Hello all trying approximate numerically eigenvalues of a matrix I get Error
sage: A=matrix(((0,1),(-1,0))) sage: B=A.eigenvalues()[0] sage: n(B) Traceback (click to the left for traceback) ... ValueError: Cannot coerce algebraic number with non-zero imaginary part to algebraic real I guess, I have to convert B into complex number, since things like sage: n(I) works well. I understand that I can also extract real and imaginary part, do numerical approximation and put things together. But it would be nice to have one command for this trivial task. How can I use the conversion into a type which can be approximated numerically? And why is the result of eigenvalues not 'sage.symbolic.expression.Expression' as other complex numbers? What is the difference. I guess that missed something relevant to complex numbers in Sage. And another question for people working with this: Do we have in Sage a function which prints the number of positive eigenvalues, negative eigenvalues, complex with positive real part and complex with negative real part? Thank you Robert Marik --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
