Discuss the below:
Q: Create a comment every line including and below this code piece (index=round(x*fs); ) what each line does and how it works. The more explanation the better. How the index works, everything. Step by step how all the numbers flow so to say from variable to variable like a flow chart. Finally, the code below for the five plots was great, but can you make a for loop or something to plot nth plots. Notice the input used to be 6 for 6 clicks of the mouse, now it is () to signify infinite clicks of the mouse, so need a for loop instead of plotting one at a time for t1,t2.....
CODE:
%Gregory Leist/Dr. Saed/Project 5 takes a wav file Dr. Saed created for
%tones, read file and plot the file. Use ginput to take 6 data points.
%Plot waveforms.
clear,clc,close all;
%get project5.wav file from moodle, right click, save and drag to m file
%directory used in matlab so matlab can find it.
filename=input('Enter wavfilname: "project5.wav" > ','s');
%enter at prompt>> project5.wav
%-------------------------------------------------------------------------
[wav,fs]=wavread(filename);
t=(0:length(wav)-1)/fs;
plot(t,wav);
[x,y]=ginput(); % 6 means 6 mouse clicks only to work on plot
%Be sure to click on 6 different places on plot
%cause if plot on same waveform("square wave")
%twice the final plots are messed up.
%-------------------------------------------------------------------------
%then on command window see x = a number
% a number, etc.
% y = a number
% a number etc.
%but actually do not cause added a ";" to code to
%supress all the numbers being placed on the
%command window.
%only want x axis, so ignore y axis and to do so..
%--------------------------------------------------------------------------
index=round(x*fs);
figure; %so plots will not override
t1=t(index(1):index(2)-1);
sig1=wav(index(1):index(2)-1); %wav is variable for x plot values
N=length(t1); %take clicked portion length
fft1=abs(fftshift(fft(sig1)))/N; %get spectrum
freq1=[-N/2:N/2-1]'*fs/N;
t2=t(index(2):index(3)-1);
sig2=wav(index(2):index(3)-1);
subplot(5,2,2);plot(sig2);
N=length(t2);
fft2=abs(fftshift(fft(sig2)))/N;
freq2=[-N/2:N/2-1]'*fs/N;
t3=t(index(3):index(4)-1);
sig3=wav(index(3):index(4)-1);
subplot(5,2,3);
plot(sig3);
N=length(t3);
fft3=abs(fftshift(fft(sig3)))/N;
freq3=[-N/2:N/2-1]'*fs/N;
t4=t(index(4):index(5)-1);
sig4=wav(index(4):index(5)-1);
subplot(5,2,4);
plot(sig4);
N=length(t4);
fft4=abs(fftshift(fft(sig4)))/N;
freq4=[-N/2:N/2-1]'*fs/N;
t5=t(index(5):index(6));
sig5=wav(index(5):index(6));
subplot(5,2,5);
plot(sig5);
N=length(t5);
fft5=abs(fftshift(fft(sig5)))/N;
freq5=[-N/2:N/2-1]'*fs/N;
subplot(5,2,1);plot(t1,sig1);
subplot(5,2,2);plot(freq1,fft1);
subplot(5,2,3);plot(t2,sig2);
subplot(5,2,4);plot(freq2,fft2);
subplot(5,2,5);plot(t3,sig3);
subplot(5,2,6);plot(freq3,fft3);
subplot(5,2,7);plot(t4,sig4);
subplot(5,2,8);plot(freq4,fft4);
subplot(5,2,9);plot(t5,sig5);
subplot(5,2,10);plot(freq5,fft5);