| 1 | /**************************************** |
|---|
| 2 | * Computer Algebra System SINGULAR * |
|---|
| 3 | ****************************************/ |
|---|
| 4 | /* $Id: khstd.cc,v 1.5 1997-11-25 15:29:57 pohl Exp $ */ |
|---|
| 5 | /* |
|---|
| 6 | * ABSTRACT:utils for hilbert driven std |
|---|
| 7 | */ |
|---|
| 8 | |
|---|
| 9 | #include "mod2.h" |
|---|
| 10 | #include "tok.h" |
|---|
| 11 | #include "febase.h" |
|---|
| 12 | #include "polys.h" |
|---|
| 13 | #include "intvec.h" |
|---|
| 14 | #include "kutil.h" |
|---|
| 15 | #include "stairc.h" |
|---|
| 16 | #include "kstd1.h" |
|---|
| 17 | #include "khstd.h" |
|---|
| 18 | |
|---|
| 19 | /*2 |
|---|
| 20 | * compare the given hilbert series with the current one, |
|---|
| 21 | * delete not needed pairs (if possible) |
|---|
| 22 | */ |
|---|
| 23 | void khCheck( ideal Q, intvec *w, intvec *hilb, int &eledeg, int &count, |
|---|
| 24 | kStrategy strat) |
|---|
| 25 | /* ideal S=strat->Shdl, poly p=strat->P.p */ |
|---|
| 26 | /* |
|---|
| 27 | * compute the number eledeg of elements with a degree >= deg(p) going into std, |
|---|
| 28 | * p is already in S and for all further q going into S yields deg(q) >= deg(p), |
|---|
| 29 | * the real computation is only done if the degree has changed, |
|---|
| 30 | * then we have eledeg == 0 on this degree and we make: |
|---|
| 31 | * - compute the Hilbert series newhilb from S |
|---|
| 32 | * (hilb is the final Hilbert series) |
|---|
| 33 | * - compute the eledeg from newhilb-hilb for the first degree deg with |
|---|
| 34 | * newhilb-hilb != 0 |
|---|
| 35 | * (Remark: consider the Hilbert series with coeff. up to infinity) |
|---|
| 36 | * - clear the set L for degree < deg |
|---|
| 37 | * the number count is only for statistics (in the caller initialise count = 0), |
|---|
| 38 | * in order to get a first computation, initialise eledeg = 1 in the caller. |
|---|
| 39 | * The weights w are needed in the module case, otherwise NULL. |
|---|
| 40 | */ |
|---|
| 41 | { |
|---|
| 42 | intvec *newhilb; |
|---|
| 43 | int deg,l,ln,mw; |
|---|
| 44 | pFDegProc degp=pFDeg; |
|---|
| 45 | if (pFDeg!=kModDeg) { degp=pTotaldegree;}//quasihomogen!! |
|---|
| 46 | |
|---|
| 47 | eledeg--; |
|---|
| 48 | if (eledeg == 0) |
|---|
| 49 | { |
|---|
| 50 | l = hilb->length()-1; |
|---|
| 51 | mw = (*hilb)[l]; |
|---|
| 52 | newhilb = hHstdSeries(strat->Shdl,w,Q); |
|---|
| 53 | ln = newhilb->length()-1; |
|---|
| 54 | deg = degp(strat->P.p)-mw; |
|---|
| 55 | loop // compare the series in degree deg, try to increase deg ----------- |
|---|
| 56 | { |
|---|
| 57 | if (deg < ln) // deg may be out of range |
|---|
| 58 | { |
|---|
| 59 | if (deg < l) |
|---|
| 60 | eledeg = (*newhilb)[deg]-(*hilb)[deg]; |
|---|
| 61 | else |
|---|
| 62 | eledeg = (*newhilb)[deg]; |
|---|
| 63 | } |
|---|
| 64 | else |
|---|
| 65 | { |
|---|
| 66 | if (deg < l) |
|---|
| 67 | eledeg = -(*hilb)[deg]; |
|---|
| 68 | else // we have newhilb = hilb |
|---|
| 69 | { |
|---|
| 70 | while (strat->Ll>=0) |
|---|
| 71 | { |
|---|
| 72 | count++; |
|---|
| 73 | if(TEST_OPT_PROT) |
|---|
| 74 | { |
|---|
| 75 | PrintS("h"); |
|---|
| 76 | mflush(); |
|---|
| 77 | } |
|---|
| 78 | deleteInL(strat->L,&strat->Ll,strat->Ll,strat); |
|---|
| 79 | } |
|---|
| 80 | return; |
|---|
| 81 | } |
|---|
| 82 | } |
|---|
| 83 | if (eledeg != 0) |
|---|
| 84 | break; |
|---|
| 85 | deg++; |
|---|
| 86 | } /* loop */ |
|---|
| 87 | delete newhilb; |
|---|
| 88 | while ((strat->Ll>=0) && (degp(strat->L[strat->Ll].p)-mw < deg)) // the essential step |
|---|
| 89 | { |
|---|
| 90 | count++; |
|---|
| 91 | if(TEST_OPT_PROT) |
|---|
| 92 | { |
|---|
| 93 | PrintS("h"); |
|---|
| 94 | mflush(); |
|---|
| 95 | } |
|---|
| 96 | deleteInL(strat->L,&strat->Ll,strat->Ll,strat); |
|---|
| 97 | } |
|---|
| 98 | } |
|---|
| 99 | } |
|---|
