# Difference between revisions of "ApCoCoA-1:DA.LD"

From ApCoCoAWiki

S schuster (talk | contribs) |
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<command> | <command> | ||

− | <title> | + | <title>DA.LD</title> |

<short_description>the leading derivative of a differential polynomial</short_description> | <short_description>the leading derivative of a differential polynomial</short_description> | ||

<syntax> | <syntax> | ||

− | + | DA.LD(F:POLY):POLY | |

</syntax> | </syntax> | ||

<description> | <description> | ||

− | LD computes the leading derivative of polynomial F wrt. the current differential term ordering, or the hereby induced ranking respectivly. | + | DA.LD computes the leading derivative of polynomial F wrt. the current differential term ordering, or the hereby induced ranking respectivly. |

+ | <itemize> | ||

+ | <item>@param F A differential polynomial.</item> | ||

+ | <item>@return The leading derivative of F.</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("DegOrd")); |

F:=x[1,2]^2*x[1,1]-x[2,4]^3; | F:=x[1,2]^2*x[1,1]-x[2,4]^3; | ||

− | + | DA.LD(F); | |

------------------------------- | ------------------------------- | ||

x[2,4] | x[2,4] | ||

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</example> | </example> | ||

</description> | </description> | ||

− | <see> | + | <types> |

+ | <type>polynomial</type> | ||

+ | </types> | ||

+ | <see>DA.DiffTO</see> | ||

+ | <key>LD</key> | ||

+ | <key>DA.LD</key> | ||

+ | <key>diffalg.LD</key> | ||

+ | <key>differential.LD</key> | ||

<wiki-category>Package_diffalg</wiki-category> | <wiki-category>Package_diffalg</wiki-category> | ||

</command> | </command> |

## Revision as of 13:35, 22 April 2009

## DA.LD

the leading derivative of a differential polynomial

### Syntax

DA.LD(F:POLY):POLY

### Description

DA.LD computes the leading derivative of polynomial F wrt. the current differential term ordering, or the hereby induced ranking respectivly.

@param F A differential polynomial.

@return The leading derivative of F.

#### Example

Use Q[x[1..2,0..20]]; Use Q[x[1..2,0..20]], Ord(DA.DiffTO("DegOrd")); F:=x[1,2]^2*x[1,1]-x[2,4]^3; DA.LD(F); ------------------------------- x[2,4] -------------------------------