Curve Fitting for an equation
4 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Hello
I have an equation like a*(x1^2)+ b(x2^2)+c((x1-x2)^2)+d((x12)^2)=1. Here I have variables of x1, x2, x12. x12 is the variable in the first quardrant. I have data of 12 Points passing through x1, x2 and x12.
I tried fitting the data to the above equation with different ways. But it did not turned out good. I tried with custom equation and some other methods. Could someone help me with getting the coefficients to this equation.
12 Kommentare
Akzeptierte Antwort
Torsten
am 1 Okt. 2018
Bearbeitet: Torsten
am 1 Okt. 2018
function main xdata = [...]; % x coordinates of your 12 point ydata = [...]; % y coordaintes of your 12 points x0 = [1 1 1]; % initial values for a, b and c x = lsqnonlin(@(x)fun(x,xdata,ydata),x0) end
function res = fun(x,xdata,ydata) res = x(1)*xdata.^2+x(2)*ydata.^2+x(3)*(xdata-ydata).^2-1; end
4 Kommentare
Weitere Antworten (1)
Pratik Bajaria
am 28 Sep. 2018
4 Kommentare
Pratik Bajaria
am 29 Sep. 2018
Well all equations can be written in y=f(x). Take any of the variables to be y (let's say x12) and all the other variables can be x. Since you have data points available try to write x12=f(x1,x2) and it must work.
Regards.
Siehe auch
Kategorien
Mehr zu Get Started with Curve Fitting Toolbox finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!