Hi I would like to fit a custom defined function (not continuous) to experimental time series data. My problem is that fittype does not accept my function although the function itself works fine and the syntax worked for similar functions. below you will find the fittype command I use, the error and the function that I would like to fit. Thank you in advance for any suggestions.
Lorenz
fittype command: ft1=fittype('Exp_delay_v2(t, tau1, tau2, a, b, dt1, dt2)','independent','t','coeff',{'tau1','tau2','a','b','dt1','dt2'});
Error using fittype>iCreateFittype (line 368) Expression Exp_delay_v2(t, tau1, tau2, a, b, dt1, dt2) is not a valid MATLAB expression, has non-scalar coefficients, or cannot be evaluated: Error in fittype expression ==> Exp_delay_v2(t, tau1, tau2, a, b, dt1, dt2) ??? Index exceeds matrix dimensions.
function y = Exp_delay_v2(t, tau1, tau2, a, b, dt1, dt2)
y=zeros(size(t));
s = 10.8*200;
d1=dt1*200;
d2=dt2*200;
t1a = t(1:s-d2);
t1b = t(s-d2+1:2*s-d2+d1);
t2 = t(1:2*s-d1+d2);
y(1:s+d1) = ( (a+b) - b.*(1-exp(-(t1b)./tau2)) );
y(s+1+d1:3*s+d2) = ( a + b.*(1-exp(-(t2)./tau1)) );
y(3*s+d2+1:end) = ( (a+b) - b.*(1-exp(-(t1a)./tau2)) );