initial commit / add all books

6 files changed, 78 insertions, 0 deletions

diff --git a/22/CH8/EX8.10/ch8ex10.jpg b/22/CH8/EX8.10/ch8ex10.jpg
new file mode 100755
index 000000000..fab067071
--- /dev/null
+++ b/22/CH8/EX8.10/ch8ex10.jpg
diff --git a/22/CH8/EX8.10/ch8ex10.sce b/22/CH8/EX8.10/ch8ex10.sce
new file mode 100755
index 000000000..281be40a6
--- /dev/null
+++ b/22/CH8/EX8.10/ch8ex10.sce
@@ -0,0 +1,25 @@
+//signals and systems

+// sampling: the bridge between continuous to discrete

+T_0 = 4;

+N_0 = 32;

+T = T_0/N_0;n = 0:N_0-1;r = n;

+x_n = [ones(1,4),0.5,zeros(1,23),0.5,ones(1,3)]';

+H_r = [ones(1,8),0.5,zeros(1,15),0.5,ones(1,7)]';

+X_r = fft(x_n,-1);

+Y_r = H_r .*(X_r);y_n = mtlb_ifft(Y_r);

+subplot(2,2,1);

+plot2d3(n,x_n);

+plot(n,x_n,'r.')

+xtitle('xn','n')

+subplot(2,2,2);

+plot2d3(r,real(X_r));

+plot(r,real(X_r),'ro')

+xtitle('Xr','r')

+subplot(2,2,3);

+plot2d3(n,real(y_n));

+plot(n,real(y_n),'r.')

+xtitle('yn','n')

+subplot(2,2,4);

+plot2d3(r,(X_r).*H_r);

+plot(r,(X_r).*H_r,'ro')

+xtitle('XrHr','r')
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diff --git a/22/CH8/EX8.8/ch8ex8.jpg b/22/CH8/EX8.8/ch8ex8.jpg
new file mode 100755
index 000000000..990adb892
--- /dev/null
+++ b/22/CH8/EX8.8/ch8ex8.jpg
diff --git a/22/CH8/EX8.8/ch8ex8.sce b/22/CH8/EX8.8/ch8ex8.sce
new file mode 100755
index 000000000..9061675c3
--- /dev/null
+++ b/22/CH8/EX8.8/ch8ex8.sce
@@ -0,0 +1,26 @@
+//signals and systems

+//sampling:the bridge from continuous to discrete

+//DFT to compute the fourier transform of e^-2t.u(t)

+T_0 = 4;

+N_0 = 256;

+T = T_0/N_0;

+t = (0:T:T*(N_0-1))';

+x = T*exp(-2*t);

+x = mtlb_i(x,1,(T*(exp(-2*T_0)+1))/2);

+X_r = fft(x);

+r = (-N_0/2:N_0/2-1)';

+omega_r = ((r*2)*%pi)/T_0;

+omega = linspace(-%pi/T,%pi/T,4097);

+X = 1 ./(%i*omega+2);

+subplot(2,1,1);

+a = gca();

+a.y_location ="origin";

+a.x_location ="origin";

+plot(omega,abs(X),"k",omega_r,fftshift(abs(X_r)),"ko");

+xtitle("magnitude of X(omega) for true FT and DFT");

+subplot(2,1,2);

+a = gca();

+a.y_location ="origin";

+a.x_location ="origin";

+plot(omega,atan(imag(X),real(X)),"k",omega_r,fftshift(atan(imag(X_r),real(X_r))),"ko");

+xtitle("angle of X(omega) for true FT and DFT");
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diff --git a/22/CH8/EX8.9/ch8ex9.jpg b/22/CH8/EX8.9/ch8ex9.jpg
new file mode 100755
index 000000000..16e0ae9c4
--- /dev/null
+++ b/22/CH8/EX8.9/ch8ex9.jpg
diff --git a/22/CH8/EX8.9/ch8ex9.sce b/22/CH8/EX8.9/ch8ex9.sce
new file mode 100755
index 000000000..161d190e9
--- /dev/null
+++ b/22/CH8/EX8.9/ch8ex9.sce
@@ -0,0 +1,27 @@
+//signals and systems

+//sampling:the bridge from continuous to discrete

+//DFT to compute the fourier transform of 8rect(t)

+T_0 = 4;

+N_0 = 32;

+T = T_0/N_0;

+x_n = [ones(1,4) 0.5 zeros(1,23) 0.5 ones(1,3)]';

+size(x_n)

+x_r = fft(x_n);r = (-N_0/2:(N_0/2)-1)';

+omega_r = ((r*2)*%pi)/T_0;

+size(omega_r)

+size(omega)

+omega = linspace(-%pi/T,%pi/T,4097);

+X = 8*(sinc(omega/2));

+size(X)

+figure(1);

+subplot(2,1,1);

+plot(omega,abs(X),"k");

+plot(omega_r,fftshift(abs(x_r)),"ko")

+xtitle("angle of X(omega) for true FT and DFT");

+a=gca();

+subplot(2,1,2);

+a = gca();

+a.y_location ="origin";

+a.x_location ="origin";

+plot(omega,atan(imag(X),real(X)),"k",omega_r,fftshift(atan(imag(x_r),real(x_r))),'r.');

+xtitle("angle of X(omega) for true FT and DFT");