Michael

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18 years, 11 days

MaplePrimes Activity


These are replies submitted by Michael

I have seen similar things which were never resolved.

You should know that even with a restart, unlike any other computer program you've ever seen, Maple doesn't always follow the same path each time it is run for reasons that escape me, but somehow make sense to the Maple developers. You often see this if you are using pattern matching and/or substitution - consecutive identical runs don't always succeed because the patterns are different but equivalent (two minus signs instead of a plus, for example). It makes programming difficult to say the least, unless you cover all possible variations that Maple may come up with.

So, even if you are restarting your program, it doesn't necessarily follow the same path each time, and once-in-a-while goes off on a path that you (or the developers) may not have considered. Try trivial things like changing the order of two statements where it shouldn't matter. I have noticed that "simplify" is especially prone to this problem. If you are using "simplify", try using one of the options to limit its operation to your case. I have long suspected that many of the built-in commands call "simplify" internally, in which case you have no control.

Also, be careful with your definition of freezing - sometimes the program path is just taking a long time. If the time clock on the bottom right changes, even at long intervals, and memory report jumps once-in-a-while, its not frozen, just taking its own sweet time (which can approximate eternity). In this case, the problem is that Maple has run out of memory.

Use taskmanager to keep an eye on this - the disk may be thrashing as memory is swapped in and out and whether or not you get a "freeze" will depend on the state of your machine.  Buy more memory if possible. Try judicious use of garbage collection (gc).

Good luck.

One of the reasons I upgraded to Maple 15 was the (unsupported) thought that maybe the "Latex export" facility in version 11 would have been improved by version 15.

My original post and your followup, shows that it wasn't. On April 26, 2011 I asked tech support to look into the issue. On July 27, 2011 I received the following:

"This is indeed a bug and we hope to have it fixed in a future release.
Thank you for providing us with this information."

So, for Latex export, I am now back to using Maple 11, which is bad, but not worse, and I am also squirrelling away  pennies for an eventual upgrade to Maple 19.

It escapes me how the purveyors of Maple can continue to distribute code with known bugs, and require that their customers purchase new versions to fix known flaws. No other manufacturer would get away with that.

Predictions

1. Someday, the consumer watchdogs will take a look at this issue and initiate class-action lawsuits.

2. In future, tech support will never acknowledge a bug.

Could you please interpret the statement "plot( [ <<L1>|<L2>>, <<L1>|<L3>> ] );" ?

I've been using Maple for many years and never seen the "bra-ket" "< >" notation ever used.

Nor does t he "help" give me any enlightenment. Is this some sort of Boolean operation?

It works, but why?

Thank you.

Could you please interpret the statement "plot( [ <<L1>|<L2>>, <<L1>|<L3>> ] );" ?

I've been using Maple for many years and never seen the "bra-ket" "< >" notation ever used.

Nor does t he "help" give me any enlightenment. Is this some sort of Boolean operation?

It works, but why?

Thank you.

I suppose it encourages the complainant to upgrade to the next version.

I have a collection of replies from technical support saying that bugs I have found "will be fixed in a future version".

How about a change of policy prior to Maple 17 - fix bugs as they are found.

(I have often wondered about the legality (as opposed to the wisdom) of continuing to distribute code with known bugs... Maybe someone would care to comment on that)

Sorry - I should have added that I am now "graduated" to Maple 15. There is no classic worksheet.

In Maple 11, I always used classic worksheet, and cut/paste was no problem.

Sorry - I should have added that I am now "graduated" to Maple 15. There is no classic worksheet.

In Maple 11, I always used classic worksheet, and cut/paste was no problem.

@Lark 

Hi:

I just figured out what is happening.

As you say, when you are moving through the document, there is a vertical (blinking) bar that indicates which statement is about to be executed, or where you are in the worksheet.  There is also a cursor that moves with the mouse.

When you press "return" to execute, the cursor changes to a busy symbol (hourglass or animated circle or whatever), but the vertical blinking bar stays remains exactly where it was positioned when you pressed "return".

In my previous version (Maple 11), the blinking vertical bar vanished when you pressed "return" and the cursor turned busy.

So, if the cursor happens to be off-screen when it turns"busy", it is not seen, and the program looks like it has hung because the blinking vertical pointer is still sitting where it was and there is no visible indication that something is happening.

And that is what was happening - its the difference between the two versions of Maple. 

I was accustomized to the older version, where the vertical blinking pointer disappeared during a lengthy calculation, so you knew you had to look for an hourglass or whatever to see if anything was happening (sometimes even the time update takes big jumps during a lengthy sub-calculation, so checking for time isn't always a reliable indicator that the program is doing anything).

 

By the way, Maple 15 runs about 30% faster than Maple 11 (what used to take 3 hours now takes 2), although taskmanager doesn't show much multicore action going on.

 

@Lark 

Hi:

I just figured out what is happening.

As you say, when you are moving through the document, there is a vertical (blinking) bar that indicates which statement is about to be executed, or where you are in the worksheet.  There is also a cursor that moves with the mouse.

When you press "return" to execute, the cursor changes to a busy symbol (hourglass or animated circle or whatever), but the vertical blinking bar stays remains exactly where it was positioned when you pressed "return".

In my previous version (Maple 11), the blinking vertical bar vanished when you pressed "return" and the cursor turned busy.

So, if the cursor happens to be off-screen when it turns"busy", it is not seen, and the program looks like it has hung because the blinking vertical pointer is still sitting where it was and there is no visible indication that something is happening.

And that is what was happening - its the difference between the two versions of Maple. 

I was accustomized to the older version, where the vertical blinking pointer disappeared during a lengthy calculation, so you knew you had to look for an hourglass or whatever to see if anything was happening (sometimes even the time update takes big jumps during a lengthy sub-calculation, so checking for time isn't always a reliable indicator that the program is doing anything).

 

By the way, Maple 15 runs about 30% faster than Maple 11 (what used to take 3 hours now takes 2), although taskmanager doesn't show much multicore action going on.

 

Thank you very much. That works as I wanted.

 

Please:

 

What is the difference between

... assuming n::integer;

AND

... assuming n,integer;

 

The second form works as expected, but only sometimes, and I can never figure out when it is going to work.

What is that form supposed to do?

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