value of scale in CWT

Question

Dingguo Lu 2011-8-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/13104-value-of-scale-in-cwt

I am working on the wavelet coefficients of Morlet wavelet. while using cwt(x,scales,'wname') command, how to determine the value of "scales".

Someone said the scales value is related to the center frequency of wavelet, then what is the relationship.

Thanks in advance.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Wayne King 2011-8-18

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/13104-value-of-scale-in-cwt#answer_19129

The relationship is far from straightforward. You can use scal2frq in the Wavelet Toolbox to get an approximate scale to frequency conversion for a specified wavelet. To guide you in constructing a scale vector to input into cwt.m, you should think about what scales you wish to investigate and how fine the spacing between those scales should be.

2 个评论
显示无隐藏无

Dingguo Lu 2011-8-18

Wayne, please have a look at the following paper, if you have time:

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1703938&tag=1

In this paper, page 4-6, the author mentioned 3 to7 correspond freq. from 700 to 1700 Hz at sampling freq. of 5000 Hz. He also mentioned 1 to 12 correspond freq. from 1.667 to 20 kHz at sampling freq. of 20kHz.

But when I use "scal2frq", it gives me different values. It is quite confusing. Would you please help to explain in detail?

Dingguo Lu 2011-8-18