MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

# sine wave plot

Asked by aaa on 24 Apr 2012

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?

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Answer by Rick Rosson on 24 Apr 2012

```   %% 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

## 1 Comment

Rajasekaran on 14 Mar 2013