elo2

clear all; close all;

dx = (2*pi)/100;
x = 0 : dx : 4*pi;
N = length(x);
y = sin(x);  yr = cos(x);


d1 = [ -1 1];               d1=fliplr(d1);   N1=length(d1);
d2 = [ -1 0 1];             d2=fliplr(d2);   N2=length(d2);
d3 = 1/12*[1 -8 0 8 -1];    d3=fliplr(d3);   N3=length(d3);

SNR = [240, 80, 50, 30, 20 ];

for k = 1 : length(SNR)
    k, SNR(k),
    yn = awgn(y,SNR(k));

    yd1 = conv(yn, d1 ) / dx;
    yd2 = conv(yn, d2 ) / (2*dx);
    yd3 = conv(yn, d3 ) / dx;

    figure
    plot( x,yr,'k', ...
        x(1:N-1)+pi/100,yd1(N1:end-N1+1),'r' ...
        ,x(2:N-1),yd2(N2:end-N2+1),'g', ...
        x(3:N-2),yd3(N3:end-N3+1),'b');
end


x1 = zeros(1,100);
x2 = zeros(1,99);
for i=1:100
    x1(i) = x(i);
end
for i=1:99
    x2(i) = x(i);
end
y1 = sin(x);
y1 = awgn(y1, 20);
y2 = cos(x);
P = zeros(1,101);
wstecz = zeros(1,100);
centralny = zeros(1,99);
for i=1:100
    wstecz(i) = (y1(i+1)-y1(i))/(x(i+1)-x(i));
end
for i=2:100
    centralny(i-1) = (y1(i+1)-y1(i-1))/(x(i+1)-x(i-1));
end
fir = firls(4, [0 0.5 0.7 1], [0 0.5*pi 0 0], 'differentiator');
filtr = filter(fir, 1, y1);
plot(x,y2,'r', x1,wstecz,'b', x2,centralny,'g');
%plot();
%plot(x2,centralny,'g');


MM = [10,25,50,100];

dx = (2*pi)/200;
x = 0 : dx : 8*pi;
N = length(x);
y = sin(x);  yr = cos(x);

for k = 1 : length(MM)
    k, MM(k)
    %yn=y;
    yn = awgn(y,20);
    % zaszumienie
    M=MM(k);
    m=-M:1:M;
    h = cos(pi*m)./m;
    h(M+1)=0;  % odp. impulsowa filtru r�nicz.
    w = blackman(2*M+1)';
    h = h .* w; % opcjonalne wyg�adzenie brzeg�w
    yd4 = conv(yn, h)/dx;            % operacja splotu (filtracji)

    figure
    plot(x,yn,'b', x,yr,'k',x(M+1:N-M),yd4(2*M+1:end-2*M),'r'); grid
    %plot(x,yn,'b', x,yr,'k',x,yd4,'r'); grid
  end