File r37/lisp/csl/html/r37_0369.html artifact 56e3d75922 part of check-in d9e362f11e

<A NAME=groebner_walk>

<TITLE>groebner_walk</TITLE></A>
<b><a href=r37_idx.html>INDEX</a></b><p><p>



<B>GROEBNER\_WALK</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
<P>
 
The operator <em>groebner_walk</em> computes a <em>lex</em> basis 
from a given <em>graded</em> (or <em>weighted</em>) one. 
 <P> <H3> 
syntax: </H3>
<P>
<P>
<em>groebner_walk</em>(&lt;g&gt;) 
<P>
<P>
<P>
where &lt;g&gt; is a <em>graded</em> basis (or <em>weighted</em> basis 
with a weight vector with one repeated element) of the polynomial ideal. 
<em>Groebner_walk</em> computes a sequence of monomial bases, each 
time lifting the full system to a complete basis. <em>Groebner_walk</em> 
should be called only in cases, where a normal <em>kex</em> computation 
would take too much computer time. 
<P>
<P>
The operator 
<A HREF=r37_0354.html>torder</A> has to be called before in order to 
define the variable sequence and the term order mode of &lt;g&gt;. 
<P>
<P>
The variable 
<A HREF=r37_0371.html>gvarslast</A> is not set. 
<P>
<P>
Do not call <em>groebner_walk</em> with <em>on</em> 
<A HREF=r37_0370.html>groebopt</A>. 
<P>
<P>
<em>Groebner_walk</em>includes some overhead (such as e. g. 
computation with division). On the other hand, sometimes 
<em>groebner_walk</em> is faster than a direct <em>lex</em> computation. 
<P>
<P>