Skip to main content
R
RantEng14-Alexandrite
14-Alexandrite
January 10, 2023
Solved

Change to symbolic calculation

  • January 10, 2023
  • 1 reply
  • 1756 views

In earlier versions of Mathcad Prime, I could write the following expression:

RantEng_0-1673356974880.png

Simply put, I could define a variable symbolically and display the answer.  With the changes to the symbolic engine on Primate, this can no longer be done:

RantEng_1-1673357085070.png

This feature was great because I often used Mathcad during Engineering lectures to work examples problems.  My work around is:

RantEng_2-1673357243677.png

The first properly should use the symbolic equal to "=" and not the mathematical definition ":=" but it still works.  Anyone have any better suggestions or work arounds?

 

Bob

 

Best answer by RantEng

Thanks Werner!

 

I completely missed that option because I really didn't understand the PTC explanation of it.  I had experimented with the setting in the past but didn't see what change it made.  

 

Bob

1 reply

W
Werner_E25-Diamond I
25-Diamond I
January 10, 2023

I can't verify this, as I haven't bothered to install a newer version of Prime yet (I'm still using Prime 6).

But chances are that you ran into Primes infamous auto-labeling bug.

You may try to enable units and constants in symbolic calculations, recalculate and see if it helps

Werner_E_0-1673358553168.png

 

 

R
RantEng14-AlexandriteAuthorAnswer
14-Alexandrite
January 10, 2023

Thanks Werner!

 

I completely missed that option because I really didn't understand the PTC explanation of it.  I had experimented with the setting in the past but didn't see what change it made.  

 

Bob

W
Werner_E25-Diamond I
25-Diamond I
January 10, 2023
@RantEng wrote:

Thanks Werner!

 

I completely missed that option because I really didn't understand the PTC explanation of it.  I had experimented with the setting in the past but didn't see what change it made.  

 

Bob

This calculation options is sometimes a cure when experiencing problems with symbolic operations with expressions and quantities containing  units. But this forum already showed a lot of examples where enabling this option unfortunately still is no cure to a problem.

The reason the evaluation failed in your case seemed to have been that the unit "mm" was not labeled as being a unit and so was treated as an unknown variable. And maybe development changed the way expressions are handed over to the numeric engine when a symbolic evaluation is directly followed by a numeric evaluation.

Glad to see that in your case turning on this calc option solves the problem.

Terms & ConditionsAccessibility statement