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This solve used to work but now not in ver 15- why??

BrianP
3-Visitor

This solve used to work but now not in ver 15- why??

I have a MCAD file from a version 12 that now requires a different set of tricks in ver 15 to make it work. I'm trying to understand why, and if there is really a better way to approach to original solution. We are not using MCAD Prime at this time.

thanks,

Brian

14 REPLIES 14
Fred_Kohlhepp
23-Emerald I
(To:BrianP)

Recognize that if Rs is not zero then the numerator must be zero, throw out the denominator.

(The difference between version 12 and 15 is Maple vs Mupad.)

Thanks Fred,

Oh yeah I forgot about the symbolic engine difference. As far as your suggestion, I get that in this one case but in general if the denominator is also a function of x, then there might be a case where you get 0/0. Its possible that by inspection one might see such a case in advance of sicking MAD on it as well. But if you have to do too much of this then the tool isn;t much good.

I guess I'm wondering why MathCad needs so much help to do it. Not sure why it jsut doesn't "work".

Fred_Kohlhepp
23-Emerald I
(To:BrianP)

Your denominator is zero if x is 0 or 1 (unless h or b is zero, so your 0/0 is not probable.

Sure, I get it for this specific example. I was generalizing and commenting that if it is not obvious by inspection what will happen with the denominator, such that you do the work for Mathcad, then the tool isn't much use in a case like this.

I'm interested in knowing why the tool doesn't work- and the question is even more realvent if practically by inspection it can be solved and yet the tool barfs.

Werner_E
24-Ruby V
(To:BrianP)

I'm interested in knowing why the tool doesn't work

I guess this question was already answered. You are comparing two completely different symbolic engines (Maple and MuPad) and its no surprise they act differently in some situations. Most users of Mathcad bemoan the change from Maple to MuPad as Maple was the superior tool.

Anyway, when you use Mathcad 15 you will have to live with the drawbacks of the new symbolic processor.

Ever so often MuPad switches automatically to some sort of float mode while Maple is able to present an exact solution.

Maple (Mathcad 11):

1.png

MuPad (Mathcad 15) - it knows about the Lambert W function but isn't able to find it as a solution for the equation:

2.png

Also Maple is able to solve some equations which MuPad simple refuses to do

Maple (Mathcad 11):

3.png

MuPad (Mathcad 15):

4.png

MikeArmstrong
5-Regular Member
(To:Werner_E)

Good work Werner and a clear example of the advantages of the Maple processor over the MuPad processor.

Did we ever find out why the processor was changed?

Mike Armstrong wrote:

Good work Werner and a clear example of the advantages of the Maple processor over the MuPad processor.

Did we ever find out why the processor was changed?

I am not aware of any reliable rumor.

But the symbolic engine was changed from Maple to MuPad at quite the same time in MatLab and in Mathcad (while Mathworks was clever enough to buy MuPad). So one guess is that MapleSoft either raised their fees too far or they were not willing at all to further license their software anymore to its competitors.

MikeArmstrong
5-Regular Member
(To:Werner_E)

Werner Exinger wrote:

So one guess is that MapleSoft either raised their fees too far or they were not willing at all to further license their software anymore to its competitors.

Which makes sense I suppose. Such a shame as it is widely acknowledged on here that Mathcad 11 was the best version.

Mike Armstrong wrote:

Werner Exinger wrote:

So one guess is that MapleSoft either raised their fees too far or they were not willing at all to further license their software anymore to its competitors.

Which makes sense I suppose. Such a shame as it is widely acknowledged on here that Mathcad 11 was the best version.

I appreciat some of the handling feature which were introduced later, but basically I agree. Mathcad 11 was a damn good version and I sure quite often miss the Maple engine.

MikeArmstrong
5-Regular Member
(To:Werner_E)

Werner Exinger wrote:

Mike Armstrong wrote:

Werner Exinger wrote:

So one guess is that MapleSoft either raised their fees too far or they were not willing at all to further license their software anymore to its competitors.

Which makes sense I suppose. Such a shame as it is widely acknowledged on here that Mathcad 11 was the best version.

I appreciat some of the handling feature which were introduced later, but basically I agree. Mathcad 11 was a damn good version and I sure quite often miss the Maple engine.

And we are now stuck with Prime . Having said that, I have not even touched on Prime's symbolic's so cannot really pass judgement.

And we are now stuck with Prime . Having said that, I have not even touched on Prime's symbolic's so cannot really pass judgement.

As far as I am aware there is no change in the symbolics in Prime.

It was made more user friendly because it is streamlined now as you can't hide the left hand side, you can't hide the keywords and you can't make the arrow look like a normal equal sign. So you don't have to worry if you should do that or not. Thats the new user friendliness and ease of use - simplicity is the key.

MikeArmstrong
5-Regular Member
(To:Werner_E)

Werner Exinger wrote:

And we are now stuck with Prime . Having said that, I have not even touched on Prime's symbolic's so cannot really pass judgement.

As far as I am aware there is no change in the symbolics in Prime.

It was made more user friendly because it is streamlined now as you can't hide the left hand side, you can't hide the keywords and you can't make the arrow look like a normal equal sign. So you don't have to worry if you should do that or not. Thats the new user friendliness and ease of use - simplicity is the key.

Streamlined by reduced functionality!!!! Maybe that is PTC's plan....

Streamlined by reduced functionality!!!! Maybe that is PTC's plan....

PTC's plan? You're such an optimist!

But at least that what they are actually doing.

MikeArmstrong
5-Regular Member
(To:Werner_E)

Werner Exinger wrote:

Streamlined by reduced functionality!!!! Maybe that is PTC's plan....

PTC's plan? You're such an optimist!

But at least that what they are actually doing.

They have a plan, don't they???????..........

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