Skip to main content
C
CLE_MW6-Contributor
6-Contributor
March 29, 2022
Solved

Trouble with symbolic calculation (integrals) with Prime 8.0

  • March 29, 2022
  • 5 replies
  • 3874 views

I am using Mathcad Prime Release 8.0 and Datecode8.0.0.0

I just moved from Prime 5.0 to 8.0, and some integrals (symbolic calculation with units) no longer calculate: while it tool a couple of minutes only, the orange disk turns infinitely without success.
I'm wondering whether I made a spelling error due to new engine, but I cannot find the solution.

Best answer by Werner_E

Looks like the problem is solved in the current version (at the time 10.0.1.0).

The whole sheet (the original one, not v3) calculates in less than 10 seconds (old and rather slow machine) and if you turn on the option to respect Units/Constants in Symbolics, the units correctly cancel in the symbolic calculation of Omega2.

Guess the thread can now be closed after three years 😉

5 replies

L
LucMeekes23-Emerald IV
23-Emerald IV
March 29, 2022

Did you set the calculation option "Units/Constants in Symbolics" on the Calculation tab?

 

Success!
Luc

C
CLE_MW6-ContributorAuthor
6-Contributor
March 30, 2022

Hi Luc,

Yes, I did, unsuccessfully. Thanks for hint anyway,

Cedric

W
Werner_E25-Diamond I
25-Diamond I
March 30, 2022

I opened your file in Prime 6 where both symbolic engines are available.

Using the legacy engine (muPad) the calculation of Omega1.1 took way less than a minute with n.s=2.

Switching to the new engine I cancelled the operation after about 10 minutes, so I can't tell if if would run forever or not.

Setting the "Units/Constants in Symbolics" option did not change anything.

 

I guess this means that even in version 8 the new symbolic engine still is less powerful and much slower compared to its predecessor muPad (which, in turn, was less powerful than its predecessor Maple).

C
CLE_MW6-ContributorAuthor
6-Contributor
March 30, 2022

Hi, thanks for having taken time to replicate my case. I got a similar reply from PTC team, who could replicate it as well.

Their first conclusion is something in the new engine as well.

I was expecting some time savings with the upgrade, but the contrary actually happens!

Rgds,

Cédric

M
MichaelW17-Peridot
17-Peridot
March 31, 2022

Hello

 

the observed behavior regarding units is intended and works to product specification for of Mathcad Prime.

According to this Case Solution article: https://www.ptc.com/en/support/article/CS249189

the cause and solution is to tell the Symbolic evaluation whether you require units or not:

Try Calculation > Units/Constants in Symbolics to get what you want

 

image.png

 

Also refer to the Mathcad Prime Help center: Symbolics > About Units and Constants in Symbolics

 

According to the observed "regression" in the symbolics:

you are right, the symbolic engine has been replaced (again).

The new symbolic engine introduced in Mathcad Prime 6, is replacing the legacy symbolic engine.

This is since Mathcad Prime new symbolic engine is (for legal reasons) a complete re-design, rather than an upgrade.
We are sorry if one face any engine regression where improvement is expected with that replacement.

Thank you for understanding and filing new Technical Support cases against it.
 

With regards, Michael, Technical Support

ttokoro
21-Topaz I
ttokoro21-Topaz I
21-Topaz I
March 30, 2022

Second page note. Change the first page unit m to only unit and not auto as shown below. Then you get what you want in second page. 

image.pngimage.png

t.t.
L
LucMeekes23-Emerald IV
23-Emerald IV
March 31, 2022

You should (get less of this kind of problems if you) use symbolics to do just the symbolics. I propose you define:

LucMeekes_8-1648742672187.png

 

Then with:

LucMeekes_1-1648742006781.png

You can have symbolic results, e.g.:

LucMeekes_9-1648742732302.png

and

LucMeekes_10-1648742787583.png

 

And if you supply numerical values (with units as appropriate):

LucMeekes_4-1648742131123.png

You can have meaningful numerical results, such as:

LucMeekes_5-1648742200030.png

Success!
Luc

 

 

C
CLE_MW6-ContributorAuthor
6-Contributor
April 1, 2022

Hi,

Thanks for this powerful hint. It's completely different approach to what I used to do, but that's very efficient, in addition to clarity. I gave it a try, and it simplifies the calculations, as well as it seems to shorten them...then many thanks again.

However, the problem remains as soon ns=2 is set. Whatever the method, MC has to integrate this function

CLE_MW_0-1648830518841.png

And even with some numerical values substituted, Prime 8.0 doesn't find the solution. I'll leave it running over the night and see!

Thanks,

Cedric

 

L
LucMeekes23-Emerald IV
23-Emerald IV
April 1, 2022

Hi Cedric,

 

It really shouldn't be that hard, even for Prime.

With the numerical values so far, these are the results for that integral for n.s =1 and 2:

LucMeekes_0-1648835870462.png

Can you attach your Prime file?

 

Success!
Luc

W
Werner_E25-Diamond IAnswer
25-Diamond I
April 3, 2025

Looks like the problem is solved in the current version (at the time 10.0.1.0).

The whole sheet (the original one, not v3) calculates in less than 10 seconds (old and rather slow machine) and if you turn on the option to respect Units/Constants in Symbolics, the units correctly cancel in the symbolic calculation of Omega2.

Guess the thread can now be closed after three years 😉

    C
    CLE_MW6-ContributorAuthor
    6-Contributor
    April 4, 2025

    Hi,

    Yes, I admit I had forgotten this one. It was solved in a few seconds on my side as well. 

    Terms & ConditionsCookie settingsAccessibility statement