Rational power of a positive definite matrix

4 vues (au cours des 30 derniers jours)
Qian Feng
Qian Feng le 13 Fév 2017
Commenté : Qian Feng le 13 Fév 2017
q = sym([4 2 ; 2 4]);
f = sqrtm(q)^(-1) - sqrtm(q^(-1));
f should be zero here since q is positive definite.
However, the program yielded a non zero f here. Is this due to the calculation error ? Note that I am using symbolic calculation here so there should be no error at all I assume.

Connectez-vous pour répondre à cette question.

Réponse acceptée

John D'Errico
John D'Errico le 13 Fév 2017
Modifié(e) : John D'Errico le 13 Fév 2017
Sometimes the answer is just "simple".
simplify(f)
ans =
[ 0, 0]
[ 0, 0]
Symbolic results are not always returned in the most simple possible form.
  1 commentaire
Qian Feng
Qian Feng le 13 Fév 2017
Thanks for the suggestion. I should have realized that.

Connectez-vous pour commenter.

Plus de réponses (0)

Catégories

En savoir plus sur Symbolic Math Toolbox dans Help Center et File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by