FIR滤波器M文件

clcclearcloseallchoosetype=1;%1BOXCAR;2BARTLETT;3HANN;4HAMMING;5BLACKMAN;choose=4;%1lp;2hp;3bp;4bsswitchchoosecase1wp=2*pi;ws=4*pi;s=20;width=(ws-wp)/pi/s;wc=(wp+ws)/2/pi/s;case2wp=4*pi;ws=2*pi;s=20;width=(wp-ws)/pi/s;wc=0.5-(wp+ws)/2/pi/s;case3wsl=2*pi;wsh=12*pi;wpl=4*pi;wph=8*pi;s=25;wcl=(wsl+wpl)/2/pi/s;wch=(wsh+wph)/2/pi/s;F0=(wpl+wph)/2/pi/s;wc=(wsh+wph)/2/pi/s-F0;width=min((wpl-wsl),(wsh-wph))/pi/s;case4wpl=2*pi;wph=8*pi;wsl=4*pi;wsh=6*pi;s=10;wcl=(wsl+wpl)/2/s;wch=(wsh+wph)/2/s;F0=(wsl+wsh)/2/pi/s;wc=(wsh+wph)/2/pi/s-F0;width=min((wsl-wpl),(wph-wsh))/pi/s;endswitchchoosetypecase1N=13;type=BOXCAR(N);titl='BOXCAR';f=abs(fft(type,1024));f=10*log(f);case2N=31;type=BARTLETT(N);titl='BARTLETT';f=abs(fft(type,1024));f=10*log(f);case5N=ceil(5.71/width);type=BLACKMAN(N);titl='BLACKMAN';f=abs(fft(type,1024));f=10*log(f);case4N=ceil(3.47/width);type=HAMMING(N);titl='HAMMING';f=abs(fft(type,1024));f=10*log(f);case3N=ceil(3.21/width)+1;type=HANN(N);titl='HANN';f=abs(fft(type,1024));f=10*log(f);endwindow=type.';n=0:N-1;tao=(N-1)/2;switchchoosecase1hd=2*wc*sinc(2*wc*(n-tao));case2hd=2*wc*(-1).^(n-tao).*sinc(2*wc*(n-tao));case3hd=4*wc*sinc(2*(n-tao).*wc).*cos(2*pi*(n-tao).*F0);case4%hd=(n==tao)-4*wc*sinc(2*(n-tao).*wc).*cos(2*pi*(n-tao).*F0);hd=sin(pi/3*(n-tao+eps))./(pi*(n-tao+eps))+sin(pi*(n-tao+eps))./(pi*(n-tao+eps))-sin(2*pi/3*(n-tao+eps))./(pi*(n-tao+eps));endh=hd.*window;H=abs(fft(h,1024));mag=abs(H);db=20*log10((mag+eps)/max(mag));%figure%subplot(211)%stem(type)%gridon%subplot(212)%plot(f)%gridonfigureplot([0:1023]/1024,db)gridontitle(titl);clearallcloseallclcchoose=0;N=64;w=boxcar(N);%矩形窗0N=64;w1=triang(N);%三角窗1N=64;w2=hann(N);%汉宁窗2N=64;w3=hamming(N);%海明窗3N=64;w4=blackman(N);%布拉克窗4N=64;r=100;w5=chebwin(N,r);%切比雪夫窗5N=64;w6=bartlett(N);%巴特利特窗6N=200;r=4.5;w7=kaiser(N,r);%凯塞窗7switchchoosecase0wvtool(w);case1wvtool(w1);case2wvtool(w2);case3wvtool(w3);case4wvtool(w4);case5wvtool(w5);case6wvtool(w6);case7wvtool(w7);end