=================================================================== RCS file: /home/cvs/OpenXM/doc/issac2000/heterotic-network.tex,v retrieving revision 1.3 retrieving revision 1.6 diff -u -p -r1.3 -r1.6 --- OpenXM/doc/issac2000/heterotic-network.tex 2000/01/03 04:27:52 1.3 +++ OpenXM/doc/issac2000/heterotic-network.tex 2000/01/15 03:47:59 1.6 @@ -1,10 +1,23 @@ -% $OpenXM: OpenXM/doc/issac2000/heterotic-network.tex,v 1.2 2000/01/02 07:32:11 takayama Exp $ +% $OpenXM: OpenXM/doc/issac2000/heterotic-network.tex,v 1.5 2000/01/15 03:23:59 takayama Exp $ -\subsection{Heterotic Network} (Takayama) +\subsection{Heterogeneous Servers} \def\pd#1{ \partial_{#1} } -\subsubsection{Annihilating ideal} +By using OpenXM, we can treat OpenXM servers essentially +like a subroutine. +Since OpenXM provides a universal stackmachine which does not +depend each servers, +it is relatively easy to install new servers. +We can build a new computer math system by assembling +different OpenXM servers. +It is similar to building a toy house by LEGO blocks. + +We will see two examples of custom made systems +built by OpenXM servers. + +\subsubsection{Computation of annihilating ideals by kan/sm1 and ox\_asir} + Let $D = {\bf Q} \langle x_1, \ldots, x_n , \pd{1}, \ldots, \pd{n} \rangle$ be the ring of differential operators. For a given polynomial @@ -17,13 +30,16 @@ Here, $\bullet$ denotes the action of $D$ to functions The annihilating ideal can be regarded as the maximal differential equations for the function $f^{-1}$. An algorithm to determine generators of the annihilating ideal -was given by Oaku in 1995 (see, e.g., \cite[5.3]{sst-book}). +was given by Oaku (see, e.g., \cite[5.3]{sst-book}). His algorithm reduces the problem to computations of Gr\"obner bases in $D$ and to find the maximal integral root of a polynomial. -An implementation of this algorithm (the function {\tt annfs}) -on kan/sm1 \cite{kan} -calls ox\_asir to factorize polynomials to find the integral +This algorithm (the function {\tt annfs}) is implemented by +kan/sm1 \cite{kan}, for Gr\"obner basis computation in $D$, and +ox\_asir, to factorize polynomials to find the integral roots. +These two OpenXM complient systems are integrated by +OpenXM protocol. + For example, the following is a sm1 session to find the annihilating ideal for $f = x^3 - y^2 z^2$. \begin{verbatim} @@ -32,7 +48,7 @@ Starting ox_asir server. Byte order for control process is network byte order. Byte order for engine process is network byte order. [[-y*Dy+z*Dz, 2*x*Dx+3*y*Dy+6, -2*y*z^2*Dx-3*x^2*Dy, - -2*y^2*z*Dx-3*x^2*Dz, -2*z^3*Dx*Dz-3*x^2*Dy^2-2*z^2*Dx], +-2*y^2*z*Dx-3*x^2*Dz, -2*z^3*Dx*Dz-3*x^2*Dy^2-2*z^2*Dx], [-1,-139968*s^7-1119744*s^6-3802464*s^5-7107264*s^4 -7898796*s^3-5220720*s^2-1900500*s-294000]] \end{verbatim} @@ -41,30 +57,12 @@ $-12(s+1)(3s+5)(3s+4)(6s+5)(6s+7)$ and the minimal integral root is $-1$ as shown in the output. -\subsubsection{Primary ideal decomposition and -a stratification of singularity} -Let ${\cal D} = {\cal O}\langle \pd{1}, \ldots, \pd{n} \rangle$ -be the sheaf of algebraic differential operators on ${\bf C}^n$. -For a given polynomial -$f \in {\bf Q}[x_1, \ldots, x_n]$, -minimal degree non-zero polynomial $b_a(s)$ such that -$ b_a(s) f^s \in {\cal D}_{a} \bullet f^{s+1} $ -is called the local $b$-function of $f^s$ at -$x=a$. -Here, ${\cal D}_a$ denotes the germ of the sheaf ${\cal D}$ at -$x=a$. -The polynomial $b_a(s)$ depends on $a$ and ${\bf C}^n$ is -stratified into a finite algebraic sets such that -$b_a(s)$ is a constant with respect to $a$ on each -algebraic set. -An algorithm to determine the stratification -was given by Oaku in 1997 \cite{oaku-advance}. -His algorithm reduces the problem to computations of Gr\"obner bases -in $D$ and primary ideal decompositions. -An implementation of this algorithm -uses sm1 for Gr\"obner basis computation in $D$ and -ox\_asir for primary ideal decomposition and Gr\"obner basis computation -in the ring of polynomials. +Similarly, +an algorithm to stratify singularity +\cite{oaku-advance} +is implemented by +kan/sm1 \cite{kan}, for Gr\"obner basis computation in $D$, and +ox\_asir, for primary ideal decompositions. \subsubsection{A Course on Solving Algebraic Equations} @@ -73,16 +71,16 @@ which is good at Gr\"obner basis computations for zero with ${\bf Q}$ coefficients. However, it is not good at graphical presentations and numerical methods. -We used Risa/asir with ox\_sm1\_phc (based on PHC pack by Verschelde \cite{phc} +We integrated Risa/asir, ox\_phc (based on PHC pack by Verschelde \cite{phc} for the polyhedral homotopy method) and -ox\_sm1\_gnuplot (GNUPLOT) servers +ox\_gnuplot (GNUPLOT) servers to teach a course on solving algebraic equations. This course was presented with the text book \cite{CLO} which discusses on the Gr\"obner basis method and the polyhedral homotopy method to solve systems of algebraic equations. -Risa/asir has a user language like C and we could teach a course +We could teach a course with a unified environment -controlled by asir user language. +controlled by asir user language, which is similar to C. The following is an asir session to solve algebraic equations by calling the PHC pack. \begin{verbatim}