Difference between revisions of "Package sagbi/SB.SAGBITimeout"

From ApCoCoAWiki
m (changed category)
(examples and see)
 
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<example>
 
<example>
Use QQ[x[1..3]];
+
Use QQ[x,y,z];
S := SB.SAGBITimeout([x[1]^2-x[3]^2,x[1]*x[2]+x[3]^2,x[2]^2-2*x[3]^2],10);
+
S := SB.SAGBITimeout([x^2 -z^2, x*y +z^2, y^2 -2*z^2],3);
 
indent(S);
 
indent(S);
-----------------------------------------------------------------------------
+
-- [
[
+
--  y^2 -2*z^2,
   x[2]^2 -2*x[3]^2,
+
--   x*y +z^2,
   x[1]*x[2] +x[3]^2,
+
--   x^2 -z^2,
   x[1]^2 -x[3]^2,
+
--   x^2*z^2 +x*y*z^2 +(1/2)*y^2*z^2 +(-1/2)*z^4
   x[1]^2*x[3]^2 +x[1]*x[2]*x[3]^2 +(1/2)*x[2]^2*x[3]^2 +(-1/2)*x[3]^4
+
-- ]
]
 
 
</example>
 
</example>
  
 
<example>
 
<example>
 
Use QQ[x,y];
 
Use QQ[x,y];
SB.SAGBITimeout([x+y,x*y,x*y^2],10); -- K[x+y,xy,xy^2] doesn't have a finite SAGBI basis
+
SB.SAGBITimeout([x+y,x*y,x*y^2],10); -- K[x+y,xy,xy^2] does not have a finite SAGBI basis
 
-----------------------------------------------------------------------------
 
-----------------------------------------------------------------------------
 
--> ERROR: Timeout after 10.161 seconds.
 
--> ERROR: Timeout after 10.161 seconds.
Line 38: Line 37:
 
</example>
 
</example>
 
   </description>
 
   </description>
<!-- <see>SB.IsSagbi</see> -->
+
  <seealso>
<!-- <see>SB.IsSagbiOf</see> -->
+
    <see>Package sagbi/SB.SAGBI</see>
 +
    <see>Package sagbi/SB.TruncSAGBI</see>
 +
    <see>Package sagbi/SB.IsSAGBIOf</see>
 +
    <see>Package sagbi/SB.GetSAGBI</see>
 +
    <see>Package sagbi/SB.GetTruncSAGBI</see>
 +
  </seealso>
 
   <types>
 
   <types>
 
     <type>sagbi</type>
 
     <type>sagbi</type>

Latest revision as of 18:13, 27 October 2020

This article is about a function from ApCoCoA-2.

SB.SAGBITimeout

Same as SAGBI, but stops after a given time and throws an error if the computation isn't finished yet.

Syntax

SB.SAGBITimeout(G:LIST of POLY,t:RAT):LIST of POLY

Description

This function computes a SAGBI basis and throws an error if the computation isn't finished after t seconds. If the computation terminates within t seconds, a reduced SAGBI basis of the subalgebra generated by the set G is returned.

  • @param G A list of polynomials which generates a subalgebra.

  • @param t A rational number specifying the time limit.

  • @return A list of polynomials which form a finite SAGBI-basis of the subalgebra generated by G.

Example

Use QQ[x,y,z];
S := SB.SAGBITimeout([x^2 -z^2,  x*y +z^2,  y^2 -2*z^2],3);
indent(S);
-- [
--   y^2 -2*z^2,
--   x*y +z^2,
--   x^2 -z^2,
--   x^2*z^2 +x*y*z^2 +(1/2)*y^2*z^2 +(-1/2)*z^4
-- ]

Example

Use QQ[x,y];
SB.SAGBITimeout([x+y,x*y,x*y^2],10); -- K[x+y,xy,xy^2] does not have a finite SAGBI basis
-----------------------------------------------------------------------------
--> ERROR: Timeout after 10.161 seconds.
--> WHERE: at line 618 (column 2) of sagbi.cpkg5
-->  error("Timeout after " + DecimalStr(t1-t0) + " seconds.")
-->  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

See also

Package sagbi/SB.SAGBI

Package sagbi/SB.TruncSAGBI

Package sagbi/SB.IsSAGBIOf

Package sagbi/SB.GetSAGBI

Package sagbi/SB.GetTruncSAGBI