//離散フーリエ変換 clear n=128; fc=32;//Frequency of carrier fs=8;//Frequency of Signal off=0.5;//Offset of modulation as=0.3;//Amplitude of signal xd=(1:n); for k = 1:n, for l =1:n, a(k,l) = exp(-%i*(k-1)*(l-1)*2*%pi/n); end; end; a; //入力ベクトル(Sin波) for k=1:n, x(k)=sin(2*%pi*fc*k/n)*(as*sin(2*%pi*fs*k/n)+off); end; //入力ベクトル(のこぎり波) //x=[1:1:n]'; //DFT変換 y=a*x; xbasc(); plot2d(xd,[n*x/16 abs(y)]); //bar(xd,abs(y),0.5); e=gce(); e.children(1).polyline_style=3; //Frequency area e.children(2).polyline_style=1; //Time area