DATA PERCOBAAN “SAMPLING DAN ALIASSING”

1. Mengamati pengaruh pemilihan frekuensi sampling secara visual

1. Program

%sin_diskrit.m

fs=8;%frekuensi sampling

t=(0:fs-1)/fs;%proses normalisasi

s1=sin(2*pi*t*2);

subplot(421)

stem(t,s1)

title('fs = 8 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

axis([0 1 -1.2 1.2])

%sin_diskrit.m

fs=10;%frekuensi sampling

t=(0:fs-1)/fs;%proses normalisasi

s1=sin(2*pi*t*2);

subplot(422)

stem(t,s1)

title('fs = 10 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

axis([0 1 -1.2 1.2])

%sin_diskrit.m

fs=12;%frekuensi sampling

t=(0:fs-1)/fs;%proses normalisasi

s1=sin(2*pi*t*2);

subplot(423)

stem(t,s1)

title('fs = 12 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

axis([0 1 -1.2 1.2])

%sin_diskrit.m

fs=14;%frekuensi sampling

t=(0:fs-1)/fs;%proses normalisasi

s1=sin(2*pi*t*2);

subplot(424)

stem(t,s1)

title('fs = 14 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

axis([0 1 -1.2 1.2])

%sin_diskrit.m

fs=16;%frekuensi sampling

t=(0:fs-1)/fs;%proses normalisasi

s1=sin(2*pi*t*2);

subplot(425)

stem(t,s1)

title('fs = 16 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

axis([0 1 -1.2 1.2])

%sin_diskrit.m

fs=20;%frekuensi sampling

t=(0:fs-1)/fs;%proses normalisasi

s1=sin(2*pi*t*2);

subplot(426)

stem(t,s1)

title('fs = 20 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

axis([0 1 -1.2 1.2])

%sin_diskrit.m

fs=30;%frekuensi sampling

t=(0:fs-1)/fs;%proses normalisasi

s1=sin(2*pi*t*2);

subplot(427)

stem(t,s1)

title('fs = 30 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

axis([0 1 -1.2 1.2])

2. Gambar sinyal

2. Mengamati pengaruh pemilihan frekuensi sampling pada efek audio

1. Program

%sampling_2.m

clear all;

clf

Fs=1000;

n=0:1/Fs:0.25;

t=0:0.00001:0.25;

f=100;

xn=sin(2*pi*f*n);

xt=sin(2*pi*f*t);

subplot(521)

plot(t(1:1000),xt(1:1000),'r'),hold on

legend ('analog/kontinu')

stem(n(1:10),xn(1:10))

title ('f = 100 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

sound(xn,Fs)

Fs=1000;

n=0:1/Fs:0.25;

t=0:0.00001:0.25;

f=200;

xn=sin(2*pi*f*n);

xt=sin(2*pi*f*t);

subplot(522)

plot(t(1:1000),xt(1:1000),'r'),hold on

legend ('analog/kontinu')

stem(n(1:10),xn(1:10))

title ('f = 200 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

sound(xn,Fs)

Fs=1000;

n=0:1/Fs:0.25;

t=0:0.00001:0.25;

f=300;

xn=sin(2*pi*f*n);

xt=sin(2*pi*f*t);

subplot(523)

plot(t(1:1000),xt(1:1000),'r'),hold on

legend ('analog/kontinu')

stem(n(1:10),xn(1:10))

title ('f = 300 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

sound(xn,Fs)

Fs=1000;

n=0:1/Fs:0.25;

t=0:0.00001:0.25;

f=400;

xn=sin(2*pi*f*n);

xt=sin(2*pi*f*t);

subplot(524)

plot(t(1:1000),xt(1:1000),'r'),hold on

legend ('analog/kontinu')

stem(n(1:10),xn(1:10))

title ('f = 400 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

sound(xn,Fs)

Fs=1000;

n=0:1/Fs:0.25;

t=0:0.00001:0.25;

f=500;

xn=sin(2*pi*f*n);

xt=sin(2*pi*f*t);

subplot(525)

plot(t(1:1000),xt(1:1000),'r'),hold on

legend ('analog/kontinu')

stem(n(1:10),xn(1:10))

title ('f = 500 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

sound(xn,Fs)

Fs=1000;

n=0:1/Fs:0.25;

t=0:0.00001:0.25;

f=600;

xn=sin(2*pi*f*n);

xt=sin(2*pi*f*t);

subplot(526)

plot(t(1:1000),xt(1:1000),'r'),hold on

legend ('analog/kontinu')

stem(n(1:10),xn(1:10))

title ('f = 600 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

sound(xn,Fs)

Fs=1000;

n=0:1/Fs:0.25;

t=0:0.00001:0.25;

f=700;

xn=sin(2*pi*f*n);

xt=sin(2*pi*f*t);

subplot(527)

plot(t(1:1000),xt(1:1000),'r'),hold on

legend ('analog/kontinu')

stem(n(1:10),xn(1:10))

title ('f = 700 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

sound(xn,Fs)

Fs=1000;

n=0:1/Fs:0.25;

t=0:0.00001:0.25;

f=800;

xn=sin(2*pi*f*n);

xt=sin(2*pi*f*t);

subplot(528)

plot(t(1:1000),xt(1:1000),'r'),hold on

legend ('analog/kontinu')

stem(n(1:10),xn(1:10))

title ('f = 800 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

sound(xn,Fs)

Fs=1000;

n=0:1/Fs:0.25;

t=0:0.00001:0.25;

f=900;

xn=sin(2*pi*f*n);

xt=sin(2*pi*f*t);

subplot(529)

plot(t(1:1000),xt(1:1000),'r'),hold on

legend ('analog/kontinu')

stem(n(1:10),xn(1:10))

title ('f = 900 Hz (Ervina Ariyanti)')

xlabel('waktu(detik)')

ylabel('amplitudo(volt)')

sound(xn,Fs)

2. Gambar Sinyal

Gundul Program

%gundul.m

clf;

clear all;

Fs=16000;

t=0:1/Fs:0.25;

c=sin(2*pi*262*t);

d=sin(2*pi*294*t);

e=sin(2*pi*330*t);

f=sin(2*pi*249*t);

g=sin(2*pi*392*t);

a=sin(2*pi*440*t);

b=sin(2*pi*494*t);

c1=sin(2*pi*523*t);

nol = [zeros(size(t))];

nada1 = [c,e,c,e,f,g,g,nol,b,c1,b,c1,b,g,nol,nol];

nada2 = [c,e,c,e,f,g,g,nol,b,c1,b,c1,b,g,nol];

nada3 = [c,nol,e,nol,g,nol,f,f,g,f,e,c,f,e,c,nol];

nada4 = [c,nol,e,nol,g,nol,f,f,g,f,e,c,f,e,c];

lagu=[nada1,nada2,nada3,nada4];

sound(lagu,Fs)

wavwrite(lagu, 'gundul.wav')

[A,Bit]=wavread('gundul.wav')

stem (A)

stem(A(1:50));

gambar