J F Ogilvie

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17 years, 26 days

MaplePrimes Activity


These are replies submitted by J F Ogilvie

@Axel Vogt   John Ogilvie

@acer One part in 1000 would likely be satisfactory.

I neglected to state that

s_max := 20;  R := 1680;  k := 1/4;  gam := 1/2;

values of parameters were indeed specified.

@Thomas Richard  It is sad and scandalous that Maple, after all these years, still has so poor facility to solve integral equations.  What little does exist originated as a contribution to Maple Share library (become Maple Application Centre) from a student of a professor (Rob Corless) in University of Western Ontario, slightlly enhanced.  In 1977, i.e. three years before Maple was even born, David Stoutemyer, originator of MuMath and Derive, published some methods of solution of non-linear integral equations based on Reduce, but, despite being informed of this achievement, Maplesoft has failed to respond to the opportunity, shamefully.  I do not expect that methods to handle integral equations of non-integer order will appear imminently, but for other methods the results are long overdue.

@Carl Love I suppose that your reservation applies to Maple17, which is more than a few years old.

@ecterrab I seem to recall that Maple has already the best record of solution of differential equations. Could you please be more specific than "skyrocketed" (a dubious past participle at best), by stating the number of solutions of second-order linear differential equations in Maple 2020 and the number in Maple 2021?

It is also worth mentioning that some second-order linear differential equations that yield solutions generate them in terms of unwieldy Heun functions, even though likely Lame functions would provide easier usage, but those Lame functions are conspicuous by their absence from Maple despite calls for their inclusion along with other functions in Abramowitz and Stegun.

J. F. Ogilvie

@acer    I have incorporated your suggestion into a few such integrations, with marvelous improvements of not only completion but also speed.  I trust that this regression problem witll not appear in future releases of Maple.

@acer I posted that screen shot of the error message about the loss of contact of the kernel not that I doubted that you found the same effect but because I should have originally provided that screen shot. 

 Thanks for your original response.  Thus informed and inspired I found that merely inserting 'simplify' instead of both simplify and unapply solves the problem. 

The question remains why this loss of kernel occurs with Maple 2020.2 but not with preceding releases, such as Maple 17.  Is this effect a 'bug' that has been caused by somebody tinkering with code somewhere?

@acer 

I am not sure what that information means, but I attach a screen shot of the result of operation of Maple 2020.  Anybody can readily test that the results are a sequence of 1 for the several cases of j. Morsint.docx

@acer 

Alll that information seems normal, no excessive memory, brief duration, but in Maple 2020.2 that loss of connection to the kernel occurs consistently.  very strange!

@vv 

I should have preferred a symbolic result of the sum, but as that seems impracticable the numerical result is most helpful and valuable.

@TechnicalSupport 

My first attempt yesterday to install updates to Maple 2020.0 32-bit version resulted in only 2020.1, but a repeated attempt today was successful in installing 202.2 32-bit. My first test of the update was the differential equation for which Dr. Cheb-Terrab had thanked me for reporting on November 10 the defective code that yielded no answer, but, characteristically, the update announced on November 19 still fails to produce an answer.  How long does it take to incorporate a simple correction to the code that Dr. Cheb-Terrab directly recognised?

I installed the update for the 64-bit version but was unable to do so for the 32-bit version.

@ecterrab 

Tests with Maple 17, Maple 2015, Maple 2016 and Maple 2017 prove that this problem did not exist with those releases.  Evidently during further development this error was introduced because of inadequate testing after programming changes were made, yet again.

It seems that the Maple Primes site is poorly managed, because this announcement of the imminent conference continues to appear even after the conference has concluded.  Likewise, in the Maplesoft Blog Posts, I still read that Maple Student Edition is free to use until the end of June, which occurred more than four months ago.

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