clear all; close all;
Fs=8000; N=5; F1=250;
mysig=[];
myperiod=[ones(1,Fs/F1/2) -ones(1,Fs/F1/2)];
for idx=1:(F1*N)
   mysig=[mysig myperiod];
end
stem(mysig);
ylim([-2,2]); xlim([0,200]);
figure;
mySp=fft(mysig);
stem (abs(mySp));
display("hram orig. signal, stlac klavesu"); 
sound(mysig, Fs); pause;
figure;
sigLen=Fs*N;
z1=F1*N;
mySp(z1+1)=0;
mySp(sigLen-z1+1)=0;
stem (abs(mySp));
figure;
mysigA=real(ifft(mySp));
stem(mysigA);
ylim([-2,2]); xlim([0,200]);
display("hram filt. signal"); 
sound(mysigA, Fs);