- 29 questions asked
- 9 answers
- 1 accepted answer
- reputation: 5
sine wave plot
Latest activity Commented on by Nauman Hafeez
on 28 Dec 2018
- 0 questions asked
- 1 answer
- 0 accepted answers
- reputation: 0
Hi,
I am having some trouble plotting a sine wave and i'm not sure where i am going wrong.
i have
t = [0:0.1:2*pi]
a = sin(t);
plot(t,a)
this works by itself, but i want to be able to change the frequency. When i run the same code but make the change
a = sin(2*pi*60*t)
the code returns something bad. What am i doing wrong? How can i generate a sin wave with different frequencies?
4 Answers
- 1 question asked
- 596 answers
- 203 accepted answers
- reputation: 1 306
Answer by Rick Rosson
on 24 Apr 2012
- 1 question asked
- 596 answers
- 203 accepted answers
- reputation: 1 306
Accepted Answer
Please try:
%%Time specifications:
Fs = 8000; % samples per second
dt = 1/Fs; % seconds per sample
StopTime = 0.25; % seconds
t = (0:dt:StopTime-dt)'; % seconds
%%Sine wave:
Fc = 60; % hertz
x = cos(2*pi*Fc*t);
% Plot the signal versus time:
figure;
plot(t,x);
xlabel('time (in seconds)');
title('Signal versus Time');
zoom xon;
HTH.
Rick
2 Comments
Thanks for your reply & detailed answer.
How to calculate Fs for a particular frequency signal?
I am generating a stimulating signal using matlab for my impedance meter and it gives me different results on different Fs.
Sign in to comment.
- 0 questions asked
- 1 answer
- 0 accepted answers
- reputation: 6
Dear Mr. Rick, Is it possible to create knit structure in Matlab as follows:
0 Comments
Sign in to comment.
- 0 questions asked
- 1 answer
- 0 accepted answers
- reputation: 0
Answer by omphile hahilton
on 3 Mar 2015
- 0 questions asked
- 1 answer
- 0 accepted answers
- reputation: 0
I would like to generate the product of 2 sine waves at frequencies 697Hz and 1209Hz and sample them and then generate the spectrum of the signal. then play the sine wave through my soundcard speakers help me..........thanks in advanced
0 Comments
Sign in to comment.
- 6 questions asked
- 7 answers
- 0 accepted answers
- reputation: 3
aaa,
What goes wrong: by multiplying time vector t by 2*pi*60 your discrete step size becomes 0.1*2*pi*60=37.6991. But you need at least two samples per cycle (2*pi) to depict your sine wave. Otherwise you'll get an alias frequency, and in you special case the alias frequency is infinity as you produce a whole multiple of 2*pi as step size, thus your plot never gets its arse off (roundabout) zero.
Using Rick's code you'll be granted enough samples per period.
Best regs
Robert
0 Comments
Sign in to comment.
See Also
Discover what MATLAB® can do for your career.
Opportunities for recent engineering grads.
Apply Today
2 Comments
Ahmed Grera (view profile)
Direct link to this comment:
https://se.mathworks.com/matlabcentral/answers/36428-sine-wave-plot#comment_481564
Govinda Nahak (view profile)
Direct link to this comment:
https://se.mathworks.com/matlabcentral/answers/36428-sine-wave-plot#comment_489408
Sign in to comment.