修改以下M文件程序并给出修改过后的代码要求：1 显示图像代码用与下面代码方式不同的方式显示图像2 修改代码中窗函数设计为矩形窗3 将代码中Min-Max design 参数修改为其他值代码如下：clc;clear all; close all;loadexam_tsmat;x=h_ts_data;x_1st=x1;x_3rd=x3;Ndot=lengthx_1st;fs=maxfreq_axis2

clc; clear all; close all; load('exam_ts.mat'); x=h_ts_data; x_1st=x(1,:); x_3rd=x(3,:); Ndot=length(x_1st); fs=max(freq_axis)2; Nfft=512; %1 [PXX_1ST,F]=periodogram(x_1st,rectwin(Ndot),Ndot,fs); [PXX_3RD,F]=periodogram(x_3rd,rectwin(Ndot),Ndot,fs); %2 design a filter fcuts=[0.05fs/2 0.1*fs/2]; mags=[0 1]; devs=[0.01 0.02]; %2.1 kasier window [Nfilter1,wn,beta,ftype]=kaiserord(fcuts,mags,devs,fs); h_kaiser=fir1(Nfilter1,wn,ftype,kaiser(Nfilter1+1,beta),'noscale'); %2.2 Min-Max design devs=[0.02 0.01]; [Nfilter2,fpts,mag,wt]=remezord(fcuts,mags,devs,fs); b=remez(Nfilter2,fpts,mag,wt); %3.filter y_1st_ka=filter(h_kaiser,1,x_1st); y_1st_re=filter(b,1,x_1st); y_3rd_ka=filter(h_kaiser,1,x_3rd); y_3rd_re=filter(b,1,x_3rd); %3.1 spectrum [PXX_Y_1ST_ka,F]=periodogram(y_1st_ka,rectwin(Ndot),Ndot,fs); [PXX_Y_1ST_re,F]=periodogram(y_1st_re,rectwin(Ndot),Ndot,fs); [PXX_Y_3RD_ka,F]=periodogram(y_3rd_ka,rectwin(Ndot),Ndot,fs); [PXX_Y_3RD_re,F]=periodogram(y_3rd_re,rectwin(Ndot),Ndot,fs); %3.2 TDFT FT_Y_1ST_ka=fftshift(fft(y_1st_ka,Nfft)); FT_Y_1ST_re=fftshift(fft(y_1st_re,Nfft)); FT_Y_3RD_ka=fftshift(fft(y_3rd_ka,Nfft)); FT_Y_3RD_re=fftshift(fft(y_3rd_re,Nfft));

figure(1) plot(freq_axis,10log10(fftshift(PXX_1ST)),'b',freq_axis,10log10(fftshift(PXX_3RD)),'r'); legend('spectra of 1st range samples','spectra of 3rd range samples') grid; xlabel('frequency(Hz)'); ylabel('power spectrum density(dB)'); velocity=150*nyquist_velocity/max(freq_axis)

figure(2) freqz(h_kaiser); title([num2str(Nfilter1),'th notch filter based on kaiser window'])

figure(3) freqz(b); title([num2str(Nfilter2),'th notch filter based on Min-max design'])

figure(4) subplot(411) plot(F,10log10(fftshift(PXX_Y_1ST_ka)),'b',F,10log10(fftshift(PXX_Y_3RD_ka)),'r'); legend('spectra of 1st range samples filterd','spectra of 3rd range samples filterd') title('spectra of 1st and 3rd range samples after kasier filter') grid; xlabel('frequency(Hz)'); ylabel('PSD(dB)'); subplot(412) plot(F,10log10(fftshift(PXX_Y_1ST_re)),'b',F,10log10(fftshift(PXX_Y_3RD_re)),'r'); legend('spectra of 1st range samples filterd','spectra of 3rd range samples filterd') title('spectra of 1st and 3rd range samples after Min-max filter') grid; xlabel('frequency(Hz)'); ylabel('PSD(dB)');

subplot(413) plot((-Nfft/2:Nfft/2-1)*fs/Nfft,abs(FT_Y_1ST_ka),'b',(-Nfft/2:Nfft/2-1)*fs/Nfft,abs(FT_Y_3RD_ka),'r'); legend('TDFT of 1st range samples filterd','TDFT of 3rd range samples filterd') title('TDFT of 1st and 3rd range samples after kasier filter') grid; xlabel('frequency(Hz)'); ylabel('H(e^{j{\omega}})'); subplot(414) plot((-Nfft/2:Nfft/2-1)*fs/Nfft,abs(FT_Y_1ST_re),'b',(-Nfft/2:Nfft/2-1)*fs/Nfft,abs(FT_Y_3RD_re),'r'); legend('TDFT of 1st range samples filterd','TDFT of 3rd range samples filterd') title('TDFT of 1st and 3rd range samples after Min-max filter') grid; xlabel('frequency(Hz)'); ylabel('H(e^{j{\omega}})')