ApCoCoA-1:DA.Initial: Difference between revisions

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{{Version|1}}
<command>
<command>
     <title>diffalg.Initial</title>
     <title>DA.Initial</title>
     <short_description>the initial of a differential polynomial</short_description>
     <short_description>Computes the initial of a differential polynomial.</short_description>
<syntax>
<syntax>
$diffalg.Initial(F:POLY):POLY
DA.Initial(F:POLY):POLY
</syntax>
</syntax>
<description>
<description>
Initial returns the initial of polynomial F wrt. the current differential term ordering, or the hereby induced ranking, respectively.
<ref>ApCoCoA-1:DA.Initial|DA.Initial</ref> returns the initial of polynomial <tt>F</tt> wrt. the current differential term ordering, or the hereby induced ranking, respectively.
 
<itemize>
 
<item>@param <em>F</em> A differential polynomial.</item>
<item>@return The initial of <tt>F</tt>.</item>
</itemize>
<example>
<example>
Use Q[x[1..2,0..20]];
Use QQ[x[1..2,0..20]];
Use Q[x[1..2,0..20]], Ord($diffalg.DiffTO("Lex"));
Use QQ[x[1..2,0..20]], Ord(DA.DiffTO("Lex"));


F:=x[1,2]^3x[2,2]^2 + x[1,1]^3x[2,2]^2 + 1/4x[1,2];
F:=x[1,2]^3x[2,2]^2 + x[1,1]^3x[2,2]^2 + 1/4x[1,2];


$diffalg.LD(F);
DA.LD(F);
-------------------------------
-------------------------------
x[2,2]
x[2,2]
-------------------------------
-------------------------------
$diffalg.LPot(F);
DA.LPot(F);
-------------------------------
-------------------------------
x[2,2]^2
x[2,2]^2
-------------------------------
-------------------------------
$diffalg.Initial(F);
DA.Initial(F);
-------------------------------
-------------------------------
x[1,2]^3 + x[1,1]^3
x[1,2]^3 + x[1,1]^3
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</example>
</example>
</description>
</description>
<see>Diffalg.LD</see>
<types>
<see>Diffalg.LPot</see>
<type>polynomial</type>
<see>Diffalg.DiffTO</see>
</types>
<wiki-category>Package_diffalg</wiki-category>
<see>ApCoCoA-1:DA.LD|DA.LD</see>
<see>ApCoCoA-1:DA.LPot|DA.LPot</see>
<see>ApCoCoA-1:DA.DiffTO|DA.DiffTO</see>
 
<key>Initial</key>
<key>DA.Initial</key>
<key>diffalg.Initial</key>
<key>differential.Initial</key>
<wiki-category>ApCoCoA-1:Package_diffalg</wiki-category>
</command>
</command>

Latest revision as of 13:29, 29 October 2020

This article is about a function from ApCoCoA-1.

DA.Initial

Computes the initial of a differential polynomial.

Syntax

DA.Initial(F:POLY):POLY

Description

DA.Initial returns the initial of polynomial F wrt. the current differential term ordering, or the hereby induced ranking, respectively.

  • @param F A differential polynomial.

  • @return The initial of F.

Example

Use QQ[x[1..2,0..20]];
Use QQ[x[1..2,0..20]], Ord(DA.DiffTO("Lex"));

F:=x[1,2]^3x[2,2]^2 + x[1,1]^3x[2,2]^2 + 1/4x[1,2];

DA.LD(F);
-------------------------------
x[2,2]
-------------------------------
DA.LPot(F);
-------------------------------
x[2,2]^2
-------------------------------
DA.Initial(F);
-------------------------------
x[1,2]^3 + x[1,1]^3
-------------------------------

DA.LD

DA.LPot

DA.DiffTO