fitted curve start from zero?
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Davide Cerra on 9 Dec 2018
Commented: Star Strider on 9 Dec 2018
How can the fitting curve can stat from [0,0]?
The easiest way is to not specify a y-intercept in the model you want to fit.
x = 0:2:100;
y = 3E+3 - (x-50).^2 + (x-50) + randn(1, numel(x))*50;
B = [x(:).^2 x(:)] \ y(:);
Y = [x(:).^2 x(:)] * B;
plot(x, y, '.', x, Y, '-r')
Here, x begins at 0, and not including a y-intercept in the model is the same as forcing it through 0.
Experiment to get the result you want, with your model and data.
You can impose some constraints with lsqcurvefit and the other Optimization Toolbox functions. This depends on what you want to constrain.
I don’t have the Curve Fitting Toolbox. (I can do everything I need with the Optimization and Statistics and Machine Learning Toolboxes.)
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