www.gusucode.com > signal 案例源码程序 matlab代码 > signal/PeriodogramOfASignalWithMissingSamplesExample.m
%% Power Spectral Density of Signal with Missing Samples % If you do not have a time vector, use |NaN|'s to specify missing samples % in a signal. % Copyright 2015 The MathWorks, Inc. %% % Generate 1024 samples of a sinusoid of normalized frequency $2\pi/5$ % rad/sample embedded in white noise of variance 1/100. Estimate the power % spectral density using the Lomb-Scargle procedure. Use |plomb| with no % output arguments to plot the estimate. t = (0:1023)'; x = sin(2*pi*t/5); x = x + randn(size(x))/10; [pxx,f] = plomb(x); plomb(x) %% % Remove every other sample by assigning |NaN|'s. Use |plomb| to compute % and plot the PSD. The periodogram peaks at the same frequency because the % time axis is unchanged. xnew = x; xnew(2:2:end) = NaN; plomb(xnew) %% % Remove every other sample by downsampling. The function now estimates the % periodicity at twice the original frequency. This is probably not the % result you want. xdec = x(1:2:end); plomb(xdec)