Circuit Theory/Convolution Integral/matlab

clear

X=-2.1:0.001:4; F1=exp(-X); F1(X<0)=0; F2=abs(X)<=0.5; clf

mkdir('tmp'); [tmp zero_offset] = min(abs(X));

SyncFrames=[1 round(20.3366666*(1:numel(X)))]; frame=1; integral=nan(size(X)); for offset_i=1:numel(X); offset=X(offset_i); shift=offset_i-zero_offset; F2_shifted = circshift(F2, [0 shift]); product = F2_shifted.*F1; integral(offset_i) = sum(product)/numel(X)*(X(end)-X(1)); if offset_i==SyncFrames(frame) frame=frame+1; area(X, product, 'facecolor', 'yellow'); hold on       plot(X, F1, 'b', X, F2_shifted, 'r', X, integral, 'k', [offset offset], [0 2], 'k:') hold off axis image axis([-1.6 3.1 0 1.1]) xlabel('\tau & t'); grid on       legend('Area under f(\tau)g(t-\tau)', 'f(\tau)', 'g(t-\tau)', '(f\astg)(t)'); print('-dpng','-r72',sprintf('tmp/conv_box_spike_%06d.png', offset_i)); drawnow end end

system('"C:\Program Files\ImageMagick-6.6.3-Q16\convert.exe" -layers Optimize -delay 5 tmp/conv_box_spike_*.png conv_box_spike.gif'); delete('tmp/*'); rmdir('tmp');