Difference between revisions of "ApCoCoA-1:Num.EigenValues"

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Therefore the input matrix A has to be quadratic!
 
Therefore the input matrix A has to be quadratic!
 
It is implemented in the ApCoCoA server, so you need a running server. It was not implemented in version 0.99.4 or previous. Also please keep in mind this method is based on blas/Lapack's eigenvalue solver and uses floating point arithmetic. This is not an exact, algebraic method!
 
It is implemented in the ApCoCoA server, so you need a running server. It was not implemented in version 0.99.4 or previous. Also please keep in mind this method is based on blas/Lapack's eigenvalue solver and uses floating point arithmetic. This is not an exact, algebraic method!
The output contains of a matrix B. Each of the rows in B describe on of the eigenvalues of A. The first column of B contains the real part of the eigenvalues, the second column the imagonary ones.  
+
The output contains a matrix B. Each of the columns in B describe one of the eigenvalues of A. The first row of B contains the real part of the eigenvalues, the second row the imaginary ones.  
  
 
<example>
 
<example>

Revision as of 14:05, 19 October 2008

Numerical.EigenValues

eigenvalues of a matrix

Syntax

$numerical.EigenValues(A:Matrix):List

Description

This function returns a matrix, containing numerical approximation to A's eigenvalues.

Therefore the input matrix A has to be quadratic!

It is implemented in the ApCoCoA server, so you need a running server. It was not implemented in version 0.99.4 or previous. Also please keep in mind this method is based on blas/Lapack's eigenvalue solver and uses floating point arithmetic. This is not an exact, algebraic method! The output contains a matrix B. Each of the columns in B describe one of the eigenvalues of A. The first row of B contains the real part of the eigenvalues, the second row the imaginary ones.

Example

A:=Mat([[1,2,7,18],[2,4,9,12],[23,8,9,10],[7,5,3,2]]);
Numerical.EigenValues(A);
-- CoCoAServer: computing Cpu Time = 0.0049
-------------------------------
Mat([
  [4077234895954899/140737488355328, -3850002255576291/281474976710656, 3186113456591853/9007199254740992, 3186113456591853/9007199254740992],
  [0, 0, 6871934657603045/2251799813685248, -6871934657603045/2251799813685248]
])
-------------------------------

See also

Introduction to CoCoAServer

Numerical.QR

Numerical.SVD

Numerical.EigenValuesAndVectors

Numerical.EigenValuesAndAllVectors