expfitxy.asv

fit programme for a serials of data

function [estimates,model]=expfitxy(x,y)
%input x is 1-by-N vector
%      y is 1-by-N vector
model=@expxy;
esttimates=fminsearch(model,rand(1,2));
%output a is the coeficient of fitting formula y=a*exp(bx)
%define the function of condition for fitting formula
function f=expxy(params)
n=length(x);
f=0;
f1=@(x1) params(1)*exp(params(2)*x1)
for i=1:n
    f=f+(f1(x(i))-y(i))^2;
end
end
end