Extrapolation of an isotherm

[Moushou7]

Hello,

Please, I am intraineeship and I work on a project and I have been blocked for several days on a problem.

I trace an isotherm that arrives up to 0.23 and I want to extrapolate to 1.

If there are tools that do extrapolation on CVI thank you for helping me or give me ideas how to do.

Thank you all.

[Wolfgang]

Hello,

I teach my students that extrapolation typically is BAD and that only interpolation is permitted - the only exception is if one has a reliable (verified) model for the data. Then one can use the model to predict the behavior.

So this means that

1. you need a model function (say a square root dependence)
2. you need to verify your model in the data range of your interest (i.e., around 1) - otherwise you can just throw a dice because then the extrapolation mostly depends on your model

Concerning CVI this means that you can search for a function that does least squares fitting - and depending on your model you may have to use the NonLinearFit routine

Hope this helps

[Moushou7]

What is the right answer !!

[Moushou7]

OK thanks for your answer.
Please give me an example of using NonLinearFit, I can not find and I do not know how it is used, I have not understood the documentation

[RobertoBozzolo]

Sorry, I wasn't clear. I wanted to say my message was a wrong posting!

[Moushou7]

Okay
thanks anyway

[Wolfgang]

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@Moushou7 wrote:

OK thanks for your answer.
Please give me an example of using NonLinearFit, I can not find and I do not know how it is used, I have not understood the documentation

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In CVI, use the menu entry Help / Find Examples, enter nonlinear as keyword.

This requires that you have the Advanced Analysis Library, i.e the Full Development System of CVI (menu Help / About to find out)

[Moushou7]

Okay,
I will look
thank you very much