ApCoCoA-1:DA.InitialOfDer: Difference between revisions
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<command> | <command> | ||
<title> | <title>DA.InitialOfDer</title> | ||
<short_description>the initial wrt. a given derivative</short_description> | <short_description>Computes the initial wrt. a given derivative.</short_description> | ||
<syntax> | <syntax> | ||
DA.InitialOfDer(F:POLY, X:INDET):POLY | |||
</syntax> | </syntax> | ||
<description> | <description> | ||
InitialOfDer returns the polynomial leading coefficient of polynomial F regarded as polynomial in the derivative X. | DA.InitialOfDer returns the polynomial leading coefficient of polynomial F regarded as polynomial in the derivative X. | ||
<itemize> | |||
<item>@param F A differential polynomial.</item> | |||
<item>@param X A indeterminate.</item> | |||
<item>@return Initial of F wrt. X.</item> | |||
</itemize> | |||
<example> | <example> | ||
Use Q[x[1..2,0..20]]; | Use Q[x[1..2,0..20]]; | ||
Use Q[x[1..2,0..20]], Ord( | Use Q[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]; | ||
DA.InitialOfDer(F, x[1,2]); | |||
------------------------------- | ------------------------------- | ||
x[2,2]^2 | x[2,2]^2 | ||
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</example> | </example> | ||
</description> | </description> | ||
<see> | <types> | ||
<see> | <type>polynomial</type> | ||
</types> | |||
<see>DA.Initial</see> | |||
<see>DA.DiffTO</see> | |||
<key>InitialOfDer</key> | |||
<key>DA.InitialOfDer</key> | |||
<key>diffalg.InitialOfDer</key> | |||
<key>differential.InitialOfDer</key> | |||
<wiki-category>Package_diffalg</wiki-category> | <wiki-category>Package_diffalg</wiki-category> | ||
</command> | </command> | ||
Revision as of 13:32, 22 April 2009
DA.InitialOfDer
Computes the initial wrt. a given derivative.
Syntax
DA.InitialOfDer(F:POLY, X:INDET):POLY
Description
DA.InitialOfDer returns the polynomial leading coefficient of polynomial F regarded as polynomial in the derivative X.
@param F A differential polynomial.
@param X A indeterminate.
@return Initial of F wrt. X.
Example
Use Q[x[1..2,0..20]];
Use Q[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.InitialOfDer(F, x[1,2]);
-------------------------------
x[2,2]^2
-------------------------------
