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| − | Question 1: | + | % Question 1: |
| − | + | function[] = question1() | |
| − | Sound file: [[Media: | + | N1 = sin(2*pi*391.995436*[0:0.0001:1]); %G quarter note |
| + | N2 = sin(2*pi*466.1637615*[0:0.0001:1]); %Bflat quarter | ||
| + | N3 = sin(2*pi*523.2511306*[0:0.0001:1.5]); %C dotted quarter | ||
| + | N4 = sin(2*pi*391.995436*[0:0.0001:1]); %G quarter | ||
| + | N5 = sin(2*pi*466.1637615*[0:0.0001:1]); %Bflat quarter | ||
| + | N6 = sin(2*pi*554.3652618*[0:0.0001:0.5]); %Csharp eigth | ||
| + | N7 = sin(2*pi*523.2511306*[0:0.0001:2]); %C half | ||
| + | |||
| + | rest = [0:0.0001:2.5]; %rest half and an eigth | ||
| + | |||
| + | % smoke on the water (part a): | ||
| + | tune = [N1 N2 N3 N4 N5 N6 N7 N1 N2 N3 N2 N1 rest]; | ||
| + | wavwrite(0.02*tune, 18667, 'question1a.wav'); | ||
| + | |||
| + | % twice as fast (part b): | ||
| + | wavwrite(0.02*tune, 37333, 'question1b.wav'); | ||
| + | |||
| + | % y(t) = x(2t) (part c): | ||
| + | newtune = [1:1:(length(tune)/2)]; | ||
| + | for i=1:(length(tune)/2) | ||
| + | newtune(1,i) = tune(1,2*i); | ||
| + | end | ||
| + | wavwrite(0.02*newtune, 18667, 'question1c.wav'); | ||
| + | |||
| + | |||
| + | |||
| + | Sound files: [[Media:question1a.wav]] | ||
| + | [[Media:question1b.wav]] | ||
| + | [[Media:question1c.wav]] | ||
| + | |||
| + | |||
| + | |||
| + | |||
| + | |||
| + | % Question 2: | ||
| + | function[] = question2() | ||
| + | [y, Fs] = wavread('Beatles.wav'); | ||
| + | y = flipud(y); | ||
| + | wavwrite(y, Fs, 'question2.wav'); | ||
| + | |||
| + | |||
| + | |||
| + | Sound file: [[Media:question2.wav]] | ||
| + | |||
| + | 1. The repeated phrase was "number nine". | ||
| + | 2. I couldn't hear any message in the reversed version. | ||
Latest revision as of 19:18, 14 January 2011
% Question 1: function[] = question1() N1 = sin(2*pi*391.995436*[0:0.0001:1]); %G quarter note N2 = sin(2*pi*466.1637615*[0:0.0001:1]); %Bflat quarter N3 = sin(2*pi*523.2511306*[0:0.0001:1.5]); %C dotted quarter N4 = sin(2*pi*391.995436*[0:0.0001:1]); %G quarter N5 = sin(2*pi*466.1637615*[0:0.0001:1]); %Bflat quarter N6 = sin(2*pi*554.3652618*[0:0.0001:0.5]); %Csharp eigth N7 = sin(2*pi*523.2511306*[0:0.0001:2]); %C half
rest = [0:0.0001:2.5]; %rest half and an eigth
% smoke on the water (part a): tune = [N1 N2 N3 N4 N5 N6 N7 N1 N2 N3 N2 N1 rest]; wavwrite(0.02*tune, 18667, 'question1a.wav'); % twice as fast (part b): wavwrite(0.02*tune, 37333, 'question1b.wav');
% y(t) = x(2t) (part c):
newtune = [1:1:(length(tune)/2)];
for i=1:(length(tune)/2)
newtune(1,i) = tune(1,2*i);
end
wavwrite(0.02*newtune, 18667, 'question1c.wav');
Sound files: Media:question1a.wav Media:question1b.wav Media:question1c.wav
% Question 2:
function[] = question2()
[y, Fs] = wavread('Beatles.wav');
y = flipud(y);
wavwrite(y, Fs, 'question2.wav');
Sound file: Media:question2.wav
1. The repeated phrase was "number nine". 2. I couldn't hear any message in the reversed version.
