Eigenvalues
Eigenvalues(matrix)
get the numerical eigenvalues of the
matrix
.
See
- Wikipedia - Eigenvalues and Eigenvectors
- Youtube - Eigenvectors and eigenvalues | Essence of linear algebra, chapter 14
Examples
>> Eigenvalues({{1,0,0},{0,1,0},{0,0,1}}){1.0,1.0,1.0}
Note: Symjas implementation of the Eigenvectors
function adds zero vectors when the geometric multiplicity of the eigenvalue is smaller than its algebraic multiplicity (hence the regular eigenvector matrix should be non-square).
With these additional null vectors, the Eigenvectors
result matrix becomes square.
This happens for example with the following square matrix:
>> Eigenvectors({{1,0,0},{-2,1,0},{0,0,1}}){{-2.50055*10^-13,1.0,0.0},{0.0,0.0,1.0},{0.0,0.0,0.0}}
>> Eigenvalues({{1,0,0},{-2,1,0},{0,0,1}}){1.0,1.0,1.0}
Its characteristic polynomial is (1.0-\[lambda])^3.0
, hence is has one eigen value \[lambda]==1.0
with algebraic multiplicity 3
. However, this eigenvalue leads to only two eigenvectors
v1 = {0.0, 1.0, 0.0}
and v2 = {0.0, 0.0, 1.0}
, hence its geometric multiplicity is only 2
, not 3
.
So we add a third zero vector v3 = {0.0, 0.0, 0.0}
.
Related terms
Eigensystem, Eigenvectors, CharacteristicPolynomial
Implementation status
- ☑ - partially implemented