 | } |
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67 | omFree((ADDRESS)used_comp); |
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68 | } |
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69 | degp=pFDeg; |
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70 | // if weights for variables were given to std computations, |
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71 | // then pFDeg == degp == kHomModDeg (see kStd) |
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72 | if ((degp!=kModDeg) && (degp!=kHomModDeg)) degp=p_Totaldegree; |
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73 | // degp = pWDegree; |
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74 | l = hilb->length()-1; |
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75 | mw = (*hilb)[l]; |
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76 | newhilb = hHstdSeries(strat->Shdl,w,strat->kHomW,Q,strat->tailRing); |
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77 | ln = newhilb->length()-1; |
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78 | deg = degp(strat->P.p,currRing)-mw; |
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79 | loop // compare the series in degree deg, try to increase deg ----------- |
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80 | { |
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81 | if (deg < ln) // deg may be out of range |
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82 | { |
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83 | if (deg < l) |
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84 | eledeg = (*newhilb)[deg]-(*hilb)[deg]; |
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85 | else |
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86 | eledeg = (*newhilb)[deg]; |
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87 | } |
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88 | else |
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89 | { |
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90 | if (deg < l) |
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91 | eledeg = -(*hilb)[deg]; |
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92 | else // we have newhilb = hilb |
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93 | { |
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94 | while (strat->Ll>=0) |
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95 | { |
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96 | count++; |
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97 | if(TEST_OPT_PROT) |
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98 | { |
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99 | PrintS("h"); |
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100 | mflush(); |
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101 | } |
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102 | deleteInL(strat->L,&strat->Ll,strat->Ll,strat); |
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103 | } |
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104 | delete newhilb; |
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105 | return; |
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106 | } |
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107 | } |
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108 | if (eledeg > 0) // elements to delete |
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109 | break; |
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110 | else if (eledeg <0) // strange....see bug_43 |
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111 | return; |
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112 | deg++; |
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113 | } /* loop */ |
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114 | delete newhilb; |
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115 | while ((strat->Ll>=0) && (degp(strat->L[strat->Ll].p,currRing)-mw < deg)) // the essential step |
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116 | { |
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117 | count++; |
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118 | if(TEST_OPT_PROT) |
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119 | { |
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120 | PrintS("h"); |
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121 | mflush(); |
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122 | } |
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123 | deleteInL(strat->L,&strat->Ll,strat->Ll,strat); |
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124 | } |
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125 | } |
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126 | } |
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