Change to symbolic calculation

[RantEng]

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

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:

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

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

[Werner_E]

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

[RantEng · Accepted solution]

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

[Werner_E]

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@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

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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.

[RantEng]

Thanks again Werner,

I completely forgot how you solved that problem for me.  Had to go back and look at the old messages.

It works great when you remember to recalculate!

Bob