www.gusucode.com > signal 案例源码程序 matlab代码 > signal/WaveformGenerationTimeVectorsAndSinusoidsExample.m
%% Waveform Generation: Time Vectors and Sinusoids % Most toolbox functions require you to begin with a vector representing a % time base. Consider generating data with a 1000 Hz sample frequency, for % example. An appropriate time vector is % Copyright 2015 The MathWorks, Inc. %% t = (0:0.001:1)'; %% % where the MATLAB(R) colon operator (|:|) creates a 1001-element row % vector that represents time running from 0 to 1 seconds in steps of 1 ms. % The transpose operator (|'|) changes the row vector into a column; the % semicolon (|;|) tells MATLAB to compute, but not display, the result. %% % Given |t|, you can create a sample signal y consisting of two sinusoids, % one at 50 Hz and one at 120 Hz with twice the amplitude. y = sin(2*pi*50*t) + 2*sin(2*pi*120*t); %% % The new variable |y|, formed from vector |t|, is also 1001 elements long. % You can add normally distributed white noise to the signal and plot the % first 50 points: yn = y + 0.5*randn(size(t)); plot(t(1:50),yn(1:50))