Fitting Curve passing through zero using CFTOOL

Hi All,

below the data from a damper dyno test (attached). As you can see this shows some hysteresis.

I was interested in having only one curve passing basically in the middle (a sort of average between the bump and rebump stroke) I obtained this using the cftool (and help from the matworks answer:). In particular, I achieved that with the followings

% Create a smoothing spline  fit with the parameter I specified 
Fit_of_the_Data = fit(Velocity, Force, 'smoothingspline', 'SmoothingParam', 0.025)  

% Create a variable with the point of the fit  
Data_fitted = feval(Data_Fit,Velocity);

The fitting result is "more or less" fine (see below)

However, I wish my fitting curve to pass through zero . How can I do that?

Thanks in advance

G

Answer 1

[Mischa Kim]

Hello Giuseppe,

you could use a simple, brute-force approach to get a little closer: add a couple of (0,0) data points to the force and velocity vectors and re-do the curve fitting. If forcing the curve through (0,0) does make sense for your application is something you need to decide.