tau = 3
alfa = 3
t=1;
for x=-tau-1:.1:tau+1;
y(t)=sin(sin(10*x)/7+cos(9.5*x/2)/10)/2;
t=t+1;
end
x=-tau-1:.1:tau+1;
figure
qq=polyfit(x,y,3);
pp=polyval(x,qq);
xx=-tau-1:.001:tau+1;
nnv=spline(x,y,xx);
plot(xx,nnv);
title('Semnal sinusoidal sin(sin(10*x)/7+cos(9.5*x/2)/10)/2');
hold on;
grid;
t=1;
figure;
for x=-tau-1:.1:tau+1;
if (abs(x)<tau)
bartlett(t)=1-(x/tau)^2;
else
bartlett(t)=0;
end
t=t+1;
end
x=-tau-1:.1:tau+1;
qq=polyfit(x,bartlett,3);
pp=polyval(x,qq);
xx=-tau-1:.001:tau+1;
nnv=spline(x,bartlett,xx);
plot(xx,nnv,'r');
%title('Fereastra Welch');
hold on;
t=1;
yt1=y+bartlett;
qq=polyfit(x,yt1,3);
pp=polyval(x,qq);
xx=-tau-1:.001:tau+1;
nnv=spline(x,yt1,xx);
plot(xx,nnv);
title('Filtrarea cu ajutorul ferestrei Welch')
grid;
t=1;
figure;
for x=-tau-1:.1:tau+1;
if ((x>=-tau)&(x<=tau))
kaiser(t)=besseli(0,x)*(alfa*(1-(x/tau)^2)^(1/2)/besseli(0,alfa));
else
kaiser(t)=0;
end
t=t+1;
end
x=-tau-1:.1:tau+1;
qq=polyfit(x,kaiser,3);
pp=polyval(x,qq);
xx=-tau-1:.001:tau+1;
nnv=spline(x,kaiser,xx);
plot(xx,nnv,'r');
hold on;
%title('Fereastra Kaiser');
t=1;
%figure
yt2=y+kaiser;
qq=polyfit(x,yt2,3);
pp=polyval(x,qq);
xx=-tau-1:.001:tau+1;
nnv=spline(x,yt2,xx);
plot(xx,nnv);
title('Filtrarea cu ajutorul ferestrei Kaiser')
grid;