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MikeCon1-Visitor
1-Visitor
March 5, 2011
Solved

Symbolic Integration hangs up

  • March 5, 2011
  • 5 replies
  • 3924 views

Hi all

Recently upgraded from Mathcad version 11 to 15/Prime.

I am a heavy user of the symbolic tools and I am encountering numerous cases where symbolic integration results which were quickly evaluated in Mathcad v11 ( & 2000) are now hanging in v15.

Please refer to the typical integral in the Mathcad15 attached file.

All references within the integral ie theta, R b etc are constants set individually - the only integration variable is phi.

Any thoughts, comments or suggestions would be greatly appreciated.

Thanks

Mike

Best answer by AlanStevens

Substitute A = phi - theta/2 and integrate wrt A and M15 is quite happy!

Alan

Message was edited by: AlanStevens See attached

5 replies

ValeryOchkov24-Ruby IV
24-Ruby IV
March 5, 2011

Michael Connolly wrote:

Recently upgraded from Mathcad version 11 to 15/Prime.

Mike

Sorry!

This is a well known problem - we have in Mathcad 14/15 new symbolic engine not from Maple but from MuPAD - with new errors .

RichardJ19-Tanzanite
19-Tanzanite
March 6, 2011

The new MuPad symbolic engine is very weak when it comes to integrals. For definite integrals, it is so weak that I basically consider it to not work. I have even seen examples where it can solve the indefinite integral, but not the definite integral! In such cases it is at least possible to get to the required answer by substituting the limits yourself. Unfortunately, your example is not such a case. The only thing you can do is use version 11 to solve it, and then copy and paste the solution.

AlanStevens19-TanzaniteAnswer
19-Tanzanite
March 6, 2011

Substitute A = phi - theta/2 and integrate wrt A and M15 is quite happy!

Alan

Message was edited by: AlanStevens See attached

MikeCon1-VisitorAuthor
1-Visitor
March 9, 2011

Alan

Tried your solution and it works just fine.

I really appreciate the help

The only question is why? Can you shed any insight why a change in the variable from one form to another enables the evaluation ???

Thanks again

Mike

AlanStevens19-Tanzanite
19-Tanzanite
March 9, 2011

Michael Connolly wrote:

Alan

Tried your solution and it works just fine.

I really appreciate the help

The only question is why? Can you shed any insight why a change in the variable from one form to another enables the evaluation ???

Thanks again

Mike

Who knows how these CAS systems work? None of them are perfect. All of them benefit from a little manual help from time to time.

This is true of the human mind also - we are often able to do an integration after a change of variable that we couldn't do before!

Alan

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