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Hi, is it possible to implement a power curve fitting in Fortran 77. I have two data points and I have to predict the values between these two data points. I am trying to implement a power fit which can be represented by y=Constant*x^power. Does anyone know if there is a predefined sub routine which can fit it for the data values i provide automatically?

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Quite possibly, but in general the problem would consist of finding the best parameters to fit a larger number of points. Since you have only two points, you can solve this analytically. I will leave the details to you :). (This is not a homework exercise, is it?)

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The NIST Guide to Available Mathematical Software (GAMS) is likely to have a few curve-fitting algorithms you could examine. The web site is: https://gams.nist.gov/

Use the "problem keywords" search tool and enter "curve fit" to see the list of possibilities. You can view the source code to get an idea if one would fit your needs.

Regards, Greg

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Hi Greg, thank you for your suggestion. I shall look into it.

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I agree with Arjen, this sounds like an elementary homework problem, not a curvefit at all. But I'll give in and give you a hint. Just transform your equation from "power space" to "linear space" by taking the log of each side, then do a linear interpolation.

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