% $OpenXM: OpenXM/doc/Papers/dagb-noro.tex,v 1.8 2001/10/11 01:34:42 noro Exp $ \setlength{\parskip}{10pt} \begin{slide}{} \begin{center} \fbox{\large Part I : OpenXM and Risa/Asir --- overview and history} \end{center} \end{slide} %\begin{slide}{} %\fbox{Integration of mathematical software systems} % %\begin{itemize} %\item Data integration % %\begin{itemize} %\item OpenMath ({\tt http://www.openmath.org}) , MP [GRAY98] %\end{itemize} % %Standards for representing mathematical objects % %\item Control integration % %\begin{itemize} %\item MCP [WANG99], OMEI [LIAO01] %\end{itemize} % %Protocols for remote subroutine calls or session management % %\item Combination of two integrations % %\begin{itemize} %\item MathLink, OpenMath+MCP, MP+MCP % %and OpenXM ({\tt http://www.openxm.org}) %\end{itemize} % %Both are necessary for practical implementation % %\end{itemize} %\end{slide} \begin{slide}{} \fbox{A computer algebra system Risa/Asir} ({\tt http://www.math.kobe-u.ac.jp/Asir/asir.html}) \begin{itemize} \item Software mainly for polynomial computation \item User language with C-like syntax C language without type declaration, with list processing \item Builtin {\tt gdb}-like debugger for user programs \item Open source Whole source tree is available via CVS The latest version : see {\tt http://www.openxm.org} \item OpenXM interface \begin{itemize} \item OpenXM An infrastructure for exchanging mathematical data \item Risa/Asir is a main client in OpenXM package. \item An OpenXM server {\tt ox\_asir} \item A library with OpenXM library interface {\tt libasir.a} \end{itemize} \end{itemize} \end{slide} \begin{slide}{} \fbox{Goal of developing Risa/Asir} \begin{itemize} \item Testing new algorithms \begin{itemize} \item Development started in Fujitsu labs Polynomial factorization, Groebner basis related computation, cryptosystems , quantifier elimination , $\ldots$ \end{itemize} \item To be a general purpose, open system Since 1997, we have been developing OpenXM package containing various servers and clients Risa/Asir is a component of OpenXM \item Environment for parallel and distributed computation \end{itemize} \end{slide} %\begin{slide}{} %\fbox{Capability for polynomial computation} % %\begin{itemize} %\item Fundamental polynomial arithmetics % %recursive representation and distributed representation % %\item Polynomial factorization % %\begin{itemize} %\item Univariate : over {\bf Q}, algebraic number fields and finite fields % %\item Multivariate : over {\bf Q} %\end{itemize} % %\item Groebner basis computation % %\begin{itemize} %\item Buchberger and $F_4$ [FAUG99] algorithm % %\item Change of ordering/RUR [ROUI96] of 0-dimensional ideals % %\item Primary ideal decomposition % %\item Computation of $b$-function (in Weyl Algebra) %\end{itemize} %\end{itemize} %\end{slide} \begin{slide}{} \fbox{History of development : Polynomial factorization} \begin{itemize} \item 1989 Start of Risa/Asir with Boehm's conservative GC ({\tt http://www.hpl.hp.com/personal/Hans\_Boehm/gc}) \item 1989-1992 Univariate and multivariate factorizers over {\bf Q} \item 1992-1994 Univariate factorization over algebraic number fields Intensive use of successive extension, non-squarefree norms \item 1996-1998 Univariate factorization over large finite fields Motivated by a reseach project in Fujitsu on cryptography \item 2000-current Multivariate factorization over small finite fields (in progress) \end{itemize} \end{slide} \begin{slide}{} \fbox{History of development : Groebner basis} \begin{itemize} \item 1992-1994 User language $\Rightarrow$ C version; trace lifting [TRAV88] \item 1994-1996 Trace lifting with homogenization Omitting GB check by compatible prime [NOYO99] Modular change of ordering/RUR[ROUI96] [NOYO99] Primary ideal decomposition [SHYO96] \item 1996-1998 Efficient content reduction during NF computation [NORO97] Solved {\it McKay} system for the first time \item 1998-2000 Test implementation of $F_4$ [FAUG99] \item 2000-current Buchberger algorithm in Weyl algebra Efficient $b$-function computation[OAKU97] by a modular method \end{itemize} \end{slide} \begin{slide}{} \fbox{Timing data --- Factorization} \underline{Univariate; over {\bf Q}} $N_i$ : a norm of a polynomial, $\deg(N_i) = i$ \begin{center} \begin{tabular}{|c||c|c|c|c|} \hline & $N_{105}$ & $N_{120}$ & $N_{168}$ & $N_{210}$ \\ \hline Asir & 0.86 & 59 & 840 & hard \\ \hline Asir NormFactor & 1.6 & 2.2& 6.1& hard \\ \hline %Singular& hard? & hard?& hard? & hard? \\ \hline CoCoA 4 & 0.2 & 7.1 & 16 & 0.5 \\ \hline\hline NTL-5.2 & 0.16 & 0.9 & 1.4 & 0.4 \\ \hline \end{tabular} \end{center} \underline{Multivariate; over {\bf Q}} $W_{i,j,k} = Wang[i]\cdot Wang[j]\cdot Wang[k]$ in {\tt asir2000/lib/fctrdata} \begin{center} \begin{tabular}{|c||c|c|c|c|c|} \hline & $W_{1,2,3}$ & $W_{4,5,6}$ & $W_{7,8,9}$ & $W_{10,11,12}$ & $W_{13,14,15}$ \\ \hline Asir & 0.2 & 4.7 & 14 & 17 & 0.4 \\ \hline %Singular& $>$15min & --- & ---& ---& ---\\ \hline CoCoA 4 & 5.2 & $>$15min & $>$15min & $>$15min & 117 \\ \hline\hline Mathematica 4& 0.2 & 16 & 23 & 36 & 1.1 \\ \hline Maple 7& 0.5 & 18 & 48 & & 1.3 \\ \hline \end{tabular} \end{center} %--- : not tested \end{slide} \begin{slide}{} \fbox{Timing data --- DRL Groebner basis computation} \underline{Over $GF(32003)$} \begin{center} \begin{tabular}{|c||c|c|c|c|c|c|c|} \hline & $C_7$ & $C_8$ & $K_7$ & $K_8$ & $K_9$ & $K_{10}$ & $K_{11}$ \\ \hline Asir $Buchberger$ & 31 & 1687 & 2.6 & 27 & 294 & 4309 & --- \\ \hline Singular & 8.7 & 278 & 0.6 & 5.6 & 54 & 508 & 5510 \\ \hline CoCoA 4 & 241 & $>$ 5h & 3.8 & 35 & 402 &7021 & --- \\ \hline\hline Asir $F_4$ & 5.3 & 129 & 0.5 & 4.5 & 31 & 273 & 2641 \\ \hline FGb(estimated) & 0.9 & 23 & 0.1 & 0.8 & 6 & 51 & 366 \\ \hline \end{tabular} \end{center} \underline{Over {\bf Q}} \begin{center} \begin{tabular}{|c||c|c|c|c|c|} \hline & $C_7$ & $Homog. C_7$ & $K_7$ & $K_8$ & $McKay$ \\ \hline Asir $Buchberger$ & 389 & 594 & 29 & 299 & 34950 \\ \hline Singular & --- & 15247 & 7.6 & 79 & $>$ 20h \\ \hline CoCoA 4 & --- & 13227 & 57 & 709 & --- \\ \hline\hline Asir $F_4$ & 989 & 456 & 90 & 991 & 4939 \\ \hline FGb(estimated) & 8 &11 & 0.6 & 5 & 10 \\ \hline \end{tabular} \end{center} --- : not tested \end{slide} \begin{slide}{} \fbox{Summary of performance} \begin{itemize} \item Factorizer \begin{itemize} \item Multivariate : reasonable performance \item Univariate : obsoleted by M. van Hoeij's new algorithm [HOEI00] \end{itemize} \item Groebner basis computation \begin{itemize} \item Buchberger Singular shows nice perfomance Trace lifting is efficient in some cases over {\bf Q} \item $F_4$ FGb is much faster than Risa/Asir But we observe that {\it McKay} is computed efficiently by $F_4$ \end{itemize} \end{itemize} \end{slide} \begin{slide}{} \fbox{Summary} \begin{itemize} \item Total performance is not excellent, but not so bad \item A completely open system The whole source is available \item Interface compliant to OpenXM RFC-100 The interface is fully documented \end{itemize} \end{slide} %\begin{slide}{} %\fbox{CMO = Serialized representation of mathematical object} % %\begin{itemize} %\item primitive data %\begin{eqnarray*} %\mbox{Integer32} &:& ({\tt CMO\_INT32}, {\sl int32}\ \mbox{n}) \\ %\mbox{Cstring}&:& ({\tt CMO\_STRING},{\sl int32}\, \mbox{ n}, {\sl string}\, \mbox{s}) \\ %\mbox{List} &:& ({\tt CMO\_LIST}, {\sl int32}\, len, ob[0], \ldots,ob[m-1]) %\end{eqnarray*} % %\item numbers and polynomials %\begin{eqnarray*} %\mbox{ZZ} &:& ({\tt CMO\_ZZ},{\sl int32}\, {\rm f}, {\sl byte}\, \mbox{a[1]}, \ldots %{\sl byte}\, \mbox{a[$|$f$|$]} ) \\ %\mbox{Monomial32}&:& ({\tt CMO\_MONOMIAL32}, n, \mbox{e[1]}, \ldots, \mbox{e[n]}, \mbox{Coef}) \\ %\mbox{Coef}&:& \mbox{ZZ} | \mbox{Integer32} \\ %\mbox{Dpolynomial}&:& ({\tt CMO\_DISTRIBUTED\_POLYNOMIAL},\\ % & & m, \mbox{DringDefinition}, \mbox{Monomial32}, \ldots)\\ %\mbox{DringDefinition} % &:& \mbox{DMS of N variables} \\ % & & ({\tt CMO\_RING\_BY\_NAME}, name) \\ % & & ({\tt CMO\_DMS\_GENERIC}) \\ %\end{eqnarray*} %\end{itemize} %\end{slide} % %\begin{slide}{} %\fbox{Stack based communication} % %\begin{itemize} %\item Data arrived a client % %Pushed to the stack % %\item Result % %Pushd to the stack % %Written to the stream when requested by a command % %\item The reason why we use the stack % %\begin{itemize} %\item Stack = I/O buffer for (possibly large) objects % %Multiple requests can be sent before their execution % %A server does not get stuck in sending results %\end{itemize} %\end{itemize} %\end{slide} \begin{slide}{} \fbox{OpenXM (Open message eXchange protocol for Mathematics) } \begin{itemize} \item An environment for parallel distributed computation Both for interactive, non-interactive environment \item OpenXM RFC-100 = Client-server architecture Client $\Leftarrow$ OX (OpenXM) message $\Rightarrow$ Server OX (OpenXM) message : command and data \item Data Encoding : CMO (Common Mathematical Object format) Serialized representation of mathematical object --- Main idea was borrowed from OpenMath ({\tt http://www.openmath.org}) \item Command stack machine command --- server is a stackmachine + server's own command sequences --- hybrid server \end{itemize} \end{slide} \begin{slide}{} \fbox{Example of distributed computation --- $F_4$ vs. $Buchberger$ } \begin{verbatim} /* competitive Gbase computation over GF(M) */ /* Cf. A.28 in SINGULAR Manual */ /* Process list is specified as an option : grvsf4(...|proc=P) */ def grvsf4(G,V,M,O) { P = getopt(proc); if ( type(P) == -1 ) return dp_f4_mod_main(G,V,M,O); P0 = P[0]; P1 = P[1]; P = [P0,P1]; map(ox_reset,P); ox_cmo_rpc(P0,"dp_f4_mod_main",G,V,M,O); ox_cmo_rpc(P1,"dp_gr_mod_main",G,V,0,M,O); map(ox_push_cmd,P,262); /* 262 = OX_popCMO */ F = ox_select(P); R = ox_get(F[0]); if ( F[0] == P0 ) { Win = "F4"; Lose = P1;} else { Win = "Buchberger"; Lose = P0; } ox_reset(Lose); /* simply resets the loser */ return [Win,R]; } \end{verbatim} \end{slide} \begin{slide}{} \fbox{References} [BERN97] L. Bernardin, On square-free factorization of multivariate polynomials over a finite field, Theoretical Computer Science 187 (1997), 105-116. [FAUG99] J.C. Faug\`ere, A new efficient algorithm for computing Groebner bases ($F_4$), Journal of Pure and Applied Algebra (139) 1-3 (1999), 61-88. [GRAY98] S. Gray et al, Design and Implementation of MP, A Protocol for Efficient Exchange of Mathematical Expression, J. Symb. Comp. {\bf 25} (1998), 213-238. [HOEI00] M. van Hoeij, Factoring polynomials and the knapsack problem, to appear in Journal of Number Theory (2000). [LIAO01] W. Liao et al, OMEI: An Open Mathematical Engine Interface, Proc. ASCM2001 (2001), 82-91. [NORO97] M. Noro, J. McKay, Computation of replicable functions on Risa/Asir. Proc. PASCO'97, ACM Press (1997), 130-138. \end{slide} \begin{slide}{} [NOYO99] M. Noro, K. Yokoyama, A Modular Method to Compute the Rational Univariate Representation of Zero-Dimensional Ideals. J. Symb. Comp. {\bf 28}/1 (1999), 243-263. [OAKU97] T. Oaku, Algorithms for $b$-functions, restrictions and algebraic local cohomology groups of $D$-modules. Advances in Applied Mathematics, 19 (1997), 61-105. [ROUI96] F. Rouillier, R\'esolution des syst\`emes z\'ero-dimensionnels. Doctoral Thesis(1996), University of Rennes I, France. [SHYO96] T. Shimoyama, K. Yokoyama, Localization and Primary Decomposition of Polynomial Ideals. J. Symb. Comp. {\bf 22} (1996), 247-277. [TRAV88] C. Traverso, \gr trace algorithms. Proc. ISSAC '88 (LNCS 358), 125-138. [WANG99] P. S. Wang, Design and Protocol for Internet Accessible Mathematical Computation, Proc. ISSAC '99 (1999), 291-298. \end{slide} \begin{slide}{} \begin{center} \fbox{\large Part II : Algorithms and implementations in Risa/Asir} \end{center} \end{slide} \begin{slide}{} \fbox{Ground fields} \begin{itemize} \item The rational number field \item Algebraic number fields represented by successive extensions \item Finite fields \begin{itemize} \item $GF(p)$ ($p<2^{30}$); represented by a single word \item $GF(p^n)$ ($p^n < 2^{20}$); represented by a primitive root \item $GF(2^n)$; represented by a bit string \item $GF(p)$ ($p$ : arbitrary prime) \item $GF(p^n)$ ($p$ : arbitrary odd prime) \end{itemize} \item Real and complex number fields \begin{itemize} \item Double float \item PARI bigfloat \end{itemize} \end{itemize} \end{slide} \begin{slide}{} \fbox{Polynomial factorization} \begin{itemize} \item Univariate factorization \begin{itemize} \item Over the rationals Berlekamp-Zassenhaus (classical; knapsack has not yet implemented) \item Over algebraic number fields Trager's algorithm + some improvement \item Over finite fields DDF + Cantor-Zassenhaus; FFT for large finite fields \end{itemize} \item Multivariate factorization \begin{itemize} \item Over the rationals Classical EZ algorithm \item Over small finite fields Modified Bernardin's square free algorithm [BERN97], possibly Hensel lifting over extension fields \end{itemize} \end{itemize} \end{slide} \begin{slide}{} \fbox{Groebner basis computation --- Buchberger algorithm} \begin{itemize} \item Polynomial rings \begin{itemize} \item Over finite fields Any finite field is available as a ground field \item Over the rationals Guess of a groebner basis by detecting zero reduction by modular computation + check (trace lifting) Homogenization+guess+dehomogenization+check \end{itemize} \item Weyl Algebra \begin{itemize} \item Groebner basis of a left ideal Key : an efficient implementation of Leibniz rule \end{itemize} \end{itemize} \end{slide} \begin{slide}{} \fbox{$F_4$ algorithm} \begin{itemize} \item Over small finite fields ($GF(p)$, $p < 2^{30}$) \begin{itemize} \item More efficient than our Buchberger algorithm implementation but less efficient than FGb by Faug\`ere \end{itemize} \item Over the rationals \begin{itemize} \item Very naive implementation Modular computation + CRT + Checking the result at each degree \item Less efficient than Buchberger algorithm except for one example (={\it McKay}) \end{itemize} \end{itemize} \end{slide} \begin{slide}{} \fbox{Change of ordering for zero-dimensional ideals} \begin{itemize} \item Any ordering to lex ordering \begin{itemize} \item Modular change of ordering Guess of the support by modular FGLM + solving linear systems by Hensel lifting \end{itemize} \item RUR (generalized shape lemma) \begin{itemize} \item Modular RUR (only implemented on the shape base case) Almost the same as modular change of ordering \end{itemize} \end{itemize} \end{slide} \begin{slide}{} \fbox{Primary decomposition --- Shimoyama-Yokoyama algorithm} \begin{itemize} \item Only implemented over the rationals Finite field version will soon be available \item Pseudo primary ideal An ideal whose radical is prime \item Prime decomp. of the radical $\Rightarrow$ pseudo primary decomp. \item Extraction of embedded components \end{itemize} \end{slide} \begin{slide}{} \fbox{Computation of $b$-function} $D=K\langle x,\partial \rangle$ : Weyl algebra $b(s)$ : a polynomial of the smallest degree s.t. there exists $P(s) \in D[s]$, $P(s)f^{s+1}=b(s)f^s$ $b(s)$ : $b$-function of a polynomial $f$ $\Rightarrow$ $b(s)$ can be computed by Oaku's algorithm On Risa/Asir : $b(s)$ is computed by A groebner basis $\Rightarrow$ guess of $\deg(b(s))$ by modular computation $\Rightarrow$ solving a linear system \end{slide} \begin{slide}{} \fbox{Interface to PARI library} \begin{itemize} \item Data conversion \begin{itemize} \item Only primitive data can be passed to PARI Rational number, bignum, bigfloat, polynomial, vector, matrix \item Results are converted to Risa objects \end{itemize} \item Evaluation of transcendental functions \begin{itemize} \item Most of univariate functions in PARI can be evaluated by {\tt eval()} \end{itemize} \item Calling PARI functions \begin{itemize} \item One can call PARI functions by {\tt pari({\it parifunction},{\it args})} The knapsack factorization is available via {\tt pari(factor,{\it poly})} \end{itemize} \end{itemize} \end{slide} \begin{slide}{} \fbox{OpenXM server interface in Risa/Asir} \begin{itemize} \item TCP/IP stream \begin{itemize} \item Launcher A client executes a launcher on a host. The launcher launches a server on the same host. \item Server Reads from the descriptor 3 Writes to the descriptor 4 \end{itemize} \item Subroutine call In Risa/Asir subroutine library {\tt libasir.a}: OpenXM functionalities are implemented as function calls pushing and popping data, executing stack commands etc. \end{itemize} \end{slide} \begin{slide}{} \fbox{OpenXM client interface in Risa/Asir} \begin{itemize} \item Primitive interface functions Pushing and popping data, sending commands etc. \item Convenient functions Launching servers, Calling remote functions, Resetting remote executions etc. \item Parallel distributed computation Simple parallelization is practically important Competitive computation is easily realized ($\Rightarrow$ demo) \end{itemize} \end{slide} \begin{slide}{} \fbox{Executing functions on a server (I) --- {\tt SM\_executeFunction}} \begin{enumerate} \item (C $\rightarrow$ S) Arguments are sent in binary encoded form. \item (C $\rightarrow$ S) The number of arguments is sent as {\sl Integer32}. \item (C $\rightarrow$ S) A function name is sent as {\sl Cstring}. \item (C $\rightarrow$ S) A command {\tt SM\_executeFunction} is sent. \item The result is pushed to the stack. \item (C $\rightarrow$ S) A command {\tt SM\_popCMO} is sent. \item (S $\rightarrow$ C) The result is sent in binary encoded form. \end{enumerate} $\Rightarrow$ Communication is fast, but functions for binary data conversion are necessary. \end{slide} \begin{slide}{} \fbox{Executing functions on a server (II) --- {\tt SM\_executeString}} \begin{enumerate} \item (C $\rightarrow$ S) A character string representing a request in a server's user language is sent as {\sl Cstring}. \item (C $\rightarrow$ S) A command {\tt SM\_executeString} is sent. \item The result is pushed to the stack. \item (C $\rightarrow$ S) A command {\tt SM\_popString} is sent. \item (S $\rightarrow$ C) The result is sent in readable form. \end{enumerate} $\Rightarrow$ Communication may be slow, but the client parser may be enough to read the result. \end{slide} %\begin{slide}{} %\fbox{History of development : ---1994} % %\begin{itemize} %\item --1989 % %Several subroutines were developed for a Prolog program. % %\item 1989--1992 % %\begin{itemize} %\item Reconfigured as Risa/Asir with a parser and Boehm's conservative GC % %\item Developed univariate and multivariate factorizers over the rationals. %\end{itemize} % %\item 1992--1994 % %\begin{itemize} %\item Started implementation of Buchberger algorithm % %Written in user language $\Rightarrow$ rewritten in C (by Murao) % %$\Rightarrow$ trace lifting [TRAV88] % %\item Univariate factorization over algebraic number fields % %Intensive use of successive extension, non-squarefree norms %\end{itemize} %\end{itemize} % %\end{slide} % %\begin{slide}{} %\fbox{History of development : 1994-1996} % %\begin{itemize} %\item Free distribution of binary versions from Fujitsu % %\item Primary ideal decomposition % %\begin{itemize} %\item Shimoyama-Yokoyama algorithm [SHYO96] %\end{itemize} % %\item Improvement of Buchberger algorithm % %\begin{itemize} %\item Trace lifting+homogenization % %\item Omitting check by compatible prime % %\item Modular change of ordering, Modular RUR % %These are joint works with Yokoyama [NOYO99] %\end{itemize} %\end{itemize} % %\end{slide} % %\begin{slide}{} %\fbox{History of development : 1996-1998} % %\begin{itemize} %\item Distributed computation % %\begin{itemize} %\item A prototype of OpenXM %\end{itemize} % %\item Improvement of Buchberger algorithm % %\begin{itemize} %\item Content reduction during normal form computation % %\item Its parallelization by the above facility % %\item Computation of odd order replicable functions [NORO97] % %Risa/Asir : it took 5days to compute a DRL basis ({\it McKay}) % %Faug\`ere FGb : computation of the DRL basis 53sec %\end{itemize} % % %\item Univariate factorization over large finite fields % %\begin{itemize} %\item To implement Schoof-Elkies-Atkin algorithm % %Counting rational points on elliptic curves % %--- not free But related functions are freely available %\end{itemize} %\end{itemize} % %\end{slide} % %\begin{slide}{} %\fbox{History of development : 1998-2000} %\begin{itemize} %\item OpenXM % %\begin{itemize} %\item OpenXM specification was written by Noro and Takayama % %Borrowed idea on encoding, phrase book from OpenMath % %\item Functions for distributed computation were rewritten %\end{itemize} % %\item Risa/Asir on Windows % %\begin{itemize} %\item Requirement from a company for which Noro worked % %Written in Visual C++ %\end{itemize} % %\item Test implementation of $F_4$ % %\begin{itemize} %\item Implemented according to [FAUG99] % %\item Over $GF(p)$ : pretty good % %\item Over the rationals : not so good except for {\it McKay} %\end{itemize} %\end{itemize} %\end{slide} % %\begin{slide}{} %\fbox{History of development : 2000-current} %\begin{itemize} %\item The source code is freely available % %\begin{itemize} %\item Noro moved from Fujitsu to Kobe university % %Started Kobe branch %\end{itemize} % %\item OpenXM % %\begin{itemize} %\item Revising the specification : OX-RFC100, 101, (102) % %\item OX-RFC102 : communications between servers via MPI %\end{itemize} % %\item Weyl algebra % %\begin{itemize} %\item Buchberger algorithm [TAKA90] % %\item $b$-function computation [OAKU97] % %Minimal polynomial computation by modular method %\end{itemize} %\end{itemize} % %\end{slide} \begin{slide}{} \end{slide} \begin{slide}{} \end{slide} \begin{slide}{} \end{slide} \begin{slide}{} \end{slide}