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Annotation of OpenXM_contrib/pari/src/language/sumiter.c, Revision 1.1

1.1     ! maekawa     1: /********************************************************************/
        !             2: /**                                                                **/
        !             3: /**                  BIBLIOTHEQUE  MATHEMATIQUE                    **/
        !             4: /**                (sommes, produits, iterations)                  **/
        !             5: /**                                                                **/
        !             6: /********************************************************************/
        !             7: /* $Id: sumiter.c,v 1.3 1999/09/23 17:50:57 karim Exp $ */
        !             8: #include "pari.h"
        !             9: #include "anal.h"
        !            10:
        !            11: /********************************************************************/
        !            12: /**                                                                **/
        !            13: /**                        ITERATIONS                              **/
        !            14: /**                                                                **/
        !            15: /********************************************************************/
        !            16:
        !            17: void
        !            18: forpari(entree *ep, GEN a, GEN b, char *ch)
        !            19: {
        !            20:   long av,av0 = avma, lim;
        !            21:
        !            22:   b = gcopy(b); av=avma; lim = stack_lim(av,1);
        !            23:  /* gcopy nedeed in case b gets overwritten in ch, as in
        !            24:   * b=10; for(a=1,b, print(a);b=1)
        !            25:   */
        !            26:   push_val(ep, a);
        !            27:   while (gcmp(a,b) <= 0)
        !            28:   {
        !            29:     long av1=avma; (void)lisseq(ch); avma=av1;
        !            30:     if (loop_break()) break;
        !            31:     a = (GEN) ep->value; a = gadd(a,gun);
        !            32:     if (low_stack(lim, stack_lim(av,1)))
        !            33:     {
        !            34:       if (DEBUGMEM>1) err(warnmem,"forpari");
        !            35:       a = gerepileupto(av,a);
        !            36:     }
        !            37:     ep->value = (void*)a;
        !            38:   }
        !            39:   pop_val(ep); avma = av0;
        !            40: }
        !            41:
        !            42: static int negcmp(GEN x, GEN y) { return gcmp(y,x); }
        !            43:
        !            44: void
        !            45: forstep(entree *ep, GEN a, GEN b, GEN s, char *ch)
        !            46: {
        !            47:   long ss, av,av0 = avma, lim, i, lgv;
        !            48:   GEN v = NULL;
        !            49:   int (*cmp)(GEN,GEN);
        !            50:
        !            51:   b = gcopy(b); av=avma; lim = stack_lim(av,1);
        !            52:   push_val(ep, a);
        !            53:   if (is_vec_t(typ(s)))
        !            54:   {
        !            55:     v=s; lgv=lg(v)-1; s=gzero;
        !            56:     for (i=1; i<=lgv; i++) s = gadd(s,(GEN)v[i]);
        !            57:   }
        !            58:   ss = gsigne(s);
        !            59:   if (!ss) err(talker, "step equal to zero in forstep");
        !            60:   cmp = (ss > 0)? gcmp: negcmp;
        !            61:   i = 0;
        !            62:   while (cmp(a,b) <= 0)
        !            63:   {
        !            64:     long av1=avma; (void)lisseq(ch); avma=av1;
        !            65:     if (loop_break()) break;
        !            66:     if (v) { if (++i > lgv) i=1; s = (GEN)v[i]; }
        !            67:     a = (GEN) ep->value; a = gadd(a,s);
        !            68:
        !            69:     if (low_stack(lim, stack_lim(av,1)))
        !            70:     {
        !            71:       if (DEBUGMEM>1) err(warnmem,"forstep");
        !            72:       a = gerepileupto(av,a);
        !            73:     }
        !            74:     ep->value = (void*)a;
        !            75:   }
        !            76:   pop_val(ep); avma = av0;
        !            77: }
        !            78:
        !            79: void
        !            80: forprime(entree *ep, GEN ga, GEN gb, char *ch)
        !            81: {
        !            82:   long av = avma, a,b;
        !            83:   long prime[] = {evaltyp(t_INT)|m_evallg(3), evalsigne(1)|evallgefint(3), 0};
        !            84:   byteptr p=diffptr;
        !            85:
        !            86:   ga = gceil(ga); gb = gfloor(gb);
        !            87:   if (is_bigint(ga) || is_bigint(gb)) err(primer1);
        !            88:   a = itos(ga); if (a<=0) a = 1;
        !            89:   b = 0; while (*p && a > b) b += *p++;
        !            90:   prime[2] = b; b = itos(gb);
        !            91:   avma = av; push_val(ep, prime);
        !            92:   while (prime[2] <= b)
        !            93:   {
        !            94:     if (!*p) err(primer1);
        !            95:     (void)lisseq(ch); if (loop_break()) break;
        !            96:     avma = av; prime[2] += *p++;
        !            97:   }
        !            98:   pop_val(ep);
        !            99: }
        !           100:
        !           101: void
        !           102: fordiv(GEN a, entree *ep, char *ch)
        !           103: {
        !           104:   long i,av2,l, av = avma;
        !           105:   GEN t = divisors(a);
        !           106:
        !           107:   push_val(ep, NULL); l=lg(t); av2 = avma;
        !           108:   for (i=1; i<l; i++)
        !           109:   {
        !           110:     ep->value = (void*) t[i];
        !           111:     (void)lisseq(ch); if (loop_break()) break;
        !           112:     avma = av2;
        !           113:   }
        !           114:   pop_val(ep); avma=av;
        !           115: }
        !           116:
        !           117: /* Embedded for loops:
        !           118:  *   fl = 0: execute ch (a), where a = (ai) runs through all n-uplets in
        !           119:  *     [m1,M1] x ... x [mn,Mn]
        !           120:  *   fl = 1: impose a1 <= ... <= an
        !           121:  *   fl = 2:        a1 <  ... <  an
        !           122:  */
        !           123: static GEN *fv_a, *fv_m, *fv_M;
        !           124: static long fv_n, fv_fl;
        !           125: static char *fv_ch;
        !           126:
        !           127: /* general case */
        !           128: static void
        !           129: fvloop(long i)
        !           130: {
        !           131:   fv_a[i] = fv_m[i];
        !           132:   if (fv_fl && i > 1)
        !           133:   {
        !           134:     GEN p1 = gsub(fv_a[i], fv_a[i-1]);
        !           135:     if (gsigne(p1) < 0)
        !           136:       fv_a[i] = gadd(fv_a[i], gceil(gneg_i(p1)));
        !           137:     if (fv_fl == 2 && gegal(fv_a[i], fv_a[i-1]))
        !           138:       fv_a[i] = gadd(fv_a[i], gun);
        !           139:   }
        !           140:   if (i+1 == fv_n)
        !           141:     while (gcmp(fv_a[i], fv_M[i]) <= 0)
        !           142:     {
        !           143:       long av = avma; (void)lisseq(fv_ch); avma = av;
        !           144:       if (loop_break()) { fv_n = 0; return; }
        !           145:       fv_a[i] = gadd(fv_a[i], gun);
        !           146:     }
        !           147:   else
        !           148:     while (gcmp(fv_a[i], fv_M[i]) <= 0)
        !           149:     {
        !           150:       long av = avma; fvloop(i+1); avma = av;
        !           151:       if (!fv_n) return;
        !           152:       fv_a[i] = gadd(fv_a[i], gun);
        !           153:     }
        !           154: }
        !           155:
        !           156: /* we run through integers */
        !           157: static void
        !           158: fvloop_i(long i)
        !           159: {
        !           160:   fv_a[i] = setloop(fv_m[i]);
        !           161:   if (fv_fl && i > 1)
        !           162:   {
        !           163:     int c = cmpii(fv_a[i], fv_a[i-1]);
        !           164:     if (c < 0)
        !           165:     {
        !           166:       fv_a[i] = setloop(fv_a[i-1]);
        !           167:       c = 0;
        !           168:     }
        !           169:     if (c == 0 && fv_fl == 2)
        !           170:       fv_a[i] = incloop(fv_a[i]);
        !           171:   }
        !           172:   if (i+1 == fv_n)
        !           173:     while (gcmp(fv_a[i], fv_M[i]) <= 0)
        !           174:     {
        !           175:       long av = avma; (void)lisseq(fv_ch); avma = av;
        !           176:       if (loop_break()) { fv_n = 0; return; }
        !           177:       fv_a[i] = incloop(fv_a[i]);
        !           178:     }
        !           179:   else
        !           180:     while (gcmp(fv_a[i], fv_M[i]) <= 0)
        !           181:     {
        !           182:       long av = avma; fvloop_i(i+1); avma = av;
        !           183:       if (!fv_n) return;
        !           184:       fv_a[i] = incloop(fv_a[i]);
        !           185:     }
        !           186: }
        !           187:
        !           188: void
        !           189: forvec(entree *ep, GEN x, char *c, long flag)
        !           190: {
        !           191:   long i, av = avma, tx = typ(x), n = fv_n, fl = fv_fl;
        !           192:   GEN *a = fv_a, *M = fv_M, *m = fv_m;
        !           193:   char *ch = fv_ch;
        !           194:   void (*fv_fun)(long) = fvloop_i;
        !           195:
        !           196:   if (!is_vec_t(tx)) err(talker,"not a vector in forvec");
        !           197:   if (fl<0 || fl>2) err(flagerr);
        !           198:   fv_n = lg(x);
        !           199:   fv_ch = c;
        !           200:   fv_fl = flag;
        !           201:   fv_a = (GEN*)cgetg(fv_n,t_VEC); push_val(ep, (GEN)fv_a);
        !           202:   fv_m = (GEN*)cgetg(fv_n,t_VEC);
        !           203:   fv_M = (GEN*)cgetg(fv_n,t_VEC);
        !           204:   if (fv_n == 1) lisseq(fv_ch);
        !           205:   else
        !           206:   {
        !           207:     for (i=1; i<fv_n; i++)
        !           208:     {
        !           209:       GEN *c = (GEN*) x[i];
        !           210:       tx = typ(c);
        !           211:       if (! is_vec_t(tx) || lg(c)!=3)
        !           212:        err(talker,"not a vector of two-component vectors in forvec");
        !           213:       if (gcmp(c[1],c[2]) > 0) fv_n = 0;
        !           214:       /* in case x is an ep->value and c destroys it, we have to copy */
        !           215:       if (typ(c[1]) != t_INT) fv_fun = fvloop;
        !           216:       fv_m[i] = gcopy(c[1]);
        !           217:       fv_M[i] = gcopy(c[2]);
        !           218:     }
        !           219:     fv_fun(1);
        !           220:   }
        !           221:   pop_val(ep);
        !           222:   fv_n = n;
        !           223:   fv_ch = ch;
        !           224:   fv_fl = fl;
        !           225:   fv_a = a;
        !           226:   fv_m = m;
        !           227:   fv_M = M; avma = av;
        !           228: }
        !           229:
        !           230: /********************************************************************/
        !           231: /**                                                                **/
        !           232: /**                              SUMS                              **/
        !           233: /**                                                                **/
        !           234: /********************************************************************/
        !           235:
        !           236: GEN
        !           237: somme(entree *ep, GEN a, GEN b, char *ch, GEN x)
        !           238: {
        !           239:   long av,av0 = avma, lim;
        !           240:   GEN p1;
        !           241:
        !           242:   if (typ(a) != t_INT) err(talker,"non integral index in sum");
        !           243:   if (!x) x = gzero;
        !           244:   if (gcmp(b,a) < 0) return gcopy(x);
        !           245:
        !           246:   b = gfloor(b);
        !           247:   a = setloop(a);
        !           248:   av=avma; lim = stack_lim(av,1);
        !           249:   push_val(ep, a);
        !           250:   for(;;)
        !           251:   {
        !           252:     p1 = lisexpr(ch); if (did_break()) err(breaker,"sum");
        !           253:     x=gadd(x,p1); if (cmpii(a,b) >= 0) break;
        !           254:     a = incloop(a);
        !           255:     if (low_stack(lim, stack_lim(av,1)))
        !           256:     {
        !           257:       if (DEBUGMEM>1) err(warnmem,"sum");
        !           258:       x = gerepileupto(av,x);
        !           259:     }
        !           260:     ep->value = (void*) a;
        !           261:   }
        !           262:   pop_val(ep); return gerepileupto(av0,x);
        !           263: }
        !           264:
        !           265: GEN
        !           266: suminf(entree *ep, GEN a, char *ch, long prec)
        !           267: {
        !           268:   long fl,G,tetpil, av0 = avma, av,lim;
        !           269:   GEN p1,x = realun(prec);
        !           270:
        !           271:   if (typ(a) != t_INT) err(talker,"non integral index in suminf");
        !           272:   a = setloop(a);
        !           273:   av = avma; lim = stack_lim(av,1);
        !           274:   push_val(ep, a);
        !           275:   fl=0; G = bit_accuracy(prec) + 5;
        !           276:   for(;;)
        !           277:   {
        !           278:     p1 = lisexpr(ch); if (did_break()) err(breaker,"suminf");
        !           279:     x = gadd(x,p1); a = incloop(a);
        !           280:     if (gcmp0(p1) || gexpo(p1) <= gexpo(x)-G)
        !           281:       { if (++fl==3) break; }
        !           282:     else
        !           283:       fl=0;
        !           284:     if (low_stack(lim, stack_lim(av,1)))
        !           285:     {
        !           286:       if (DEBUGMEM>1) err(warnmem,"suminf");
        !           287:       x = gerepileupto(av,x);
        !           288:     }
        !           289:     ep->value = (void*)a;
        !           290:   }
        !           291:   pop_val(ep); tetpil=avma;
        !           292:   return gerepile(av0,tetpil,gsub(x,gun));
        !           293: }
        !           294:
        !           295: GEN
        !           296: divsum(GEN num, entree *ep, char *ch)
        !           297: {
        !           298:   long av=avma,d,n,d2;
        !           299:   GEN y,z, p1 = icopy(gun);
        !           300:
        !           301:   push_val(ep, p1); n=itos(num); /* provisoire */
        !           302:   y=gzero;
        !           303:   for (d=d2=1; d2 < n; d++, d2 += d+d-1)
        !           304:     if (n%d == 0)
        !           305:     {
        !           306:       p1[2]=d; y=gadd(y, lisexpr(ch));
        !           307:       if (did_break()) err(breaker,"divsum");
        !           308:       p1[2]=n/d; z = lisexpr(ch);
        !           309:       if (did_break()) err(breaker,"divsum");
        !           310:       y=gadd(y,z);
        !           311:     }
        !           312:   if (d2 == n)
        !           313:   {
        !           314:     p1[2]=d; z = lisexpr(ch);
        !           315:     if (did_break()) err(breaker,"divsum");
        !           316:     y=gadd(y,z);
        !           317:   }
        !           318:   pop_val(ep); return gerepileupto(av,y);
        !           319: }
        !           320:
        !           321: /********************************************************************/
        !           322: /**                                                                **/
        !           323: /**                           PRODUCTS                             **/
        !           324: /**                                                                **/
        !           325: /********************************************************************/
        !           326:
        !           327: GEN
        !           328: produit(entree *ep, GEN a, GEN b, char *ch, GEN x)
        !           329: {
        !           330:   long av,av0 = avma, lim;
        !           331:   GEN p1;
        !           332:
        !           333:   if (typ(a) != t_INT) err(talker,"non integral index in sum");
        !           334:   if (!x) x = gun;
        !           335:   if (gcmp(b,a) < 0) return gcopy(x);
        !           336:
        !           337:   b = gfloor(b);
        !           338:   a = setloop(a);
        !           339:   av=avma; lim = stack_lim(av,1);
        !           340:   push_val(ep, a);
        !           341:   for(;;)
        !           342:   {
        !           343:     p1 = lisexpr(ch); if (did_break()) err(breaker,"prod");
        !           344:     x = gmul(x,p1); if (cmpii(a,b) >= 0) break;
        !           345:     a = incloop(a);
        !           346:     if (low_stack(lim, stack_lim(av,1)))
        !           347:     {
        !           348:       if (DEBUGMEM>1) err(warnmem,"prod");
        !           349:       x = gerepileupto(av,x);
        !           350:     }
        !           351:     ep->value = (void*) a;
        !           352:   }
        !           353:   pop_val(ep); return gerepileupto(av0,x);
        !           354: }
        !           355:
        !           356: GEN
        !           357: prodinf0(entree *ep, GEN a, char *ch, long flag, long prec)
        !           358: {
        !           359:   switch(flag)
        !           360:   {
        !           361:     case 0: return prodinf(ep,a,ch,prec);
        !           362:     case 1: return prodinf1(ep,a,ch,prec);
        !           363:   }
        !           364:   err(flagerr);
        !           365:   return NULL; /* not reached */
        !           366: }
        !           367:
        !           368: GEN
        !           369: prodinf(entree *ep, GEN a, char *ch, long prec)
        !           370: {
        !           371:   long fl,G,tetpil, av0 = avma, av,lim;
        !           372:   GEN p1,x = realun(prec);
        !           373:
        !           374:   if (typ(a) != t_INT) err(talker,"non integral index in prodinf");
        !           375:   a = setloop(a);
        !           376:   av = avma; lim = stack_lim(av,1);
        !           377:   push_val(ep, a);
        !           378:   fl=0; G = -bit_accuracy(prec)-5;
        !           379:   for(;;)
        !           380:   {
        !           381:     p1 = lisexpr(ch); if (did_break()) err(breaker,"prodinf");
        !           382:     x=gmul(x,p1); a = incloop(a);
        !           383:     if (gexpo(gsubgs(p1,1)) <= G) { if (++fl==3) break; } else fl=0;
        !           384:     if (low_stack(lim, stack_lim(av,1)))
        !           385:     {
        !           386:       if (DEBUGMEM>1) err(warnmem,"prodinf");
        !           387:       x = gerepileupto(av,x);
        !           388:     }
        !           389:     ep->value = (void*)a;
        !           390:   }
        !           391:   pop_val(ep); tetpil=avma;
        !           392:   return gerepile(av0,tetpil,gcopy(x));
        !           393: }
        !           394:
        !           395: GEN
        !           396: prodinf1(entree *ep, GEN a, char *ch, long prec)
        !           397: {
        !           398:   long fl,G,tetpil, av0 = avma, av,lim;
        !           399:   GEN p1,p2,x = realun(prec);
        !           400:
        !           401:   if (typ(a) != t_INT) err(talker,"non integral index in prodinf1");
        !           402:   a = setloop(a);
        !           403:   av = avma; lim = stack_lim(av,1);
        !           404:   push_val(ep, a);
        !           405:   fl=0; G = -bit_accuracy(prec)-5;
        !           406:   for(;;)
        !           407:   {
        !           408:     p2 = lisexpr(ch); if (did_break()) err(breaker,"prodinf1");
        !           409:     p1 = gadd(p2,gun); x=gmul(x,p1); a = incloop(a);
        !           410:     if (gcmp0(p1) || gexpo(p2) <= G) { if (++fl==3) break; } else fl=0;
        !           411:     if (low_stack(lim, stack_lim(av,1)))
        !           412:     {
        !           413:       if (DEBUGMEM>1) err(warnmem,"prodinf1");
        !           414:       x = gerepileupto(av,x);
        !           415:     }
        !           416:     ep->value = (void*)a;
        !           417:   }
        !           418:   pop_val(ep); tetpil=avma;
        !           419:   return gerepile(av0,tetpil,gcopy(x));
        !           420: }
        !           421:
        !           422: GEN
        !           423: prodeuler(entree *ep, GEN a, GEN b, char *ch, long prec)
        !           424: {
        !           425:   long prime,tetpil, av,av0 = avma, lim;
        !           426:   GEN p1,x = realun(prec);
        !           427:   byteptr p=diffptr;
        !           428:
        !           429:   prime = 0;
        !           430:   b = gfloor(b); a = gceil(a);
        !           431:   while (*p && cmpis(a,prime)>0) prime += *p++;
        !           432:   if (cmpsi(prime,b) > 0)
        !           433:   {
        !           434:     av=avma; if (gcmp1(subii(a,b))) { avma=av; return x; }
        !           435:     err(talker,"incorrect indices in prodeuler");
        !           436:   }
        !           437:   av=avma; lim = stack_lim(avma,1);
        !           438:   a = stoi(prime); push_val(ep, a);
        !           439:   do
        !           440:   {
        !           441:     if (!*p) err(primer1);
        !           442:     p1 = lisexpr(ch); if (did_break()) err(breaker,"prodeuler");
        !           443:     x=gmul(x,p1); a = addsi(*p++,a);
        !           444:     if (low_stack(lim, stack_lim(av,1)))
        !           445:     {
        !           446:       GEN *gptr[2]; gptr[0]=&x; gptr[1]=&a;
        !           447:       if (DEBUGMEM>1) err(warnmem,"prodeuler");
        !           448:       gerepilemany(av,gptr,2);
        !           449:     }
        !           450:     ep->value = (void*)a;
        !           451:   }
        !           452:   while (gcmp(a,b)<=0);
        !           453:   pop_val(ep); tetpil=avma;
        !           454:   return gerepile(av0,tetpil,gcopy(x));
        !           455: }
        !           456:
        !           457: GEN
        !           458: direuler(entree *ep, GEN a, GEN b, char *ch)
        !           459: {
        !           460:   GEN p1,x,x1,s,polnum,polden,c0;
        !           461:   long av0 = avma,av,tetpil,lim = (av0+bot)>>1, prime = 0,q,n,i,j,k,k1,tx,lx;
        !           462:   byteptr p = diffptr;
        !           463:
        !           464:   if (typ(a) != t_INT) err(talker,"non integral index in direuler");
        !           465:   if (gcmpgs(b,2)<0) { x=cgetg(2,t_VEC); x[1]=un; return x; }
        !           466:   if (gcmpgs(a,2) < 0) a = gdeux;
        !           467:   if (gcmpgs(b, MAXHALFULONG-1) > 0) b = stoi(MAXHALFULONG-1);
        !           468:   n = itos(b);
        !           469:
        !           470:   x1=cgetg(n+1,t_VEC); b = gcopy(b); av=avma;
        !           471:   x=cgetg(n+1,t_VEC); x[1]=un; for (i=2; i<=n; i++) x[i]=zero;
        !           472:
        !           473:   while (*p && gcmpgs(a,prime) > 0) prime += *p++;
        !           474:   a = stoi(prime); push_val(ep, a);
        !           475:   while (gcmp(a,b)<=0)
        !           476:   {
        !           477:     if (!*p) err(primer1);
        !           478:     p1 = lisexpr(ch); if (did_break()) err(breaker,"direuler");
        !           479:     polnum=numer(p1); polden=denom(p1);
        !           480:     tx = typ(polnum);
        !           481:     if (is_scalar_t(tx))
        !           482:     {
        !           483:       if (!gcmp1(polnum))
        !           484:        err(talker,"constant term not equal to 1 in direuler");
        !           485:     }
        !           486:     else
        !           487:     {
        !           488:       if (tx != t_POL) err(typeer,"direuler");
        !           489:       c0 = truecoeff(polnum,0);
        !           490:       if (!gcmp1(c0)) err(talker,"constant term not equal to 1 in direuler");
        !           491:       for (i=1; i<=n; i++) x1[i]=x[i];
        !           492:       prime=itos(a); q=prime; j=1; lx=lgef(polnum)-3;
        !           493:       while (q<=n && j<=lx)
        !           494:       {
        !           495:        c0=(GEN)polnum[j+2];
        !           496:        if (!gcmp0(c0))
        !           497:          for (k=1,k1=q; k1<=n; k1+=q,k++)
        !           498:            x[k1] = ladd((GEN)x[k1], gmul(c0,(GEN)x1[k]));
        !           499:        q*=prime; j++;
        !           500:       }
        !           501:     }
        !           502:     tx=typ(polden);
        !           503:     if (is_scalar_t(tx))
        !           504:     {
        !           505:       if (!gcmp1(polden))
        !           506:        err(talker,"constant term not equal to 1 in direuler");
        !           507:     }
        !           508:     else
        !           509:     {
        !           510:       if (tx != t_POL) err(typeer,"direuler");
        !           511:       c0 = truecoeff(polden,0);
        !           512:       if (!gcmp1(c0)) err(talker,"constant term not equal to 1 in direuler");
        !           513:       prime=itos(a); lx=lgef(polden)-3;
        !           514:       for (i=prime; i<=n; i+=prime)
        !           515:       {
        !           516:        s=gzero; k=i; j=1;
        !           517:        while (!(k%prime) && j<=lx)
        !           518:        {
        !           519:          c0=(GEN)polden[j+2]; k/=prime; j++;
        !           520:          if (!gcmp0(c0)) s=gadd(s,gmul(c0,(GEN)x[k]));
        !           521:         }
        !           522:        x[i]=lsub((GEN)x[i],s);
        !           523:       }
        !           524:     }
        !           525:     if (low_stack(lim, stack_lim(av,1)))
        !           526:     {
        !           527:       GEN *gptr[2]; gptr[0]=&x; gptr[1]=&a;
        !           528:       if (DEBUGMEM>1) err(warnmem,"direuler");
        !           529:       gerepilemany(av,gptr,2);
        !           530:     }
        !           531:     a = addsi(*p++,a); ep->value = (void*) a;
        !           532:   }
        !           533:   pop_val(ep); tetpil=avma;
        !           534:   return gerepile(av0,tetpil,gcopy(x));
        !           535: }
        !           536:
        !           537: /********************************************************************/
        !           538: /**                                                                **/
        !           539: /**                       VECTORS & MATRICES                       **/
        !           540: /**                                                                **/
        !           541: /********************************************************************/
        !           542:
        !           543: GEN
        !           544: vecteur(GEN nmax, entree *ep, char *ch)
        !           545: {
        !           546:   GEN y,p1;
        !           547:   long i,m;
        !           548:   long c[]={evaltyp(t_INT)|m_evallg(3), evalsigne(1)|evallgefint(3), 0};
        !           549:
        !           550:   if (typ(nmax)!=t_INT || signe(nmax) < 0)
        !           551:     err(talker,"bad number of components in vector");
        !           552:   m=itos(nmax); y=cgetg(m+1,t_VEC);
        !           553:   if (!ep || !ch)
        !           554:   {
        !           555:     for (i=1; i<=m; i++) y[i] = zero;
        !           556:     return y;
        !           557:   }
        !           558:   push_val(ep, c);
        !           559:   for (i=1; i<=m; i++)
        !           560:   {
        !           561:     c[2]=i; p1 = lisseq(ch);
        !           562:     if (did_break()) err(breaker,"vector");
        !           563:     y[i] = isonstack(p1)? (long)p1 : (long)forcecopy(p1);
        !           564:   }
        !           565:   pop_val(ep); return y;
        !           566: }
        !           567:
        !           568: GEN
        !           569: vvecteur(GEN nmax, entree *ep, char *ch)
        !           570: {
        !           571:   GEN y = vecteur(nmax,ep,ch);
        !           572:   settyp(y,t_COL); return y;
        !           573: }
        !           574:
        !           575: GEN
        !           576: matrice(GEN nlig, GEN ncol,entree *ep1, entree *ep2, char *ch)
        !           577: {
        !           578:   GEN y,z,p1;
        !           579:   long i,j,m,n,s;
        !           580:   long c1[]={evaltyp(t_INT)|m_evallg(3), evalsigne(1)|evallgefint(3), 1};
        !           581:   long c2[]={evaltyp(t_INT)|m_evallg(3), evalsigne(1)|evallgefint(3), 1};
        !           582:
        !           583:   s=signe(ncol);
        !           584:   if (typ(ncol)!=t_INT || s<0) err(talker,"bad number of columns in matrix");
        !           585:   if (!s) return cgetg(1,t_MAT);
        !           586:
        !           587:   s=signe(nlig);
        !           588:   if (typ(nlig)!=t_INT || s<0) err(talker,"bad number of rows in matrix");
        !           589:   m=itos(ncol)+1;
        !           590:   n=itos(nlig)+1; y=cgetg(m,t_MAT);
        !           591:   if (!s)
        !           592:   {
        !           593:     for (i=1; i<m; i++) y[i]=lgetg(1,t_COL);
        !           594:     return y;
        !           595:   }
        !           596:   if (!ep1 || !ep2 || !ch)
        !           597:   {
        !           598:     for (i=1; i<m; i++)
        !           599:     {
        !           600:       z=cgetg(n,t_COL); y[i]=(long)z;
        !           601:       for (j=1; j<n; j++) z[j] = zero;
        !           602:     }
        !           603:     return y;
        !           604:   }
        !           605:   push_val(ep1, c1);
        !           606:   push_val(ep2, c2);
        !           607:   for (i=1; i<m; i++)
        !           608:   {
        !           609:     c2[2]=i; z=cgetg(n,t_COL); y[i]=(long)z;
        !           610:     for (j=1; j<n; j++)
        !           611:     {
        !           612:       c1[2]=j; p1=lisseq(ch);
        !           613:       if (did_break()) err(breaker,"matrix");
        !           614:       z[j] = isonstack(p1)? (long)p1 : (long)forcecopy(p1);
        !           615:     }
        !           616:   }
        !           617:   pop_val(ep2);
        !           618:   pop_val(ep1); return y;
        !           619: }
        !           620:
        !           621: /********************************************************************/
        !           622: /**                                                                **/
        !           623: /**                    SOMMATION DE SERIES                         **/
        !           624: /**                                                                **/
        !           625: /********************************************************************/
        !           626:
        !           627: GEN
        !           628: sumalt0(entree *ep, GEN a, char *ch, long flag, long prec)
        !           629: {
        !           630:   switch(flag)
        !           631:   {
        !           632:     case 0: return sumalt(ep,a,ch,prec);
        !           633:     case 1: return sumalt2(ep,a,ch,prec);
        !           634:     default: err(flagerr);
        !           635:   }
        !           636:   return NULL; /* not reached */
        !           637: }
        !           638:
        !           639: GEN
        !           640: sumpos0(entree *ep, GEN a, char *ch, long flag, long prec)
        !           641: {
        !           642:   switch(flag)
        !           643:   {
        !           644:     case 0: return sumpos(ep,a,ch,prec);
        !           645:     case 1: return sumpos2(ep,a,ch,prec);
        !           646:     default: err(flagerr);
        !           647:   }
        !           648:   return NULL; /* not reached */
        !           649: }
        !           650:
        !           651: GEN
        !           652: sumalt(entree *ep, GEN a, char *ch, long prec)
        !           653: {
        !           654:   long av = avma, tetpil,k,N;
        !           655:   GEN s,az,c,x,e1,d;
        !           656:
        !           657:   if (typ(a) != t_INT) err(talker,"non integral index in sumalt");
        !           658:
        !           659:   push_val(ep, a);
        !           660:   e1=addsr(3,gsqrt(stoi(8),prec));
        !           661:   N=(long)(0.4*(bit_accuracy(prec) + 7));
        !           662:   d=gpuigs(e1,N); d=shiftr(addrr(d,divsr(1,d)),-1);
        !           663:   az=negi(gun); c=d; s=gzero;
        !           664:   for (k=0; ; k++)
        !           665:   {
        !           666:     x = lisexpr(ch); if (did_break()) err(breaker,"sumalt");
        !           667:     c = gadd(az,c); s = gadd(s,gmul(x,c));
        !           668:     az = divii(mulii(mulss(N-k,N+k),shifti(az,1)),mulss(k+1,k+k+1));
        !           669:     if (k==N-1) break;
        !           670:     a = addsi(1,a); ep->value = (void*) a;
        !           671:   }
        !           672:   tetpil=avma; pop_val(ep);
        !           673:   return gerepile(av,tetpil,gdiv(s,d));
        !           674: }
        !           675:
        !           676: GEN
        !           677: sumalt2(entree *ep, GEN a, char *ch, long prec)
        !           678: {
        !           679:   long av = avma, tetpil,k,N;
        !           680:   GEN x,s,dn,pol;
        !           681:
        !           682:   if (typ(a) != t_INT) err(talker,"non integral index in sumalt");
        !           683:
        !           684:   push_val(ep, a);
        !           685:   N=(long)(0.31*(bit_accuracy(prec) + 5));
        !           686:   s=gzero; pol=polzagreel(N,N>>1,prec+1); dn=poleval(pol,gun);
        !           687:   pol[2]=lsub((GEN)pol[2],dn); pol=gdiv(pol,gsub(polx[0],gun));
        !           688:   N=lgef(pol)-2;
        !           689:   for (k=0; k<N; k++)
        !           690:   {
        !           691:     x = lisexpr(ch); if (did_break()) err(breaker,"sumalt2");
        !           692:     s=gadd(s,gmul(x,(GEN)pol[k+2]));
        !           693:     if (k==N-1) break;
        !           694:     a = addsi(1,a); ep->value = (void*) a;
        !           695:   }
        !           696:   tetpil=avma; pop_val(ep);
        !           697:   return gerepile(av,tetpil,gdiv(s,dn));
        !           698: }
        !           699:
        !           700: GEN
        !           701: sumpos(entree *ep, GEN a, char *ch, long prec)
        !           702: {
        !           703:   long av = avma,tetpil,k,kk,N,G;
        !           704:   GEN p1,r,q1,reel,s,az,c,x,e1,d, *stock;
        !           705:
        !           706:   if (typ(a) != t_INT) err(talker,"non integral index in sumpos");
        !           707:
        !           708:   push_val(ep, NULL);
        !           709:   a=subis(a,1); reel=cgetr(prec);
        !           710:   e1=addsr(3,gsqrt(stoi(8),prec));
        !           711:   N=(long)(0.4*(bit_accuracy(prec) + 7));
        !           712:   d=gpuigs(e1,N); d=shiftr(addrr(d,divsr(1,d)),-1);
        !           713:   az=negi(gun); c=d; s=gzero;
        !           714:   G = -bit_accuracy(prec) - 5;
        !           715:   stock=(GEN*)new_chunk(N+1); for (k=1; k<=N; k++) stock[k]=NULL;
        !           716:   for (k=0; k<N; k++)
        !           717:   {
        !           718:     if (k&1 && stock[k]) x=stock[k];
        !           719:     else
        !           720:     {
        !           721:       x=gzero; r=stoi(2*k+2);
        !           722:       for(kk=0;;kk++)
        !           723:       {
        !           724:         long ex;
        !           725:        q1 = addii(r,a); ep->value = (void*) q1;
        !           726:         p1 = lisexpr(ch); if (did_break()) err(breaker,"sumpos");
        !           727:         gaffect(p1,reel); ex = expo(reel)+kk; setexpo(reel,ex);
        !           728:        x = gadd(x,reel); if (kk && ex < G) break;
        !           729:         r=shifti(r,1);
        !           730:       }
        !           731:       if (2*k<N) stock[2*k+1]=x;
        !           732:       q1 = addsi(k+1,a); ep->value = (void*) q1;
        !           733:       p1 = lisexpr(ch); if (did_break()) err(breaker,"sumpos");
        !           734:       gaffect(p1,reel); x = gadd(reel, gmul2n(x,1));
        !           735:     }
        !           736:     c=gadd(az,c); p1 = k&1? gneg_i(c): c;
        !           737:     s = gadd(s,gmul(x,p1));
        !           738:     az = divii(mulii(mulss(N-k,N+k),shifti(az,1)),mulss(k+1,k+k+1));
        !           739:   }
        !           740:   tetpil=avma; pop_val(ep);
        !           741:   return gerepile(av,tetpil,gdiv(s,d));
        !           742: }
        !           743:
        !           744: GEN
        !           745: sumpos2(entree *ep, GEN a, char *ch, long prec)
        !           746: {
        !           747:   long av = avma,tetpil,k,kk,N,G;
        !           748:   GEN p1,r,q1,reel,s,pol,dn,x, *stock;
        !           749:
        !           750:   if (typ(a) != t_INT) err(talker,"non integral index in sumpos2");
        !           751:
        !           752:   push_val(ep, a);
        !           753:   a=subis(a,1); reel=cgetr(prec);
        !           754:   N=(long)(0.31*(bit_accuracy(prec) + 5));
        !           755:   G = -bit_accuracy(prec) - 5;
        !           756:   stock=(GEN*)new_chunk(N+1); for (k=1; k<=N; k++) stock[k]=NULL;
        !           757:   for (k=1; k<=N; k++)
        !           758:   {
        !           759:     if (odd(k) || !stock[k])
        !           760:     {
        !           761:       x=gzero; r=stoi(2*k);
        !           762:       for(kk=0;;kk++)
        !           763:       {
        !           764:         long ex;
        !           765:        q1 = addii(r,a); ep->value = (void*) q1;
        !           766:         p1 = lisexpr(ch); if (did_break()) err(breaker,"sumpos2");
        !           767:         gaffect(p1,reel); ex = expo(reel)+kk; setexpo(reel,ex);
        !           768:        x=gadd(x,reel); if (kk && ex < G) break;
        !           769:         r=shifti(r,1);
        !           770:       }
        !           771:       if (2*k-1<N) stock[2*k]=x;
        !           772:       q1 = addsi(k,a); ep->value = (void*) q1;
        !           773:       p1 = lisexpr(ch); if (did_break()) err(breaker,"sumpos2");
        !           774:       gaffect(p1,reel); stock[k] = gadd(reel, gmul2n(x,1));
        !           775:     }
        !           776:   }
        !           777:   pop_val(ep); s = gzero;
        !           778:   pol=polzagreel(N,N>>1,prec+1); dn=poleval(pol,gun);
        !           779:   pol[2]=lsub((GEN)pol[2],dn); pol=gdiv(pol,gsub(gun,polx[0]));
        !           780:   for (k=1; k<=lgef(pol)-2; k++)
        !           781:   {
        !           782:     p1 = gmul((GEN)pol[k+1],stock[k]);
        !           783:     if (k&1) p1 = gneg_i(p1);
        !           784:     s = gadd(s,p1);
        !           785:   }
        !           786:   tetpil=avma; return gerepile(av,tetpil,gdiv(s,dn));
        !           787: }
        !           788:
        !           789: /********************************************************************/
        !           790: /**                                                                **/
        !           791: /**                NUMERICAL INTEGRATION (Romberg)                 **/
        !           792: /**                                                                **/
        !           793: /********************************************************************/
        !           794: GEN
        !           795: intnum0(entree *ep, GEN a, GEN b, char *ch, long flag, long prec)
        !           796: {
        !           797:   switch(flag)
        !           798:   {
        !           799:     case 0: return qromb  (ep,a,b,ch,prec);
        !           800:     case 1: return rombint(ep,a,b,ch,prec);
        !           801:     case 2: return qromi  (ep,a,b,ch,prec);
        !           802:     case 3: return qromo  (ep,a,b,ch,prec);
        !           803:     default: err(flagerr);
        !           804:   }
        !           805:   return NULL; /* not reached */
        !           806: }
        !           807:
        !           808: #define JMAX 25
        !           809: #define JMAXP JMAX+3
        !           810: #define KLOC 4
        !           811:
        !           812: /* we need to make a copy in any case, cf forpari */
        !           813: static GEN
        !           814: fix(GEN a, long prec)
        !           815: {
        !           816:   GEN p = cgetr(prec);
        !           817:   gaffect(a,p); return p;
        !           818: }
        !           819:
        !           820: GEN polint_i(GEN xa, GEN ya, GEN x, long n, GEN *ptdy);
        !           821:
        !           822: GEN
        !           823: qromb(entree *ep, GEN a, GEN b, char *ch, long prec)
        !           824: {
        !           825:   GEN ss,dss,s,h,p1,p2,qlint,del,x,sum;
        !           826:   long av = avma, av1, tetpil,j,j1,j2,lim,it,sig;
        !           827:
        !           828:   a = fix(a,prec);
        !           829:   b = fix(b,prec);
        !           830:   qlint=subrr(b,a); sig=signe(qlint);
        !           831:   if (!sig)  { avma=av; return gzero; }
        !           832:   if (sig<0) { setsigne(qlint,1); s=a; a=b; b=s; }
        !           833:
        !           834:   s=new_chunk(JMAXP);
        !           835:   h=new_chunk(JMAXP);
        !           836:   h[0] = (long)realun(prec);
        !           837:
        !           838:   push_val(ep, a);
        !           839:   p1=lisexpr(ch); if (p1 == a) p1=rcopy(p1);
        !           840:   ep->value = (void*)b;
        !           841:   p2=lisexpr(ch);
        !           842:   s[0]=lmul2n(gmul(qlint,gadd(p1,p2)),-1);
        !           843:   for (it=1,j=1; j<JMAX; j++,it=it<<1)
        !           844:   {
        !           845:     h[j]=lshiftr((GEN)h[j-1],-2);
        !           846:     av1=avma; del=divrs(qlint,it); x=addrr(a,shiftr(del,-1));
        !           847:     for (sum=gzero,j1=1; j1<=it; j1++,x=addrr(x,del))
        !           848:     {
        !           849:       ep->value = (void*) x; sum=gadd(sum,lisexpr(ch));
        !           850:     }
        !           851:     sum = gmul(sum,del); p1 = gadd((GEN)s[j-1],sum);
        !           852:     tetpil = avma;
        !           853:     s[j]=lpile(av1,tetpil,gmul2n(p1,-1));
        !           854:
        !           855:     if (j>=KLOC)
        !           856:     {
        !           857:       tetpil=avma; ss=polint_i(h+j-KLOC,s+j-KLOC,gzero,KLOC+1,&dss);
        !           858:       j1=gexpo(ss); j2=gexpo(dss); lim=bit_accuracy(prec)-j-6;
        !           859:       if (j1-j2 > lim || (j1 < -lim && j2<j1-1))
        !           860:       {
        !           861:         pop_val(ep); if (gcmp0(gimag(ss))) ss=greal(ss);
        !           862:        tetpil=avma; return gerepile(av,tetpil,gmulsg(sig,ss));
        !           863:       }
        !           864:       avma=tetpil;
        !           865:     }
        !           866:   }
        !           867:   err(intger2); return NULL; /* not reached */
        !           868: }
        !           869:
        !           870: GEN
        !           871: qromo(entree *ep, GEN a, GEN b, char *ch, long prec)
        !           872: {
        !           873:   GEN ss,dss,s,h,p1,qlint,del,ddel,x,sum;
        !           874:   long av = avma,av1,tetpil,j,j1,j2,lim,it,sig;
        !           875:
        !           876:   a = fix(a, prec);
        !           877:   b = fix(b, prec);
        !           878:   qlint=subrr(b,a); sig=signe(qlint);
        !           879:   if (!sig)  { avma=av; return gzero; }
        !           880:   if (sig<0) { setsigne(qlint,1); s=a; a=b; b=s; }
        !           881:
        !           882:   s=new_chunk(JMAXP);
        !           883:   h=new_chunk(JMAXP);
        !           884:   h[0] = (long)realun(prec);
        !           885:
        !           886:   p1 = shiftr(addrr(a,b),-1); push_val(ep, p1);
        !           887:   p1=lisexpr(ch); s[0]=lmul(qlint,p1);
        !           888:
        !           889:   for (it=1, j=1; j<JMAX; j++, it*=3)
        !           890:   {
        !           891:     h[j] = ldivrs((GEN)h[j-1],9);
        !           892:     av1=avma; del=divrs(qlint,3*it); ddel=shiftr(del,1);
        !           893:     x=addrr(a,shiftr(del,-1)); sum=gzero;
        !           894:     for (j1=1; j1<=it; j1++)
        !           895:     {
        !           896:       ep->value = (void*)x; sum=gadd(sum,lisexpr(ch)); x=addrr(x,ddel);
        !           897:       ep->value = (void*)x; sum=gadd(sum,lisexpr(ch)); x=addrr(x,del);
        !           898:     }
        !           899:     sum = gmul(sum,del); p1 = gdivgs((GEN)s[j-1],3);
        !           900:     tetpil = avma; s[j]=lpile(av1,tetpil,gadd(p1,sum));
        !           901:
        !           902:     if (j>=KLOC)
        !           903:     {
        !           904:       tetpil=avma; ss=polint_i(h+j-KLOC,s+j-KLOC,gzero,KLOC+1,&dss);
        !           905:       j1=gexpo(ss); j2=gexpo(dss); lim=bit_accuracy(prec)-(3*j/2)-6;
        !           906:       if ( j1-j2 > lim || (j1 < -lim && j2<j1-1))
        !           907:       {
        !           908:         pop_val(ep); if (gcmp0(gimag(ss))) ss=greal(ss);
        !           909:        tetpil=avma; return gerepile(av,tetpil,gmulsg(sig,ss));
        !           910:       }
        !           911:       avma=tetpil;
        !           912:     }
        !           913:   }
        !           914:   err(intger2); return NULL; /* not reached */
        !           915: }
        !           916:
        !           917: #undef JMAX
        !           918: #undef JMAXP
        !           919: #define JMAX 16
        !           920: #define JMAXP JMAX+3
        !           921:
        !           922: GEN
        !           923: qromi(entree *ep, GEN a, GEN b, char *ch, long prec)
        !           924: {
        !           925:   GEN ss,dss,s,h,q1,p1,p,qlint,del,ddel,x,sum;
        !           926:   long av = avma, av1,tetpil,j,j1,j2,lim,it,sig;
        !           927:
        !           928:   p=cgetr(prec); gaffect(ginv(a),p); a=p;
        !           929:   p=cgetr(prec); gaffect(ginv(b),p); b=p;
        !           930:   qlint=subrr(b,a); sig= -signe(qlint);
        !           931:   if (!sig)  { avma=av; return gzero; }
        !           932:   if (sig>0) { setsigne(qlint,1); s=a; a=b; b=s; }
        !           933:
        !           934:   s=new_chunk(JMAXP);
        !           935:   h=new_chunk(JMAXP);
        !           936:   h[0] = (long)realun(prec);
        !           937:
        !           938:   x=divsr(2,addrr(a,b)); push_val(ep, x);
        !           939:   p1=gmul(lisexpr(ch),mulrr(x,x));
        !           940:   s[0]=lmul(qlint,p1);
        !           941:   for (it=1,j=1; j<JMAX; j++, it*=3)
        !           942:   {
        !           943:     h[j] = ldivrs((GEN)h[j-1],9);
        !           944:     av1=avma; del=divrs(qlint,3*it); ddel=shiftr(del,1);
        !           945:     x=addrr(a,shiftr(del,-1)); sum=gzero;
        !           946:     for (j1=1; j1<=it; j1++)
        !           947:     {
        !           948:       q1 = ginv(x); ep->value = (void*)q1;
        !           949:       p1=gmul(lisexpr(ch), gsqr(q1));
        !           950:       sum=gadd(sum,p1); x=addrr(x,ddel);
        !           951:
        !           952:       q1 = ginv(x); ep->value = (void*)q1;
        !           953:       p1=gmul(lisexpr(ch), gsqr(q1));
        !           954:       sum=gadd(sum,p1); x=addrr(x,del);
        !           955:     }
        !           956:     sum = gmul(sum,del); p1 = gdivgs((GEN)s[j-1],3);
        !           957:     tetpil=avma;
        !           958:     s[j]=lpile(av1,tetpil,gadd(p1,sum));
        !           959:
        !           960:     if (j>=KLOC)
        !           961:     {
        !           962:       tetpil=avma; ss=polint_i(h+j-KLOC,s+j-KLOC,gzero,KLOC+1,&dss);
        !           963:       j1=gexpo(ss); j2=gexpo(dss); lim=bit_accuracy(prec)-(3*j/2)-6;
        !           964:       if (j1-j2 > lim || (j1 < -lim && j2 < j1-1))
        !           965:       {
        !           966:         pop_val(ep); if (gcmp0(gimag(ss))) ss=greal(ss);
        !           967:        tetpil=avma; return gerepile(av,tetpil,gmulsg(sig,ss));
        !           968:       }
        !           969:     }
        !           970:   }
        !           971:   err(intger2); return NULL; /* not reached */
        !           972: }
        !           973:
        !           974: GEN
        !           975: rombint(entree *ep, GEN a, GEN b, char *ch, long prec)
        !           976: {
        !           977:   GEN aa,bb,mun,p1,p2,p3;
        !           978:   long l,av,tetpil;
        !           979:
        !           980:   l=gcmp(b,a); if (!l) return gzero;
        !           981:   if (l<0) { bb=a; aa=b; } else { bb=b; aa=a; }
        !           982:   av=avma; mun = negi(gun);
        !           983:   if (gcmpgs(bb,100)>=0)
        !           984:   {
        !           985:     if (gcmpgs(aa,1)>=0) return qromi(ep,a,b,ch,prec);
        !           986:     p1=qromi(ep,gun,bb,ch,prec);
        !           987:     if (gcmpgs(aa,-100)>=0)
        !           988:     {
        !           989:       p2=qromo(ep,aa,gun,ch,prec); tetpil=avma;
        !           990:       return gerepile(av,tetpil,gmulsg(l,gadd(p1,p2)));
        !           991:     }
        !           992:     p2=qromo(ep,mun,gun,ch,prec); p3=gadd(p2,qromi(ep,aa,mun,ch,prec));
        !           993:     tetpil=avma; return gerepile(av,tetpil,gmulsg(l,gadd(p1,p3)));
        !           994:   }
        !           995:   if (gcmpgs(aa,-100)>=0) return qromo(ep,a,b,ch,prec);
        !           996:   if (gcmpgs(bb,-1)>=0)
        !           997:   {
        !           998:     p1=qromi(ep,aa,mun,ch,prec); p2=qromo(ep,mun,bb,ch,prec); tetpil=avma;
        !           999:     return gerepile(av,tetpil,gmulsg(l,gadd(p1,p2)));
        !          1000:   }
        !          1001:   return qromi(ep,a,b,ch,prec);
        !          1002: }
        !          1003:
        !          1004: /********************************************************************/
        !          1005: /**                                                                **/
        !          1006: /**                  ZAGIER POLYNOMIALS (for sumiter)              **/
        !          1007: /**                                                                **/
        !          1008: /********************************************************************/
        !          1009:
        !          1010: GEN
        !          1011: polzag(long n, long m)
        !          1012: {
        !          1013:   long d1,d,r,k,av=avma,tetpil;
        !          1014:   GEN p1,p2,pol1,g,s;
        !          1015:
        !          1016:   if (m>=n || m<0)
        !          1017:     err(talker,"first index must be greater than second in polzag");
        !          1018:   d1=n-m; d=d1<<1; d1--; p1=gsub(gun,gmul2n(polx[0],1));
        !          1019:   pol1=gsub(gun,polx[0]); p2=gmul(polx[0],pol1); r=(m+1)>>1;
        !          1020:   g=gzero;
        !          1021:   for (k=0; k<=d1; k++)
        !          1022:   {
        !          1023:     s=binome(stoi(d),(k<<1)+1); if (k&1) s=negi(s);
        !          1024:     g=gadd(g,gmul(s,gmul(gpuigs(polx[0],k),gpuigs(pol1,d1-k))));
        !          1025:   }
        !          1026:   g=gmul(g,gpuigs(p2,r));
        !          1027:   if (!(m&1)) g=gadd(gmul(p1,g),gmul2n(gmul(p2,derivpol(g)),1));
        !          1028:   for (k=1; k<=r; k++)
        !          1029:   {
        !          1030:     g=derivpol(g); g=gadd(gmul(p1,g),gmul2n(gmul(p2,derivpol(g)),1));
        !          1031:   }
        !          1032:   g = m ? gmul2n(g,(m-1)>>1):gmul2n(g,-1);
        !          1033:   s=mulsi(n-m,mpfact(m+1));
        !          1034:   tetpil=avma; return gerepile(av,tetpil,gdiv(g,s));
        !          1035: }
        !          1036:
        !          1037: #ifdef _MSC_VER /* Bill Daly: work around a MSVC bug */
        !          1038: #pragma optimize("g",off)
        !          1039: #endif
        !          1040: GEN
        !          1041: polzagreel(long n, long m, long prec)
        !          1042: {
        !          1043:   long d1,d,r,j,k,k2,av=avma,tetpil;
        !          1044:   GEN p2,pol1,g,h,v,b,gend,s;
        !          1045:
        !          1046:   if (m>=n || m<0)
        !          1047:     err(talker,"first index must be greater than second in polzag");
        !          1048:   d1=n-m; d=d1<<1; d1--; pol1=gadd(gun,polx[0]);
        !          1049:   p2=gmul(polx[0],pol1); r=(m+1)>>1; gend=stoi(d);
        !          1050:   v=cgetg(d1+2,t_VEC); g=cgetg(d1+2,t_VEC);
        !          1051:   v[d1+1]=un; b=mulri(realun(prec),gend); g[d1+1]=(long)b;
        !          1052:   for (k=1; k<=d1; k++)
        !          1053:   {
        !          1054:     v[d1-k+1]=un;
        !          1055:     for (j=1; j<k; j++)
        !          1056:       v[d1-k+j+1]=(long)addii((GEN)v[d1-k+j+1],(GEN)v[d1-k+j+2]);
        !          1057:     k2=k+k; b=divri(mulri(b,mulss(d-k2+1,d-k2)),mulss(k2,k2+1));
        !          1058:     for (j=1; j<=k; j++)
        !          1059:       g[d1-k+j+1]=(long)mpadd((GEN)g[d1-k+j+1],mulri(b,(GEN)v[d1-k+j+1]));
        !          1060:     g[d1-k+1]=(long)b;
        !          1061:   }
        !          1062:   h=cgetg(d1+3,t_POL); h[1]=evalsigne(1)+evallgef(d1+3);
        !          1063:   for (k=0; k<=d1; k++) h[k+2]=g[k+1];
        !          1064:   g=gmul(h,gpuigs(p2,r));
        !          1065:   for (j=0; j<=r; j++)
        !          1066:   {
        !          1067:     if (j) g=derivpol(g);
        !          1068:     if (j || !(m&1))
        !          1069:     {
        !          1070:       h=cgetg(n+3,t_POL); h[1]=evalsigne(1)+evallgef(n+3);
        !          1071:       h[2]=g[2];
        !          1072:       for (k=1; k<n; k++)
        !          1073:        h[k+2]=ladd(gmulsg(k+k+1,(GEN)g[k+2]),gmulsg(k<<1,(GEN)g[k+1]));
        !          1074:       h[n+2]=lmulsg(n<<1,(GEN)g[n+1]); g=h;
        !          1075:     }
        !          1076:   }
        !          1077:   g = m ?gmul2n(g,(m-1)>>1):gmul2n(g,-1);
        !          1078:   s=mulsi(n-m,mpfact(m+1));
        !          1079:   tetpil=avma; return gerepile(av,tetpil,gdiv(g,s));
        !          1080: }
        !          1081: #ifdef _MSC_VER
        !          1082: #pragma optimize("g",on)
        !          1083: #endif
        !          1084:
        !          1085: /********************************************************************/
        !          1086: /**                                                                **/
        !          1087: /**            SEARCH FOR REAL ZEROS of an expression              **/
        !          1088: /**                                                                **/
        !          1089: /********************************************************************/
        !          1090:
        !          1091: GEN
        !          1092: zbrent(entree *ep, GEN a, GEN b, char *ch, long prec)
        !          1093: {
        !          1094:   long av=avma,tetpil,sig,iter,itmax;
        !          1095:   GEN c,d,e,tol,toli,min1,min2,fa,fb,fc,p,q,r,s,xm;
        !          1096:
        !          1097:   a = fix(a,prec);
        !          1098:   b = fix(b,prec); sig=cmprr(b,a);
        !          1099:   if (!sig) { avma = av; return gzero; }
        !          1100:   if (sig<0) { c=a; a=b; b=c; }
        !          1101:
        !          1102:   push_val(ep, a);      fa = lisexpr(ch);
        !          1103:   ep->value = (void*)b; fb = lisexpr(ch);
        !          1104:   if (gsigne(fa)*gsigne(fb) > 0)
        !          1105:     err(talker,"roots must be bracketed in solve");
        !          1106:   itmax = (prec<<(TWOPOTBITS_IN_LONG+1)) + 1;
        !          1107:   tol = realun(3); setexpo(tol, 5-bit_accuracy(prec));
        !          1108:   fc=fb;
        !          1109:   for (iter=1; iter<=itmax; iter++)
        !          1110:   {
        !          1111:     if (gsigne(fb)*gsigne(fc) > 0)
        !          1112:     {
        !          1113:       c=a; fc=fa; d=subrr(b,a); e=d;
        !          1114:     }
        !          1115:     if (gcmp(gabs(fc,0),gabs(fb,0)) < 0)
        !          1116:     {
        !          1117:       a=b; b=c; c=a; fa=fb; fb=fc; fc=fa;
        !          1118:     }
        !          1119:     toli=mulrr(tol,gmax(tol,absr(b)));
        !          1120:     xm=shiftr(subrr(c,b),-1);
        !          1121:     if (cmprr(absr(xm),toli) <= 0 || gcmp0(fb))
        !          1122:     {
        !          1123:       tetpil=avma; pop_val(ep);
        !          1124:       return gerepile(av,tetpil,rcopy(b));
        !          1125:     }
        !          1126:     if (cmprr(absr(e),toli) >= 0 && gcmp(gabs(fa,0),gabs(fb,0)) > 0)
        !          1127:     {
        !          1128:       s=gdiv(fb,fa);
        !          1129:       if (cmprr(a,b)==0)
        !          1130:       {
        !          1131:        p=gmul2n(gmul(xm,s),1); q=gsubsg(1,s);
        !          1132:       }
        !          1133:       else
        !          1134:       {
        !          1135:        q=gdiv(fa,fc); r=gdiv(fb,fc);
        !          1136:        p=gmul2n(gmul(gsub(q,r),gmul(xm,q)),1);
        !          1137:        p=gmul(s,gsub(p,gmul(gsub(b,a),gsubgs(r,1))));
        !          1138:        q=gmul(gmul(gsubgs(q,1),gsubgs(r,1)),gsubgs(s,1));
        !          1139:       }
        !          1140:       if (gsigne(p) > 0) q=gneg_i(q); else p=gneg_i(p);
        !          1141:       min1=gsub(gmulsg(3,gmul(xm,q)),gabs(gmul(q,toli),0));
        !          1142:       min2=gabs(gmul(e,q),0);
        !          1143:       if (gcmp(gmul2n(p,1),gmin(min1,min2)) < 0)
        !          1144:         { e=d; d=gdiv(p,q); }
        !          1145:       else
        !          1146:         { d=xm; e=d; }
        !          1147:     }
        !          1148:     else { d=xm; e=d; }
        !          1149:     a=b; fa=fb;
        !          1150:     if (gcmp(gabs(d,0),toli) > 0) b=gadd(b,d);
        !          1151:     else
        !          1152:     {
        !          1153:       if (gsigne(xm)>0)
        !          1154:         b = addrr(b,toli);
        !          1155:       else
        !          1156:         b = subrr(b,toli);
        !          1157:     }
        !          1158:     ep->value = (void*)b; fb=lisexpr(ch);
        !          1159:   }
        !          1160:   err(talker,"too many iterations in solve");
        !          1161:   return NULL; /* not reached */
        !          1162: }

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