Difference between revisions of "ApCoCoA-1:DA.NthDerivation"
From ApCoCoAWiki
(Corrected example.) |
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</itemize> | </itemize> | ||
<example> | <example> | ||
| − | Use | + | Use QQ[x[1..2,0..20]]; |
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.NthDerivation(F, 2); | DA.NthDerivation(F, 2); | ||
Revision as of 11:08, 28 April 2009
DA.NthDerivation
Computes the N-th derivation of a differential polynomial.
Syntax
DA.NthDerivation(F:POLY, N:INT):POLY
Description
Computes the N-th derivation of the differential polynomial F. If the order of the result would exceed the given maximum order as implied by the current ring, an error is thrown.
@param F A differential polynomial.
@param N An integer.
@return The N-th derivation of F.
Example
Use QQ[x[1..2,0..20]]; F:=x[1,2]^2*x[1,1]-x[2,4]^3; DA.NthDerivation(F, 2); ------------------------------- 5x[1,2]^2x[1,3] + 2x[1,1]x[1,3]^2 + 2x[1,1]x[1,2]x[1,4] - 6x[2,4]x[2,5]^2 - 3x[2,4]^2x[2,6] -------------------------------
Example
Use Q[x[1..2,0..20]]; F:=x[1,2]^2*x[1,1]-x[2,4]^3; DA.NthDerivation(F, 20); ------------------------------- ERROR: Maximum order is exceeded. CONTEXT: Error(<quotes>Maximum order is exceeded.</quotes>) -------------------------------
