fitting parabolic looking data to an exponential function

Hello,

I have data which looks like many different parabolas. I would like to fit each parabolic data set to an exponential function and determine if it is cubic quadratic or so.

I tried this

g = fittype('a*exp(b*x)');

f0 = fit(x,y,g,'StartPoint',[0,0,0]);

plot(x,y,'o')

hold on;

plot(f0(xx),'r-');

but it gives me a line. Perhaps something is wrong with my code. Any ideas? :)

Answer 1

[Matt J]

Nothing is wrong with your code, but I recommend using the built-in 'exp1' model instead, which doesn't require a start point.

f0 = fit(x,y,'exp1');