| 1 | #include <kernel/polys.h> |
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| 2 | #include <libpolys/polys/monomials/p_polys.h> |
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| 3 | #include <singularWishlist.h> |
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| 4 | |
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| 5 | #include <Singular/ipid.h> |
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| 6 | |
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| 7 | /*** |
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| 8 | * changes a polynomial g with the help p-t such that |
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| 9 | * 1) each term of g has a distinct monomial in x |
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| 10 | * 2) no term of g has a coefficient divisible by p |
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| 11 | * in particular, this means that all g_\alpha can be obtained |
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| 12 | * by reading the coefficients and that g is initially reduced |
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| 13 | * with respect to p-t |
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| 14 | **/ |
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| 15 | static bool pReduce(poly g, const number p) |
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| 16 | { |
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| 17 | poly toBeChecked = pNext(g); |
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| 18 | pNext(g) = NULL; poly gEnd = g; |
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| 19 | poly gCache; |
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| 20 | |
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| 21 | number coeff, pPower; int power; poly subst; |
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| 22 | while(toBeChecked) |
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| 23 | { |
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| 24 | for (gCache = g; gCache; pIter(gCache)) |
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| 25 | if (p_LeadmonomDivisibleBy(gCache,toBeChecked,currRing)) break; |
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| 26 | if (gCache) |
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| 27 | { |
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| 28 | n_Power(p,p_GetExp(toBeChecked,1,currRing)-p_GetExp(gCache,1,currRing),&pPower,currRing->cf); |
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| 29 | coeff = n_Mult(p_GetCoeff(toBeChecked,currRing),pPower,currRing->cf); |
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| 30 | p_SetCoeff(gCache,n_Add(p_GetCoeff(gCache,currRing),coeff,currRing->cf),currRing); |
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| 31 | n_Delete(&pPower,currRing->cf); n_Delete(&coeff,currRing->cf); |
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| 32 | toBeChecked=p_LmDeleteAndNext(toBeChecked,currRing); |
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| 33 | } |
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| 34 | else |
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| 35 | { |
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| 36 | if (n_DivBy(p_GetCoeff(toBeChecked,currRing),p,currRing->cf)) |
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| 37 | { |
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| 38 | coeff=n_Div(p_GetCoeff(toBeChecked,currRing),p,currRing->cf); |
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| 39 | power=1; |
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| 40 | while (n_DivBy(coeff,p,currRing->cf)) |
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| 41 | { |
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| 42 | coeff=n_Div(p_GetCoeff(pNext(g),currRing),p,currRing->cf); |
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| 43 | power++; |
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| 44 | if (power<1) |
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| 45 | { |
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| 46 | WerrorS("pReduce: overflow in exponent"); |
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| 47 | return true; |
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| 48 | } |
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| 49 | } |
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| 50 | subst=p_LmInit(toBeChecked,currRing); |
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| 51 | p_AddExp(subst,1,power,currRing); |
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| 52 | p_SetCoeff(subst,coeff,currRing); |
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| 53 | p_Setm(subst,currRing); pTest(subst); |
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| 54 | toBeChecked=p_LmDeleteAndNext(toBeChecked,currRing); |
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| 55 | toBeChecked=p_Add_q(toBeChecked,subst,currRing); |
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| 56 | pTest(toBeChecked); |
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| 57 | } |
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| 58 | else |
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| 59 | { |
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| 60 | pNext(gEnd)=toBeChecked; |
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| 61 | pIter(gEnd); pIter(toBeChecked); |
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| 62 | pNext(gEnd)=NULL; |
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| 63 | } |
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| 64 | } |
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| 65 | } |
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| 66 | return false; |
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| 67 | } |
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| 68 | |
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| 69 | #ifndef NDEBUG |
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| 70 | BOOLEAN pReduce(leftv res, leftv args) |
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| 71 | { |
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| 72 | leftv u = args; |
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| 73 | if ((u != NULL) && (u->Typ() == POLY_CMD)) |
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| 74 | { |
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| 75 | poly g; number p = n_Init(3,currRing->cf); |
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| 76 | omUpdateInfo(); |
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| 77 | Print("usedBytesBefore=%ld\n",om_Info.UsedBytes); |
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| 78 | g = (poly) u->CopyD(); |
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| 79 | pReduce(g,p); |
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| 80 | p_Delete(&g,currRing); |
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| 81 | omUpdateInfo(); |
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| 82 | Print("usedBytesAfter=%ld\n",om_Info.UsedBytes); |
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| 83 | g = (poly) u->CopyD(); |
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| 84 | pReduce(g,p); |
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| 85 | n_Delete(&p,currRing->cf); |
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| 86 | res->rtyp = POLY_CMD; |
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| 87 | res->data = (char*) g; |
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| 88 | return FALSE; |
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| 89 | } |
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| 90 | return TRUE; |
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| 91 | } |
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| 92 | #endif //NDEBUG |
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| 93 | |
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| 94 | |
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| 95 | |
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