       Re: Work on Basic Mathematica Stephen!

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• Subject: [mg130808] Re: Work on Basic Mathematica Stephen!
• From: Murray Eisenberg <murray at math.umass.edu>
• Date: Fri, 17 May 2013 04:35:26 -0400 (EDT)
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```If I understand this proposal aa), then I completely disagree. It is *essential* to have the ability to use a function Chop that, e.g., does the following:

Chop[4. + 10.^-16 I]
4.

The reason is that even when one starts with strictly real functions, it is often the case that Mathematica uses complex-function methods and, due to roundoff, returns results with some pure imaginary "fuzz".

On May 16, 2013, at 3:28 AM, Peter Klamser <klamser at googlemail.com> wrote:

> . .. A) First proposal: Identify useless or false constructions in Mathematica
>
> aa) Eliminating Chop[] for complex numbers. Complex numbers are
> oderless and therefore nobody call estimate, weather the distance of 1
> + 10^-google i to the real numbers is small or big. Chop[] is the
> result of Mathematica design, that it presents often complex results, where
> real values are the simpler result and can be reached by
> ComplexExpand[].
> The simplest solution is always the best solution.

---
Murray Eisenberg                                    murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower            phone 413 549-1020 (H)
University of Massachusetts                               413 545-2838 (W)
710 North Pleasant Street                         fax   413 545-1801
Amherst, MA 01003-9305

```

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