t=0:200;
f=20;
x1 = sin(2*pi*(2/200)*t);%sin 1
x2 = sin(2*pi*(50/200)*t); %sin 2
x3= x1+x2; %dodanie sinus 1 i sinus 2
plot(t,x3)
b = fir1(58,20/200,'low'); %dolno przpustowy fg=20
c= fliplr(b);


m=length(x3);
n=length(c);

X=[x3,zeros(1,n)];
H=[c,zeros(1,m)];


for i = 1:n+m-1
 	   Y(i)=0;
 	   for j = 1:m
  	      if(i-j+1>0)
  	          Y(i)=Y(i)+X(j)*H(i-j+1);
 	       else
    end
    end
end
 plot(Y)
 figure()
  plot(X)