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VorazbekUT1-Visitor
1-Visitor
February 12, 2014
Solved

Gremlins in my mathcad - data analysis in nonlinear regression

  • February 12, 2014
  • 6 replies
  • 3034 views

Hello, I'm having a problem with a Mathcad file - I am able to get the mathcad file to work if I separate it into two different files. However, in the same file it gives me an error about a variable being undefined. I'm not sure what's up with this. It's a first order absorption and elimination problem.

I've attached the files to show what the second part of the program is suppose to do and what it does if it works. I tried changing the variable names and references but something strange that I can't figure out is happening. I would appreciate any advice or wisdom on the matter.

Best answer by Werner_E

The reason that the Find() at the end of your gremlin sheet is failing is the superfluous "Given" at the top of your sheet after the definition of C.min. There is no closing Find, Odesolve, maximize, minerr, etc. for this given and so you can delete it and at least Find() will give you a solution.

6 replies

ValeryOchkov24-Ruby IV
24-Ruby IV
February 12, 2014

I hope same problem is here http://twt.mpei.ac.ru/TTHB/New-Chem-Kin/En-ChemKin.html

I witll find it.

But may be so:

tt.png

VladimirN24-Ruby IV
24-Ruby IV
February 12, 2014

Some correction for the plot in "7.7works" worksheet can be found in attachment.

    ValeryOchkov24-Ruby IV
    24-Ruby IV
    February 12, 2014

    Steven Clise wrote:

    I've attached the files to show what the second part of the program is suppose to do and what it does if it works.

    ttgiven.png

      AlanStevens19-Tanzanite
      19-Tanzanite
      February 12, 2014

      You have a factor of 2 missing in h(D) - see below. Also, I'm not sure that your Tmax in "gremlins" matches any t in "works".

      Alan

      deriv.PNG

        Werner_E
        Werner_E25-Diamond IAnswer
        25-Diamond I
        February 12, 2014

        The reason that the Find() at the end of your gremlin sheet is failing is the superfluous "Given" at the top of your sheet after the definition of C.min. There is no closing Find, Odesolve, maximize, minerr, etc. for this given and so you can delete it and at least Find() will give you a solution.

          VorazbekUT1-VisitorAuthor
          1-Visitor
          February 13, 2014

          This is what was causing my problem, thank you! I must have absent mindedly typed it and forgot it was there. I was originally going to solve the first part with conditions rather a root finder, thanks!

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