How does SageMath compute the Jordan form of a block diagonal matrix? [closed]

asked 2022-12-11 10:08:27 +0200

Let $M$ be a block diagonal matrix $diag(B_1, \dots, B_m)$. Let $(p_i)$ be the orthogonal projections such that $B_i = p_i M p_i$. If you compute the Jordan form of $M$ using SageMath as follows:

sage: jf, q = M.jordan_form(transformation=True)

Question: Is it true that $q$ commutes with $p_i$ for all $i$?

It would be true if SageMath computes the Jordan form of $M$ by computing the Jordan form of each $B_i$.

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Closed for the following reason duplicate question by tmonteil
close date 2022-12-11 11:27:10.210487