Question

write comments for each line of the matlab code and explain

. I need explanation in each line

clear all;
	close all;
	load nb2_noise_data.mat;
	fs = 1000;
	N = 256;
	fl1 = 170;
	fh1 = 230;
	fl2 = 370;
	fh2 = 430;
	f = [0, fl1, fl1, fh1, fh1, fl2, fl2, fh2, fh2, fs/2] /(fs/2);
	G = [0, 0 ,1 , 1 , 0, 0, 1, 1, 0 , 0 ];
	figure;
	plot(f*(fs/2),G);
	[b,a] = yulewalk(12,f,G);
	X = filtfilt(b,a,x);
	f = (0:N-1) * fs / N;
	H_before = abs(fft(x,N));
	H_after = abs(fft(X,N));
	figure;
	subplot(2,1,1);
	plot(f(1:N/2), H_before(1:N/2));
	subplot(2,1,2);
	plot(f(1:N/2), H_after(1:N/2));

Answer 1

clear all;/ clear all variables from workspace or memory
	close all;/ close all preexisting figures
	load nb2_noise_data.mat;/load particular file variables into workspace
	fs = 1000;/ define value
	N = 256;/ define value
	fl1 = 170;/define value
	fh1 = 230;/define value
	fl2 = 370;
	fh2 = 430;
	f = [0, fl1, fl1, fh1, fh1, fl2, fl2, fh2, fh2, fs/2] /(fs/2);/define matrix of all the earlier defined notation
	G = [0, 0 ,1 , 1 , 0, 0, 1, 1, 0 , 0 ];/another matrix G defined
	figure;/to get figures plot of later function
	plot(f*(fs/2),G);/plot the figure between f*(fs/2) on Y-axis and G on X-axis
	[b,a] = yulewalk(12,f,G);/return the recursive digital IIR filter of 12 order
	X = filtfilt(b,a,x);/zero phase digital filtering with input x
	f = (0:N-1) * fs / N;/ calculate values of 'f' as defined function
	H_before = abs(fft(x,N));/absolute normal value of N point fft
	H_after = abs(fft(X,N));/absolute normal value of N point fft
	figure;/plot a figure
	subplot(2,1,1);/location of plot described as 2×1 matrix in first location (make a 2×1 grid and at first place plot the figure)
	plot(f(1:N/2), H_before(1:N/2));/plot f versus of H_before on X-axis
	subplot(2,1,2);/ plot figure at secons position in 2×1 gridor matrix
	plot(f(1:N/2), H_after(1:N/2));/plot f vs H_after on X-axis