initial commit / add all books

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diff --git a/22/CH8/EX8.8/ch8ex8.jpg b/22/CH8/EX8.8/ch8ex8.jpg
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diff --git a/22/CH8/EX8.8/ch8ex8.sce b/22/CH8/EX8.8/ch8ex8.sce
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+//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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