version 1.11, 2003/04/28 06:43:10 |
version 1.13, 2004/09/13 09:23:30 |
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@comment $OpenXM: OpenXM/src/asir-doc/parts/groebner.texi,v 1.10 2003/04/28 03:09:23 noro Exp $ |
@comment $OpenXM: OpenXM/src/asir-doc/parts/groebner.texi,v 1.12 2003/12/27 11:52:07 takayama Exp $ |
\BJP |
\BJP |
@node $B%0%l%V%J4pDl$N7W;;(B,,, Top |
@node $B%0%l%V%J4pDl$N7W;;(B,,, Top |
@chapter $B%0%l%V%J4pDl$N7W;;(B |
@chapter $B%0%l%V%J4pDl$N7W;;(B |
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* $B4pK\E*$JH!?t(B:: |
* $B4pK\E*$JH!?t(B:: |
* $B7W;;$*$h$SI=<($N@)8f(B:: |
* $B7W;;$*$h$SI=<($N@)8f(B:: |
* $B9`=g=x$N@_Dj(B:: |
* $B9`=g=x$N@_Dj(B:: |
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* Weight:: |
* $BM-M}<0$r78?t$H$9$k%0%l%V%J4pDl7W;;(B:: |
* $BM-M}<0$r78?t$H$9$k%0%l%V%J4pDl7W;;(B:: |
* $B4pDlJQ49(B:: |
* $B4pDlJQ49(B:: |
* Weyl $BBe?t(B:: |
* Weyl $BBe?t(B:: |
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* Fundamental functions:: |
* Fundamental functions:: |
* Controlling Groebner basis computations:: |
* Controlling Groebner basis computations:: |
* Setting term orderings:: |
* Setting term orderings:: |
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* Weight:: |
* Groebner basis computation with rational function coefficients:: |
* Groebner basis computation with rational function coefficients:: |
* Change of ordering:: |
* Change of ordering:: |
* Weyl algebra:: |
* Weyl algebra:: |
Line 1055 beforehand, and some heuristic trial may be inevitable |
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Line 1057 beforehand, and some heuristic trial may be inevitable |
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\E |
\E |
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\BJP |
\BJP |
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@node Weight ,,, $B%0%l%V%J4pDl$N7W;;(B |
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@section Weight |
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\E |
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\BEG |
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@node Weight,,, Groebner basis computation |
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@section Weight |
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\E |
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\BJP |
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$BA0@a$G>R2p$7$?9`=g=x$O(B, $B3FJQ?t$K(B weight ($B=E$_(B) $B$r@_Dj$9$k$3$H$G(B |
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$B$h$j0lHLE*$J$b$N$H$J$k(B. |
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\E |
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\BEG |
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Term orders introduced in the previous section can be generalized |
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by setting a weight for each variable. |
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\E |
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@example |
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[0] dp_td(<<1,1,1>>); |
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3 |
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[1] dp_set_weight([1,2,3])$ |
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[2] dp_td(<<1,1,1>>); |
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6 |
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@end example |
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\BJP |
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$BC19`<0$NA4<!?t$r7W;;$9$k:](B, $B%G%U%)%k%H$G$O(B |
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$B3FJQ?t$N;X?t$NOB$rA4<!?t$H$9$k(B. $B$3$l$O3FJQ?t$N(B weight $B$r(B 1 $B$H(B |
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$B9M$($F$$$k$3$H$KAjEv$9$k(B. $B$3$NNc$G$O(B, $BBh0l(B, $BBhFs(B, $BBh;0JQ?t$N(B |
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weight $B$r$=$l$>$l(B 1,2,3 $B$H;XDj$7$F$$$k(B. $B$3$N$?$a(B, @code{<<1,1,1>>} |
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$B$NA4<!?t(B ($B0J2<$G$O$3$l$rC19`<0$N(B weight $B$H8F$V(B) $B$,(B @code{1*1+1*2+1*3=6} $B$H$J$k(B. |
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weight $B$r@_Dj$9$k$3$H$G(B, $BF1$89`=g=x7?$N$b$H$G0[$J$k9`=g=x$,Dj5A$G$-$k(B. |
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$BNc$($P(B, weight $B$r$&$^$/@_Dj$9$k$3$H$G(B, $BB?9`<0$r(B weighted homogeneous |
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$B$K$9$k$3$H$,$G$-$k>l9g$,$"$k(B. |
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\E |
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\BEG |
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By default, the total degree of a monomial is equal to |
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the sum of all exponents. This means that the weight for each variable |
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is set to 1. |
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In this example, the weights for the first, the second and the third |
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variable are set to 1, 2 and 3 respectively. |
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Therefore the total degree of @code{<<1,1,1>>} under this weight, |
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which is called the weight of the monomial, is @code{1*1+1*2+1*3=6}. |
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By setting weights, different term orders can be set under a term |
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order type. For example, a polynomial can be made weighted homogeneous |
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by setting an appropriate weight. |
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\E |
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\BJP |
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$B3FJQ?t$KBP$9$k(B weight $B$r$^$H$a$?$b$N$r(B weight vector $B$H8F$V(B. |
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$B$9$Y$F$N@.J,$,@5$G$"$j(B, $B%0%l%V%J4pDl7W;;$K$*$$$F(B, $BA4<!?t$N(B |
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$BBe$o$j$KMQ$$$i$l$k$b$N$rFC$K(B sugar weight $B$H8F$V$3$H$K$9$k(B. |
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sugar strategy $B$K$*$$$F(B, $BA4<!?t$NBe$o$j$K;H$o$l$k$+$i$G$"$k(B. |
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$B0lJ}$G(B, $B3F@.J,$,I,$:$7$b@5$H$O8B$i$J$$(B weight vector $B$O(B, |
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sugar weight $B$H$7$F@_Dj$9$k$3$H$O$G$-$J$$$,(B, $B9`=g=x$N0lHL2=$K$O(B |
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$BM-MQ$G$"$k(B. $B$3$l$i$O(B, $B9TNs$K$h$k9`=g=x$N@_Dj$K$9$G$K8=$l$F(B |
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$B$$$k(B. $B$9$J$o$A(B, $B9`=g=x$rDj5A$9$k9TNs$N3F9T$,(B, $B0l$D$N(B weight vector |
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$B$H8+$J$5$l$k(B. $B$^$?(B, $B%V%m%C%/=g=x$O(B, $B3F%V%m%C%/$N(B |
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$BJQ?t$KBP1~$9$k@.J,$N$_(B 1 $B$GB>$O(B 0 $B$N(B weight vector $B$K$h$kHf3S$r(B |
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$B:G=i$K9T$C$F$+$i(B, $B3F%V%m%C%/Kh$N(B tie breaking $B$r9T$&$3$H$KAjEv$9$k(B. |
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\E |
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\BEG |
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A list of weights for all variables is called a weight vector. |
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A weight vector is called a sugar weight vector if |
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its elements are all positive and it is used for computing |
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a weighted total degree of a monomial, because such a weight |
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is used instead of total degree in sugar strategy. |
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On the other hand, a weight vector whose elements are not necessarily |
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positive cannot be set as a sugar weight, but it is useful for |
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generalizing term order. In fact, such a weight vector already |
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appeared in a matrix order. That is, each row of a matrix defining |
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a term order is regarded as a weight vector. A block order |
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is also considered as a refinement of comparison by weight vectors. |
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It compares two terms by using a weight vector whose elements |
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corresponding to variables in a block is 1 and 0 otherwise, |
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then it applies a tie breaker. |
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\E |
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\BJP |
@node $BM-M}<0$r78?t$H$9$k%0%l%V%J4pDl7W;;(B,,, $B%0%l%V%J4pDl$N7W;;(B |
@node $BM-M}<0$r78?t$H$9$k%0%l%V%J4pDl7W;;(B,,, $B%0%l%V%J4pDl$N7W;;(B |
@section $BM-M}<0$r78?t$H$9$k%0%l%V%J4pDl7W;;(B |
@section $BM-M}<0$r78?t$H$9$k%0%l%V%J4pDl7W;;(B |
\E |
\E |
Line 1412 strategy $B$K$h$k7W;;(B, @code{hgr()} $B$O(B trace |
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Line 1492 strategy $B$K$h$k7W;;(B, @code{hgr()} $B$O(B trace |
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@item |
@item |
@code{dgr()} $B$GI=<($5$l$k;~4V$O(B, $B$3$NH!?t$,<B9T$5$l$F$$$k%W%m%;%9$G$N(B |
@code{dgr()} $B$GI=<($5$l$k;~4V$O(B, $B$3$NH!?t$,<B9T$5$l$F$$$k%W%m%;%9$G$N(B |
CPU $B;~4V$G$"$j(B, $B$3$NH!?t$N>l9g$O$[$H$s$IDL?.$N$?$a$N;~4V$G$"$k(B. |
CPU $B;~4V$G$"$j(B, $B$3$NH!?t$N>l9g$O$[$H$s$IDL?.$N$?$a$N;~4V$G$"$k(B. |
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@item |
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$BB?9`<0%j%9%H(B @var{plist} $B$NMWAG$,J,;6I=8=B?9`<0$N>l9g$O(B |
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$B7k2L$bJ,;6I=8=B?9`<0$N%j%9%H$G$"$k(B. |
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$B$3$N>l9g(B, $B0z?t$NJ,;6B?9`<0$OM?$($i$l$?=g=x$K=>$$(B @code{dp_sort} $B$G(B |
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$B%=!<%H$5$l$F$+$i7W;;$5$l$k(B. |
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$BB?9`<0%j%9%H$NMWAG$,J,;6I=8=B?9`<0$N>l9g$b(B |
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$BJQ?t$N?tJ,$NITDj85$N%j%9%H$r(B @var{vlist} $B0z?t$H$7$FM?$($J$$$H$$$1$J$$(B |
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($B%@%_!<(B). |
\E |
\E |
\BEG |
\BEG |
@item |
@item |
Line 1440 Therefore this function is useful to reduce the actual |
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Line 1528 Therefore this function is useful to reduce the actual |
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The CPU time shown after an exection of @code{dgr()} indicates |
The CPU time shown after an exection of @code{dgr()} indicates |
that of the master process, and most of the time corresponds to the time |
that of the master process, and most of the time corresponds to the time |
for communication. |
for communication. |
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@item |
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When the elements of @var{plist} are distributed polynomials, |
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the result is also a list of distributed polynomials. |
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In this case, firstly the elements of @var{plist} is sorted by @code{dp_sort} |
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and the Grobner basis computation is started. |
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Variables must be given in @var{vlist} even in this case |
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(these variables are dummy). |
\E |
\E |
@end itemize |
@end itemize |
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