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Symbolic Simplification Issue

CD_9999850
8-Gravel

Symbolic Simplification Issue

Prime 10

 

I'm trying to use Mathcad's symbolic calculations, and it is not simplifying my expressions properly.  

 

See below for an example: if I use the full equation, it does not simplify anything inside of the parentheses, but if I separate that section out and calculate it as its own entity, it simplifies everything correctly.

 

CD_9999850_0-1730463375438.png

 

  1. Why is it simplifying if I split it out, but not if I have everything together?
  2. What steps can I take to get Mathcad to fully simplify the full expression?

Thank you

ACCEPTED SOLUTION

Accepted Solutions
Werner_E
25-Diamond I
(To:CD_9999850)

Prime sure is not first choice when it comes to symbolic operations.

The symbolics in Mathcad & Prime had undergone a lot of changes.

In older Mathcad versions a subset of  Maple was used as symbolic engine. Later Maple was replaced for MuPad in Mathcad 14.

The reason was presumably that Maplesoft refused to licence its engine any further.
As a result, both Mathworks with MatLab and Mathsoft with Mathcad were forced to switch from Maple to another engine. Both selected MuPad, which was originally a free software developed by the University of Paderborn. The only difference was that Mathworks bought this software, made it commercial and continued to develop it, while Mathsoft and subsequently PTC had to pay licence fees for the MuPad core (which was hardly developed further over the years) to Mathworks.
PTC then decided to replace MuPad with a variant of the free FriCAS/Axiom system (first introduced in Prime 6) and to continue developing it itself.
However, MuPad and FriCAS have never been able to achieve the quality of Maple or Mathematica and are rather to be seen as a nice addition to the number cruncher Mathcad, whose proven strengths lie above all in dealing with units and natural input and display.

 

I played with your expression and simplified it down to

Werner_E_2-1730475866709.png

 

It was always hard to control the output of the symbolics. Sometimes changing the order the keywords are placed could help, sometimes throwing in "collect" or using "factor" instead of "simplify" would do the job.
I tried but could not make it simplify once a term was placed in the denominator.

 

Just out of curiosity I tried the very same in Mathcad 15 (with muPad) and this was the result

Werner_E_3-1730475885119.png

 

I am pretty sure that Mathcad 11 with Maple under the hood could simplify as well.

 

So I guess its now up to you to open a case with official PTC support and report this inability of the symbolics and hope that the engine will get improved in one of the upcoming versions.

View solution in original post

5 REPLIES 5
Werner_E
25-Diamond I
(To:CD_9999850)

Prime sure is not first choice when it comes to symbolic operations.

The symbolics in Mathcad & Prime had undergone a lot of changes.

In older Mathcad versions a subset of  Maple was used as symbolic engine. Later Maple was replaced for MuPad in Mathcad 14.

The reason was presumably that Maplesoft refused to licence its engine any further.
As a result, both Mathworks with MatLab and Mathsoft with Mathcad were forced to switch from Maple to another engine. Both selected MuPad, which was originally a free software developed by the University of Paderborn. The only difference was that Mathworks bought this software, made it commercial and continued to develop it, while Mathsoft and subsequently PTC had to pay licence fees for the MuPad core (which was hardly developed further over the years) to Mathworks.
PTC then decided to replace MuPad with a variant of the free FriCAS/Axiom system (first introduced in Prime 6) and to continue developing it itself.
However, MuPad and FriCAS have never been able to achieve the quality of Maple or Mathematica and are rather to be seen as a nice addition to the number cruncher Mathcad, whose proven strengths lie above all in dealing with units and natural input and display.

 

I played with your expression and simplified it down to

Werner_E_2-1730475866709.png

 

It was always hard to control the output of the symbolics. Sometimes changing the order the keywords are placed could help, sometimes throwing in "collect" or using "factor" instead of "simplify" would do the job.
I tried but could not make it simplify once a term was placed in the denominator.

 

Just out of curiosity I tried the very same in Mathcad 15 (with muPad) and this was the result

Werner_E_3-1730475885119.png

 

I am pretty sure that Mathcad 11 with Maple under the hood could simplify as well.

 

So I guess its now up to you to open a case with official PTC support and report this inability of the symbolics and hope that the engine will get improved in one of the upcoming versions.

LucMeekes
23-Emerald III
(To:Werner_E)

Here you go, Mathcad 11/Maple:

LucMeekes_0-1730486406257.png

Success!
Luc

Werner_E
25-Diamond I
(To:LucMeekes)

The problem of Prime not simplifying fully occurs when f(a,b,n) is divided by some other variable c. As you can see in the screenshot above Prime does not cancel variable b in this case.

But I am pretty sure that this is no problem for MC11.

LouP
12-Amethyst
(To:LucMeekes)

This is the first time I've seen the "normal" keyword used in mcd11 (after decades of use). It appears to be an undocumented symbolic keyword/modifier. A few others in this class that I know of are: trig, exp, numer, denom. Any others lurking out there I can add to my own documentation?

 

Lou

Werner_E
25-Diamond I
(To:LouP)


@LouP wrote:

This is the first time I've seen the "normal" keyword used in mcd11 (after decades of use). It appears to be an undocumented symbolic keyword/modifier. A few others in this class that I know of are: trig, exp, numer, denom. Any others lurking out there I can add to my own documentation?

 

Lou


I am not aware of 'normal' and 'trig', but 'exp', 'numer' and 'denom' are documented - at least in versions after MC11 (just had a quick look and could not spot them in the MC11 User's Guide).

According to the MC14 User's Guide they are were introduced but in MC14 - see snippet below.

'exp' not only as a function but also as a modifier to be used in conjunction with 'rewrite' and 'numer' and 'denom' are not modifiers or keywords in an symbolic evaluation but rather functions which only can be evaluated symbolically.

 

From Mathcad 14 User's Guide:

Werner_E_0-1730574910414.png

 

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