How do I linspace this plot?
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Warm Cup
on 14 Jun 2019
Edited: KALYAN ACHARJYA
on 14 Jun 2019
I'm trying to slice a plot into sectors using linspace. This is the code I'm using:
c = 3e+8; % Speed of light [m/sec]
lambda = 1665e-9; % Wavelength [nm]
freq = c/lambda; % Actual Frequency of light [THz]
fsamp = freq*10; % Sampling frequency
fs = 1/fsamp; % Unit time [fs]
Ls = 200; % Length of signal
sig = 8e-15; % Pulse duration
ts = (0:Ls-1)*fs; % Time base
t0 = max(ts)/2; % Used to centering the pulse
Egauss = (exp(-2*log(2)*(ts-t0).^2/(sig)^2)).*cos(-2*pi*freq*(ts-t0));
subplot(2,1,1)
plot(ts/1e-15,real(Egauss),'b');
title(['Gaussian Pulse \sigma=', num2str(sig),'s']);
xlabel('Time (fs)');
ylabel('Amplitude');
ylim([-1 1])
%xlim([30e-15 70e-15])
grid on
NFFT = 2^nextpow2(Ls);
X = fft(Egauss,NFFT)/Ls;
freq = 0.5*fsamp*linspace(0,1,NFFT/2+1); % (full range) Frequency Vector
subplot(2,1,2)
plot(freq/1e+12,2*abs(X(1:NFFT/2+1)))
title('Magnitude of FFT');
xlabel('Frequency (THz)')
ylabel('Magnitude |X(f)|');
xlim([65 300])
grid on
%f = linspace(60*10^12,280*10^12,1000)';
I need to get a 1000 frequency slices from 'freq' plot that starts from 60 to 280 THz. How do I linspace the frequency domain of the gaussian pulse(fft of the time domain)?
2 Comments
KALYAN ACHARJYA
on 14 Jun 2019
'm trying to slice a plot into sectors using linspace...slice 2 D Plot?
Accepted Answer
KALYAN ACHARJYA
on 14 Jun 2019
Edited: KALYAN ACHARJYA
on 14 Jun 2019
stem(freq/1e+12,2*abs(X(1:NFFT/2+1)))
Use stem, instead of plot
2 Comments
KALYAN ACHARJYA
on 14 Jun 2019
Edited: KALYAN ACHARJYA
on 14 Jun 2019
reduce fsamp, like as follows
fsamp = freq*5; % Sampling frequency;
%............^ I hav decresed this value from 10 to 5, check it.
For second question get the value, add the following line at end on the code
disp(2*abs(X(1:NFFT/2+1)));
Run it and check in command window
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