短时傅里叶变换-matlab程序

clearall%窗口函数%n1=40;window=boxcar(n1);w1=window;figure(1);stem(w1);%非平稳信号产生%fs=1000;a=0:1/fs:1;f0=0;f1=150;y1=chirp(a,f0,1,f1);x=y1(1:510);figure(2);plot(x);%短时傅里叶变换%t=1:length(x);n=length(x);[tfr,t,f]=tfrstft(x,t,n,w1,0);contour(t,f,abs(tfr))clcclearall%窗口函数%n1=40;window=boxcar(n1);w1=window;figure(1);stem(w1);%非平稳信号产生%fs=1000;a=0:1/fs:1;f0=0;f1=150;y1=chirp(a,f0,1,f1);x=y1(1:510);figure(2);plot(x);%短时傅里叶变换%t=1:length(x);n=length(x);[S,F,T,P]=spectrogram(x,w1,32,256);surf(T,F,10*log10(abs(P)));axistight;view(0,90);