Difference between revisions of "Hw1 ECE301S11 Sharifah Fareena Aljunid" - Rhea

Latest revision as of 07:54, 19 January 2011

% Sharifah Fareena Aljunid % BME 301 Homework 1 % Professor Mimi Boutin

% Part 1
clear
clc
delta = 0.00005;

% A loop is made to separate Question 1 into 3 parts

for p = 1:3

   if p ==2
       bpm = 112*2; % indicating the tune will be twice as fast
   else
       bpm = 112; % normal beats per minute
   end
   
   % Calculation to determine the length of the  in seconds
   H = 0:delta:(2*60/bpm);
   Q = 0:delta:(1*60/bpm);
   E = 0:delta:(0.5*60/bpm);
   DQ = 0:delta:(1.5*60/bpm);
   
   % Part 3, rescaling the frequency of A4
   if p == 3
       fa = 880; % the frequency is double the original as y(t) = x(2t)
   else
       fa = 440; % original frequency of A4
   end
   
   % Calculation of the frequency of any note related to the frequency of A4
   fG = 2^(-2/12)*fa;
   fC = 2^(3/12)*fa;
   fBf = 2^(1/12)*fa;
   fDf = 2^(4/12)*fa;
   
   % Calculation of all note length using a sine wave
   GQ = sin(2*pi*fG*Q);
   BfQ = sin(2*pi*fBf*Q);
   CDQ = sin(2*pi*fC*DQ);
   DfE = sin(2*pi*fDf*E);
   CH = sin(2*pi*fC*H);
   
   % The tune of the song to be played
   z = [GQ, BfQ, CDQ, GQ, BfQ, DfE, CH, GQ, BfQ, CDQ, BfQ, GQ];
   sound(z,1/delta);
   
   % Adjust song according to what is asked for in Question 1
   if p == 1
       wavwrite(z,1/delta,32,'Normal melody')
   elseif p == 2
       wavwrite(z,1/delta,32,'Faster melody')
   else
       wavwrite(z,1/delta,32,'Transformation x(2t)')
   end

end

Media:Normal melody.wav
Media:Faster melody.wav
Media:Transformation x(2t).wav

% Part 2

clear

clc
% Use wavread to read and store the Beatles song
[song,Fs] = wavread('Beatles.wav');
song_reversed = flipud(song); % this will flip the song and play it in reverse
sound(song_reversed,Fs);

The song played in forward say "Number Nine".
When it is played in reversed the sound that comes out is "Turn me on dead man".