ejemplos dft- matlab

EJEMPLO (1)

clc close all clear all k=1:1:64; z= sin(((pi).*k)/8)+ 2*sin(((2.5*pi).*k)/8); w1=real(z); w2=imag(z); t=fft(z); t1=real(t); t2=imag(t); figure,subplot(2,2,1) h1 = stem(k,w1,'fill','--'); set(get(h1,'BaseLine'),'LineStyle','-') set(h1,'MarkerFaceColor','r') title('Parte Real de z') subplot(2,2,2) h2 = stem(k,w2,'fill','--'); set(get(h2,'BaseLine'),'LineStyle','-') set(h2,'MarkerFaceColor','r') title('Parte Imaginaria de z') subplot(2,2,3) h3 = stem(k,t1,'fill','--'); set(get(h3,'BaseLine'),'LineStyle','-') set(h3,'MarkerFaceColor','c') title('Parte Real de DFT(z)') subplot(2,2,4) h4 = stem(k,t2,'fill','--'); set(get(h4,'BaseLine'),'LineStyle','-') set(h4,'MarkerFaceColor','c') title('Parte Imaginaria de DFT(z)')

EJEMPLO (2)

clc close all clear all x=[0 1 2 3 4 5]; z=[4+i,2-3i,3-i,2i,3-2i,2+3i]; w1=real(z); w2=imag(z); D= circshift(z, [0, 2]); t1=real(D); t2=imag(D); figure,subplot(2,2,1) h1 = stem(x,w1,'fill','--'); set(get(h1,'BaseLine'),'LineStyle','-') set(h1,'MarkerFaceColor','r') title('Parte Real de z') subplot(2,2,2) h2 = stem(x,w2,'fill','--'); set(get(h2,'BaseLine'),'LineStyle','-') set(h2,'MarkerFaceColor','r') title('Parte Imaginaria de z') subplot(2,2,3) h3 = stem(x,t1,'fill','--'); set(get(h3,'BaseLine'),'LineStyle','-')

set(h3,'MarkerFaceColor','c') title('Parte Real de Desplaz(z)') subplot(2,2,4) h4 = stem(x,t2,'fill','--'); set(get(h4,'BaseLine'),'LineStyle','-') set(h4,'MarkerFaceColor','c') title('Parte Imaginaria de Desplaz(z)')

EJEMPLO (3)

clc close all clear all n=1:1:128; z=cos(2*pi*(7/128).*n)+4*cos(2*pi*(12/128).*n); t=fft(z); t1=real(t); t2=imag(t); figure,plot(n,z,'r') figure,h1 = stem(n,t1,'fill','--'); set(get(h1,'BaseLine'),'LineStyle','-') set(h1,'MarkerFaceColor','c') title('DFT(z)')

EJEMPLO (4)

clc close all clear all n=1:1:512; z=3*sin(2*pi*(7/512).*n)-4*cos(2*pi*(8/512).*n); t=fft(z); t1=real(t); t2=imag(t); figure,plot(n,z,'r') figure,subplot(1,2,1) h1 = stem(n,t1,'fill','--'); set(get(h1,'BaseLine'),'LineStyle','-') set(h1,'MarkerFaceColor','b') title('Parte real de DFT(z)') subplot(1,2,2) h2 = stem(n,t2,'fill','--'); set(get(h2,'BaseLine'),'LineStyle','-') set(h2,'MarkerFaceColor','b') title('Parte Imaginaria de DFT(z)')

EJEMPLO (5)

clc close all clear all n=1:1:4; z=[1,i,2+i,-3]; w1=real(z); w2=imag(z); t=fft(z); t1=real(t); t2=imag(t);

g=ifft(t); g1=real(g); g2=imag(g); figure,subplot(3,2,1) h1 = stem(n,w1,'fill','--'); set(get(h1,'BaseLine'),'LineStyle','-') set(h1,'MarkerFaceColor','r') title('Parte Real de z') subplot(3,2,2) h2 = stem(n,w2,'fill','--'); set(get(h2,'BaseLine'),'LineStyle','-') set(h2,'MarkerFaceColor','r') title('Parte Imaginaria de z') subplot(3,2,3) h3 = stem(n,t1,'fill','--'); set(get(h3,'BaseLine'),'LineStyle','-') set(h3,'MarkerFaceColor','b') title('Parte Real de DFT(z)') subplot(3,2,4) h4 = stem(n,t2,'fill','--'); set(get(h4,'BaseLine'),'LineStyle','-') set(h4,'MarkerFaceColor','b') title('Parte Imaginaria de DFT(z)') subplot(3,2,5) h5 = stem(n,g1,'fill','--'); set(get(h5,'BaseLine'),'LineStyle','-') set(h5,'MarkerFaceColor','b') title('Parte Real de IDFT(DFT((z))') subplot(3,2,6) h6 = stem(n,g2,'fill','--'); set(get(h6,'BaseLine'),'LineStyle','-') set(h6,'MarkerFaceColor','b') title('Parte Imaginaria de IDFT(DFT(z))')

EJEMPLO (6)

clc close all clear all n=0:1:15; z0=cos(2*pi*0*n/16); z1=cos(2*pi*1*n/16); z2=cos(2*pi*2*n/16); z3=cos(2*pi*3*n/16); z7=cos(2*pi*7*n/16); z8=cos(2*pi*8*n/16); z9=cos(2*pi*9*n/16); figure,h0 = stem(n,z0,'fill','--'); title('m=0') figure,h1 = stem(n,z1,'fill','--');title('m=1') figure,h2 = stem(n,z2,'fill','--');title('m=2') figure,h3 = stem(n,z3,'fill','--');title('m=3') figure,h7 = stem(n,z7,'fill','--');title('m=7') figure,h8 = stem(n,z8,'fill','--');title('m=8') figure,h9 = stem(n,z9,'fill','--');title('m=9')

EJEMPLO (7)

clc close all clear all n=0:1:15; t=0:0.01:15; z15=cos(2*pi*15*n/16); z=cos(2*pi*15*t/16); figure, plot(t,z,'r');title('variable t-continua') figure,h15 = stem(n,z15,'fill','--'); title('m=15') figure, hold on plot(t,z,'r');title('variable t-continua') h15 = stem(n,z15,'fill','--'); title('superposicion') hold off