Inserting a constant value in custom expression of Curve Fitting app.

Expression: Y = A*(d^n)*exp(B*X)+ C*X;

Here, X = Independent Variable Vector

Y = Dependent Variable Vector

A,B,C,n = Constants for fitting

d = distance value (Known)

I want to use the known d value but donot know how to use in curve fitting app ?

Answer 1

[Ashu]

To use your expression in the Curve Fitter app, you can follow these steps:

1. Open the Curve Fitter app and import your data.
2. In the "Equation Settings" section, select "Custom Equation".
3. Enter the modified expression in the "Equation" field: A*(d^n)*exp(B*X) + C*X.
4. In the "Coefficients" section,the four coefficient will automatically reflect. If not, then you can add them mannually.
5. In the "Coefficient Starting Values" section, enter initial guesses for the four constants.
6. Since 'd' is a known constant, you can set the start, upper and lower limit as same values.

By fixing the value of d as a constant, the curve fitting app will estimate the values of A, B, C, and n that best fit the data while keeping d fixed at its known value.

To know more about the interactive curve and surface fitting, you can refer to the following documentation

https://www.mathworks.com/help/curvefit/interactive-curve-and-surface-fitting.html