Difference between revisions of "ApCoCoA-1:LinBox.CharPoly"

From ApCoCoAWiki
(Short description update.)
(Added parameter and return value list.)
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This function returns the characteristic polynomial of <tt>M</tt> in the indeterminate <tt>X</tt> computed by the ApCoCoAServer using LinBox functions.
 
This function returns the characteristic polynomial of <tt>M</tt> in the indeterminate <tt>X</tt> computed by the ApCoCoAServer using LinBox functions.
 +
<itemize>
 +
  <item>@param <em>M</em> A matrix with whose components do not contain the indeterminate X.</item>
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  <item>@param <em>X</em> An indeterminate.</item>
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  <item>@return The characteristic polynomial of M in the indeterminate X.</item>
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</itemize>
 
<example>
 
<example>
 
Use R ::= Z/(19)[x];
 
Use R ::= Z/(19)[x];

Revision as of 17:22, 22 April 2009

LinBox.CharPoly

Compute the characteristic polynomial of a matrix.

Syntax

LinBox.CharPoly(M:MAT, X:POLY):LIST

Description

X is an indeterminate, and M is a square matrix whose entries do not involve X.

This function returns the characteristic polynomial of M in the indeterminate X computed by the ApCoCoAServer using LinBox functions.

  • @param M A matrix with whose components do not contain the indeterminate X.

  • @param X An indeterminate.

  • @return The characteristic polynomial of M in the indeterminate X.

Example

Use R ::= Z/(19)[x];
LinBox.CharPoly(BringIn(Mat([[1,2,3],[4,5,6],[7,8,9]])), x);
-- CoCoAServer: computing Cpu Time = 0
-------------------------------
x^3 + 4x^2 + x
-------------------------------

Use R ::= Z[x];
LinBox.CharPoly(Mat([[1,2,3],[4,5,6],[7,8,9]]), x);
-- WARNING: Coeffs are not in a field
-- GBasis-related computations could fail to terminate or be wrong

-------------------------------
-- WARNING: Coeffs are not in a field
-- GBasis-related computations could fail to terminate or be wrong
-- CoCoAServer: computing Cpu Time = 0
-------------------------------
x^3 - 15x^2 - 18x
-------------------------------

CharPoly