Comments on: Ordinary Differential Equations, Stiffness https://blogs.mathworks.com/cleve/2014/06/09/ordinary-differential-equations-stiffness/?s_tid=feedtopost Cleve Moler is the author of the first MATLAB, one of the founders of MathWorks, and is currently Chief Mathematician at the company. He writes here about MATLAB, scientific computing and interesting mathematics. Sat, 25 Feb 2017 01:11:50 +0000 hourly 1 https://wordpress.org/?v=6.2.2 By: Cleve Moler https://blogs.mathworks.com/cleve/2014/06/09/ordinary-differential-equations-stiffness/#comment-4516 Thu, 17 Jul 2014 00:44:30 +0000 https://blogs.mathworks.com/cleve/?p=990#comment-4516 In reply to Michele Zaffalon.

1) The analogies are crude at best and I don’t think the connections go very deep.
2) You can’t make a change of variable that alters the time scale of just part of the problem. Unless you have decoupled problems.

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By: Michele Zaffalon https://blogs.mathworks.com/cleve/2014/06/09/ordinary-differential-equations-stiffness/#comment-4509 Fri, 11 Jul 2014 21:52:37 +0000 https://blogs.mathworks.com/cleve/?p=990#comment-4509 Interesting reading, well presented as usual.

1) It seems that you numerical people like so much the analogy with the hike along a narrow and long canyon that you also use it to explain why the steepest descent is also a slow method compared to conjugate gradient. Is the similarity only a coincidence or is there something common to the two problems, stiffness and minimization?

2) In the section “Stiffness in Action” you make the remark ” You don’t want to change the differential equation”. If the problem of stiffness boils down to having a differential equation with two or more very different time scale, could one make use of a transformation that contracts the times?

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By: Tek Bahadur Chhetri https://blogs.mathworks.com/cleve/2014/06/09/ordinary-differential-equations-stiffness/#comment-4455 Thu, 12 Jun 2014 02:37:08 +0000 https://blogs.mathworks.com/cleve/?p=990#comment-4455 These examples given in example pages are very useful to learn more and more for climatic studies. I enjoy very much to read something in the Cleve’s Corner. I love it.

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