% This program finds the maximum of the function.
% It finds the local maximums, and hopefully finds 
% the global maximum too.

clear
% x=-2:0.01:2;
% y1=exp(1./(1+x.^2))+0.1*sin(20*x);

% x=-10:0.01:10;
% y1=(x-2).*cos(x);

x=0:255;
y1=sin((pi*x)/256);

plot(x,y1)
axis([-1 256 0 1.05])
hold on
grid on

%y=inline('exp(1./(1+x.^2))+0.1*sin(20*x)');
%y=inline('(x-2).*cos(x)');
y=inline('sin((pi*x)/256)');

%temp_x=(floor(100*((20*rand)-10)))/100;
%temp_x=(floor(100*((4*rand)-2)))/100;
temp_x=floor((256*rand));

temp_y=y(temp_x);
t=temp_x;

if y(t+1) > y(t-1)
    direction = 2;                          % right
elseif y(t+1) < y(t-1)
    direction = 1;                          % left
else
    direction = 0;                          % flat
end

if direction ==2
    while y(t+1) > y(t)
        t=t+1;
        x_lokal_max=t;
        y_lokal_max=y(x_lokal_max);
        plot(x_lokal_max,y_lokal_max,'r*')
        pause(0.01)
    end
end

if direction ==1
    while y(t-1) > y(t)
        t=t-1;
        x_lokal_max=t;
        y_lokal_max=y(x_lokal_max);
        plot(x_lokal_max,y_lokal_max,'r*')
        pause(0.01)
    end
end