Continuous Wavelet Transform (CWT) Niño3 SST =============================================== This is the final result: .. image:: nino_wavelet.png :width: 650pt How can anyone turn a 1D to 2D information? The code will explain to you! The code is structed in two scripts: - lib_wavelet.py : python's functions library - wavetest.py : call functions and plot :: +----------------+ | wavetest.py | +----------------+ | +----------------+ | lib_wavelet.py | +----------------+ | +----------------+ +----------------+ | def wavelet |--| def wave_signif| +----------------+ +----------------+ | +----------------+ +----------------+ | def nextpow2 |--| def wave_bases | +----------------+ +----------------+ .. note:: The Morlet wavelet is used as default in this code. Building the puzzle ... Why/when should I use the wavelet analysis ----------------------------------------------- The wavelet analysis is used for detecting and characterizing its possible singularities, and in particular the continuous wavelet transform is well suited for analyzing the local differentiability of a function (Farge, 1992). "Therefore the wavelet analysis or synthesis can be performed locally on the signal, as opposed to the Fourier transform which is inherently nonlocal due to the space-filling nature of the trigonometric functions. " (Farge,1992). +----------+-----------------+----------------+ | | Fourier | Wavelet | +==========+=================+================+ |context | sound | image | +----------+-----------------+----------------+ |character | stationary | nonstationary | +----------+-----------------+----------------+ |to see | global features | singularities | +----------+-----------------+----------------+ Choose the right glasses for what you want to see ! .. image:: lennon_glasses.png :width: 150pt More info: ---------- .. image:: info.png :width: 500pt Fonte: Domingues (2012) Papers: -------- Farge, M. 1992. Wavelet transforms and their applications to turbulence. Annu. Rev. Mech., 24: 395-457 Domingues, M. O.; Kaibar, M.K. 2012. Wavelet biortogonais. Revista brasileira de Ensino de Física,n.3, 34: 3701