I cannot get Spectrogram to highlight a single frequency signal

2020 6 15
1 个回答
回答已采纳
更新时间：2020 6 16
3 次查看（30 天）

0 个投票

I want to use the spectrogram function in matlab, before I do I wanted to make sure I understand it. So I did a small example with a sin wave with 440 Hz as the frequency. However, when I run the spectrogram function its shows that the strongest frequency is around 70 Hz. I would love some clarification.
x = 1:.001:5;
y = sin(440*x);
figure(1); plot(x,y)
figure(2); spectrogram(y, 1000, 500, [], 1000, 'yaxis');
Thanks

2 个评论
显示 无 隐藏 无

dpb
dpb 2020-6-15
sin() is in radians -- 440/2pi ==> 70.03
John Hunt
John Hunt 2020-6-16
Well, that would make the difference. Thank you for pointing that out to me.

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

John Hunt
John Hunt 2020-6-16

0 个投票

dpb answered this question in the comments sin() uses radians and the conversion from radians to hertz is 1/(2pi) and 440/(2pi) is 70.03.

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Time-Frequency Analysis 的更多信息

产品

版本

R2019b

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by