ampx = zeros(1,41);
ampy = zeros(1,41);
ampyint = zeros(1,41);
b = fir1(10,25/50);
bint = fix(b*1024);
fs = 10000;
ts = 1/fs;
nx = 200;
x = zeros(1,nx);
y = zeros(1,nx);
yint = zeros(1,nx);

ii = 1;

for kF = 1:40,
    F = kF*100;
    ki = 1;
    kt = 0;
    for k =1:nx,
        x(k) = sin(2*pi*F*k*ts);
    end

    y(1) = x(1)*b(1);
    y(2) = x(2)*b(1)+x(1)*b(2);
    y(3) = x(3)*b(1)+x(2)*b(2)+x(1)*b(3);
    y(4) = x(4)*b(1)+x(3)*b(2)+x(2)*b(3)+x(1)*b(4);
    y(5) = x(5)*b(1)+x(4)*b(2)+x(3)*b(3)+x(2)*b(4)+x(1)*b(5);
    y(6) = x(6)*b(1)+x(5)*b(2)+x(4)*b(3)+x(3)*b(4)+x(2)*b(5)+x(1)*b(6);
    y(7) = x(7)*b(1)+x(6)*b(2)+x(5)*b(3)+x(4)*b(4)+x(3)*b(5)+x(2)*b(6)+x(1)*b(7);
    y(8) = x(8)*b(1)+x(7)*b(2)+x(6)*b(3)+x(5)*b(4)+x(4)*b(5)+x(3)*b(6)+x(2)*b(7)+x(1)*b(8);
    y(9) = x(9)*b(1)+x(8)*b(2)+x(7)*b(3)+x(6)*b(4)+x(5)*b(5)+x(4)*b(6)+x(3)*b(7)+x(2)*b(8)+x(1)*b(9);
    y(10) = x(10)*b(1)+x(9)*b(2)+x(8)*b(3)+x(7)*b(4)+x(6)*b(5)+x(5)*b(6)+x(4)*b(7)+x(3)*b(8)+x(2)*b(9)+x(1)*b(10);
    for k = 11:nx,
        y(k) = x(k)*b(1)+x(k-1)*b(2)+x(k-2)*b(3)+x(k-3)*b(4)+x(k-4)*b(5)+x(k-5)*b(6)+x(k-6)*b(7)+x(k-7)*b(8)+x(k-8)*b(9)+x(k-9)*b(10)+x(k-10)*b(11);
    end
%-------------
    yint(1) = x(1)*bint(1);
    yint(2) = x(2)*bint(1)+x(1)*bint(2);
    yint(3) = x(3)*bint(1)+x(2)*bint(2)+x(1)*bint(3);
    yint(4) = x(4)*bint(1)+x(3)*bint(2)+x(2)*bint(3)+x(1)*bint(4);
    yint(5) = x(5)*bint(1)+x(4)*bint(2)+x(3)*bint(3)+x(2)*bint(4)+x(1)*bint(5);
    yint(6) = x(6)*bint(1)+x(5)*bint(2)+x(4)*bint(3)+x(3)*bint(4)+x(2)*bint(5)+x(1)*bint(6);
    yint(7) = x(7)*bint(1)+x(6)*bint(2)+x(5)*bint(3)+x(4)*bint(4)+x(3)*bint(5)+x(2)*bint(6)+x(1)*bint(7);
    yint(8) = x(8)*bint(1)+x(7)*bint(2)+x(6)*bint(3)+x(5)*bint(4)+x(4)*bint(5)+x(3)*bint(6)+x(2)*bint(7)+x(1)*bint(8);
    yint(9) = x(9)*bint(1)+x(8)*bint(2)+x(7)*bint(3)+x(6)*bint(4)+x(5)*bint(5)+x(4)*bint(6)+x(3)*bint(7)+x(2)*bint(8)+x(1)*bint(9);
    yint(10) = x(10)*bint(1)+x(9)*bint(2)+x(8)*bint(3)+x(7)*bint(4)+x(6)*bint(5)+x(5)*bint(6)+x(4)*bint(7)+x(3)*bint(8)+x(2)*bint(9)+x(1)*bint(10);
    for k = 11:nx,
        yint(k) = x(k)*bint(1)+x(k-1)*bint(2)+x(k-2)*bint(3)+x(k-3)*bint(4)+x(k-4)*bint(5)+x(k-5)*bint(6)+x(k-6)*bint(7)+x(k-7)*bint(8)+x(k-8)*bint(9)+x(k-9)*bint(10)+x(k-10)*bint(11);
    end

    
    
%------
    ampx(ii) = max(abs(x(20:200)));
    ampy(ii) = max(abs(y(20:200)));
    ampyint(ii) =  max(abs(yint(20:200)))/1024;   
    
    ii = ii+1;
    kF
end

subplot(3,1,1); plot(ampx); ylabel('X(n)'); 
subplot(3,1,2); plot(ampy); ylabel('y(n) real');  
subplot(3,1,3); plot(ampy);xlabel('Frequency  (Hz)'); ylabel('y(n) integer');