Matlab fitting data to a function, where the function is a summation and periodic, syntax -

i attempting fit temperature data on last 50 years using lsqcurvefit, concerned fitting function has bad syntax.

the fitting function of form:

∑(ai+bi*t+ci*t^2)*(cos(vt+p)) 

summing i=1 n. t correspond time vector called time. ideally fitting should return values a, b, c, v, , p describe temperature data

i attempting fit daily maximum temperatures, vector called tmax.

so far have:

lsqcurvefit(fitfn(1,2,time),5,time,tmax) 

where fitfn defined in script as

function f = fitfn(i,n,t) f=0; i=1:n     f =@(i,n,a,b,c,v,p,t) f + (a+b*t+c*t^2)*(cos(v*t+p)); end 

however whenever run lsqcurvefit error

error using fitfn>@(i,n,a,b,c,v,p,t)f+(a+b*t+c*t^2)*(cos(v*t+p)) (line 4) not enough input arguments.  error in lsqcurvefit (line 199)             initvals.f =             feval(funfcn_x_xdata{3},xcurrent,xdata,varargin{:});  caused by:     failure in initial user-supplied objective function     evaluation. lsqcurvefit cannot continue. 

i sure i'm making simple error i'm @ loss. i'm new matlab , don't quite understand how use anonymous functions. appreciated.

thanks reading

your fitfn wrong. think want:

f = @(x,t) (x(1)+x(2)*t+x(3)*t.^2)*cos(x(4)*t+x(5)) lsqcurvefit(f,zeros(1,5),time,tmax)