Carl Love

## 23943 Reputation

9 years, 309 days
Natick, Massachusetts, United States
My name was formerly Carl Devore.

## Bad solution display from LPSolve...

Maple 2022

The solution from LPSolve shown in the worksheet below is displayed very weirdly:

1. The first element is rounded to 3 significant digits.
2. The variable indices have decimal points.
3. Zeros are displayed as just decimal points with no digit 0.

Closer inspection (with, say, lprint) will reveal that the weirdness is only with the prettyprinting; the actual entries are as expected.

 > restart:
 > <(kernelopts,interface)(version), interface~([prettyprint, typesetting])[]>;

 > (a,b,c):= (2,4,5):
 > X:= Matrix((a,b), symbol= x): Y:= Matrix((b,c), symbol= y): Z:= Matrix((a,c), symbol= z):
 > RegionC:= <5, 15, 8, 10, 15>:
 > RegionA:= <90, 75>:
 > RegionB:= <35, 20, 30, 15>:
 > Cost1:= <     2, 1, 3/2,   3;   5/2, 2, 7/2, 3/2 >:
 > Cost2:= <     3/2, 4/5, 1/2, 3/2,   3;       1, 1/2, 1/2,   1, 1/2;       1, 3/2,   2,   2, 1/2;     5/2, 3/2, 3/5, 3/2, 1/2 >:
 > Cost3:= <     11/4, 7/2, 5/2, 3,   5/2;        3, 7/2, 7/2, 5/2, 2 >:
 > CapB:= add(X[i], i= 1..a) <=~ RegionB:
 > CapA:= add([..,j], j= 1..b+c) <=~ RegionA:
 > ReqC:= add([i], i= 1..a+b) >=~ RegionC:
 > InEqOutB:= add([i], i= 1..a+c) =~ 0:
 > Cons:= seq~({CapA, CapB, ReqC, InEqOutB}):
 > Sol:= Optimization:-LPSolve(Cost__Total, Cons, assume= nonnegative);

 >

## Is "Delete As Spam" broken?...

MaplePrimes

The last several times that I've tried to use the Delete As Spam feature I've gotten an error message Error Generating Page, and the spam was not deleted. Anyone know what's happening?

## Why can't I display any worksheet?...

MaplePrimes

It's been about a year since I've been able to display any worksheet at all on MaplePrimes. In the example below, I took a very simple worksheet that had been displayed in an Answer to another recent Question and tried to upload it. So, we know that it's somehow possible to display this particular worksheet on MaplePrimes.

Maple Worksheet - Error
Failed to load the worksheet /maplenet/convert/prove.mw .

## Why does RootOf rename its bound variabl...

Maple

[Perhaps this should be a Post rather than a Question.]

As far as I can tell, RootOf is the only Maple command that takes a bound variable on input and returns an unevaluated form with the bound variable renamed (to _Z). Why is that? Either all should do it (definite integrals, limit, sum, etc.) or none should.

Pros:

Making a substitution for a variable that occurs both free and bound in the same expression is a major source of programming error. Renaming bound variables helps to ameliorate that.

Cons:

The unexpected appearance of _Z in their results seems to be a great source of confusion to new users. However, if more commands did this, perhaps it would be more expected.

Feel free to start a brainstorming discussion on this, as if it were a Post, even if you don't have a direct Answer for the Question. If that's the way that the thread heads, I'll change it to a Post.

## What is the benefit of option threadsafe...

Maple 2020

The help for option threadsafe (on page ?option) includes this sentence:

• Portions of the kernel may recognize this option and allow the procedure to be called in multiple threads simultaneously.

Huh? What exactly does that mean? Isn't it already capable of being called in multiple threads simultaneously?

I understand the significance of this option for procedures to be compiled, mentioned later in the same paragraph. But is there any benefit for a non-compiled procedure that will be used in multithreaded code? If my code has numerous one-liner arrow procedures, is there any point to cluttering up my code by turning them all into procs with option threadsafe? (Y'all know how I hate cluttered code.)

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