clear all; close all;

% nonlinear curve fit

x=[1 2 3 4 5 6 7 8 9 10];
y=[10 13 15 14 11 9 7 8 10 13];

% A sin(Bx+C) + D

%coeff=fminsearch('sinfit',[5 pi/5 -pi/5 10.5]);
coeff=fminsearch('sinfit',[5 10 -pi/5 10.5]);


A=coeff(1); B=coeff(2); C=coeff(3); D=coeff(4);
xfit=1:0.1:10;
yfit=A*sin(B*xfit+C)+D;

plot(x,y,'ro',xfit,yfit,'k')

% e2 error
format long e
E=sqrt(  sum( (A*sin(B*x+C)+D-y).^2 )/length(x) )