Thomas Klimpel
Reputation
3,908
Top tag
Next privilege 5,000 Rep.
Approve tag wiki edits
 Dec 7 revised Zero divided by zero must be equal to zero corrected typo, and added more context and applications to the answer Dec 5 revised Zero divided by zero must be equal to zero wrote down one symbolic expression for a/b+c/d, just to show that one can still compute Dec 5 answered Zero divided by zero must be equal to zero Nov 13 accepted Are pseudoheaps and heaps the same thing? Nov 9 asked Are pseudoheaps and heaps the same thing? Oct 10 comment Why do $f(x)= \frac {{x²-1}}{{x-1} }$ and $g(x)=x+1$ not have the same domain of definition, but are the same? Voted to reopen, because this question has 6 upvoted and 1 downvoted answers. This is a pretty strong indication that the question itself is not really unclear. Partially undefined operations are indeed annoying, but it's no solution to pretend that questions about them are invalid or unclear. (The solution motivated by category theory to always specify domain and codomain and only consider total function is indeed quite powerful, but it is not the only possible solution. In the context of (complex) function theory, other solutions are more appropriate.) Sep 25 comment SVD methods for minimal polynomial It's not really a start point with respect to SVD. There is a close connection between Krylov subspace methods and minimal polynomials. It wasn't even a SVD, but just a general Eigen-decomposition. It should be clear how to get the minimal polynomial of a square matrix from its Eigen-decomposition. But they do use it for sequence extrapolation of transient (linear response) behavior when resonances are present, which could otherwise become annoying. Sep 24 comment SVD methods for minimal polynomial I'm pretty sure that an explanation of continuation by fast Krylov subspace Eigen-decomposition methods together with references to the original publications was in some introduction or appendix at least in the published book of ccrma.stanford.edu/~bilbao/master/goodcopy.html. I couldn't find it again at the moment, but why should I care? Sep 22 awarded Popular Question Sep 1 comment Differential algebra and differential-algebraic equations @Calle If you speak German, then section 3.2.1 in mod_geom_betr_klas_diffop.pdf gives a good idea for a relation between symmtries and structural properties, i.e. coupling or non-zero structure. Here are visualizations of non-zero structure of DAEs in integral form and non-zero structure of DAEs in semi-explicit form. See "Matrices and Matroids for System Analysis" Sep 1 answered Differential algebra and differential-algebraic equations Aug 1 answered Can a biased physical random source be post-processed to control the bias? Jun 23 awarded Yearling Jun 17 revised Are Horn clauses always universally quantified? Horn structure <-> closure under product. Universal Horn structure -> closure under composition May 21 answered Why do the interesting antihomomorphisms tend to be involutions? Apr 13 comment Does the “equality semigroup” have an accepted name? If you introduce the name "subatom" for an element which is either the bottom or an "atom", then you can no longer pretend that you are using established terminology. If you slightly abuse existing terminology on the other hand, then you are just following established mathematical practice. (red herring principle...) Apr 13 comment Does the “equality semigroup” have an accepted name? In any partial ordered set with a bottom element, the meet-semilattice of atoms (en.wikipedia.org/wiki/Atom_(order_theory)) is a well-defined semilattice. So I would call it just this: "meet-semilattice of atoms". Apr 10 answered What does the term “undefined” actually mean? Mar 12 answered Maximal Principle: Why using the new transition matrix $\tilde{P}$? Mar 12 revised Maximal Principle: Why using the new transition matrix $\tilde{P}$? either always \tilde{p}, or never...