scipy.signal.cwt's documentation says:

scipy.signal.cwt(data, wavelet, widths)

wavelet : functionWavelet function, which should take 2 arguments. The first argument is the number of points that the returned vectorwill have (len(wavelet(width,length)) == length). The second is awidth parameter, defining the size of the wavelet (e.g. standarddeviation of a gaussian). See ricker, which satisfies theserequirements.wavelet : function Wavelet function, which should take 2 arguments.

Beyond scipy.signal.ricket, what are the other built-in wavelet functions that I can pass to scipy.signal.cwt?

I see in scipy / scipy / signal / wavelets.py

__all__ = ['daub', 'qmf', 'cascade', 'morlet', 'ricker', 'cwt']

and looking at the arguments of each of those wavelet functions, only ricket seems to work with scipy.signal.cwt(data, wavelet, widths) (as only ricker takes precisely 2 arguments).

I asked the question on the SciPy Users List , answer 1:

I found the module for CWT quite confusing, so I rolled my own:

https://github.com/Dapid/fast-pycwt

It is built for speed (I got my running time from 4 h down to 20 min).It is not thoroughly tested, and it is limited to single and double;but for me it is in a "good enough" state.

Answer 2:

You might also find my version useful:

https://github.com/aaren/wavelets

I also found scipy wavelets confusing. My version includes a fastercwt that can take wavelets expressed in either frequency or time.

I found it more intuitive to have wavelet functions that taketime/frequency and width as arguments rather than the present method(I prefer thinking in real space rather than sample space).

Presently, the morlet wavelet that comes with scipy,scipy.signal.wavelets.morlet, cannot be used as input to cwt. Thisis unfortunate I think.

Additionally, the present cwt doesn't allow complex output. Thisdoesn't make a difference for ricker but wavelet functions are complexin general.

My modified 'cwt' method is here:

https://github.com/aaren/wavelets/blob/master/wavelets.py#L15

It can accept wavelet functions defined in time or frequency space,uses fftconvolve, and allows complex output.

My background on this is based on a reading of Torrence and Compo:

Torrence and Compo, 'A Practical Guide to Wavelet Analysis' (BAMS,1998)

http://paos.colorado.edu/research/wavelets/

hope that helps a bit,

aaron