HW1.1 Jacob Pfister ECE301Fall2008mboutin - Rhea

MATLAB Code

%Jacob Pfister
%HW1.1

clear
clc

delta = 1/44100;
sec = 1/delta;
i = 1;

%a) Hail, Hail to old Purdue
for t = 0:delta:0.5
    y(i) = sin(2*pi*264*t);
    i = i + 1;
end
for t = (0.5 + delta):delta:0.75
    y(i) = sin(2*pi*297*t);
    i = i + 1;
end
for t = (0.75 + delta):delta:1
    y(i) = sin(2*pi*330*t);
    i = i + 1;
end
for t = (1 + delta):delta:1.5
    y(i) = sin(2*pi*352*t);
    i = i + 1;
end
for t = (1.5 + delta):delta:1.625
    y(i) = sin(2*pi*396*t);
    i = i + 1;
end
for t = (1.625 + delta):delta:1.75
    y(i) = sin(2*pi*440*t);
    i = i + 1;
end

%b) 2 Times faster

for t = (1.75 + delta):delta:2
    y(i) = sin(2*pi*264*t);
    i = i + 1;
end
for t = (2 + delta):delta:2.125
    y(i) = sin(2*pi*297*t);
    i = i + 1;
end
for t = (2.125 + delta):delta:2.5
    y(i) = sin(2*pi*330*t);
    i = i + 1;
end
for t = (2.5 + delta):delta:3
    y(i) = sin(2*pi*352*t);
    i = i + 1;
end
for t = (3 + delta):delta:3.0625
    y(i) = sin(2*pi*396*t);
    i = i + 1;
end
for t = (3.0625 + delta):delta:3.125
    y(i) = sin(2*pi*440*t);
    i = i + 1;
end

%c) y(t) = x(2t)
for t = 3.125:delta:3.625
    y(i) = sin(4*pi*264*t);
    i = i + 1;
end
for t = (3.625 + delta):delta:3.875
    y(i) = sin(4*pi*297*t);
    i = i + 1;
end
for t = (3.875 + delta):delta:4.125
    y(i) = sin(4*pi*330*t);
    i = i + 1;
end
for t = (4.125 + delta):delta:4.625
    y(i) = sin(4*pi*352*t);
    i = i + 1;
end
for t = (4.625 + delta):delta:4.75
    y(i) = sin(4*pi*396*t);
    i = i + 1;
end
for t = (4.75 + delta):delta:4.875
    y(i) = sin(4*pi*440*t);
    i = i + 1;
end

%play
sound(y,44100);

%write file
wavwrite(y,44100,32,'HailPurdueRemix.wav');

Sound File

Media:HailPurdueRemix_ECE301Fall2008mboutin.wav

Comments

I'm not sure I got the the lengths of the different notes exactly right, but it' pretty close. The transformation y(t) = x(2t) doubles the frequency, which effectively bumps the tune up an octave. This result is demonstrated in the sound file above.